Essential amino acid composition and biological quality of yambean, Sphenostylis stenocarpa (Hochst ex A. Rich) harms

The essential amino acids and protein bioavailability of raw, roasted and pre-soaked, pressure cooked yambean were evaluated. Roasting caused decrease of 8% while soaking with pressure cooking caused decrease of 15-39% in the lysine composition of yambean. Rats fed raw, unprocessed bean diet showed overt signs of diarrhoea, poor protein utilization and hence poor growth. Processing considerably improved all growth indices--food conversion efficiency, protein efficiency ratio, digestibility, biological value, net protein utilization, protein retention efficiency and net protein ratio.     

Nutritional quality of storage proteins during germination of Indian bean (Dolichos lablab. var. lignosus) seeds

The dry Indian bean seed composed of starch is the major component (33%) and protein accounted for 25% of dry weight. The ability of germination to increase the nutritional quality of storage proteins was studied by germinating the Indian bean seeds for 0, 8, 16, 24 and 32 h and evaluated the nutritional quality through an in vitro protein digestibility (IVPD), protein efficiency ratio (PER), apparent and true digestibility. The IVPD of raw Indian bean seeds by pepsin alone was 60.12% and the digestibility by pepsin and trypsin together improved to 64.24%. The in vitro digestibility by both processes increased appreciably with germination and marked increase was noticed in the early stage of germination. The PER values followed the same pattern as the value of weight gain of rats fed with diets containing raw and germinated Indian bean. The lowest PER values were observed with raw bean diet. However, the value increased in rats fed with diets of Indian bean germinated for different intervals of time, reaching comparable PER values with the group maintained on casein diet. The true and apparent nitrogen digestibility of raw bean low being only 82 and 72%, respectively observed with casein diet. Diets with germinated bean protein showed a marked increase in both parameters, although the values were still less than that displayed by the casein fed rats. Germination is a simple biochemical enrichment tool and significantly improves palatability, digestibility and the nutritive utilisation of proteins in Indian bean seeds.     

Factors Affecting the Protein Quality of Yogurt and Acidophilus Milk

The apparent protein digestibility in vivo, the protein digestibility in vitro, the net protein ratio, and computed protein efficiency ratio were used to assess the protein quality of yogurt and acidophilus milk as affected by heat treatment, direct acidification, addition of culture, or fermentation. Rats fed diets containing either heated mix or yogurt tended to eat more and gain more weight than rats fed diets containing either unheated mix or the acidified yogurt. Feed efficiency was also significantly higher for rats fed heated mix and yogurt. The apparent protein digestibility in vivo was significantly higher in yogurt diet than in the unheated yogurt mix diet. The net protein ratio of the yogurt diet was significantly higher than that of either the unheated mix or the acidified yogurt but not significantly different from the heated mix. The computed protein efficiency ratio values were also increased with both heating and fermentation. The direct acidified yogurt had a significantly lower net protein ratio and lower computed protein efficiency ratio than the fermented yogurt. Rats fed either sweet acidophilus (unfermented) or acidophilus milk exhibited a significantly higher protein digestibility than rats fed heated milk, indicating that the lactic culture may have a direct effect on protein digestibility. Despite their increased protein digestibilities, the acidophilus products did not display any significant increase in net protein ratio or computed protein efficiency ratio.     

Repeated use of oil for frying fish. Effects of feeding the fried fish to rats

Four groups of weanling male albino rats (Wistar strain) were fed isonitrogenous diet (10% protein) identical in all respects except in the nature of the protein source, for 4 weeks. Control group (group 1) had steamed mackerel meat as the protein source, whereas groups 2, 3 and 4 had mackerel fried on the 1st, 3rd and 4th days in the same coconut oil repeatedly used for frying each day. Four groups of adult male rats weighing around 130 g were fed on the same diet for 12 weeks. Weanlings fed on fish fried on the 4th day showed significantly lower feed consumption and weight gain compared to the other three groups. All the three groups of adult rats fed on fried fish compared well with control rats in weight gain and hepatosomatic index. There was a decrease in the total lipid and cholesterol content of the liver of rats fed with fried fish in comparison with the control rats. The total lipid and cholesterol in heart and serum cholesterol levels increased significantly from control rats through group 4. The C22:6/C20:5 ratio in the heart lipid showed a very high value compared to the dietary lipids. Histopathological examination showed initial stages of cell damage in the liver and kidney of rats fed with fish fried on the 4th day. In-vitro digestibility of proteins of fried fish were lower than that of steamed fish, but the difference in this respect between proteins of fish fried on different days was not significant.     

Nutritional assessment of cookies supplemented with defatted wheat germ

Replacement of wheat flour with defatted wheat germ (DFWG) at levels of 0–25% was investigated for its effect on functional and nutritional properties of cookies. The crude protein content of DFWG was as high as 27.8% with a highly valuable amino acid profile, rich in essential amino acids, especially lysine (2.32 g/100 g). The physicochemical and sensory evaluation of cookies, revealed that up to 15% substitution of wheat flour with DFWG produced acceptable cookies similar to the control (100% wheat flour) cookies. The protein quality of the cookies was assessed through weanling albino rats by feeding a diet of cookies for 10 days, which was formulated to supply 10% protein, with a casein diet as a control. The cookies containing 15% DFWG, were best regarding protein bioavailability in rats. The protein efficiency ratio (PER), net protein utilization (NPU), biological value (BV) and true digestibility (TD) differed significantly among diets containing cookies with 0–10% DFWG, and casein diet when fed to rats. Diets containing 15% DFWG have values, of these parameters, similar to the casein diet.     

Effect of thermal processing on the nutritive value of wheat germ protein

Wheat germs are used as industrial products for nourishment so that it was necessary to determine the nutritive value of proteins in raw and in roasted wheat germs (temperature: 130–150 °C for 20 min). Protein quality evaluation has been determined by a biological method - feeding young growing rats. The rats were fed 10% level protein diets, based on raw and roasted wheat germs. The results show that protein of roasted wheat germs has higher digestibility (D) and protein efficiency ratio (PER) than the raw wheat germs which proves that roasting destroyed digestion enzymes inhibitors. Furthermore, the net protein utilization (NPU) has also been improved by roasting. Biological value (BV) of raw germs approximates to the value of roasted germs. The results lead us to the conclusion that roasting saves and improves protein parameters in wheat germs.     

Canavalia brasiliensis seeds. Protein quality and nutritional implications of dietary lectin

This study reports on the performance of rats fed with diets based on Canavalia brasiliensis seed proteins. The raw seeds are not a good regime, causing the animals to lose weight, exhibiting low net protein utilization (NPU) values, high nitrogen excretion and macroscopic alterations of key internal organs. Heat treatment, but not dialysis of the seed meal, had a beneficial effect on the nutritional parameters. Feeding rats with a diet containing pure lectin showed a lower digestibility and NPU, a much higher dry matter and nitrogen excretion, impaired growth rate and small-intestine enlargement in comparison with rats pair-fed on egg-white protein. In addition, lectin was detected fully active against rabbit erythrocytes in the faeces of rats fed lectin-containing diets. It was suggested that the seed lectin acts as an antinutritive dietary component.     

Influence of cooking upon the nutritive value of potato and maize in diets for growing pigs

Diets containing 50% of the dry matter (DM) as barley, cooked flaked maize, ground maize, cooked flaked potato, or 22% of the DM as raw potato had metabolisable energy (ME) values of 14.5, 15.2, 15.1, 15.1 and 14.5 MJ/kg DM respectively, and efficiencies of N retention of 0.40, 0.41, 0.42, 0.42 and 0.31. Cooking potato had a positive effect upon the ME value and the efficiency with which ingested nitrogen (N) was retained. Any single nutritive value for raw potato was considered inappropriate due to the influence of raw potato on the digestibility of other diet components. Pigs fed a diet containing cooked potato grew faster and converted feed to live weight more efficiently than pigs fed the same amount of a diet containing between 14 and 26% of the DM as raw potato. The presence of raw potato in diets was also found to reduce appetite. Cooking maize appeared to have only a small effect upon the nutritive value of maize. Pigs fed diets containing cooked flaked maize grew slightly faster than pigs fed ground maize.     

Value of yeast protein for poultry feeds

Evaluation of yeast as a main source of protein to replace fish meal or soybean meal in chicken feeds was reviewed in the attempt to establish another source of protein in chicken nutrition. Various substrates used for yeast growth were compiled. The chemical composition and vitamin B content of yeasts were summarized. Amino acids and nucleic acids of yeasts as well as net protein utilization, true digestibility, biological value, and protein efficiency ratio of yeasts and other protein foods were discussed to ascertain the nutritive value of yeast proteins. The results of studies conducted under practical conditions where yeasts were used to replace the extracted soybean meal and fish meal individually or together in commercial feeds were tabulated in detail in terms of growth, feed intake, feed conversion ratio, etc. It appeared that the growth of broilers fed the feeds containing yeast at a level of up to 15 to 20% was almost identical when yeast was added in place of soybean meal, but somewhat retarded when yeast was added in place of all fish meal and part of soybean meal. Poorer growth was observed with an increase in dietary yeast above this level. It was recommended to add synthetic DL‐methionine to yeast‐based rations for poultry in order to obtain good growth performance. It has been demonstrated that appetite and growth rates of broilers maintained on yeast‐containing diets properly balanced in energy, protein, calcium, and phosphorus were superior to those in which the nutrients were not carefully adjusted. The blood plasma uric acid levels of broilers were not affected by levels of up to 20% n‐paraffin yeast in the diet. Up to 20% of the diet can be composed of alkane‐grown yeasts without any deleterious effects on egg quality or reproductive performance of laying and breeding hens. Chickens fed for prolonged periods of time with hydrocarbon‐grown yeasts failed to show any changes in protein metabolism, hematologic, or morphological indices which might be associated with undesirable characteristics of poultry products.     

Protein digestibility in dog. Effect of the quantity and quality of dietary fat (virgin olive oil and sunflower oil)

Protein digestibility has been estimated in dog when fed on two similar diets except their lipid quality (virgin olive oil and sunflower oil) from weaning up to 6 months of life. Experiments were carried out at 60, 105 and 150 days of adaptation to either diet. In dog, age does not seem to affect the protein digestive and metabolic utilization when fed on a high lipid content diet. A higher dietary fat percentage led to an increase of the mentioned parameters which could be caused to a delayed gastric emptying due to fat. As far as the fat quality is concerned, an improved protein digestive and metabolic utilization was evidenced in adult animals fed on olive oil. On the other hand, the weight progress was normal in both experimental groups. These results suggest that olive oil may have beneficial effects on protein digestibility as compared to sunflower oil.     

Effect of grain level and protein source on ruminal fermentation, degradability, and digestion in milking cows fed silage

Five primiparous Holstein cows (483 kg BW) of low productivity were used in a 4 x 5 incomplete Latin square design to study the effects of feeding two levels of grain containing soybean meal and one level of grain containing fish meal on feed intake, milk production, digestibility, and rumen fermentation. Animals all were fed alfalfa silage for ad libitum intake. Collection of data was between wk 11 and 24 of lactation. The four treatments were an all silage diet (control), silage and medium concentrate fed at 1.8% BW containing soybean meal, and silage and low concentrate fed at 1.3% BW containing either soybean meal or fish meal. Treatments other than control were designed to give similar CP intake from the concentrate, which was based on high moisture corn and cob meal. Milk production and composition were similar among treatments except for fat percentage, which was significantly lower for low grain soybean meal. Intake of DM was higher on medium grain soybean meal compared with the other treatments. Average BW and change in BW (.11 kg/d) were not affected by treatments. Digestibility of DM was higher for cows fed grain (68 to 73%) than for those fed the control diet (60%). Generally, feeding concentrate at 1.3 or 1.8% BW and supplementing with soybean meal or fish meal resulted in pH and concentrations of NH3 N and VFA similar to those observed on the all silage diet. Feeding concentrate at 1.3 or 1.8% BW and supplying fish meal or soybean meal did not change feed utilization enough to increase milk production in low producing cows compared with an all silage diet.     

Nutritional evaluation of protein from Clanis bilineata (Lepidoptera), an edible insect

BACKGROUND: This study was carried out to determine the nutritive quality of protein from Clanis bilineata (CB), an edible insect. RESULTS: The protein content of dried CB was 685.3 g kg^?1 and its essential amino acid content was 528.4 g kg^?1, both of which are comparable to those of milk and eggs. Three groups of rats were fed diets containing either casein or CB protein (CBP) as protein source or a protein‐free diet for 10 days. The nutritional parameters measured for the group fed the diet containing CBP showed a positive nitrogen balance of 1.37, a net protein retention of 2.9 and a true digestibility of 95.8%, comparable to those measured for the group fed the casein diet. CONCLUSION: The results suggest that CBP may be a suitable alternative dietary protein source for humans. Copyright © 2011 Society of Chemical Industry     

Quality changes of Nigerian traditionally processed freshwater fish species.

Traditionally smoked (TS), traditionally solar dried (TD), oven dried (OD), Ife solar dried (ISD), and fresh (FF) Clarim lazeru, Sarotherodon niloticus, Sarotherodon galileus, Tilapia zilli, and Hemichromis fmciatus were assessed for proximate composition, nutritive value and organoleptic changes.
Proximate composition of the fish treatment groups were similar, and this increased with decreasing moisture content.
Biological value (BV), true digestibility (TD), net protein utilization (NPU), protein efficiency ratio (PER), were greater than casein (P < 0.01), although they are not statistically different from each other.
From consumer-type taste panel, no statistically significant differences between fish species and organoleptic attributes scores could be discerned. However, a comparison between fish treatment and organoleptic attributes showed obvious differences. The fresh fish always scored highest while TD scored lowest.
The findings are discussed.     

Reactions of chlorogenic acid and quercetin with a soy protein isolate--influence on the in vivo food protein quality in rats

Plant phenolic compounds are known to interact with proteins producing changes in the food (e. g., biological value (BV), color, taste). Therefore, the in vivo relevance, especially, of covalent phenol-protein reactions on protein quality was studied in a rat bioassay. The rats were fed protein derivatives at a 10% protein level. Soy proteins were derivatized with chlorogenic acid and quercetin (derivatization levels: 0.056 and 0.28 mmol phenolic compound/gram protein). Analysis of nitrogen in diets, urine, and fecal samples as well as the distribution of amino acids were determined. Depending on the degree of derivatization, the rats fed with soy-protein derivatives showed an increased excretion of fecal and urinary nitrogen. As a result, true nitrogen digestibility, BV, and net protein utilization were adversely affected. Protein digestibility corrected amino acid score was decreased for lysine, tryptophan, and sulfur containing amino acids.     

Diet digestibility and growth of holstein calves fed acidified milk replacers containing soy protein concentrate

Three experiments were conducted to determine the effects of acidification of milk replacers containing soy protein concentrate on diet digestibility and growth of Holstein bull calves. In Experiment 1, six calves (6 wk old) were fed at 10% of BW/d either acidified milk replacer containing soy protein concentrate or untreated milk replacer containing soy protein concentrate. Replacers were reconstituted to 12.5% DM for 10-d adjustment and 4-d collection periods to determine digestibility and N balance. Digestibilities of DM, ether extract, and N were similar between treatments. Nitrogen retention and N retention as a percentage of that absorbed were higher for calves fed the acidified diet. In Experiment 2, 20 calves (1 wk old) were fed diets identical to those diets fed in Experiment 1 at 20% of BW/d for 4 wk. Calves were allowed to adjust to the diet for 5 d. Growth parameters were measured and amount of feed offered was adjusted weekly. Calves fed the untreated diet had higher daily weight gains, girth gains, height gains, and better feed utilization. In Experiment 3, 21 calves were fed either the aforementioned diets or a replacer based on milk proteins at 10% of BW/d (12.5% DM) for 4 wk. Growth parameters were measured and DM intakes were adjusted weekly. Growth and feed conversion were similar across diets. Replacers containing soy protein concentrate or large amounts of whey may need to be supplemented with additional methionine to maximize rate of gain.     

Influence of Legume Starches on Protein Utilization and Availability of Lysine and Methionine to Albino Rats

Starch was extracted from red gram (Cajanus cajan), Bengal gram (Cicer arietinum), black gram (Phaseolus mungo), and green gram (Phaseolus aureus). The effect of these starches on the utilization of casein was tested in albino rats using PPER, digestibility co-efficient, biological value, and net protein utilization as parameters. Lysine and methionine available to rats was also determined. The phaseolus starches promoted growth similar to corn starch but the growth of rats fed on red gram and Bengal gram starch was significantly less (P < 0.05). The digestibility coefficient of casein was reduced significantly when supplemented with red gram starch compared to the other legume starches. No difference was noticed in the biological value of casein supplemented with the four legume starches. However the net protein utilization of casein was significantly (P < 0.05) higher when supplemented with black gram starch compared to other legume starches. Availability of lysine to rats fed with phaseolus starches was significantly higher than for rats fed with other legume starches.     

The influence of selected technological processes on the improvement of rapeseed meal and flour feed quality. Part 2. Effect of hydrothermal treatment and ethanol extraction on the nutritional value of rapeseed products

In experiments with rats the effect of feeding flours (dehulled and defatted seeds) and concentrates (flour extracted with ethanol) prepared from non-heated and heated seeds of low-glucosinolate rapeseed var. Jantar was studied. Flours and concentrates were fed either as the main protein supplement in cereal-based diets or as the only protein sources in semi-synthetic diets; ethanolic extracts were either administered by stomach tube or fed with the diets. Heat treatment of seeds reduced ITC + VOT contents about 27 % and did not affect phenol contents; ethanol extraction removed both ITC + VOT and phenols. Feeding the flours from heated and non-heated seeds resulted in the increase of thyroid and liver weights as compared with rats from the control group fed on soybean diet. Heat treatment of seeds improved protein digestibility of flours and concentrates and did not modify negative effect of ethanol extract on protein digestibility. Biological value of protein of flours and concentrates was not affected by heat treatment of seeds. Feeding concentrates influenced positively animal growth performance, elimenated hypertrophic effect of the flour on thyroid and liver, increased biological value of protein as compared with flour. Administration of ethanolic extracts containing ITC + VOT and phenols to rats fed on soya-bean mael diet did not induce hypertrophy of thyroid and liver similar to that observed in rats fed on flours containing these antinutritional substances.     

Varietal variation in the anti-nutritive effects of field beans (Vicia faba) when fed to rats.

Testa and cotyledons were separated from white and coloured flowered varieties of field beans (Vicia faba) and incorporated into complete diets for rats. Diets containing 10% testa from the coloured variety caused a 15% reduction in live weight gain compared with the diets containing testa from the white flowered variety. This was accompanied by a reduction in the true digestibility of nitrogen and the apparent digestibility of carbohydrates and lipids. The protein efficiency ratio and the net protein utilisation were also reduced but the biological value of protein was not significantly affected. The efficiency of utilisation of ingested feed dry matter was significantly reduced for the diets containing coloured flower testa but when live weight gain was expressed as a fraction of ingested digestible dry matter there were no significant differences. Live weight gain and digestibility of organic matter components were highly negatively correlated with the total phenolic content of the diet. It was concluded that the reduction in live weight gain of animals fed diets containing testa of a coloured variety compared with that of a white flowered variety was caused mainly by the reduction in digestibility of organic matter brought about by the complexing of dietary and digestive enzyme proteins by the high content of phenolic compounds present in the testa of the coloured variety. A 10% reduction in live weight gain was recorded for animals consuming diets containing cotyledons of coloured varieties compared with those consuming white flowered cotyledons. This reduction was not accompanied by any change in the digestibility of organic matter components and the true digestibility of nitrogen and protein efficiency ratio were not significantly different. There was, however, a significant reduction in the biological value which was a result of increased urinary nitrogen output. It was concluded that the cotyledons of the coloured flowered variety contained an anti-nutritive factor which was not a tannin-like compound and which had an effect on the protein metabolism of the animal.     

The effect of dietary antibiotics on protein and energy metabolism in rats: possible significance of the gut microflora.

The influence of the intestinal microbial activity on protein metabolism was tested in rats with three diets fed without and with antibiotics (Nebacitin). True protein digestibility, biological value, net protein utilisation, true amino acid digestibility and apparent digestible energy were measured. The intestinal microbial activity was on average reduced to one-fifth by antibiotics. On a diet low in crude fibre (2.5%) but high in crude protein (17.6%), this reduction had only a minor influence on the parameters for protein quality that were measured. However, true digestibilities of histidine and cystine were strongly reduced by the antibiotic treatment. The digestibility of energy was also significantly reduced (5%). For diets higher in crude fibre and lower in protein, the influence of the microbial activity was more pronounced. Digestibility of protein and energy were severely reduced by the dietary antibiotic treatment. In general, antibiotic supplementation decreased the parameters that were measured.     

Effect of formic acid or formaldehyde treatment of alfalfa silage on nutrient utilization by dairy cows.

Third-cutting alfalfa with 37% DM was ensiled untreated or treated with either 2.8 g of formic acid/100 g of DM or .31 g of formaldehyde/100 g of DM and fed to lactating dairy cows in two experiments. Silage treated with formic acid had the lowest pH and concentrations of NPN, NH3, and total free AA. Both treatments decreased rumen in vitro protein degradability but did not affect in vitro rumen plus pepsin digestibility. In trial 1, part 1, 22 Holstein cows received a standard diet for 18 d postpartum and then were fed for 6 wk one of three diets containing 98% alfalfa silage DM. Although DMI was comparable, yields of milk, SCM, fat, protein, lactose, and SNF were higher when treated silages were fed. Plasma concentrations of branched-chain, essential, and total AA increased when formic acid-treated silage was fed. Rumen pH and concentrations of NH3 and VFA were similar for all diets. Rumen escape protein, estimated using 15N as a microbial protein marker, was increased more by formic acid than by formaldehyde treatment. In trial 1, part 2, supplementation with 4.8% fish meal increased concentration of milk protein and yields of milk, protein, lactose, and SNF. Milk urea concentration was higher on the untreated silage diet. Total tract apparent DM and N digestibilities were not affected by silage treatment, although fish meal decreased apparent DM digestibility. In trial 2, 80:20 alfalfa silage:ground corn diets were fed to 12 midlactation cows in a 3 x 3 Latin square study. Milk production was unaffected, but milk protein concentration and DMI were higher when treated silages were fed. Feeding treated silages increased plasma concentrations of branched-chain AA, essential AA, and total AA. Formaldehyde and especially formic acid treatment effectively improved utilization of nutrients in alfalfa silage by lactating dairy cows.