| 1. |
- Mårtensson, O, et al.
(författare)
-
Comparison of growth characteristics and exopolysaccharide formation of two lactic acid bacteria strains, Pediococcus damnosus 2.6 and Lactobacillus brevis G-77, in an oat-based, non-dairy medium.
- 2003
-
Ingår i: LWT - Food Science and Technology. - 0023-6438. ; 36:3, s. 353-357
-
Tidskriftsartikel (refereegranskat)abstract
- The fermentation characteristics of two strains of lactic acid bacteria (LAB), Lactobacillus brevis G-77 and Pediococcus damnosus 2.6 were compared in an oat-based, nondairy milk medium (Adavena® G40). Viscosity and ropiness were the main growth parameters studied. Both strains are reported to produce an exopolysaccharide (EPS) with a -glucan structure; in addition, the L. brevis strain produces also an EPS with an -glucan structure. Both strains were able to ferment and produce EPS in the oat-based, nondairy medium to the extent that an obvious change was observed in terms of viscosity and ropiness during the fermentation period. These results show the potential of both LAB strains as possible starter cultures in new kinds of fermented, nondairy milk products.
|
|
| 2. |
- Sjöö, Malin, et al.
(författare)
-
Gelatinization and retrogradation of potato (Solanum tuberosum) starch in situ as assessed by differential scanning calorimetry (DSC).
- 2003
-
Ingår i: LWT - Food Science and Technology. - 0023-6438. ; 36:8, s. 735-741
-
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.
|
|
| 3. |
- Eide, M.H., et al.
(författare)
-
Life cycle assessment (LCA) of cleaning-in-place processes in dairies
- 2003
-
Ingår i: Lebensmittel-Wissenschaft + Technologie. - 0023-6438 .- 1096-1127. ; 36:3, s. 303-314
-
Tidskriftsartikel (refereegranskat)abstract
- Four Cleaning-In-Place (CIP) methods for dairies were compared using life cycle assessment (LCA). The methods were conventional alkaline/acid cleaning with hot water disinfection, one-phase alkaline cleaning with acid chemical disinfection, enzyme-based cleaning with acid chemical disinfection and the conventional method with disinfection by cold nitric acid at pH 2. Production of detergents, transport, the user phase in the dairy and waste management of containers were included. The user phase was found to be the most important part of the life cycle. The CIP methods with small volumes and low temperatures, such as enzyme-based cleaning and one-phase alkaline cleaning, turned out to be the best alternatives for the impact categories energy use, global warming, acidification, eutrophication and photo-oxidant formation. Milk residues flushed out in the rinsing phase were the main contributor to eutrophication, but the phosphorus and nitrogen in the detergents also influenced the results. Evaluation of toxic substances poses a methodological problem in LCA. In this study, detergents partly composed of toxic substances were included, and the overall assessment was that the one-phase alkaline cleaning method was preferable from an environmental point of view. A qualitative assessment of toxicity was performed. © 2003 Published by Elsevier Science Ltd. on behalf of Swiss Society of Food Science and Technology.
|
|
| 4. |
- Ofstad, R., et al.
(författare)
-
Liquid-holding capacity and structural changes in comminuted salmon (Salmo salar) muscle as influenced by pH, salt and temperature
- 1995
-
Ingår i: Lebensmittel-Wissenschaft + Technologie. - 0023-6438 .- 1096-1127. ; 28:3, s. 329-339
-
Tidskriftsartikel (refereegranskat)abstract
- The loss of liquid in salmon muscle comminuted with salt was studied as a function of pH and heating temperature. A factorial experiment was designed to compare the effects of; the raw material, NaCl concentration, pH, degree of comminution and heating temperature in order to evaluate both main effects and interaction effects. The liquid-holding capacity was measured by a low speed centrifugation net test. The changes in microstructure in the samples were investigated by light microscopy using fat- and protein-staining techniques. The heating temperature, pH, NaCl concentration, variation of raw material and degree of comminution influenced liquid loss according to a second-order interaction linear model. The interaction effect between low pH, low salt concentration and high temperature was strongest. Addition of salt extracted the myofibrillar proteins and resulted in a homogeneous protein matrix with few intact fibres and uniformly dispersed fat droplets. Liquid loss was closely related to the microstructure of the comminutions. When heated above 30 °C, enlarged pores and gaps, some of them forming channels, occurred in the protein matrix. In comminutions prepared with a low salt concentration and/or a low pH the more frequent presence of pores and gaps enhanced the liquid loss. © 1995 Academic Press Limited.
|
|
| 5. |
- Topakas, E., et al.
(författare)
-
Bioconversion of ferulic acid into vanillic acid by the thermophilic fungus Sporotrichum thermophile
- 2003
-
Ingår i: Lebensmittel-Wissenschaft + Technologie. - 0023-6438 .- 1096-1127. ; 36:6, s. 561-565
-
Tidskriftsartikel (refereegranskat)abstract
- Sporotrichum thermophile is capable of promoting the formation of vanillic acid during ferulic acid degradation. Ferulic acid metabolism by S. thermophile apparently occurred via the propenoic chain degradation and the formation of 4-hydroxy-3-methoxystyrene (4-vinylguaiacol) was observed which was presumably metabolized to vanillic acid. Guaiacol was detected in addition to the above-mentioned intermediates, usually as a result of nonoxidative decarboxylation of vanillic acid. The bioconversion of ferulic into vanillic acid was affected by the amount of ferulic acid that was treated and the carbon source on which the biomass was grown. Under optimum conditions vanillic acid production from ferulic acid by S. thermophile attained very high levels of 4798 mg/L with a molar yield of 35%
|
|
| 6. |
- Aalaei, Kataneh, et al.
(författare)
-
Storage stability of freeze-dried, spray-dried and drum-dried skim milk powders evaluated by available lysine
- 2016
-
Ingår i: LWT - Food Science and Technology. - : Elsevier BV. - 0023-6438. ; 73, s. 675-682
-
Tidskriftsartikel (refereegranskat)abstract
- Formation of Maillard products and the influencing factors, which are of crucial importance for both manufacturers and consumers, are still not fully understood. Thus in this study available lysine was used as a marker to monitor the extent of Maillard reactions in freeze-dried, spray-dried and drum-dried skim milk powders during 200 days of storage at highly controlled atmospheres. Storage variables included two temperatures (20 °C, 30 °C) and two relative humidities (33%, 52%). The available lysine in five replicates was quantified at pre-determined intervals by a dye-binding method using Acid-orange 12, validated in our previous work. Findings of this study show that temperature and relative humidity during storage have a profound influence on the rate of available lysine loss. Choice of the drying technology as the other investigated variable also had a significant impact. The drying process least affected the available lysine content in freeze-dried powders, followed by spray-dried and drum-dried powders. Storage at 52% relative humidity and 30 °C for 200 days led to a 39.2–45.9% decrease in the available lysine content, regardless of the drying of skim milk powder, while the powders stored at 33% relative humidity and 20 °C did not show a significant loss during the same period of time.
|
|
| 7. |
- Abdollahi, Mehdi, 1985, et al.
(författare)
-
Physicochemical and gel-forming properties of protein isolated from salmon, cod and herring by-products using the pH-shift method
- 2019
-
Ingår i: LWT - Food Science and Technology. - : Elsevier BV. - 1096-1127 .- 0023-6438. ; 101, s. 678-684
-
Tidskriftsartikel (refereegranskat)abstract
- The impacts of variation in fish filleting by-products origin including white muscle (cod), dark muscle (herring) and farmed fish (salmon) on physicochemical and gel-forming properties of protein recovered using the pH-shift method were studied. The effects of different solubilization pHs (acid or alkaline) on protein yield/composition, and its properties were also studied. Alkaline version (pH 11.5–12.5) resulted in maximum protein yield for the three resources which ranked them as: salmon > herring > cod. Increasing solubilization pH from 11.5 to 12.5 increased protein yield in salmon and herring, while maximum protein yield of cod was obtained at pH 12. However, increasing solubilization pH from 11.5 to 12.5 required a two-fold higher amount of alkali compared to the adjustment to 11.5. All recovered proteins had gel-forming capacity; however, cod gels showed higher WHC and breaking force compared with salmon and herring protein gels. Increasing solubilization pH from 11.5 to 12.5 negatively affected the breaking force and color of the salmon and cod protein gels, but improved heme pigment removal, breaking force and whiteness of herring protein gels. The pH-shift process thus showed good potential for recovering high quality protein from the by-products, but protein solubilization pH should be carefully selected based on the target species.
|
|
| 8. |
- Ahrné, Lilia, et al.
(författare)
-
Effect of crust temperature and water content on acrylamide formation during baking of white bread : Steam and falling temperature baking
- 2007
-
Ingår i: Lebensmittel-Wissenschaft + Technologie. - : Elsevier BV. - 0023-6438 .- 1096-1127. ; 40:10, s. 1708-1715
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of crust temperature and water content on acrylamide formation was studied during the baking of white bread. To assess the effect of over-baking, we used a full factorial experimental design in which the baking time was increased by 5 and 10 min at each baking temperature. Additional experiments were performed with steam baking and falling temperature baking. Immediately after baking, the crust was divided into the outer and inner crust fractions, and the water content and acrylamide concentration of each fraction was measured. The outer crust had a significantly lower water content and higher acrylamide concentration than the inner crust did. Crust temperature in combination with water content had a significant effect on acrylamide formation, higher temperatures resulting in higher acrylamide concentrations. However, at very high temperatures and lower water contents, acrylamide concentration was observed to decrease, though the bread colour was then unacceptable for consumption. Steam and falling temperature baking, on the other hand, decreased the acrylamide content while producing bread crust with an acceptable colour. The lowest acrylamide values and an acceptable crust colour were produced by steam baking. © 2007 Swiss Society of Food Science and Technology.
|
|
| 9. |
- Andersson, Karin, et al.
(författare)
-
Including environmental aspects in production development : A case study of tomato ketchup
- 1999
-
Ingår i: Lebensmittel-Wissenschaft + Technologie. - 0023-6438 .- 1096-1127. ; 32:3, s. 134-141
-
Tidskriftsartikel (refereegranskat)abstract
- An environmental Life Cycle Assessment (LCA) study of a specific tomato ketchup was carried out. The objectives of the work were to illustrate how LCA can be used in production development; to investigate the influence of the geographical location of certain processes; and to find ways to improve the product's environmental performance. In the screening LCA which includes the whole life cycle, the packaging and processing sub-systems were found to be significant in the total environmental impact made by ketchup. Accordingly, six alternative systems, including packaging, processing and transportation, were modelled and simulated. The environmental impact categories included were energy use, global warming, acidification, eutrophication, photo-oxidant formation and the generation of radioactive waste. It was concluded that the current geographical location of the production of ketchup is preferable; the contributions to acidification can be reduced significantly; and the environmental profile of the product can be improved for either the type of tomato paste currently used or a less concentrated tomato paste. A shift to a less concentrated paste would also mean that traditional quality parameters of the ketchup could be improved. © 1999 Academic Press.
|
|
| 10. |
- Andersson, Karin, et al.
(författare)
-
Influence of oxygen concentration and light on the oxidative stability of cream powder
- 1998
-
Ingår i: Lebensmittel-Wissenschaft + Technologie. - 0023-6438 .- 1096-1127. ; 31:2, s. 169-176
-
Tidskriftsartikel (refereegranskat)abstract
- The production of volatile oxidation products and consumption of oxygen were measured in cream powder stored for 35 weeks at 30 °C in darkness or exposed to fluorescent light. The headspace of the bottles contained either air (209 mL O 2/L) or 13, 3.5, 0.4 or 0.3 mL/L oxygen in nitrogen. The exposure to light strongly influenced both the rate of hexanal production and oxygen consumption. After the first 5 weeks of storage in light, significantly different oxygen-dependent increases in hexanal were found for all samples. Although the samples stored in darkness showed a much smaller hexanal increase, it was still significant during storage. After 35 weeks of storage, the dark-stored sample in air showed a highly significant larger hexanal increase than all the other samples stored in darkness, but after the same storage period, the hexanal increase in the 13, 3.6 and 0.4 mL O 2/L samples was the same. The production of the Strecker aldehyde, 3-methylbutanal, was found to depend on light and to some extent on oxygen concentration, which indicates that lipid oxidation also influenced the conditions of the Maillard reaction. © 1998 Academic Press Limited.
|
|
