摘要:

SUMMARY—A softening of olives, called “sloughing,” has occurred during the processing of California “ripe” olives for many years. The spoilage is characterized by the softening and ultimate sloughing of at least part of the skin and tissue from the pit of the olive. Control of the spoilage was accomplished largely by reducing the washing period from the customary four to a maximum of three days. The gram‐negative bacteria associated with the spoilage include species allocated to five different genera. Aerobacter, Escherichia, Paracolobactrum, Aeromonas, and Achromobacter. The characteristics of these bacteria, their ability to cause softening of olives, and the kinds of pectolytic enzymes they produce ar

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10326.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—An improved method for the rapid determination of free proline in grapes and wine is given. No significant interference from other amino acids in amounts found in grapes and wine would normally be expected. The method is applicable to most biological material as long as lysine, hydroxyproline, tryptophan and glutamine are not present in total amounts greatly exceeding that of proline. Lysine caused greatest interference and this was only 6% error on equal mole amounts. A direct dilution technique instead of the usual extraction of reaction product by benzene increased accuracy and speed of this method. The relative standard deviation between pairs of samples of grape juice averaged about 3% and for wine about 4

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10327.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—Active enzyme preparations were obtained from mature orange fruit in a quest for the various enzymes associated with terpenoid synthesis. These preparations were examined systematically for the presence of enzymes involved in the biosynthetic pathway to mevalonic acid. Orange fruit was shown to contain acetyl‐CoA synthetase (EC.6.2.1.1) forming acetyl coenzyme A from acetate. It also contained the iodoacetamide‐sensitive acetoacetyl‐CoA thlolase (EC.2.3.1.9) the enzyme responsible for the synthesis of acetoacetyl coenzyme A. Hydroxymethylglutaryl‐CoA synthase (EC.4.1.3.5) and the corresponding reductase (EC.1.1.1.34), however, were not found in preparations from orange fruit. Nonetheless, acetoacetyl coenzyme A, formed by the thiolase, was further metabolized in the mature fruit via 3‐hydroxybutyryl‐CoA dehydrogenase (EC.1.1.1.35), a constituent enzyme in lipid biosynthesis. These results suggest that mature orange fruit derives mevalonic acid or other necessary basic intermediates for terpenoid biosynthesis from

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10328.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—A preliminary study has been made of these enzymic activities along the growth of vanilla pods looking for information about biochemical reactions which lead to the production of the aroma. Proteinase activity decreases with pod age. The activities of glucosidase, peroxidase and polyphenoloxidase increase with stage of growth reaching a maximum near or at ripening. Possibly these enzymes play some role in reactions taking place in curing vanilla, either directly or indirectly supplying the initial products to be transformed into those responsible for color and odor. Partially purified polyphenoloxidase shows a ration catecholase‐cresolase activity of

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10329.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—The recovery of polio virus inoculated into a variety of foods was studied as a function of four food processing operations: freeze dehydration, “pasteurization” by exposure to Cobalt‐60 gamma irradiation, refrigerated storage at 4°C, and storage at 20°C. In general, a decrease in virus recovery was noted following each of the operations. Complete loss in recoverability was observed only in highly acid foods (below pH 2.9) stored at 20°C for 96 or 168 hr. Use of a DEAE Sephadex chromatographic column was found to have potential application for separation of v

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10330.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—Myosin and actin were isolated from rabbit skeletal muscle. The gelation of myosin, actin and actomyosin, as well as of heavy and light meromyosins derived from myosin by trypsin treatment, by heat was studied in various systems. The data indicate that the heat gelling properties of these protein solutions do not run parallel with those of saline model systems composed of these proteins and stroma.Actin does not exert any influence on the binding properties of the system, but when F‐actin and myosin A were both present the resulting binding properties were considerably improved. Since heavy and light meromyosins have little influence on binding properties, it may be concluded that an intact molecule of myosin is required for development of binding properties upon heat

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10331.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—The low‐boiling neutral components of a commercial Montmorency cherry essence were concentrated by distillation. Individual components were separated and identified by gas cohromatography and mass spectrometry. The identifications were confirmed by gas co‐chromatography with known compounds. Ethanol and methanol were the most abundant low‐bolling substances. These compounds were estimated to comprise 9 and 0.5% of the essence, respectively. The next most abundant compound was acetaldehyde. Other compounds present included diethyl ether, propionaldehyde, acetone, isobutyraldehyde, methyl acetate and ethyl acetate. The estimated concentrations of these compounds in the original essence are given in each i

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10332.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARY—The effect of different variables on ascospore production was studied quantitatively. Maximal populations were obtained in 5% malt extract broth, pH 2‐3, after an incubation of 7‐14 days at 30°C. Tests on nine different fruit and vegetable juices showed that eight afforded good sporulation. Prune, grape and pineapple yielded the greatest numbers. Plating methods were found to underestimate the true ascospore populations because of spore dormancy and because a majority of the asci, each containing eight ascospores, remained

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10333.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYA threshold pattern for the even‐numbered free fatty acids (FFA) in butter depended on chian‐length. Butyric acid had the lowest total average flavor threshold (AFT) of the more volatile FFA, and the total AFT values increased as chain‐length increased through hexanoic and octanoic acids. Threshold values decreased from octanoic acid through dodecanoic acid as the chain‐length increased. The determination of AFT values for FFA in butter allowed an estimation of the importance of fatty acids in butter flavor. Mixture threshold results obtained support the concept that flavor components interact at subthreshold concentrations. Decrease in preference was shown for butter containing suprathershold levels of to

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10334.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYSamples of genuine Israel lemon oil were examined by the usual standard methods and by gas‐liquid chromatography. The variations obtained are discussed, and were evaluated statistically. Chi‐square equations were computed for the evaluation of samples of doubtful origin. Sophisticated adulterations of the other of 10% were clearly detecta

ISSN:0022-1147    

DOI:10.1111/j.1365-2621.1969.tb10335.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY