| 1. |
- Boostani, Sareh, et al.
(författare)
-
Development and characterization of medium and high internal phase novel multiple Pickering emulsions stabilized by hordein nanoparticles
- 2022
-
Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146. ; 372
-
Tidskriftsartikel (refereegranskat)abstract
- Medium and high internal phase W1/O/W2 multiple Pickering emulsions (MPEs) were fabricated by physically-modified hordein nanoparticles. A triphasic system was developed at dispersed phase volume fraction (Φ) of 0.5 with an overrun value of ∼40%. No overrun was detected in high internal phase MPEs (Φ 0.8). Optical and confocal laser scanning microscopy confirmed the formation of MPEs. Monomodal droplet size distribution with a mean diameter of 32.90 and 21.48 μm was observed for MPEs at Φ 0.5 and Φ 0.8, respectively. Static multiple light scattering confirmed that creaming was the main mechanism behind the instability of MPEs. Both MPEs revealed pseudo-plastic behavior and predominant storage modulus (G′) over the applied frequency range. The encapsulation efficiency of vitamin B12 in MPEs was 98.3% and remained relatively constant during 28 d. These results suggested the excellent potential of hordein nanoparticles as appropriate candidate for designing multi-structural colloidal systems using plant proteins.
|
|
| 2. |
- Boostani, Sareh, et al.
(författare)
-
The influence of emulsion parameters on physical stability and rheological properties of Pickering emulsions stabilized by hordein nanoparticles
- 2020
-
Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 101
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, the effect of pH (3–8), ionic strength (I, 0.01–1 M), protein particle concentration (C, 0.5%–2%), and dispersed phase volume fraction (Φ, 0.25–0.8) on the efficacy of hordein-based colloidal nanoparticles in the stabilization of Pickering structures was investigated. Colloidal particles were synthesized via anti-solvent method. Depending on pH and I, the average size and zeta-potential of hordein particles ranged from 425 to around 4000 nm, and +27.5 to −15.63 mV, respectively. The intense aggregation of particles at pH close to isoelectric point and also at high I led to poor formation and stability of Pickering emulsions. The overrun value was influenced by various emulsion parameters. At pH 3, triphasic (with the overrun value of 75%) and high internal phase (HIP) emulsions with an average droplet size of 15.6–86.7 μm were formed at Φ 0.25 and 0.8, respectively. At Φ 0.5 and 0.8, an elastic gel-like behavior (i.e., storage modulus (G′) > loss modulus (G″)) was observed over the applied frequency range. At Φ 0.25, a predominant viscous character (G">G′) was observed at low frequencies; while, at higher frequencies, G′ exceeded G″ due to the foam collapse. The morphology was studied by optical microscopy and confocal laser scanning microscopy (CLSM). Monitoring the physical stability using static multiple light scattering (MLS) revealed three destabilization profiles of foam-like, emulsion-foam and gel-like structures. The results of this study might help in designing triphasic Pickering systems (using plant-based proteins) and developing solid-like structured vegetable oils from the gel-like HIP emulsions.
|
|
| 3. |
- Hadi, Nabilah Abdul, et al.
(författare)
-
Comparison of three methods to determine the degree of substitution of quinoa and rice starch acetates, propionates, and butyrates : Direct stoichiometry, FTIR, and 1H-NMR
- 2020
-
Ingår i: Foods. - : MDPI AG. - 2304-8158. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- Rice and quinoa starch esters were prepared by acylation using short-chain fatty acid anhydrides with different chain lengths (acetic, propionic, and butyric anhydride). A direct stoichiometric method based on the acylation reaction was used to determine the degree of substitution (DS) and acyl content (AC). In addition, Fourier-transform infrared spectroscopy (FTIR) was used to validate the conformational changes of acylated starch and 1H-NMR was used as a DS reference method. DS by stoichiometric calculation was shown to be in agreement with FTIR and was comparable with DS obtained from Proton nuclear magnetic resonance (1H-NMR). Based on this study, stoichiometric calculation allows rapid and direct determination of substitution levels and acyl content without the loss of samples, which provides efficiency and optimization of manufacturing procedures in producing the desired level of esterified starches.
|
|
| 4. |
- Helstad, Amanda, et al.
(författare)
-
High-Pressure Pasteurization of Oat Okara
- 2023
-
Ingår i: Foods. - 2304-8158. ; 12:22
-
Tidskriftsartikel (refereegranskat)abstract
- The issue of the short microbiological shelf life of residues from the plant-based beverage industry creates a large food waste problem. Today, the oat beverage residue, in this study referred to as oat okara, is generally converted to energy or used as animal feed. High-pressure pasteurization (200 MPa, 400 MPa, and 600 MPa) was applied to oat okara to investigate the effect on shelf life and microbiological activity. A 4-week microbiological storage study was performed and thermal properties, viscosity, and water and oil holding capacities were analyzed. The total aerobic count, including yeast and mold, was significantly reduced (p < 0.05) by 600 MPa after four weeks of storage at 4 °C. The content of lactic acid bacteria after four weeks of storage was low for untreated oat okara (3.2 log CFU/g) but, for 600 MPa, the content remained at the detection limit (2.3 log CFU/g). Conversely, the treatments of 200 MPa and 400 MPa increased the microbial content of the total aerobic count significantly (p < 0.05) after two weeks in comparison to untreated oat okara. The thermal properties of untreated and high-pressure-treated oat okara demonstrated an increase in protein denaturation of the 12S globulin, avenalin, when higher pressure was applied (400–600 MPa). This was also confirmed in the viscosity measurements where a viscosity peak for avenalin was only present for untreated and 200 MPa treated oat okara. The water holding capacity did not change as a function of high-pressure treatment (3.5–3.8 mL/g) except for the treatment at 200 MPa, which was reduced (2.7 mL/g). The oil holding capacity was constant (1.2–1.3 mL/g) after all treatments. High-pressure pasteurization of 600 MPa reduced the microbial content in oat okara resulting in a shelf life of 2–4 weeks. However, more research is required to identify the microorganisms in oat okara to achieve a microbiologically safe product that can be used for food applications.
|
|
| 5. |
- Helstad, Amanda, et al.
(författare)
-
High-Pressure Pasteurization of Soy Okara
- 2023
-
Ingår i: Foods. - 2304-8158. ; 12:20, s. 1-15
-
Tidskriftsartikel (refereegranskat)abstract
- Okara is a by-product from the production of soy beverages, which has a high content of protein and fiber. Even though it has a high nutritional value, it is generally discarded or used as animal feed or compost. The problem is its short shelf life due to its high water content and high water activity. The aim of this study was to investigate the effect of high-pressure pasteurization at 200 MPa, 400 MPa, and 600 MPa on the shelf life of soy okara. Microbiological growth, as well as thermal properties, viscosity, water holding capacity, and oil holding capacity, was evaluated after the pressure treatments. Treatment at 600 MPa significantly reduced (p < 0.05) the growth of total aerobic count, yeast and mold, and lactic acid bacteria for up to four weeks of storage at 4 °C. The pasting properties were increased while the water and oil holding capacities of the soy okara did not significantly change (p > 0.05) after high-pressure pasteurization at 400 MPa and 600 MPa. High-pressure pasteurization is therefore a potential application technique for soy okara to produce a microbiologically safe product with maintained functional properties. However, more research is needed to optimize the process and to further investigate the microbiological species present in untreated soy okara to exclude any potential food safety risks.
|
|
| 6. |
- Marefati, Ali, et al.
(författare)
-
Encapsulation of Lactobacillus reuteri in W1/O/W2 double emulsions : Formulation, storage and in vitro gastro-intestinal digestion stability
- 2021
-
Ingår i: LWT. - : Elsevier BV. - 0023-6438. ; 146
-
Tidskriftsartikel (refereegranskat)abstract
- Encapsulation of Lactobacillus reuteri in the internal aqueous phase of W1/O/W2 emulsions was investigated. Microstructure of the emulsions was evaluated using a particle size analyzer and light microscopy. The encapsulation properties were evaluated in terms of encapsulation efficiency (EE) for freshly prepared samples and encapsulation stability (ES) during storage and in vitro digestion and the results were compared to control. Particle size analysis showed that encapsulation of the bacteria increased the droplet sizes of W1/O emulsions significantly (P < 0.05) from 3.5 ± 0.2 to 4.8 ± 0.4 μm which was verified by microscopy. Neither encapsulation nor storage changed (P > 0.05) the droplet sizes for double emulsions (14.9 ± 0.3 μm) compared to control (15.5 ± 0.4 μm) which remained stable through storage period. The EE was 7.23 ± 0.07 Log CFU/mL. During cold storage, the ES decreased with a higher pace for control (from 6.18 ± 0.03 to <1 Log CFU/mL) compared to formulations with encapsulated bacteria (from 7.23 ± 0.07 to 2.82 ± 0.10 Log CFU/mL). Finally, during in vitro digestion, the ES decreased with a higher rate for control (from 6.25 ± 0.36 to 2.69 ± 0.06 Log CFU/mL) compared to encapsulated samples (from 6.69 ± 0.07 to 4.64 ± 0.06 Log CFU/mL). The results showed that encapsulation of Lactobacillus reuteri using double emulsions can protect the probiotics during storage and in vitro gastro-intestinal digestion.
|
|
| 7. |
- Marefati, Ali, et al.
(författare)
-
Fabrication of encapsulated oil powders from starch granule stabilized W/O/W Pickering emulsions by freeze-drying
- 2015
-
Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 51, s. 261-271
-
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.
|
|
| 8. |
- Marefati, Ali, et al.
(författare)
-
Freezing and freeze-drying of Pickering emulsions stabilized by starch granules
- 2013
-
Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 436, s. 512-520
-
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.
|
|
| 9. |
- Marefati, Ali, et al.
(författare)
-
In vitro intestinal lipolysis of emulsions based on starch granule Pickering stabilization
- 2019
-
Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 95, s. 468-475
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of barrier properties on in vitro intestinal lipolysis of three different types of emulsions based on oil-in-water starch granule Pickering stabilization has been investigated including non-heat treated, heat treated (gelatinized) and heat treated and stored (retrograded) emulsions. The stability of starch covered oil-water interfaces towards in vitro intestinal lipolysis was correlated to the rate of lipid hydrolysis using a pH-stat method. The results were compared with a sodium caseinate stabilized emulsion. The shape and size of the starch granules were characterized by scanning electron microscopy and light scattering. The physical properties of the emulsions were characterized by a light scattering particle size analyzer and light microscopy. In all cases, Pickering emulsions showed lower extents of lipolysis compared to the protein stabilized emulsion. In addition, heat treated starch Pickering emulsions were more susceptible to lipolysis compared to freshly prepared emulsions with no heat treatment. This was thought to be due to the gelatinized starch barrier being more susceptible to amylase present in the pancreatin. The results of this study demonstrate the interfacial layer properties can affect the rate and extent of lipolysis.
|
|
| 10. |
- Marefati, Ali, et al.
(författare)
-
Quinoa Starch Granules as Emulsion Stabilizers
- 2022
-
Ingår i: Biology and Biotechnology of Quinoa : Super Grain for Food Security - Super Grain for Food Security. - Singapore : Springer Singapore. - 9789811638329 - 9789811638312 ; , s. 283-324
-
Bokkapitel (refereegranskat)abstract
- Quinoa (Chenopodium quinoa Willd.) has gained recent popularity mainly due to its attractive nutritional profile and its ability to grow under extreme conditions such as salinity, acidity, drought, flooding, and frost as well as the functionality of its component. Starch is the main component of quinoa grain which constitutes up to 60% of the dry grain and plays a crucial role in the functional properties of quinoa. Quinoa starch granules are small, polygonal, and in the range of 0.5–3 μm, with unique physicochemical properties. These unique features have created research interest in the application of the quinoa starch for functional products such as stabilizer for creating Pickering emulsions. This chapter summarizes the application of starch granules in native and modified forms as particles in the stabilization of Pickering emulsions.
|
|
