摘要:

ABSTRACTTotal lipid extracted from chicken breast, thigh, drumstick and wing muscles and the corresponding skin was analyzed for triacylglycerols and phospholipids as well as their fatty acid composition and also for malonaldehyde and lipid oxidation fluorescent products (LOFP) content.Muscles consist of only 1.2–3.2% lipid, but lipid concentration in the skin ranges from 22.2–31.7%. The percentage of phospholipid in muscle lipid was 20 times more than that of the skin. The fatty acids of triacylglycerols from muscles and skin contained less than 2% of polyunsaturated fatty acids (PUFA). Fatty acids from phospholipid of the meat contained over 15% arachidonic acid and substantial amounts of PUFA with 22 carbon atoms. Skin phospholipid had 10.6–13.2% of all PUFA.Differences in the lipid composition of muscles and skin resulted in a concentration of malonaldehyde in muscle lipids of 30–50 mg/g, a value more than 15 times greater than in lipids of the skin. However, the TBA number of the skin was the same or a little bit lower as compared to muscles. The relative levels of LOFP in the organic phase of Folch‐extracted muscle and skin tissues paralleled the trend found for malonaldehyde concentrations.It was concluded that the simultaneous determination of total lipid content and malonaldehyde concentration in lipid extracted from various chicken muscles and corresponding skin was the most informative method for evaluation of precursors of lipid oxidation in fre

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00409.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThis review focuses on the studies reported on carotenoids of edible molluscs in the 1980s. Following an introduction to edible molluscs, it covers the literature published in areas such as localization of carotenoids, sources of carotenoids for molluscs, functions of carotenoids in molluscs and prospective biotechnological uses of carotenoids.

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00410.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTTransmission electron microscopic examination of samples from fresh and 7 days‐cold‐stored white croaker skeletal muscle did not reveal apparent changes in overall structure of contractile elements of muscle. However, when purified myofibrils obtained from fresh and stored muscles were extracted with 0.6 MKI and the residues were examined in the scanning electron microscope, a progressive disappearance of exosarcomeric longitudinal filaments connecting successive Z structures was observed. Electrophoretic analysis of myofibrillar proteins obtained from fresh and stored muscles showed a marked degradation of nebulin, a major component of the endosarcomeric cytoskeletal network, whereas the other protein constituents of myofibrils remained practically unchanged. These alterations in elements of both cytoskeletal lattices of muscle may have important effects on physical properties of fish m

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00411.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTA potato glycoprotein, patatin, was originally isolated by concanvalin A‐ (Con A) Sepharose chromatography. An equally successful method was developed using Octyl‐ Sepharose. The new method was applicable to cultivated and wildSolanumspec

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00412.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTKappa‐casein A was treated with chymosin in order to isolate the caseino‐macropeptide corresponding to the C‐terminal 106–169 residues of K‐casein. Whole casein, K‐casein and the caseinomacropeptide (CMP) were studied for their water solubility and emulsifying activity. The CMP was soluble over the range of pH from 1 to 10, with a “minimum” solubility (88%) in the range of pH 1–5 and a “maximum” solubility (98%) in the range of pH 5–10. For whole casein and K‐casein, at pH values above 5.5, the emulsifying activity increased when pH increased and the maximum value was obtained for very alkaline solutions; for pH values below 4.5, the increase in emulsifying activity was much more pronounced at pH 2.5; below pH 2.5, emulsifying activity decreased. For CMP, the increase in emulsifying activity was much more pronounced in the acidic range than in the alkaline range. After 24 h storage and heating of the emulsion, a large pH‐dependant decrease of emulsifying activity (22–60%) was observed for CMP for pH values below 4.0; under the same conditions, the emulsifying activity of whole casein and K‐casein showed a 5–19% and a 1–21% decrease, respectively. For pH values above 6.0, a 22–59% decrease was observed for CMP as compared to a 1–12% and a 4–17% decrease wit

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00413.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTPlasmin (EC 3.4.21.7) is the principal indigenous protease in bovine milk. Kinetic parameters for thermal degradation of plasmin were determined using a miniature continuous flow pasteurizer designed for heat treatment of small quantities of liquid. Plasmin activity was measured using a pH‐stat titration, which measures the release of H+from a caseinate substrate.Heating milk at various temperatures resulted in significant difference (P>0.01) in residual plasmin activity and linear decrease in activity at each temperature. The calculated D‐values were: 105, 90, 76.5, 62, and 47 s at 72, 78, 85, 92, and 100°C, respectively. The Z‐value for plasmin inactivation was estimated to be 77.5°C, and the Arrhenius activation energy was 7.04 kcal/mole.UHT milk containing plasmin was heated for an equivalent of 5 D inactivation of the enzyme at 100°C. After storage for 30 days at 4°C, no enzyme regeneration was

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00414.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Book reviewed in this article:Colloidal Systems and Interfaces. Sydney Ross and Ian D. MorrisonDurum Wheat: Chemistry and Technology.G. Fabriani and C. Lintas, eds.Cheese Starters: Developments and Applications of the Lewis System.J. E. Lewis

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00415.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00416.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY