摘要:

AbstractRecent outbreaks of listeriosis associated with consumption of milk products contaminated withListeria monocytogeneshave focused attention on the importance of food‐borne transmission of this disease. This review outlines current knowledge of the incidence ofL monocytogenesin raw milk and its incidence in, and ability to survive, the manufacturing process for other dairy products—notably soft cheeses. Discrepancies in results obtained by researchers concerning growth of the organism at refrigeration temperatures and the bacterium's ability to survive pasteurisation are discus

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470202

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe effect of adding annual doses of 14 000 kg ha−1of urban compost to a soil is compared with the addition of 500 kg ha−1of a 15–15–15 compound NPK fertiliser. Two rotation cycles of sorghum/wheat were carried out during the experiment, and the crop yields were not significantly affected by treatments. It is observed that compost added in the proportion used does not cause any statistically significant change in the initial level of available phosphorus in the soil, but causes an increase of the potassium potential.Soil total contents of copper and zinc as well as available levels of both metals show noticeable increases, but other metals are scarcely affected by the addition of compost. The results suggest that larger doses could be an important cause of pollution of the soil with heavy

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470203

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractIndigestible residues from black beans (B; Phaseolus vulgaris L cv Tacarigua), green beans (G; Phaseolus vulgaris L), carrots (C; Daucus carota L) and rice bran (R; from Oryza saliva L) were prepared by the pepsin/pancreatin method of Hellendoorn et al and their effect on trypsin and pancreatic α‐amylase was evaluated comparing two experimental procedures. When the remaining caseinolytic enzyme activity was assayed in the soluble fraction of the fibre/trypsin mixtures, a statistically significant decrease was observed with C, R and G residues. However, assessment of trypsin activity in the presence of residues showed that C has a stronger inhibitory effect, followed in intensity by G and B. With the exception of carrot residue, the highest inhibitory effect was observed if a synthetic substrate of trypsin (BAPNA) is employed. Although all of the residues assayed inhibited α‐amylase activity on soluble starch, the effect of black bean fibre seems to be due to its tannin content. As observed for trypsin, the magnitude of α‐amylase inhibition by indigestible residue proved to be dependent on the experimental system employed. These results indicate that both experimental procedure and type of substrate have an influence on the enzyme inhibitory effect of fibre. C, R and B indigestible residues produced a slight but statistically significant decrease of in‐vitro casein digestibi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470204

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractSubtilisin isoinhibitors (SI) were isolated from jack bean (Canavalia ensiformis L) and broad bean (Vicia faba L) seeds. Jack beans contain three isoinhibitors (pI 6.6, 6.3 and 6.0) that constitute 0.021 g per 100 g of dry seeds, while the two active proteins from broad beans (pI 5.7 and 5.1) represent 0.028%. The molecular weight, determined by gel filtration, is around 8000 D in both legumes. Large variations in specific activity of SI against subtilisin Carlsberg were detected in six species of the Canavalia genus, whereas only slight changes were found among six cultivars of C ensiformis. Antibodies raised against SI isolated from jack beans are specific for SI from different varieties of this and other species of theCanavaliagenus. However, they do not recognise SI from broad beans and other legume seeds tested. In broad beans the variability between cultivars is significant. Cv Canaria has two active bands and four are detected in the ‚dark’︁ variety, which is 2.7 times less active than the former. SI are specific towards microbial serine proteases, showing high affinity for proteinase K. No appreciable activity against animal proteases or plant thiol enzymes can be detected. SI are also inactive against 4 alpha‐amylases of different origins. Reversible limited proteolysis of the reactive site bond suggests that SI interact with subtilisin by the ‚standard mechanism’︁ usually accepted for the inhibition of trypsin by its proteinaceo

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470205

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe mechanism of oxidation of 4‐hydroxyindolyl‐3‐methyl glucosinolate (4‐hydroxyglucobrassicin) has been investigated using 4‐hydroxyindole as a model compound. By trapping the reactive intermediate with aniline, the oxidation has been shown to proceed via the formation of the indole (4, 7) par

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470206

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractEcotypes of the native Spanish speciesLupinus hispanicuswere analysed for seed nutrient composition. Comparisons were made between the two subspecies (ssphispanicus(Boiss et Reut) and sspbicolor(Merino)). OtherLupinusspecies were also analysed. The seed protein content ofLupinus hispanicusis fairly high (420 g kg−1), and the tryptophan content is higher than that of other species (15–20 g kg−1). The oil content (30 g kg−1) is lower than that ofLupinus mutabilisandLupinus albus. Of the sterols, β‐sitosterol and campesterol are high and cholesterol is low. The mineral content was similar for all species studied but some ecotypes ofL hispanicushad high values of Mn though much lower thanL albus(361 and 2396 mg kg−1, r

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470207

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractEcotypes of the native Spanish speciesLupinus hispanicuswere analysed for the presence of the toxic and antinutritional factors in the seed. Comparisons were made between the two subspecies ( ssphispanicus(Boiss et Reut) and sspbicolor(Merino)). OtherLupinusspecies were also analysed.Total alkaloid content was 20 g kg−1, similar to that ofL luteusL. Of the main alkaloids, gramme is found in both subspecies, lupinine in ssphispanicus andepilupinine only in sspbicolor.The saponin content (12 g kg−1) is similar to that in the other species, as is the content of oligosaccharides of the raffinose family.Phytic acid values (9–20 g kg−1) were lower than in some varieties ofL mutabilis (Sweet) and L albusL. Vicine and convicine were absent in allLupinusspecies, and haemagglutinins were no

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470208

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe influence of 1‐tetradecanol, 1‐hexadecanol, 1‐octadecanol and 1‐eicosanol in concentrations of 5 to 80 mmol kg−1on the autoxidation of various types of lipid systems (sunflower and olive oils, lard, tristearin and olive oil methyl esters) is investigated at 70–135°C. A pro‐oxidative effect of the fatty alcohols introduced into the systems is established. The extent of this effect depends on the type and degree of unsaturation in the lipid system, its hydroperoxide content, and the chain length and concentration of the alcohols. A further factor is the valency of the alcohols with which the fatty acids are esterified; thus the pro‐oxidative effect of the fatty alcohols is less pronounced with triacyl glycerols than with fatty acid methyl esters given the same oxidation rate. The results obtained are explained on the basis of the theory of a radical chain process of

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470209

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe quality of fresh, chilled and frozen mince made from the flesh of pond‐bred silvercarp (Hypophthalmichthys molitrix (Val)) was evaluated. Flavour panel scores for all minces were acceptable and this quality did not deteriorate during storage for one week in a domestic refrigerator (5–6°C) or for one year at −20°C. The levels of oxidative rancidity (2‐thiobarbituric acid analysis) in the minces were consistent with this maintenance of quality.Aerobic plate counts at 25°C of fresh mince rose from 7–9 × 104to 1.1 × 105after 6 days' storage at 5–6°C. Coliform and psychrotroph counts rose from 1.0 × 101and 7–8 × 103to 5–4 × 102and 1.3 × 104, respectively. The functional and textural properties of pond‐bred silvercarp mince in terms of salt‐soluble protein content, water binding capacity and penetrometer values were measured on fresh, refrigerated and frozen samples. All‐fish sausages and frankfurters developed from pond‐bred silvercarp mince were assessed in laboratory and consumer tests against commercial beef sausages and frankfurters. The fish products competed well and achieved levels of acceptance similar to those of the beef‐containing products. Texture measurements revealed slight changes in the fish products during storage for 7 days at 5–6°C. No spoilage was detected in any of the products after a week at 5–6°C. The nutritional advantages of the fis

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470210

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe submerged culture of edible mushroom mycelium has been studied because of its potential to produce food, food additives and food supplements. One of the species of edible mushrooms which have been cultivated in submerged culture for the production of mycelial biomass isPleurotus ostreatus(Zadrazil 1978). The growth ofP ostreatuscon peat and its mycelium cultivation in peat extracts have also been reported (Manu‐Tawiah and Martin 1986, 1987

ISSN:0022-5142    

DOI:10.1002/jsfa.2740470211

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY