| 1. |
- Ekström, Linda M N K, et al.
(författare)
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Oat β-glucan containing bread increases the glycaemic profile
- 2017
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Ingår i: Journal of Functional Foods. - : Elsevier BV. - 1756-4646. ; 32, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- A net postprandial glucose increment beyond 2 h has been shown to improve glucose and appetite regulation at a subsequent meal. Such an improved glycaemic profile (GP) has been reported for bread containing guar gum. In the present study three commercially available β-glucans from barley and oat were baked into yeast leavened bread products. Only oat beta-glucan containing bread met the criteria of β-glucan molecular weight and was included in a meal study. The three levels of oat β-glucans reduced the GI and glucose iPeak by 32–37% compared to a white wheat reference bread. Furthermore, the highest oat β-glucan level increased GP by 66% compared to the reference bread. It is concluded that the oat β-glucans were suitable for use in baking, since the MW remained relatively high. Thus, the oat ingredient showed an interesting potential to be used when tailoring the glycaemic profile of bread products.
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| 2. |
- Eliasson, Ann-Charlotte, et al.
(författare)
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From Molecules to Products: Some Aspects of Structure-Function Relationships in Cereal Starches
- 2013
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Ingår i: Cereal Chemistry. - 0009-0352. ; 90:4, s. 326-334
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Tidskriftsartikel (refereegranskat)abstract
- In this review, starch behavior is described from molecules in solution to the use of starch in products. The determination of molecular characteristics with asymmetrical flow field-flow fractionation is described, and the behavior of starch in binary solutions is discussed. The organization of starch in granules and the changes in organization during gelatinization and retrogradation are then described. The role of starch retrogradation in bread staling is described in some detail, and the influence of water mobility and distribution is discussed in relation to amylopectin retrogradation. Finally, the use of starch as emulsifier is described. Hydrophobically modified starch is one possibility for emulsion stabilization; also, the starch granule as such can be used to stabilize emulsions (so-called Pickering emulsions).
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| 3. |
- Fuentes, Catalina, et al.
(författare)
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Characterization of non-solvent precipitated starch using asymmetrical flow field-flow fractionation coupled with multiple detectors
- 2019
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 206, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Non-solvent precipitated starch (non-SPS) is a novel component for starch-based emulsions. Herein, three non-SPS materials were prepared using ethanol as a precipitant of waxy maize starch granules (WMs). The WMs were either untreated (SP) or pre-treated via acid-hydrolysis (AHSP). In addition, SP was modified using n-octenyl succinic anhydride (OSA), yielding OSASP. This study aimed to investigate the influence of the non-SPS preparation method on the size, molar mass (M), and apparent density (ρapp) of the materials when subjected to different dissolution/dispersion procedures using asymmetrical flow field-flow fractionation (AF4). The results showed that the molar mass, size, and apparent density depended on the type of non-SPS with a decrease in Mw (1.8–9.4 g/mol) and rrms (60–148 nm) upon re-dispersion in different media in the order: SP > OSASP > AHSP. Moreover, different types of non-SPS materials displayed different conformational properties and were stable in aqueous solution at room temperature in the investigated time (24 h).
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| 4. |
- Fuentes, Catalina, et al.
(författare)
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Fractionation and characterization of starch granules using field-flow fractionation (FFF) and differential scanning calorimetry (DSC)
- 2019
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 411:16, s. 3665-3674
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Tidskriftsartikel (refereegranskat)abstract
- Starch is one of the main carbohydrates in food; it is formed by two polysaccharides: amylose and amylopectin. The granule size of starch varies with different botanical origins and ranges from less than 1 μm to more than 100 μm. Some physicochemical and functional properties vary with the size of the granule, which makes it of great interest to find an efficient and accurate size-based separation method. In this study, the full-feed depletion mode of split-flow thin cell fractionation (FFD-SF) was employed for a size-based fractionation of two types of starch granules (corn and potato) on a large scale. The fractionation efficiency (FE) of fraction-a for corn and potato granules was 98.4 and 99.4%, respectively. The FFD-SF fractions were analyzed using optical microscopy (OM) and gravitational field-flow fractionation (GrFFF). The respective size distribution results were in close agreement for the corn starch fractions, while they were slightly different for the potato starch fractions. The thermal properties of FFD-SF fractions were analyzed, and the results for the potato starch showed that the peak temperature of gelatinization (T p ) slightly decreases as the size of the granules increases. Additionally, the enthalpy of gelatinization (ΔH) increases when the granule size increases and shows negative correlation with the gelatinization range (ΔT).
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| 5. |
- Fuentes, Catalina, et al.
(författare)
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Physicochemical and structural properties of starch from five Andean crops grown in Bolivia
- 2019
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130. ; 125, s. 829-838
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Tidskriftsartikel (refereegranskat)abstract
- Three Andean grains - amaranth (Amaranthus caudatus), quinoa (Chenopodium quinoa), canihua (Chenopodium pallidicaulle) - and two Andean roots starches - achira (Canna indica), maca (Lepidium meyenii) - were studied. Physicochemical properties such as granule size, crystallinity, pasting properties among other as well as structural properties such as root-mean-square radius (rrms), weight-average molar mass (Mw) and apparent density (ρapp) were analyzed in order to evaluate the relation between them. Grains were similar in most of their characteristics as roots in their i.e. granule size, shape, type of crystallinity, Mw and rrms varied according to botanical source. The starch granules from grains were in a narrow diameter range (0.5 to 2 μm) and displayed A-type X-ray diffraction pattern (XRD). Roots starch had a wide granule diameter range (1 to 100 μm) and displayed a B-type XRD. The amylose content varied between 0 and 48% where amaranth had the lowest value and achira had the highest. Furthermore, quinoa and canihua starches had very low breakdown in pasting properties, indicating high stability during cooking. A model is proposed that relates pasting properties i.e. peak viscosity and final viscosity with ρapp, gelatinization enthalpy, granule size and amylose content.
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| 6. |
- Gari, Hala, et al.
(författare)
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Amperometric In Vitro Monitoring of Penetration through Skin Membrane
- 2015
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397 .- 1521-4109. ; 27:1, s. 111-117
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to demonstrate that penetration of quercetin, hydrogen peroxide and ascorbic acid through skin membranes can be monitored amperometrically. Skin membrane was fixed on the top of chemically modified electrodes and penetration of the appropriate compound was registered as electrode current. The methodology allows the study of penetration from solution as well as from pharmaceutical creams. From real-time measurements of electrode current, fluxes and diffusion coefficients of mentioned compounds in skin membranes have been estimated.
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| 7. |
- Leeman, Margareta, et al.
(författare)
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Resistant starch formation in temperature treated potato starches varying in amylose/amylopectin ratio
- 2006
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 65:3, s. 306-313
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Tidskriftsartikel (refereegranskat)abstract
- Two genetically modified potato starches derived from the same mother line (64%, 1% and 23% amylose, respectively) were used to study the bioavailability after various heat treatments. The conditions for the treatments were of minor importance for resistant starch (RS) formation and hydrolysis results, as compared to the proportion of amylose. A high amylose content gave lower hydrolysis index (HI) and higher amounts of RS than starches with less amylose. Retrograded amylopectin contributed to a decreased HI, although only the high amylose line showed sufficient reduction in predicted glycaemic indices (Gl). The line with high amylose content contained 25-30% RS vs. in the range of 0-5% for the other starches. Results could neither be explained by the presence of intact granules, nor by the content of retrograded amylose. Therefore, a synergistic effect between the starch components was suggested to affect the RS and starch hydrolysis. (c) 2006 Elsevier Ltd. All rights reserved.
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| 8. |
- Marefati, Ali, et al.
(författare)
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Fabrication of encapsulated oil powders from starch granule stabilized W/O/W Pickering emulsions by freeze-drying
- 2015
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 51, s. 261-271
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Tidskriftsartikel (refereegranskat)abstract
- The process stability of water-in-oil-in-water (W/O/W) double emulsions stabilized with food-grade OSA modified quinoa starch granules was investigated. The effect of oils with differing melting points, as well as the effect of in situ partial gelatinization of the granules, on stability of emulsions was also investigated. The physical stability and release of a tracer (carmine) from the internal aqueous phase of double emulsions were characterized after each process stage using particle size analysis, light microscopy and spectrophotometry. When liquid shea oil was used the particle sizes varied in mode of D[4,3] from 28 +/- 2 mu m for initial fresh double emulsions to 90 +/- 7 mu m for heat treated and 210 +/- 11 mu m for heat treated, freeze-dried and reconstituted emulsions. Non-heat treated emulsions collapsed on freeze-drying due to high susceptibility of liquid oil droplets towards destabilization, when the external aqueous phase is crystalized. When solid shea oil was used the mode of D[4,3] varied from 48 +/- 0 mu m in initial emulsions to 118 +/- 3 mu m for heat treated emulsions and the freeze-dried and reconstituted emulsions showed 62 +/- 3 mu m or 85 +/- 11 mu m for non-heat treated and heat treated samples respectively. Reconstituted freeze-dried emulsion retained the encapsulated marker to over 97%. Overall, application of oil phase solid at room temperature and in situ heat treatment had a positive impact on process stability towards freezing and freeze drying. The result of this study revealed the feasibility to develop food-grade oil filled powders from OSA modified starch Pickering emulsions with approximately 70 wt% oil content by freeze-drying. (C) 2015 Elsevier Ltd. All rights reserved.
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| 9. |
- Marefati, Ali, et al.
(författare)
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Freezing and freeze-drying of Pickering emulsions stabilized by starch granules
- 2013
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 436, s. 512-520
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the possibility to produce novel powder materials based on chemically modified starch granule stabilized Pickering oil-in-water (O/W) emulsions. This study also investigated the effect of partial starch gelatinization in situ, dispersed phase type (two oil types with different melting points), freezing method and thawing, and freeze-drying and rehydrating on the overall properties of the emulsions. The emulsions showed high freeze thaw stability. The results of this study demonstrated the feasibility of the production of oil containing hydrocolloid-based powders, through combination of heat treated or even non-heat treated starch Pickering emulsions and freeze-drying. The final powders comprised high weight percentage of oil (over 80%, w/w). Upon rehydration of powders, the starch stabilized oil drops were found to be only moderately affected by the process with some aggregation observed. (C) 2013 Elsevier B.V. All rights reserved.
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| 10. |
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| 11. |
- Marku, Diana, et al.
(författare)
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Characterization of starch Pickering emulsions for potential applications in topical formulations.
- 2012
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 1873-3476 .- 0378-5173. ; 428:1-2, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work has been to characterize starch based Pickering emulsions as a first step to evaluate their possible use as vehicles for topical drug delivery. A minor phase study of emulsions with high oil content has been performed. Emulsion stability against coalescence over eight weeks and after mild centrifugation treatment has been studied. The particle size, rheological properties and in vitro skin penetration of emulsions containing three different oils (Miglyol, paraffin and sheanut oil) was investigated. It was shown that it is possible to produce oil in water starched stabilised Pickering emulsions with oil content as high as 56%. Furthermore, this emulsions show good stability during storage over eight weeks and towards mild centrifugation. The particle size of the systems are only dependent on the ratio between oil and starch and for liquid oils the type of oil do not affect the particle size. The type of oil also affects the cosmetic and rheological properties of the creams but did not affect the transdermal diffusion in in vitro tests. However, it seems as if the Pickering emulsions affected the transport over the skin, as the flux was twice that of what has been previously reported for solutions.
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| 12. |
- Matos, María, et al.
(författare)
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Preparation and encapsulation properties of double Pickering emulsions stabilized by quinoa starch granules
- 2013
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 423, s. 147-153
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Tidskriftsartikel (refereegranskat)abstract
- Double emulsions have potential applications in the food, cosmetic and pharmaceutical industries as vehicles for encapsulation and delivery of nutrients during food digestion or as drug release. The major drawback of this type of emulsions is that they are often difficult to stabilize. Particle stabilized emulsions, known as Pickering emulsions, show special features, such as being extremely stable with respect to coalescence. Starch granules have proved to be a suitable stabiliser for food grade Pickering emulsions. In this work, starch double W1/O/W2 Pickering emulsions were prepared and their encapsulation stability was studied as well as the impact of varying the lipophilic emulsifier (PGPR90) content and salt concentration in the W1 inner aqueous phase. Encapsulation properties were quantified by monitoring the release of a hydrophilic dye from the inner aqueous phase spectrophotometrically. Two double emulsion systems were studied, one with an inner aqueous phase with 0.1M NaCl and the other with 0.2M NaCl. The initial encapsulation efficiency was over 98.5% immediately after emulsification production. The encapsulation stability (ES) remained over 90% after 21 days for both systems studied, where 0.1 M NaCl W1 emulsion had a ES of 95.2% and the 0.2 M NaCl W1 emulsion had a ES of 91.1% respectively.
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| 13. |
- Perez, Sander, et al.
(författare)
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Water and Thermal Properties Characterized in Phases of Wheat Flour Dough during Thawing and Baking Conditions
- 2019
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Ingår i: Advances in Food Science and Engineering. - : Isaac Scientific Publishing Co., Ltd.. - 2520-7091 .- 2520-7105. ; 3:3, s. 48-62
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Tidskriftsartikel (refereegranskat)abstract
- Phase separation of dough is based on the thermodynamic incompatibility of its components. The studies on phase-separated systems allow to model, understand, and develop foods. Model dough systems made with water and wheat flour were disassembled into their main structural phases, i.e. liquid, gel, gluten and starch phases, by ultracentrifugation, and further characterized with differential scanning calorimetry (DSC) and microscopy. The study of phase separation, water properties and thermal transitions in phases showed that wheat flour doughs are mainly characterized by the volume fractions of liquid, gel and gluten. The different samples of flours were highly affected by flour combinations. The freezable water (FW) of each separated phase influenced the water properties of the whole dough. The FW is further related to starch thermal behaviour of dough systems at baking temperatures. The methods used here were therefore found relevant from a baking perspective for initial characterizing of flours and dough.
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| 14. |
- Plieva, Fatima, et al.
(författare)
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Pore structure in supermacroporous polyacrylamide based cryogels
- 2005
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-6848 .- 1744-683X. ; 1:4, s. 303-309
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Tidskriftsartikel (refereegranskat)abstract
- Pore size and thickness of pore walls in macroporous polyacrylamide gels, so-called cryogels (pAAm-cryogels), were controlled by varying the content of monomers in the initial reaction mixture and the cross-linker used. The thickness of pore walls in pAAm-cryogels increased with increasing concentration of monomers in the initial reaction mixture. Pore volume in the supermacroporous pAAm-cryogels was in the range of 70-93% and decreased with increasing concentration of monomers in the reaction feed. The porous structure of the pAAm-cryogels was visualized using environmental scanning electron microscopy (ESEM) that allowed monitoring of the dehydration process in pAAm-cryogels. The accessibility of ligands covalently coupled to the polymer backbone for low molecular weight target, Cu(II) ions, and high molecular weight target, the protein lysozyme, was assessed for pAAm-cryogels produced from feeds with different monomer concentration. The amount of bound Cu(II) ions increased linearly with increasing monomer concentration in the reaction feed, suggesting that all ligands are equally accessible for small targets. On the contrary, lysozyme binding demonstrated a clear maximum at monomer concentration about 18% suggesting that only ligrands present at the surface of pore walls are accessible for high molecular weight targets.
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| 15. |
- Plieva, Fatima, et al.
(författare)
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Pore structure of macroporous monolithic cryogels prepared from poly(vinyl alcohol)
- 2006
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Ingår i: Journal of Applied Polymer Science. - : Wiley. - 1097-4628 .- 0021-8995. ; 100:2, s. 1057-1066
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Tidskriftsartikel (refereegranskat)abstract
- Macroporous monolithic cryogels made from poly(vinyl alcohol) (PVA) with degree of saponification 87.7% have been prepared using a crosslinking reaction with glutaralclehyde under acidic conditions at subzero ternperatures. The porous structure of the monolithic cryogels from PVA (cryoPVA), analyzed using optical microscopy, scarinina electron microscopy, and environmental scanning electron microscopy, revealed interconnected macropores up to 150 mu m in size with a noticeable microporosity of the gel walls. Differential scanning calorimetry measurement showed that more than 90% of the water in the cryoPVA monoliths was freezable water, while the amount of polymer bound water increased with increase in the polymer concentration in the cryoPVA sample. The swelling degree of cryoPVA depended on concentration of polymer in the initial reaction mixture and degree of crosslinking. The cryoPVA monoliths were elastic and spongy-like materials that can be dried, stored in dried state, and re-swelled when required. Derivatization of hydroxyl-groups of the cryoPVA monolith allowed incorporation of required functionality. (c) 2006 Wiley Periodicals, Inc.
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| 16. |
- Purhagen, Jeanette, et al.
(författare)
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Fibre-rich additives-the effect on staling and their function in free-standing and pan-baked bread.
- 2012
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 92:6, s. 1201-1213
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The use of dietary fibre in bread products is increasing because of consumer demand for healthier products. However, an increase in dietary fibre level changes the rheological properties of the dough and also the quality properties of the final bread product. In this study, effects on dough and bread staling were followed after replacing 3% of wheat flour by fibre-rich additives (fine durum, oat bran, rye bran and wheat bran). Free-standing and pan-baked loaves were baked to compare the influence of baking method and loaf shape. RESULTS: All additives increased dough stability, with oat bran giving the greatest stability and longest development time. Parameters measured during storage were distribution, migration and loss of water, cutability, crumbliness, firmness and springiness. Furthermore, amylopectin retrogradation and amylase-lipid complex formation were assessed. Oat bran provided similar or better results than the control for all staling parameters, while other additives gave no general improvements. Cutability reached a plateau when crumb firmness was ≥ 4 N. CONCLUSION: Small amounts of fibre-rich additives had a significant influence on staling. However, the baking method (free-standing or pan-baked bread) had a greater impact on staling than the additives, thus displaying the importance of the baking method. Cutability was found to be related to firmness. Copyright © 2011 Society of Chemical Industry.
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| 17. |
- Purhagen, Jeanette, et al.
(författare)
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Staling Effects When Adding Low Amounts of Normal and Heat-Treated Barley Flour to a Wheat Bread
- 2008
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Ingår i: Cereal Chemistry. - 0009-0352. ; 85:2, s. 109-114
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Tidskriftsartikel (refereegranskat)abstract
- The properties of a white wheat bread could be changed by adding normal or heat-treated barley flour in small amounts (2 and 4%) to a white wheat bread recipe. Differences regarding gelatinisation as well as retrogradation properties were found when analysing the two flours in model systems. The heat-treated flour was fully gelatinised due to a prior time-, temperature- and pressure-treatment and could therefore absorb larger amounts of water than the other flours. In gelatinised model systems with 40% flour (dry weight basis), the heat-treated barley flour was found to contain less retrograded amylopectin as compared to normal barley flour after storage for up to 14 days, whereas no differences were found at 20%. However, stored breads showed an increased retrogradation of amylopectin (as measured by differential scanning calorimetry, DSC) when 2% pre-treated barley flour was added as compared to an addition of 2% normal barley flour. On the other hand, there were no significant differences at the 4% level. Addition of either of the barley flours resulted in less firm breads during storage as compared to the control breads. An increased water absorption in barley flour and thereby an increased water content in the breads and/or different water binding capacities of the flour blends could explain these results. The present study indicated that water had a stronger influence on the bread firmness than the retrogradation of amylopectin. This conclusion was based on breads with pre-treated barley flour being less firm than breads with normal barley flour, although the retrogradation, as determined by DSC, was higher.
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| 18. |
- Purhagen, Jeanette, et al.
(författare)
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Starch affecting anti-staling agents and their function in freestanding and pan-baked bread
- 2011
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 25:7, s. 1656-1666
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Tidskriftsartikel (refereegranskat)abstract
- Anti-staling agents with different mechanisms were added to a normal white wheat bread to investigate the relation between bread staling, amylopectin retrogradation and water-related properties (i.e. water content and distribution between crumb and crust). Bread was baked both as pan-baked and freestanding loaves. The anti-staling agents maltogenic alpha-amylase, distilled monoglyceride and lipase had a direct influence on starch retrogradation, whereas gluten and waxy wheat flour diluted the amylopectin content or changed the ratio between amylose and amylopectin. The degree of staling was measured as the firmness and springiness, together with two new methods, crumbliness and cutability. In addition, the degrees of amylopectin retrogradation and amylose-lipid complex formation were analyzed by differential scanning calorimetry, and the water content, water loss and water migration were measured. The addition of alpha-amylase improved most staling parameters, although the changes were not as large as expected. Furthermore, monoglyceride and lipase increased the formation of amylose-lipid complexes, but only lipase gave better results regarding the specific volume and firmness. Increased amylose-lipid complex formation was seen to increase water migration from crumb to crust. Adding 10% waxy wheat flour appeared to lead to a slight overall improvement i.e. lower water migration and better cutability. Adding gluten or 3% waxy wheat flour only improved the specific volume. The method of baking the loaves, i.e. freestanding or pan-baked, had a greater influence than the anti-staling agents, which shows that bread quality is not always improved by starch affecting anti-staling agents without process changes. (C) 2011 Elsevier Ltd. All rights reserved.
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| 19. |
- Purhagen, Jeanette, et al.
(författare)
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The anti-staling effect of pre-gelatinized flour and emulsifier in gluten-free bread
- 2012
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Ingår i: European Food Research and Technology. - : Springer Science and Business Media LLC. - 1438-2377 .- 1438-2385. ; 235:2, s. 265-276
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Tidskriftsartikel (refereegranskat)abstract
- The use of gluten-free products is increasing since an increasing number of people (1-2 %) are suffering from Celiac disease and thereby need a gluten-free diet. Gluten-free bread tends to have shorter shelf life and quality compared with white wheat bread. In this study, 3 % (flour basis) of pre-gelatinized oat and barley flour as well as an emulsifier were added to a gluten-free mix to increase the water content by 1.5-2 %, affect the starch retrogradation and the formation of amylose lipid complex. The staling was followed measuring the firmness (texture analyzer), water content and distribution (nuclear magnetic resonance), amylopectin retrogradation and the formation of amylose-lipid complex (differential scanning calorimetry) in order to see the impact of both macroscopic and molecular changes on firmness. Both gluten-free bread and a white wheat bread were used as control loaves. Largest specific volume was found in the gluten-free control. The firmness varied with both the specific volume and the point of measurement. The amount of retrograded amylopectin increased the firmness, although this effect was dependent on the type of bread, in terms of distribution and availability of the water within the system. The proton relaxation time, which was representing movable water, decreased during storage and revealed that both the amylopectin retrogradation and the lipid complex formation were affecting the rigidity of the amorphous domain and not only the crystalline regions. In contrast to the other recipes, the use of emulsifier caused limited retrogradation and a low correlation between the texture properties and time-dependent events.
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| 20. |
- Purhagen, Jeanette, et al.
(författare)
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The use of normal and heat-treated barley flour and waxy barley starch as anti-staling agents in laboratory and industrial baking processes
- 2011
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774. ; 104:3, s. 414-421
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Tidskriftsartikel (refereegranskat)abstract
- Normal and heat-treated barley, both as flour and waxy starch, were added at a concentration of 3% to a white wheat bread. The effect not only of selected additives, but also of laboratory- and industrial baking processes on stalling was evaluated. Laboratory baked breads with heat-treated barley flour differed from control breads with regard to water content, firmness and amylopectin retrogradation. The influence of water content on firmness increased with storage time. All laboratory baked breads with barley additives, except normal barley flour, were less firm after 7 days of storage as compared to the control although amylopectin retrogradation tended to increase. Improved water absorption, and consequently, increased water content and/or different water binding capacities of the flour/starch could explain these results. Industrial baking caused higher water losses, especially in breads containing additives, thus reducing the effects on amylopectin retrogradation and firmness. (C) 2011 Elsevier Ltd. All rights reserved.
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| 21. |
- Rayner, Marilyn, et al.
(författare)
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Biomass-based particles for the formulation of Pickering type emulsions in food and topical applications
- 2014
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 458, s. 48-62
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Tidskriftsartikel (refereegranskat)abstract
- Pickering emulsions are emulsions that are stabilized by fine particles. They have been the focus of considerable research in the past decade due to their properties such as high stability with respect to coalescence and Ostwald ripening, as well as due to advances in nanotechnology that allows us to create and characterize nano-scale structures in new ways. This work reviews some of the recent work in the area of biomass-based particles for Pickering emulsions in the context of foods and topical creams, and discusses some of the theory and particularities of Pickering type emulsions. Formulation examples are given with a focus on two types of biomass-based particles isolated with their natural structure intact: starch granules from quinoa and egg yolk granules. In contrast to particles commonly used for Pickering emulsions such as latex, silica, and clay particles, starch (including hydrophobically modified starch) and egg-fractions are accepted food ingredients, as well as pharmaceutical and cosmetic excipients. The particle stabilization of emulsion drops is possible due to partial dual wettability of particles at the oil-water interface. Native starch is not intrinsically hydrophobic; however hydrophobicity can be increased by chemical modification with octenyl succinic anhydride. Egg-granules on the other hand are quite hydrophobic and at low ionic strength (<0.3 M NaCl) are insoluble with a compact structure. Quinoa starch granules and egg-granules can be used to generate Pickering type emulsions in the 10-100 mu m range with high levels of stability. Size decreased with increasing concentration and could be controlled by the granule to oil ratio. In the case of starch granule stabilized oil drops, heat can be applied to induce a partial gelatinization of the starch granules forming a cohesive layer at the oil-water interface increasing barrier properties. Although the droplet size of granule stabilized emulsions was relatively large, their excellent stability, encapsulation properties, and freeze-thaw stability can prove suitable for applications such as encapsulation of sensitive, bioactive ingredients in food and topical formulations. (C) 2014 Elsevier B.V. All rights reserved.
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| 22. |
- Rayner, Marilyn, et al.
(författare)
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Quinoa starch granules: a candidate for stabilising food-grade Pickering emulsions.
- 2012
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 92:9, s. 1841-1847
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Particle-stabilised emulsions, so-called Pickering emulsions, are known to possess many beneficial properties, including being extremely stable. Starch granules isolated from quinoa have been used as emulsion stabilising particles. The granules were intact, 1-3 µm in diameter and modified with octenyl succinic anhydride to increase their hydrophobicity. Starch granules, as opposed to most other particles used to generate Pickering emulsions, are edible, abundant and derived from natural sources. RESULTS: Emulsions produced by high shear homogenisation had droplet sizes of 9-70 µm depending on the starch-to-oil ratio. Droplet size decreased with increasing starch-to-oil ratio, but was unaffected by the oil phase volume over a range of 5-33% oil (v/v). Although the drops were large and subject to creaming, their size remained unchanged over a period of 7 days. By adjusting the starch-to-oil ratio drops could be made to be buoyancy neutral to prevent creaming. Rheological characterisation indicated a gel structure with an elastic modulus in the range 200-2000 Pa depending on droplet size. CONCLUSION: This work has demonstrated the successful use of starch granules to stabilise emulsions which may find applications beyond that of food, for example in cosmetics and pharmaceutical formulations. Copyright © 2012 Society of Chemical Industry.
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| 23. |
- Rayner, Marilyn, et al.
(författare)
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Quinoa starch granules as stabilizing particles for production of Pickering emulsions
- 2012
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Ingår i: Faraday Discussions. - 1364-5498. ; 158, s. 139-155
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Tidskriftsartikel (refereegranskat)abstract
- Intact starch granules isolated from quinoa (Chenopodium quinoa Willd.) were used to stabilize emulsion drops in so-called Pickering emulsions. Miglyol 812 was used as dispersed phase and a phosphate buffer (pH7) with different salt (NaCl) concentrations was used as the continuous phase. The starch granules were hydrophobically modified to different degrees by octenyl succinic anhydride (OSA) or by dry heat treatment at 120 [degree]C in order to study the effect on the resulting emulsion drop size. The degree of OSA-modification had a low to moderate impact on drop size. The highest level of modification (4.66%) showed the largest mean drop size, and lowest amount of free starch, which could be an effect of a higher degree of aggregation of the starch granules and, thereby, also the emulsion drops stabilized by them. The heat treated starch granules had a poor stabilizing ability and only the starch heated for the longest time (150 min at 120 [degree]C) had a better emulsifying capacity than the un-modified native starch granules. The effect of salt concentration was rather limited. However, an increased concentration of salt slightly increased the mean drop size and the elastic modulus.
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| 24. |
- Saari, Hisfazilah, et al.
(författare)
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A comparison of emulsion stability for different OSA-modified waxy maize emulsifiers : Granules, dissolved starch, and non-solvent precipitates
- 2019
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- This work investigates the stability of emulsions prepared by using octenyl succinic anhydride (OSA)-modified waxy maize starch in the form of granules, dissolved starch, and non-solvent precipitated starch as Pickering emulsion stabilisers. The aim of this study was to investigate the effects of different forms of starches on the stability of emulsion using light microscopy, light scattering, and static multiple light scattering. All starch samples were hydrophobically modified with 3% (w/w) n-octenyl succinyl anhydride (OSA). Starch polymer solutions were prepared by dissolving OSA- modified starch in water in an autoclave at 140C. Non-solvent precipitates were obtained through ethanol precipitation of dissolved waxy maize. The stability of the oil/water emulsions were different for the three forms of starches used. The granule-based emulsions were unstable, with only a small proportion of the granules adsorbed onto oil droplets, as viewed under a light microscope. The emulsions were observed to cream after 2 hours. The dissolved starch and non-solvent precipitate-based emulsions were stable towards creaming for months, and they had almost 100% emulsifying index (EI = 1) by visual observation and EI ~ 0.9 by multiple light scattering measurements. The results from light microscopy and multiple light scattering measurements indicated the occurrence of coalescence for all three types of emulsions. The coalescence was fastest within days for the granule stabilised system while it was slower both for the dissolved starch and non-solvent precipitate-based emulsions. The latter demonstrated the least degree of coalescence over time. Thus, it was concluded that differences in starch particle size and molecular structure influenced the emulsion droplet size and stability. A decreased particle size correlates to a decrease in droplet size, thus increasing stabilisation against creaming. However, stability towards coalescence was low for the large granules but was best for the non-solvent precipitate starch indicating that there is a window of optimal particle size for stability. Thus, best emulsifying properties were obtained with the non-solvent precipitates (~ 120 nm particle size) where the emulsions remained stable after one year of storage. In conclusion, this study illustrated the potentiality of non-solvent precipitated starch as emulsion stabilizers.
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| 25. |
- Saari, Hisfazilah, et al.
(författare)
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Pickering emulsions based on CaCl2-gelatinized oat starch
- 2018
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 82, s. 288-295
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate calcium chloride-induced gelatinization of oat starch, and its effects on the properties of oat starch-based Pickering emulsions. The starch granules were gelatinized in CaCl2 for up to 24 h and the results indicate that the salt-induced gelatinization of oat granules is not a surface phenomenon, as gelatinization and dissolution of the whole starch granule was observed. The degree of swelling differed with time and for emulsions the creaming layer changed depending on the length of salt-induced gelatinization; the least dense layer being observed after 30 min of gelatinization. The study also included OSA-modified starch. OSA modification of oat starch led to a slight decrease in the droplet size in the resulting emulsion, but the macroscopic properties of the emulsions made with OSA-modified and non-OSA-modified oat starch granules were similar. It was also investigated whether emulsions made from non-gelatinized oat starch could be gelatinized in situ. This was found to be possible and led to encapsulation of the oil. The gelatinized emulsions could be dialyzed and lyophilized without loss of oil. Leading to dry emulsions that was reformed upon reconstitution with water.
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| 26. |
- Saari, Hisfazilah, et al.
(författare)
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Preparation and Characterization of Starch Particles for Use in Pickering Emulsions
- 2016
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Ingår i: Cereal Chemistry. - 0009-0352. ; 93:2, s. 116-124
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Tidskriftsartikel (refereegranskat)abstract
- Particle-stabilized emulsions, called Pickering emulsions, can be produced by using starch particles. In this work we studied how the properties of the starch particles affect the droplet size and creaming of such emulsions. In the study, various sizes of starch particles were generated by two different methods and used to stabilize Pickering emulsions. Sedimentation according to Stokes’ law was used to separate small and large starch granules. Acid hydrolysis was another method used to obtain smaller particles. All samples were modified with octenyl succinic anhydride (OSA) to increase their hydrophobicity with a level of OSA substitution between 1.8 and 3.1%. The size of starch particles was the main factor influencing emulsion droplet sizes. Furthermore, the droplet size decreased as the starch concentration increased. Using small starch particles with sizes <10 μm produced stable emulsions with smaller droplet size compared with larger sizes of starch particles, >10 μm. When subjected to acid hydrolysis, smaller starch particles were generally obtained, which could subsequently create smaller emulsion droplets. The emulsion index increased for the acid-hydrolyzed starch owing to the size reduction of starch particles. The shape of the starch seemed to have a minor impact on the droplet size and the creaming of Pickering emulsions.
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| 27. |
- Saari, Hisfazilah, et al.
(författare)
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Production of starch nanoparticles by dissolution and non-solvent precipitation for use in food-grade Pickering emulsions
- 2017
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 157, s. 558-566
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate non-solvent precipitation of starch to produce nanoparticles that could be used in Pickering emulsions. The material used was waxy maize, modified with octenyl succinic anhydride. Different methods of non-solvent precipitation were investigated, and a method based on direct mixing of an 8% starch solution and ethanol (ratio 1:1) was found to produce the smallest particles. The particle size was measured using AFM and AF4, and was found to be in the range 100–200 nm. However, both larger particles and aggregates of nanoparticles were observed. The emulsion produced using the precipitated starch particles had a droplet size that between 0.5 and 45 μm, compared to emulsions produced from waxy maize granules, in which had a size of 10–100 μm. The drop in size contributed to increased stability against creaming. The amount of starch used for emulsion stabilization could also be substantially reduced.
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| 28. |
- Simsek, Senay, et al.
(författare)
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Chemical composition, digestibility and emulsification properties of octenyl succinic esters of various starches
- 2015
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969. ; 75, s. 41-49
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Tidskriftsartikel (refereegranskat)abstract
- Octenyl succinate starches are commonly used as emulsifiers and texturizing agents in many food-systems. Rice, tapioca, corn, wheat and potato starches were modified with octenyl succinic anhydride (OSA) at 3% level. Structural characterization, molecular weight, starch digestibility and physical properties of starch granule stabilized emulsions were studied for modified starches. Modified potato (0.022) and wheat (0.018) starches had the highest and lowest degrees of OSA substitution, respectively. For all starches, amylose and amylopectin molecular mass was significantly (P < 0.05) lower for OSA starches. OSA modification may have hydrolyzed the small amylose and amylopectin chains, or caused rearrangement of the starch molecules. Although the starch modification improved emulsification properties, botanical source showed more influence on this parameter. Overall, botanical source had more influence on functional properties than degree of substitution. Further studies on OSA group distribution and fine molecular structure of amylopectin and relationship with functional properties will be important Published by Elsevier Ltd.
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| 29. |
- Sjöö, Malin, et al.
(författare)
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Barrier properties of heat treated starch Pickering emulsions.
- 2015
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 450, s. 182-188
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Tidskriftsartikel (refereegranskat)abstract
- There is a recognized technological need for delivery systems encapsulating lipophilic substances in food and pharmaceutical products. Pickering emulsions can provide well-defined and highly stable systems, but may not provide good enough barrier properties. Starch granules, recently being used for Pickering stabilization, have the advantage of the ability to swell during gelatinization. Hence, this property could be used to tune and control barrier properties.
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| 30. |
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| 31. |
- Sjöö, Malin, et al.
(författare)
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Effects of time/temperature treatments on potato (Solanum tuberosum) starch: a comparison of isolated starch and starch in situ.
- 2003
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 83:15, s. 1587-1592
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Tidskriftsartikel (refereegranskat)abstract
- Previously, time/temperature treatments of starch have been performed mainly on starch/water systems. In this study the same time/temperature treatments were applied to starch/water systems and to potato starch in situ. Two potato varieties (Solanum tuberosum cultivars Asterix and Bintje) were used. The effect of time/temperature treatments on gelatinisation behaviour was evaluated using differential scanning calorimetry (DSC). A blanching process was simulated by heating samples to 74 °C and then cooling them to 6 °C. A DSC scan showed that starch was completely gelatinised after this treatment. Retrogradation of amylopectin increased during storage at 6 °C from 0 to 24 h after blanching. Annealing of starch, with the aim of altering cooking properties, was performed by heating samples to temperatures below the gelatinisation onset temperature. Treating samples at 50 °C for 24 h caused a shift in gelatinisation onset temperature of 11-12 °C for isolated starch and 7-11 °C for in situ samples. The extent of the annealing effect depended on the difference between onset and annealing temperatures, and prolonged treatment time increased the effect. Starch/water systems and tissue samples behaved similarly when exposed to time/temperature treatments. The most apparent difference was the shift of gelatinisation to higher temperatures in tissue samples.
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| 32. |
- Sjöö, Malin, et al.
(författare)
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Gelatinization and retrogradation of potato (Solanum tuberosum) starch in situ as assessed by differential scanning calorimetry (DSC).
- 2003
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Ingår i: LWT - Food Science and Technology. - 0023-6438. ; 36:8, s. 735-741
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Tidskriftsartikel (refereegranskat)abstract
- The thermal behavior of potato starch in situ has been studied and compared to properties of isolated starch. Gelatinization and retrogradation properties were studied by differential scanning calorimetry. One early and three late varieties with different degree of mealiness were examined. The early variety (Solanum tuberosum var. Rocket) had lower dry matter content and lower starch gelatinization temperature than the later varieties (var. Asterix, Bintje and King Edward). Samples from distinct parts of the potato tuber were analysed to compare the tissue zones. The starch in the water-rich pith appeared to gelatinize at a higher temperature than in samples from the outer parts of the tuber. This was seen for isolated starch as well as for starch in situ; however, the differences were more pronounced in situ. To investigate the influence of tuber size, samples were taken from stem end storage parenchyma. No influence of tuber size on the starch gelatinization properties was detected by the method used. Retrogradation properties were also studied for stem end storage parenchyma. Melting temperatures of recrystallized amylopectin did not differ between varieties, though there were small differences in rate of recrystallization as measured by changes in melting transition enthalpy with time.
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| 33. |
- SjÖÖ, Malin, et al.
(författare)
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Particle-stabilized emulsions
- 2015
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Ingår i: Engineering Aspects of Food Emulsification and Homogenization. - : CRC Press. - 9781466580435 - 9781466580442 ; , s. 101-122
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Bokkapitel (refereegranskat)abstract
- This chapter describes particle-stabilized emulsions, the so-called Pickering emulsions. The principles behind particle stabilization of emulsions are described. The key properties of particle-stabilized emulsions such as stability, rheology, and the influences of other ingredients on the system, as well as some additional functional properties imparted by the stabilized particles in food emulsion formulations, are highlighted.
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| 34. |
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| 35. |
- Sjöö, Malin, et al.
(författare)
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Some physical and nutritional characteristics of genetically modified potatoes varying in amylose/amylopectin ratios
- 2007
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 100:1, s. 136-146
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Tidskriftsartikel (refereegranskat)abstract
- Transgenically modified potatoes with a large spread in amylose/amylopectin ratios were analysed both as tubers and in the form of isolated starch. Different microscopic techniques were used to study starch granules and tuber tissue. Starch gelatinisation properties and recrystallisation of amylopectin and amylose were studied by differential scanning calorimetry. Starch bioavailability and resistant starch (RS) were evaluated using enzymatic in vitro procedures. Glycaemic indices (GI) were predicted from low molecular weight carbohydrates (LMWC) contents and the in vitro hydrolysis rate of the starch moiety. For many of the examined parameters, differences of varying magnitude were found between the potato lines, especially for high amylose lines. High amylose starch granules had irregular shapes and showed only a limited swelling. Moreover, contents of RS and recrystallised amylose were elevated. GI’s for the starch moiety were reduced, though elevated contents of LMWC caused a high over-all predicted GI.
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| 36. |
- Sjöö, Malin
(författare)
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Starch in Processed Potatoes -Influence of Tuber Structure, Thermal Treatments and Amylose/Amylopectin Ratio
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The potato is one of our most important food crops, being sold in its natural state or processed into a wide range of products. Starch, by far the most abundant component in the tuber, is greatly affected by heat processing. Therefore it is logical to study starch thermal properties within the tuber tissue, although most previous studies have focused on starch-water model systems. One of the main purposes of this work was to analyse thermal events such as gelatinisation, retrogradation and annealing in both tissue samples and starch-water systems, and to relate starch thermal effects to the characteristics of potato tubers and processing conditions. The main methods used were differential scanning calorimetry (DSC) and microscopy. The DSC method has been widely used to study starch and is also applicable to the analysis of potato tissue samples. Several microscopic techniques were used to study the potato microstructure at different levels of magnification. Information obtained from micrographs was further used to interpret results from DSC analyses. Several characteristics of the raw material were shown to influence the thermal properties of starch. Potato variety and cultivation year, as well as properties related to dry matter components and their distribution within the tuber, were very important, whereas the tuber size was insignificant. The gelatinisation of starch within tissue is shifted to higher temperatures as compared with starch-water systems, a fact that also influences the effects of annealing. Furthermore, starch from the central parts of the tuber had categorically higher gelatinisation temperatures than starch from other tuber tissue zones. Retrogradation rate, in terms of increased enthalpy of melting recrystallised amylopectin with time, was affected by variety whereas melting temperatures were not. However, the differences in gelatinisation and retrogradation between varieties could not be related to cooking type, i.e. mealiness. To understand more about the influence of amylose and amylopectin respectively on different starch characteristics, potatoes with large variations in amylose content were analysed. Amylose content roughly ranged from 1 to 78 %. In high-amylose starch, properties such as granule morphology, gelatinisation, and retrogradation were severely altered compared with normal starch. In starch with 99 % amylopectin differences were less extensive. When subjecting some of these starches to different temperature treatments, it was shown that important nutritional features such as resistant starch content and starch hydrolysis rate are mainly affected by amylose content. A synergistic effect between retrograded amylopectin and amylose may have an additional effect on these properties.
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| 37. |
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| 38. |
- Timgren, Anna, et al.
(författare)
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Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride
- 2013
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Ingår i: Food Science & Nutrition. - : Wiley. - 2048-7177. ; 1:2, s. 71-157
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Tidskriftsartikel (refereegranskat)abstract
- Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous phase, both with and without salt in a phosphate buffer, was also studied. Quinoa, which had the smallest granule size, had the best capacity to stabilize oil drops, especially when the granules had been hydrophobically modified by heat treatment or by OSA. The average drop diameter (d 32) in these emulsions varied from 270 to 50 μm, where decreasing drop size and less aggregation was promoted by high starch concentration and absence of salt in the system. Of all the starch varieties studied, quinoa had the best overall emulsifying capacity, and OSA modified quinoa starch in particular. Although the size of the drops was relatively large, the drops themselves were in many instances extremely stable. In the cases where the system could stabilize droplets, even when they were so large that they were visible to the naked eye, they remained stable and the measured droplet sizes after 2 years of storage were essentially unchanged from the initial droplet size. This somewhat surprising result has been attributed to the thickness of the adsorbed starch layer providing steric stabilization. The starch particle-stabilized Pickering emulsion systems studied in this work has potential practical application such as being suitable for encapsulation of ingredients in food and pharmaceutical products.
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| 39. |
- Timgren, Anna, et al.
(författare)
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Starch particles for food based Pickering emulsions
- 2011
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Ingår i: Procedia Food Science. - : Elsevier BV. - 2211-601X. ; 1, s. 95-103
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Tidskriftsartikel (refereegranskat)abstract
- Intact starch granules are a new source of particles for stabilizing emulsions, so called Pickering emulsions. Small (1-2 μm) and uni-modal starch granules at various concentrations have been used in this study to investigate the stability of the emulsions, the drop size dependence of the starch concentration and the barrier properties of the stabilizing starch layer upon heating. The granules were modified with octenyl succinic anhydride (OSA) to increase the hydrophobicity. The drops in the emulsions prepared in this study were in the 10-100 μm range depending on the starch concentration, and the drop size decreased with an increased amount of added starch granules. During the 8 week storage, the emulsion drops were stable to coalescence and the volume occluded by the emulsion phase was unaffected or even increased. In order to increase the barrier properties at the oil-water interface the emulsions were gently heated, which induced a partial gelatinization of the starch granules. The efficiency of the barrier was characterized by a lipolysis experiment where the activity of lipase was measured. The activity of lipase was decreased with nearly 70% compared to an unheated starch stabilized emulsion, which will be useful in applications where a controlled release of specific substances in the gastro intestinal tract is desirable.
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| 40. |
- Wahlgren, Marie, et al.
(författare)
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The Use of Micro- and Nanoparticles in the Stabilisation of Pickering-Type Emulsions for Topical Delivery
- 2013
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Ingår i: Current Pharmaceutical Biotechnology. - : Bentham eBooks. - 1389-2010 .- 1873-4316. ; 14:15, s. 1222-1234
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Tidskriftsartikel (refereegranskat)abstract
- This review describes the use of Pickering emulsions for topical drug delivery. The focus is on Pickering emulsions and how to formulate these. However, a short description of the challenges of topical drug delivery is also given. The article describes how Pickering emulsions might have other properties than traditional topical creams. It is our believe that Pickering emulsions could give added value to topical formulations as it is surfactant free, has new properties, and may alter the transport of drugs across the skin barrier.
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