摘要:

SUMMARYConcentrations of inosine 5′‐monophosphate (IMP) were not significantly different in the longissimus dorsi, biceps femoris, and semimembranosus muscles of six pork carcasses sampled 48 hr post‐mortem. On aging beef for 28 days at 0.1–1.5°C (33–35°F) the peak concentration of IMP (5.4 μM/g) occurred at 12.hr post‐mortem. Other values through the 4th day of post‐mortem aging were approximately the same. Following the 4th day, a gradual but steady decline in IMP content was observed until a value of only 0.75 μM/g or less than 15% of the peak IMP concentration remained after 28 days storage. A wide range of IMP concentration was observed between muscles obtained from different species, with beef sampled at 0 hr containing the highest amounts (4.71 μM/g) and pork heart muscle sampled at 0 hr containing the

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01955.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYPhysical and chemical observations were made on the loss of strength and substance by the vitelline membrane of the hen's egg during changes in ambient pH. It was found that the vitelline membrane of the freshly laid egg contains a network of fibers on its surface which tends to dissipate as the pH of the albumen rises. In conjunction with the physical deterioration of the fibrous structure on the vitelline membrane, there are significant changes in weight, protein, and hexosamine content of this membrane. Hypotheses are presented concerning the mode of action of the physiochemical changes in the vitelline membrane.

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01956.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—This research was to determine whether quantitative differences in total pigment and myoglobin concentration could be detected, chemically, in muscles which differed in visual color. For this purpose, a portion of the longissimus dorsi, psoas major, biceps femoris, and semitendinosus muscles was removed at specific locations, from choice‐grade steer carcasses, for use as experimental material. Each muscle was subjected to total pigment, myoglobin, fat, and moisture analysis. Hemoglobin content was determined by the difference between total pigment and myoglobin concentrations, Correction of total pigment and myoglobin concentration for fat and/or moisture was used to determine its influence upon the variation in the quantity of muscle pigmentation.Precise results were obtained with the total pigment and myoglobin procedures. Total pigment concentration was greatest in the biceps femoris and least in the semitendinosus. Little difference was obtained between the longissimus dorsi and psoas major. Myoglobin concentration, in decreasing order of magnitude, for the muscles studied was biceps femoris, longissimus dorsi, psoas major, and semitendinosus. The difference between myoglobin and total pigment concentration in the psoas major muscle was a result of hemoglobin constituting a greater portion of the total pigmentation. Results also indicated that hemoglobin contributed more to total pigment concentration and probably to muscle color than previously reported. The significance of the results obtained was not altered by correcting the data for fat and/or moist

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01957.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYWhole‐egg magma was irradiated, and the off‐flavor threshold intensity was determined in triangular tests by expert taste panels. The dilution technique was employed to show the degree of off‐flavor production in the dose range of 50,000–400,000 rads at 32°F. The intensity of off‐flavor increased at a nonlinear rate. Nitrogen was bled into egg magma being blended for 5, 10, and 20 set prior to irradiation. The threshold doses were determined and compared with whole‐egg magma blended for equal times without gas being added. The off‐flavor threshold doses with nitrogen added were 47,080, 71,930, and 60,050 rads for 5, 10, and 20 set, respectively. With normal blending the threshold doses were 38,570, 31,170, and 43, l 10 rads. A dose response curve was obtained similar to that reported earlier at 80°F. The implication of this work in irradiated food evaluation and treatme

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01958.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe sterol composition of several varieties of seafood was assayed by gas‐liquid chromatography. Cholesterol is the major sterol (over 90%) in haddock, pollock, salmon, shrimp, and lobster. The predominant sterols in oyster are cholesterol (41%) and 24.methylenecholesterol (26%), and in crab the major sterols are cholesterol (57%) and brassicasterol (37%). Scallop and clam contain a large number of sterols, the predominant one being cholesterol (26 and 37%, respectively). The sterols other than cholesterol give different chromogens in the calorimetric analysis for sterols, which may account in part for the variability in the “cholesterol” values found in the liter

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01959.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe anthocyanins of Royalty grapes were extracted with methanol containing 0.1% HCI and purified by adsorption on cation‐exchange resin, and the individual pigments separated by paper chromatography. Acid hydrolysis and chromatographic characteristics provided information on the nature of the acyl and sugar moieties of the anthocyanins. The anthocyanins were identified by their Rfvalues, sugar moiety, alkaline‐degradation products of the anthocyanidins, partial acid hydrolysis, and spectral characteristics in the visible and ultraviolet regions. The pigments, in decreasing order of concentration, were malvidin‐3,5‐diglucoside, malvidin‐3,5‐diglucoside acylated with p‐coumaric acid, malvidin‐3‐monoglucoside acylated with p‐coumaric acid, malvidin‐3‐monoglucoside, peonidin‐3,5‐diglucoside, malvidin‐3,5‐digluco‐side acylated with caffeic acid, peonidin‐3‐monoglucoside, peonidin‐3‐monoglucoside acylated with i)‐coumaric acid, and peonidin‐3,5‐diglucoside acylated with p‐coumaric acid. The presence of 3‐glucosides of cyanidin, delphinidin, and petun

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01960.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—Nootkatone, a sesquiterpene ketone previously reported as a primary flavoring constituent in grapefruit oil, has been tested for flavoring effect in grapefruit juice reconstituted from foam‐mat‐dried crystals. Unexpected difficulties were encountered in achieving uniform dispersion of the nootkatone. After a satisfactory method was developed, flavor thresholds and preferences were established by comparing samples of juice containing nootkatone with controls. Nootkatone was detectable at 1 ppm in water and at 6 ppm in 10.5’Brix reconstituted grapefruit juice. Threshold levels were the same in samples with and without “locked‐in” oil. Flavor effects were evaluated on four samples: 1) nootkatone isolated from grapefruit oil; 2) a sample of nootkatone synthesized from valencene, and purified repeatedly by GLC; 3) a routinely purified sample of synthetic nootkatone purified by GLC; and 4) a sample of crystalline nootkatone. All had the same threshold. To some judges the nootkatone was very bitter at a level above 7 ppm. For most iudges however, at slightly above threshold level (about 6—7 ppm) the flavor and aroma of grapefruit iuice were enhanced by the presenc

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01961.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—Changes in the free amino acid fraction of foam‐mat dried tomato powder during storage were studied using gas‐liquid chromatography. An increase of individual amino acids was found to be independent of storage temperature and possibly caused by proteolytic reaction. A simultaneous decrease in certain amino acids was accelerated at higher storage temperatures. This loss of amino acids may be involved in non‐enzymatic browning re

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01962.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—The method of drying apple and potato affects primarily the rate of sorption of water of the dehydrated product, and to a lesser degree the equilibrium isotherms. The freeze‐dried products adsorbed more water vapor than the puff‐dried and air‐dried materials. The apparent diffusivity of water vapor was considerably higher in the freeze‐dried samples than in the air‐dried materials. In puff‐dried samples, the diffusivity had an intermediate value. The diffusivity in freeze‐dried apple and potato decreased at higher relative humidities, and the effect was opposite in ai

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01963.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—The ascorbic acid content of the vegetables most commonly consumed in Nigeria ranges from 18 to 98 mg per 100 g of the fresh material. On boiling, 46–68% of the ascorbic acid is lost, while 47–87% is lost on exposure to the sun for

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb01964.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY