摘要:

SUMMARY—After thin‐layer chromatography, cocoa bean cotyledon section presented only one chromatographic spot whereas cocoa butter showed five spots. Apparently, the lipids naturally occurring in cocoa beans are not modified during farm fermentat

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00845.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—The characteristic seasoning flavor of hydrolyzed vegetable proteins has previously been attributed to α‐ketobutyric acid formed from threonine under the conditions of acid‐hydrolysis. However, pure α‐ketobutyric acid is virtually odorless and tasteless, and it develops the characteristic flavor only upon ageing. The true flavoring principle is probably α‐hydroxy‐β‐methyl‐Δ.α,β‐γ‐hexenolactone, which is formed from the acid by dimerization, lactonization, and decarboxylation. This conversion occurs spontaneously, but is greatly accelera

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00846.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—The iodimetric procedure for determining the amount of reduction of an alkaline potassium permanganate solution which is used as a measure of the content of volatile reducing substances (VRS) has been substituted by a colorimetric one. The net absorbance at 610 mp is determined from the difference in absorbance between theunreacted and reacted0.02N KMnO4inNNaOH solution. The microequivalents of reduction corresponding to the net absorbance value is read off a graph showing the linear relationship between the net absorbance and the amount of VR

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00847.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—Protein solubility and associated properties were studied in bovine sternomandibularis muscle allowed to pass into rigor in three physical states. Thirty min post‐mortem, samples were incubated at 7°C for 48 hr in one of the following conditions: minced through 1/8‐in. plate, free to shorten in a vertical position, stretched to 150% of equilibrium length. Stretched muscle exhibited greater protein solubility, higher pH values and longer sarcomeres than the remaining samples. For post‐rigor muscle, protein solubility may be related to sarcomere length and moisture press ratio. Variations in sarcomere length may be related to post‐mortem changes in pH. Possible relationships between the contractile state of proteins and the chemical, physical and quality characteristics of muscle are

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00848.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—A method is given for determining calcium and magnesium in meat. The influence of several parameters such as pH, time, orthophosphate addition, quantity of ZrOCl2and meat, has been described. Information is presented on the use of zirconylozychloride to eliminate interfering substances. The amount of calcium found is generally higher than figures given in the literature. If no orthophosphates are present in the sample, they should be adde

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00849.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—A preliminary study of the Strecker degradation of amino acids by reducing sugars in cocoa beans has revealed an unexpected temperature effect on the extent of the reaction which might influence the flavor of the product. Model amino acid/sugar systems were studied and the results support the hypothesis that there exists a relationship between the temperature of reaction, the extent of amino acid degradation and the production of flavor volatiles during the roasting of cocoa beans. A factory experiment, in which Accra cocoa beans were roasted at three different temperatures, provided supporting evidence of the influence of temperature on total flavor and on the strength of basic chocolate flavo

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00850.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—A statistical method, preferably operated by a a computer, is proposed for the analysis of data on complex mixtures where the information sought involves a number of small changes in chemical composition, each of which is individually within the normal range of variation of the mixtures. When the method is applied to the identification of geographical origins of peppermint oils and mixtures of peppermint oils, the results are a substantial improvement on those from previous methods, though still leaving some uncertainty. It is expected that more complete chemical analysis will greatly improve the confidence leve

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00851.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—A laser interferometric micro diffusion cell was used to measure the apparent diffusivity of water‐honey system. The results show that the apparent diffusivity of water in honey is very much dependent on the concentrat

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00852.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—Boneless, trimmed steaks (U. S. Good) from thelongissimns dorsimuscle (loin) andsemimembranosusmuscle (top‐round) and conventionally cut loin steaks were removed 8 days post‐mortem, quick‐frozen and stored at −18°C to −23°C for three storage periods, 0, 6, and 9 months. Steaks were sampled at each storage period and cooked to an internal temperature of 70°C in a microwave oven and electric range. Quality was evaluated by chemical tests, sensory evaluations and cooking loss data.Storage up to 6 months had little effect on loin steaks with the exception of TBA values, but significant changes occurred between 6 and 9 months. Loin steaks had increased cooking losses and decreased juiciness scores, percent moisture, and juice content. TBA values increased with each storage period. Top‐round steaks at the 9‐month period showed a decrease in collagen content and juiciness and flavor scores, and an increase in TBA values. Storage up to 9 months did not influence tenderness in either muscle.Conventionally broiled loin steaks had higher palatability scores, cooking losses, percent moisture, percent total proteins, and lower percent total lipids than did microwave cooked loin steaks. Electronically cooked top‐round steaks had higher total cooking losses and percent total proteins and lower collagen values than did conventionally roasted top‐round steaks.The qualities of boneless loin steaks did not differ significantly from those of conventionally cut loin steaks when compared

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00853.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARY—Firmness in fruits is sometimes evaluated as being the force necessary to attain a given deformation within the product. Since modulus of elasticity is defined as the ratio of stress to strain, it should measure resistance to force and, hence, the firmness of a material. Using a sonic technique, the resonant frequencies of cylindrical specimens of flesh from Valery bananas were measured and Young's modulus of elasticity was calculated. Softening of the banana during ripening was associated with a decrease in Young's modulus of elasticity from 272 × 105dynes/cm2at ripeness corresponding to a light green peel color to 85 × 105dynes/cm2at the yellow stage. Modulus of elasticity was significantly and directly correlated with starch content, but inversely correlated with luminous reflectance and the logarithm of percent reducing sug

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1967.tb00854.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY