摘要:

ABSTRACTThe effect of actinidin on the tenderness of broiled bovine semitendinosus (ST) steaks was studied. An actinidin activity of 400 U/mL resulted in Kramer shear values and sensory tenderness scores equivalent to that produced by Adolph's papain‐based meat tenderizer (18 U/mL). Both were significantly (P<0.05) more tender than steaks having no tenderizing treatment. Actinidin did not over‐tenderize the steak surface as did Adolph's meat tenderizer. Hydrolysis of myofibrillar proteins in enzyme‐treated steaks prior to broiling was considerably less for actinidin than for papain when using activities to attain equal Kramer shear values of broiled s

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00368.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTInfluence of seasonal variation (February, July and October), time elapsed before freezing, and type of processing of the muscle on several functional properties (protein solubility, emulsifying capacity, and viscosity) in two species of fish with differing seasonal behavior (hake and sardine) were studied. Correlations between the changes in these functional properties during frozen storage were established. Although proximate analyses of the hake muscle were similar throughout the year, significant differences were observed in viscosity and protein solubility during storage between lots of fish caught in different seasons. Changes in the functional properties were less evident in sardine, which undergoes wide seasonal variations. The larger differences in the functional proprities of hake muscle, depending on season, were related to differences in the dimethylamine content after the fifth month of frozen storage. High correlations were established between functional properties in fish caught in the same or different seasons. Any of the three functional properties studied can be used as a suitable index of the quality of frozen fish, irrespective of the different conditions studied.

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00369.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTAnalyses of amino acids in six samples each of soybean meal, corn and triticale by high‐performance liquid chromatography (HPLC) and gas chromatography (GC) were compared. Samples were hydrolyzed in 6N HC1, then phenylthiocarbamyl (for HPLC) and N‐heptafluorobutyryl (for GC) derivatives of free amino acids were prepared and analyzed by the appropriate system. Coefficient of variation within each feedstuff for amino acids analyzed by HPLC ranged from 1.8 (leucine) to 23.5% (methionine) in soybean meal, 2.7 (leucine) to 14.7% (methionine) in corn and 1.7 (leucine) to 14.3% (cystine) in triticale. Corresponding figures from GC analysis were 0.7 to 22.4%, 1.4 to 14.3% and 1.6 to 12.1%, respectively. Linear regression of HPLC on GC values gave good fits with R2ranging from 0.86 for cystine and 0.99 for isoleucine, leucine, lysine, methionine, phenylalanine, threonine, alanine, aspartic acid and glycine. Although some differences between the two systems were evident, feedstuff amino acid values obtained by HPLC and GC analyses compare very well. Results of this study and consideration of such factors as ease of derivatization and length of time for analysis, in our opinion, make HPLC the system of cho

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00370.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThe 4‐rhamnoglucoside of alkaloid solanidine, β2‐chaconine, was isolated from a mixture of α‐solanine with β2‐chaconine by fractionation from hot ethyl acetate. The mixture of the two glycoalkaloids is obtained by endogenous enzyme action in a homogenate of potato berries and blossoms within a 24–36 h incubation at 37° C, pH 6.00. The identity of β2‐chaconine was ascertained by m.p., [α]D° IR spectrum, TLC of sugar components and reference to partial acid hydrolysis produ

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00371.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThe action pattern ofBacillus subtilisalpha‐amylase on Jewel variety sweet potato starch, amylose and amylopectin was monitored using high performance size exclusion chromatography. A wide range of products, from high molecular weight polysaccharides to specific saccharides of low molecular weights, were observed. The hydrolysis pattern for amylose in starch was concealed by hydrolytic fragments formed from amylolysis of the greater quantity of amylopectin. Amylopectin was degraded to a more specific mixture of polysaccharide fragments. Changes in molecular size of hydrolytic fragments formed during amylolysis supported the cluster model previously proposed for amylopectin. These results also suggest that the action of alpha‐amylase on sweet potato starch is generally a nonrandom process, primarily resulting from enzymatic action on amylopectin. To support this hypothesis, a more random pattern of hydrolysis was observed from acid treated sta

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00372.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTPhenoloxidases (PO) were isolated and purified from white shrimp (Panaeus setiferus) and pink shrimp(P. duorarum).The enzyme from each source migrated as a single protein band in polyacrylamide gels with molecular weights of 30,000 for white shrimp PO and 40,000 for pink shrimp PO. Both enzymes were inhibited by p‐amino benzoic acid and NaN3. Pink shrimp PO oxidized DOPA at rates 1.8 fold faster than white shrimp PO. Free amino acid analyses of shrimp carapace indicated that pink shrimp had relatively higher levels of tyrosine and phenyialanine, the natural substrates of melanosis, than white shrim

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00373.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Book reviewed in this article:Handbook of Dietary Fiber: An Applied Approach. Edited by Mark K. Dreher.Food Chemistry. by H.‐D. Belitz and W. Grosch.Cheese: Chemistry, Physics and Microbiology. Vol. 1. General Aspects; Vol. 2. Major Cheese Groups; Edited by P.F. Fox.Food Biotechnology.Developments in Food Proteins ‐ 5. Edited by B.J.F. Hudson.MODERN CARBOHYDRATE CHEMISTRY. By Dr. Roger Binkley.Food, Nutrition and the Consumer. T.R. Gormley, G. Downey and D. O'Beirne.Food Structure and Behavior. Edited by J.M.V. Blanshard and P. Lillf

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00374.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1988.tb00367.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY