摘要:

ABSTRACTDehydrated potato chips were fried in pure coconut and groundnut oils and their blends in order to study the pattern of uptake of oil constituents during frying. Investigations on the analysis of the oil and fatty acid composition in the fried product and the oil remaining in the frying pan suggested a preferential uptake of saturated lipid constituents by the potato chips, while the oil remaining in the frying pan was rich in unsaturated constituents. This effect was accentuated in blended oils, although it was also observed in pure oils.

ISSN:1065-7258    

DOI:10.1111/j.1745-4522.1996.tb00063.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTThe Braer tanker wreck demonstrated the danger of petroleum spills to salmon farms. The water soluble fraction (WSF) of crude petroleum oils is quite different from the parent oils. It is rich in methyl‐ and alkyl‐substituted monoaromatic and lower molecular weight polyaromatic hydrocarbons, guaranteeing strong petroleum flavor. Both n‐alkanes above C9and more complex hydrocarbons above the methylnaphthalenes are virtually absent. The WSF in salmon intercellular fluids is rapidly depurated but a portion dissolves into the adipocyte cells in the salmon muscle and is retained much longer. The distribution of adipocytes along the myosepta of white muscle and in the belly flaps has been defined by histochemistry and their isolation by collagenase, centrifugation, and flotation is described. In dark muscle small fat droplets are instead found among and within the cells of muscle f

ISSN:1065-7258    

DOI:10.1111/j.1745-4522.1996.tb00064.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTThe antioxidant properties of extracts of five fruits (apple, pear, peach, plum and grapefruit), three herbs (rosemary, tarragon and basil) and one spice (black pepper) were evaluated in a series of assays involving reactive oxygen species (ROS). In general, the crude extracts possessed potent antioxidant propertiesin vitro. Rosemary extract was 50‐times more effective at preventing microsomal lipid peroxidation of human liver microsomes induced by NADPH/iron compared to peroxidation induced by iron/ascorbate, but tarragon was more effective in the iron/ascorbate dependent peroxidation. Analysis of the content of hydroxycinnamic acids of the pear, apple, plum and peach extracts measured after hydrolysis with sodium hydroxide showed that caffeic acid, p‐coumaric and ferulic acids were the principal hydroxycinnamic acids present. Although the hydroxycinnamic acids and naringin do not contribute to the inhibition of lipid peroxidation by fruit extracts, they were able to inhibit deoxyribose degradation by 30% suggesting ability to weakly scavenge hydroxyl radicals (OH). Nevertheless, extracts of herbs and spices are increasingly of interest in the food industry because they retard oxidative degradation to lip

ISSN:1065-7258    

DOI:10.1111/j.1745-4522.1996.tb00065.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTMenthyl acetate was prepared using vinyl acetate with lipase PS‐30 fromPseudomonas sp. as biocatalyst in organic media. Immobilization of the lipase by adsorption onto 0.5 mm diameter glass beads and the presence of molecular sieves improved the yield of menthyl acetate from 24 to 50%. Approximately 40% yield of menthyl acetate was achieved after 48 h incubation with the immobilized lipase. Equimolar ratio of substrates gave higher yields of product compared to higher mole ratios. Synthesis of menthyl acetate increased as the reaction temperature increased from 20 to 60C. An acceptable yield of menthyl acetate was achieved with 400 units of immobilized lipase PS. Less polar solvents appeared to be better than polar solvents for the enzymatic synthesis of menthyl acetate by transesterificatio

ISSN:1065-7258    

DOI:10.1111/j.1745-4522.1996.tb00066.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTExtracts of seeds of everlasting pea, faba bean and broad bean were prepared using 80% acetone. Five fractions were separated from each extract on a Sephadex LH‐20 column using methanol as the eluate. The antioxidant activity of fractions was investigated in a β‐carotene‐linoleate model system. For individual fractions, UV spectra were recorded and the content of total phenolics determined. Fractions were also characterized based on the number of phenolic compounds, and their antioxidant activity determined by TLC analysis. Results of β‐carotene‐linoleate model systems indicated that antioxidant activities of separated fractions were in the order of everlasting pea>faba bean>broad bean. Individual fractions contained several phenolic compounds as noted by TLC. Absorption maxima from UV spectra showed that flavonoids, and not phenolic acids, were the main phenolic compounds in separated fractions. Spots on the plates sprayed with a solution of β‐carotene and linoleic acid indicated that many of these compounds can act as natura

ISSN:1065-7258    

DOI:10.1111/j.1745-4522.1996.tb00067.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

ABSTRACTA technologically feasible cottonseed oil‐isopropyl alcohol (IPA) miscella refining process was developed to produce Prime Bleachable Summer Yellow (PBSY) quality cottonseed oil. Individual steps necessary to refine cottonseed oil‐IPA miscella were determined and improved. The miscella was first neutralized with 20 Baume (Be′) caustic solution (50% excess) using a homogenizer. After centrifugation to remove soapstock, the two remaining liquid layers were separated and desolventized. The refined oils from bottom and top layers were then water washed using 12.5 and 20% hot water (w/w), respectively. Water washing efficiently recovered the oil from the top miscella layer and reduced soap and phosphorus contents. The water washed and dried oil from the bottom and top layers were treated with 0.5 and 4% (w/w) acid‐activated bleaching clay, respectively. Good quality bleached oil was then obtained. However, the quality of bleached oil produced from the bottom layer was better than that of the top layer. Comparative experiments with both IPA and hexane miscellas showed that quality of the refined oil from cottonseed oil‐IPA miscella is as good as that produced from the cottonseed oil‐hexane miscella using the process developed in

ISSN:1065-7258    

DOI:10.1111/j.1745-4522.1996.tb00068.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY