摘要:

ABSTRACTThe chemical interaction of lipids and lipid‐containing foods with nitrite in a mild acidic aqueous system was investigated. Methyl linoleate‐coated silica gel, Intralipid, cow's milk, mayonnaise, yolk andmisoreduced a considerable amount of nitrite. Methyl linoleate‐coated silica gel and cow's milk extensively prevented the formation of carcinogenic N‐nitrosamines. It seemed likely that the unsaturated fatty acid residues were responsible for the interaction of lipids with nitrite. Methyl linoleate was changed into two or more unidentified products, neither of which was the hydroperoxides of th

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06415.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTBotulinal toxin production, residual nitrite depletion, and total microbial growth were measured in meat and/or soy‐containing frankfurter formulations during 27° C temperature abuse. Botulinal toxin production in formulations containing soy proteins was equal to or less rapid than in all‐meat samples, both in the absence and presence of nitrite. Of the nine soy proteins examined, nitrite did not delayC. botulinurntoxin production in products made from the isolate form, whereas it was an effective control in textured, flours and concentrates. In all‐meat formulations the effectiveness of nitrite decreased with increasing spore load. Residual nitrite depletion in meat wasmore rapid than in soy‐containing treatments. Among the soy proteins, nitrite depletion was more rapid in the isolate than in the textured form tested. Total microbial growth was similar in both meat and soy‐containing samples. Gas production was an inadequate index of toxin d

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06416.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTCombination hams were prepared by injecting excised porcine muscles with a brine containing solubilized isolated soy protein. The microstructure of the muscle in the combination ham was compared to that of a water added ham to determine the location of the isolated soy protein. The effect of massaging on the location of the isolated soy protein was also studied. The results showed that the isolated soy protein occupied primarily perimysial spaces and the massaging acts to incorporate these proteins into the endomysial spaces and mix them with extracted myofibrillar proteins. The isolated soy protein appeared to enhance myofibrillar protein extraction by binding water, thus increasing the effective concentration of salt and phosphate. Scanning electron microscopy showed that the gel formed by the isolated soy protein possessed a denser structure than the gel formed by a crude myosin preparation. The gel formed by a mixture of myosin and isolated soy protein possessed a structure more comparable to the structure of the crude myosin gel.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06417.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTInvestigations on the binding abilities of some nonmeat proteins showed that those studied were inferior to the binding ability previously reported for myosin. Their binding abilities in the presence of 8% salt and 2% sodium tripolyphosphate were ranked from highest to lowest as wheat gluten, egg white, corn gluten, calcium reduced dried skim milk, bovine blood plasma, isolated soy protein and sodium caseinate. Structures of gels formed by these proteins and mixtures of them with crude myosin showed that a three dimensional network of protein fibers is not indicative of good binding ability. The types of molecular interactions stabilizing their gel structures are thought to be more important.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06418.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTThe heat‐induced gelation of myosin was optimally developed at temperatures between 60° and 70°C and at pH 6.0 as studied quantitatively by measuring shear modulus of myosin in 0.6M KCl. No difference was observed in the gelation profile, when KCl was replaced by NaCl. The shear modulus of the gel formed at 65°C and pH 6.0 increased proportionally to the 1.8 power of myosin concentration. Although the heat gelling ability of myosin as measured by the shear modulus did not increase with increasing salt concentration from 0.4–1.0M, irrespective of storage time at 0°C of the stock myosin solution (0.6M KCl) or suspension (0.1M KCl), it varied drastically with time of storage at salt concentrations between 0.1 and 0.3. This variation in shear modulus at O.1–0.3M KCl was apparent due to the storage conditions. These changes in the salt concentration dependence of the heat gelation of myosin corresponded well with the changes in solubility of myosin during storage. Studies on selected physico‐chemical properties of the original stock myosin during storage indicated gradual increase in viscosity with little inactivation of ATPase as well as very slight decrease in sulfhydryl content, suggesting the spontaneous transformation (aggregation) of myosin molecules to a less so

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06419.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTThe effects of triglycerides and phospholipids on development of warmed‐over flavor (WOF) in cooked meat was studied using model systems from beef and from chicken dark and light meat. Triglycerides, total lipids, total phospholipids, phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) were added back to the lipid extracted muscle fibers in each system and WOF development was followed by the TBA test and taste panel scores after heating to 70°C and holding at 4°C for 48 hr. Total phospholipids, especially PE, were shown to be the major contributors to development of WOF in cooked meat. The triglycerides enhanced development of WOF only when combined with the phospholipids (as total lipids). Phosphatidyl choline (PC) did not influence WOF in the model system. Changes in the PUFAs of the phospholipids were shown to be related to development of WOF in cooked meat. Addition of 156 ppm of nitrite significantly (P<0.01) reduced TBA numbers and prevented development of

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06420.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTThree types of mechanically deboned turkey meat (MDTM) were obtained from a Pennsylvania poultry processing plant and studied for nutrient composition. Samples of MDTM included meat from turkey breast cages (protein 15.4%, fat 10.2%, moisture 71.3%), turkey racks (protein 13.4%, fat 17.0%, moisture 67.9%), and turkey backs (protein 13.0%, fat 21.7%, moisture 65.9%). Protein efficiency ratios (PER) were determined on each type, and with and without an antioxidant. Material without an antioxidant resulted in gross errors. Adjusted PER values of MDTM treated with an antioxidant were significantly higher than the 2.50 value for the standard casein diet. Amino acids, fatty acids, caloric content and selected minerals were also measured.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06421.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTExtracellular protease and lipase fromPseudomonas fragisignificantly (P<0.05) decreased color stability of sterile beef at 4°C and sterile beef extract at 4°C and 21°C. Concentrations of free fatty acids (FFA) in enzyme‐treated sterile beef samples were significantly (P<0.05) higher than in sterile controls held at 4°C indicating hydrolysis of glycerides by lipase fromP. fragi.Concentrations of nonprotein nitrogen (NPN) and free amino acids in sterile beef extract treated with extracellular enzyme and held at 4°C and 21°C were significantly (P<0.05) higher than in controls indicating proteolysis by protease fromP. fragi.This was confirmed by SDS‐polyacrylamide gel electrophoresis of enzyme‐treated beef extract stored at 4°C for 6 days. Sephadex G‐100 gel filtration and poly‐acrylamide disc electrophoresis indicated that the molecular size and electrophoretic mobility of the protease and lip

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06422.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTAn efficient method has been developed for the microdetermination of cholesterol and some plant sterols such as brassicasterol, campesterol, stigmasterol, and β‐sitosterol. The method is a greatly simplified analytical procedure in which samples are directly saponified, the unsaponifiable substances extracted, and the sterols estimated by gas liquid chromatography without further processing. The sterol contents from the new method are at least as high, alid generally higher, than those from the official method, indicating superior recovery. The analysis has been found to be simple, sensitive, economical of time and particularly of solvents. It is probably adaptable to a wide variety of food ingredients or produc

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06423.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

ABSTRACTThe technological conditions for the nutrification of beans by methionine infusion are described. The best conditions seem to be infusion for 1 hr with a 5% methionine solution at 50°C. By this procedure the methionine was raised from 1.2 to 24 g/100g of bean protein and the absorbed water was only 40% of the beans weight. The beans infused under these conditions, after drying, could be mixed 1:7 (w/w) with original beans and the mixture after cooking in the presence of the soaking water still contained 3% methionine on the protein basis. During soaking (prior to cooking) about one‐third of the infused methionine was diffused out in the remaining water. Therefore, elimination of the soaking water before cooking should be discouraged. Infusion with methionine raised the bean PER from 0.9 to 2.6 and the efficiency of a 10% bean protein diet from 9.4 to 26.6%. There was no difference in preference between the original and infused beans when the Directional Paired Comparison test was applied. However, when the Non Structured Scale test was used for the odor and taste of cooked beans there was no preference for the original beans when seasoning was used, whereas there was a significant difference at 5% probability level in favor of the original beans when the samples were cooked and tasted without seasoni

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1979.tb06424.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY