摘要:

ABSTRACTThe Baumann capillary suction apparatus, the cryoscopic osmometer, and moisture sorption isotherms were used to measure the water‐binding capacity (WBC) of several macromolecular food grade hydrocolloids. Although each method was able to distinguish between ingredients of different WBC's, the values obtained by the three methods were very different from each other. A significant correlation was only found between the osmometer data and the moisture sorption data at aw= 0.98, while neither method correlated with the WBC as determined by the Baumann method. The Baumann method was found to give the best prediction of a hydrocolloid's relative WBC in a low fat meat emulsion food system when compared to the typical WBC methods used for meats. Xanthan gum was found to be the best gum in retention of added wate

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14775.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTSeven selective differential plating media were evaluated for their effectiveness in recovering eight serotypes (0:3; 0:8; 0:9; 0:11,24; 0:12,25; 0.16; 0:17; and 0:28) ofY. enterocoliticafrom pure cultures and from artificially inoculated fresh ground pork homogenate. Cefsulodin‐irgasan‐novobiocin (CIN) agar was the most effective medium for the recovery ofY. enterocolitica.However,Y. enterocolitica0:12,25 was slightly inhibited on CIN agar. Bismuth sulfite agar, MacConkey, and MacConkey‐Tween 80 agars were acceptable; cellobiose‐arginine‐lysine, desoxycholate citrate, andSalmonella‐Shigellaagars were the least effe

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14776.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTThe effectiveness of electrical stimulation (ES) at two voltages (50 and 350V) and three frequencies (10,100 and 250 Hz) was evaluated on lamb sides. Twenty‐one lambs were used. Electrical stimulation at 350V with 10 Hz significantly exhibited faster postmortem glycolysis in the Longissimus dorsi (LD) and Semimembranosus muscles and less Ca++‐induced shortening in the Semitendinosus muscle than achieved by any other combinations of voltages and frequencies. This treatment also provided the greatest energy per pulse and showed fast and vigorous twitching of most muscles during stimulation. These results suggested that the ES parameters of high voltage with low frequency were more effective in accelerating postmortem glycolysis than low voltage with high frequency. However, the solubility of different protein fractions in LD muscle was not affected by any of the experimental treatme

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14777.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTLipids of stored turkey meat undergo lipolytic and oxidative degradation; partial characterization of the lipolytic activity was achieved. Gel filtration of turkey thigh muscle cytosol revealed a lipid‐protein aggregate with the major lipolytic activity. This aggregate exhibited a molecular weight of approximately 2 ± 106daltons, and contained approximately 45% lipids, and was associated with zinc and copper. Incubation of this aggregate, or cholate treatment, resulted in the appearance of lower molecular weight lipolytically active fractions. Two of these fractions, one containing copper and zinc, the second, zinc, were partially purified by ion‐exchange chromatography and gel filtration, and had molecular weights and amino acid compositions similar to those reported for rat liver copper‐chelatins. The inhibition characteristics of the lipolytic activity was similar to other l

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14778.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTChanges in biochemical properties of myofibrillar proteins of rabbit muscle, which had been subjected to electrical stimulation soon after slaughter, during postmortem storage at 0°C were investigated. Myofibrillar ATPase activity and the ATPase activity of acto‐heavy meromyosin (HMM) complex, reconstituted from actin and HMM which had been prepared from at‐death and postmortem muscles, decreased at first and then increased slightly during 7 days storage. In addition, the change of the dissociation constant of acto‐HMM complex of electrically stimulated muscle during postmortem storage was quite small, i.e., 1.59 ± 10−4M for at‐death muscle, 1.70 ± 10−4M for muscle stored for 1 day and 1.49 ± 10−4M for muscle stored for 7 days. This indicates that electrical stimulation treatment minimized the postmortem change of actin

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14779.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTLeft sides of 75 steers were electrically stimulated (ES) and right sides were nonstimulated controls (NES). NES sides had the highest pH, lowest temperature, were slower‐metabolizing (lower R values), and produced steaks that had the least desirable sensory ratings compared to ES sides. Carcass weight, fat thickness, temperature and pH accounted for 31, 32, 34 and 16% of the variation, respectively, in overall tenderness ratings for steaks from NES sides and accounted for 0, 0, 0 and 7% of the variation, respectively, for steaks from ES sides. R values accounted for 28 and 32% of the variation in overall tenderness ratings of steaks derived from NES and ES sides, respectively. Thus, metabolic rate (R value) is a good indicator of postmortem tendernes

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14780.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTEffects of heating on the emulsifying properties of selected food proteins and the protein surface hydrophobicity (So) as a predictor of these properties were investigated. The emulsifying properties of the proteins studied were differently affected by heating. Heat‐denaturation was not always accompanied by loss of emulsifying properties, but, on the contrary, in some cases resulted in great improvement. The emulsifying properties could well be predicted solely on the basis of Solevel but not on the basis of solubility level, which indicated that Sois a very important property determining protein functionality. However, the emulsifying activity, emulsion stability and fat binding capacity of the proteins studied could be explained and more accurately predicted using Soand solubility togethe

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14781.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTEdible shrimp (Penaeus aztecus) tissue contains approximately 1.2% extractable lipids, the majority of which are phospholipids. Data from the gravimetric quantitation of lipid classes isolated by column chromatography indicated that phosphatidyl choline was the predominant phospholipid and cholesterol the predominant neutral lipid in edible shrimp tissue. Fatty acid distribution data indicated that sphingomyelins contained the greatest percent by weight of unsaturated fatty acids while cholesterol esters contained the greatest proportion of saturated fatty acids. Enzymatic hydrolysis followed by gas liquid chromatography of phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl serine indicated that fatty acids located at the β position were more highly unsaturated than those at the α positio

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14782.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTChitin (β (1°4)‐N‐acetyl‐D‐glucosamine) and chitosan (deacetylated chitin) are currently available in large quantities as waste products and by‐products of the shellfish industry. Their potential as carriers for food additives was studied. Significant correlations were found between dye concentration ranging from 0.2–1.6 mg dye (FD&C Red No. 40) per g chitin or chitosan and dye‐binding capacity of chitin or chitosan. Within a pH range of 2.0–7.0, dye‐binding capacity of chitin was stable. Chitosan gelled below a pH of 5.5 and could not be evaluated but its dye‐binding capacity was constant between pH 7.0 and 5.5. Above pH 7.0 dye‐binding capacity decreased for chitin as well as for chitosan but between pH 2.0 and 6.0 no dye was released from dyed chitin containi

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14783.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

ABSTRACTProteins of eight cultivars of two lupine species (Lupinus albusandL. angustifolius) were examined by several procedures. Differences in protein solubility between the species and among varieties within a species were observed. Defatting of the lupine flour altered protein solubility. Amino acid compositions of total protein and protein fractions showed only minor differences between the species and among varieties within a species (except for cv. Kali). Sodium dodecylsulfate polyacrylamide gel electrophoresis patterns of protein fractions revealed both qualitative and quantitative differences between species and among varieties.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1983.tb14784.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY