摘要:

AbstractRhizopus oryzae and R oligosporus germinated best in a starter culture of 5% V8 juice. R oligosporus had a higher optimum temperature for germination and growth than R oryzae, R oryzae utilised starch and nitrogen‐containing salts but not urea in liquid culture. Optimum mycelial growth on membranes on agar was achieved where the protein to carbohydrate ratio of substrates was between 0.4 and 0.5 R oryzae gave higher yields than R oligosporus. The results will be used to optimise solid substrate fermentation systems for these fung

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440402

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractChanges in the content of total phenolics, condensed tannins, proanthocyanidins and flavan‐4‐ols, the degree of polymerisation, the protein precipitation capacity, the protein‐precipitable phenolic content and the specific activity (protein: tannin in the complex) were determined in Quercus incana leaves with maturity. Total phenolic content and protein precipitation capacity decreased whereas the levels of condensed tannins, proanthocyanidins, flavan‐4‐ols and degree of polymerisation increased with maturation. The protein‐precipitable phenolic content was highest in young leaves and decreased as leaves matured. The specific activity decreased slightly. The results suggest that young leaves would be more toxic to livestock than ma

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440403

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractMature green tomatoes cv Calypso were stored at 5, 7,12 or 19oC for 0,3,9, 12 or 21 days, then ripened at 19oC for 3 or 6 days before analysis for organic acids, pH and acidity. Citric acid concentration increased after storage at 5 or 7oC and decreased at 19oC. Malic acid decreased at all temperatures with the greatest decrease occurring at 19oC. The malic/citric acid ratio was 0.32 at 19oC and 0.36 at 12oC. The rate of acetic acid accumulation increased as the storage temperature was reduced. Oxalic acid concentration decreased with time but was greatest at 12oC and lowest at 19oC. Fumaric acid concentration showed similar but erratic trends. Changes in pH were variable, but greater in chilled than unchilled fruit. Titratable and total acidities increased with storage time at chilling temperatures, but decreased at 19oC. Bound acidity initially decreased with time but subsequently increased. Significant differences were found between organic acid concentrations and pH in chill‐damaged and undamaged tissu

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440404

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe antinutritional effects of rapeseed meals from cvs Darmor (‘low’ glucosinolate) and Jet Neuf (‘high’ glucosinolate), both fed for 30 d, and of the purified rapeseed glucosinolate, progoitrin (fed for 23 d), have been examined in rats, with and without the glucosinolate‐degrading enzyme, myrosinase. With all of the experimental diets, feed intake was significantly reduced, the effects being more pronounced in the final period of the experiment. Both types of rapeseed meal significantly reduced live weight gain, and addition of myrosinase enhanced this effect during the second half of the experiment. Organ weights were usually increased in animals fed the experimental diets. The diet containing progoitrin and myrosinase increased liver weight by 58%. In agreement with other workers, thyroid weights were found to be greatly increased by the feeding of rapeseed meals or progoitrin together with myrosinase, although large increases in the size of this organ are also observed in the absence of this enzyme. The major antinutritional effects observed in this study became evident after 10‐15 d, explaining the lack of such effects in earlier, short‐term experiments. The results support the view that progoitrin is a major factor limiting the more extensive use of rapeseed as an animal

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440405

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractTotal volatile nitrogen (TVN), ammonia (NH3) and amide‐N were analysed in fish stored without and with preservatives. In well preserved fish the increase in NH3‐N during storage was accompanied by a parallel decrease in amide‐N. It is concluded that NH3 may originate from glutamine and probably also from asparagine. In unpreserved material other sources may dom

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440406

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA procedure for the identification of the species of fish from the separation patterns obtained on SDS polyacrylamide gel electrophoresis is described. Extracts of either raw or cooked flesh in SDS solution were subjected to electrophoresis in a 12.5% SDS polyacrylamide slab gel system, and the separation patterns obtained on silver staining were shown to be species‐specific. Heating prior to extraction in SDS had little effect on the separation patterns obtained for a range of commercially important species. This procedure offers advantages over other methods available for the identification of the species of cooked fis

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440407

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe retrogradation of waxy maize starch in the presence of surfactants and emulsifiers was measured by differential scanning calorimetry. It was found that a surfactant (cetyltrimethylammonium bromide) and unsaturated monoglycerides reduced retrogradation, whereas lecithin and a soya bean oil influenced the retrogradation to a lesser extent. The effects were greater after 1 day of storage than after 7 days, and the influence of the surfactant was greater at +25oC than at +7oC. Different storage temperatures led to crystallised forms of amylopectin with different melting temperatures. Further, an amylopectin sample was affected by the presence of a surfactant in a way similar to the waxy maize starch.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440408

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractSoluble glutathione S‐transferase was isolated from lean pork meat by S‐hexylglutathione Sepharose 6B. A single form of the enzyme with a subunit molecular weight of 24 800, a pH optimum of 6.2 and an isoelectric point of 7.6 accounted for the majority of the transferase activity. The pure enzyme is stable upon storage at pH 6, and has a relatively low Km(87 μM) for glutathione. Substrate specificity suggests membership of class Pi. Glutathione S‐transferase was able to reduce certain primary products of lipid oxidation. Linoleic acid hydroperoxides, for example, were converted to their corresponding hydroxides (specific activity = 260 nmol min−1mg−1). The transferase could also inactivate secondary products of lipid oxidation. Trans,trans‐2, 4‐decadienal, which results from breakdown of lipid hydroperoxides, was chosen as an example of this class. A high specific activity (1400 nmol min−1mg−1) was found for conjugation of the dienal with glutathione. It is suggested that endogenous glutathione S‐transferase functions as an antioxidant in stored muscle food by removing some of the reactive products that propagate the

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440409

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe various ethnic groups of the Darjeeling district of West Bengal and Sikkim consume a variety of fermented foods including kinema (based on soya beans),gundruk (Brassica campestris leaves),sinki (radish, Raphanus sativus), mesu (bamboo shoots),churpi (milk),shel rod (rice preparation) and jnards (beers). These have not previously been investigated, and their method of preparation and consumption are reported here. The flora of murcha, the starter culture of jnards, contains mainly Pediococcus, yeasts belonging to the genera Saccharomycopsis, Pichia and Saccharomyces and the moulds Rhizopus and Mucor.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440410

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740440401

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY