摘要:

AbstractLactating cows and heifers were offered diets containing (a) no added oil, (b) added tallow and (c) an added mixture of palm oil and soya oil. Each of these diets was given at two levels of feeding. The diet containing no added oil at the high level of feeding was isoenergetic and isonitrogenous with diets (b) and (c) at the low level of feeding. This design allowed the effect of the decrease in fermentable substrate (consequent upon substituting fat for starch) on the output of short‐chain fatty acids (SCFA) in the milk fat to be quantified. Approximately 20% of the total decrease in the concentations of these acids in milk was found to be due to the loss of dietary starch when tallow was fed, the value being somewhat higher in the case of the more unsaturated acids of diet (c). These results are considered in the context of the established changes in citrate concentration of milk that occur on feeding fat. It is concluded that the major cause of decreased output of SCFA in the milk when dairy cows consume rations containing added fat is mediated within the mammary gland and is probably due to the dietary long‐chain fatty acids acting as partial inhibitors of the synthesis of the S

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361202

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe influence of neutral detergent fibre from Bengal gram on the utilisation of protein in albino rats was studied. Four market samples of Bengal gram and Bengal gram Annegeri variety harvested at three different stages of maturity were used for the study. The legumes were first analysed for proximate principles and then used as the source of nitrogen and fibre in the rat diets. Their proximate composition was similar to the values reported in literature. The content of neutral detergent fibre increased with increasing crude fibre. Growth of weanling rats was assessed on the basis of protein efficiency ratio (PER). Digestibility coefficient (DC), biological value (BV), total nitrogen retention (TNR) and net protein utilisation (NPU) were determined. PER, NPU, DC and nitrogen retention decreased with increase in fibre content in the diet. PER of Bengal gram sample with 14% neutral detergent fibre (NDF) was significantly different from the PER of all other samples. Biological value, however, was not affected by the fibre content.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361203

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe effects upon amino acid content and nitrogen characteristics of feather meal subjected to varying lengths of processing time (30 to 70 min) moisture content (50 to 70%) and added NaOH (0.2 to 0.6%) were studied by multiple regression techniques. All test products were autoclaved at constant pressure of 345 kPa. The results obtained showed that prolonged processing periods and increased concentrations of NaOH had a substantial effect on the amino acid contents and in particular on the essential ones. There was a marked degradation of cystine, and smaller losses of lysine and methionine. Most of the amino acid contents were lower in the meals with a higher moisture content. In vitro protein digestibility and solubility in alkali and acid, were generally increased by prolonged processing conditions.It was concluded that the inverse relationship between amino acid content and nitrogen characteristics should be taken into account for feather meal evaluation. Higher values for in vitro protein digestibility and solubility were considered to be favourable unless other structural modifications to the protein affect its nutritional value.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361204

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe effects of 33 mg kg−1monensin supplementation (+M) of barley (HC) or dried grass (HF) diets on aspects of propionate metabolism, insulin secretion, rumen vitamin B12synthesis and lipogenesis in sheep were investigated. Monensin had no significant effect on the estimated metabolisable energy intake, or the liveweight gain, but increased the proportion of propionate in rumen volatile fatty acids (VFA),P<0.01 andP<0.05 for HC and HF diets respectively, and increased rumen ammonia concentration,P<0.01 for both diets. Plasma propionate concentrations were increased (P<0.01) with the HC+M diet. Significant increases in adipose tissue and liver‐propionyl‐CoA carboxylase (P<0.001), a non‐significant trend toward increases in fatty acid synthetase and significant increases in malic enzyme (P<0.01), indicated an induction of the pathways of propionate metabolism and lipogenesis; this was also supported by a trend toward increases, or significant increases, in total propionate derived fatty acids (PDFA), branchedchain fatty acids (BCFA) (P<0.01) and 18:1/18:0 ratio (P<0.02) in adipose tissue triacylglycerols of sheep fed the HC+M diet. Dietary monensin did not influence plasma glucose but reduced plasma insulin concentrations with both diets,P<0.001 andP<0.05 for HC and HF diets respectively, possibly due to a direct effect of monensin on insulin secretion. Monensin supplementation led to significant increases (P<0.02) or a trend toward increases in serum vitamin B12, for HC and HF diets respectively, and to significant increases in liver vitamin B12(P<0.02) for the

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361205

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractSeventy‐two pearl millet genotypes were water stressed at panicle development and grain filling stages. Neither grain yields, yield components, protein percent nor total protein per unit area were affected by water deficit during panicle development but protein content per grain was increased. When plants were water stressed during grain filling, grain yield, grains per unit area and 1000 grain weight were reduced, but grain protein percentage increased. Total protein per unit area was reduced primarily due to lower grain yield. The protein content per grain was unaffected by stress, suggesting that the apparent increase in protein percentage is due to reduced carbohydrate accumulation under stres

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361206

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe carbohydrates soluble in 80% ethanol and in water at 100°C were extracted from two varieties of wheat, barley, oats, rye, triticale, rice and malt. The highest concentrations of sugars soluble in 80% ethanol were found in malt and rye with the lowest in rice. Barley contained the most raffinose and rye contained the most fructan. Rye had the highest levels of water‐soluble and total pentosans and barley the highest levels of water‐soluble and total (1→3), (1→4)‐β‐glucans. The total arabinose:xylose ratio varied from 1.2 in wheat and triticale to 0.3 in oats. All were very low in

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361207

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractTwo samples ofBalanites aegyptiacafruits were collected from two different regions in Sudan. The edible mesocarp contained 1.2–1.5% protein and 35–37% total sugars of which 81.3–91.1% is present as reducing sugars. The kernels contained 45.0–46.1% oil. Palmitic, stearic, oleic and linoleic acids were the main fatty acids. The ratio of saturated to unsaturated fatty acids was 10:26 in both samples. The protein was found to be low in aromatic amin

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361208

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractPolyphenoloxidase (PPO) was isolated from guava (Psidium guajavaL., cv. Kampuchea). Purification by acetone precipitation and dialysis of the Amicon concentrate resulted in 4.9‐fold and 17.2‐fold purification of the dialysed crude extract respectively. Polyacrylamide gel electrophoresis indicated that PPO had a molecular weight in the region of 120000–140000. The pH optimum of the enzyme was found to be 7.2. Heat inactivation studies showed that heating for 1.1, 3.5, and 10.1 min at 75, 65 and 55°C respectively caused a 50% loss in enzymic activity. The enzyme‐catalysed browning reaction was significantly inhibited in the presence of sodium metabisulphite, L‐cysteine hydrochloride and asc

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361209

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractA procedure was developed for the simultaneous isolation of pure vicine [2,6‐diamino‐4,5‐dihydroxypyrimidine 5‐(β‐D glucopyranoside)] and convicine [2,4,5‐trihydroxy‐6‐aminopyrimidine 5‐(β‐D glucopyranoside)]from dehulled fababeans. The procedure involved the extraction of the glycosides with an ethanol‐water (70:30, by vol.) solution, concentration of the extract to a minimal volume and adjustment of the pH of the aqueous extract to 7.2. Mixed vicine and convicine crystals, which were formed over a period of from 1 to 4 days, were harvested by centrifuging and washed with water and ethanol. Vicine was readily obtained from the mixed crystals by extraction at a low pH and recrystallised by adjustment of the pH to neutrality. Convicine, which is relatively insoluble in an acidic medium, was solubilised in an alkaline solution and recryst

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361210

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe nutritive value of some commercial baby foods commonly consumed in Pakistan was evaluated by means of chemical and biological assays. The protein content of milk based formulas and cereal‐milk blends ranged from 13.3–26.0 and 11.1–13.2%, respectively. The fat content was highest (27%) in P‐7f and was lowest (3%) in Robinson Baby Food. The available carbohydrates in milk based formulas were lower (44.1–59.9%) than cereal‐milk blends (71.5–77.7%). The highest content of ash (5.6%) was found in Ostermilk. The metabolisable energy (ME) values ranged from 428–473 and 349–391 kcal, respectively, in milk based formulas and cereal‐milk blends. The net protein utilisation (NPU) values of milk based formulas varied between 0.68 and 0.75 and NPU values of cereal‐milk blends ranged from 0.69 to 0.71. The protein quality of baby foods was compared with the standards and the low NPU values reflected the influence of the

ISSN:0022-5142    

DOI:10.1002/jsfa.2740361211

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY