Composition and protein quality of sweet lupin seed

The proportion of seed coats (hulls) of four varieties of sweet lupin seeds ranged from 19 to 25%. The amount of hull varied inversely with the weight of the seed, within each variety. Lupinus luteus cv Weiko III had 40.1% protein (dry basis); of 3 cultivars of L. angustifolius cv Uniharvest had the highest protein (36.2%), while cv Uniwhite had the lowest (28.6%). The protein content of dehulled lupins was about 20% higher than that of the whole seeds. L. angustifolius cv Uniwhite and L. luteus cv Weiko III were analysed for moisture, protein, lipid, ash, fibre, amino acids, carbohydrates, calcium, phosphorus, zinc, iron, copper and manganese. Whole seed, hulls and kernels were examined. Sulphur amino acids were limiting. The protein efficiency ratios of the two varieties, supplemented with methionine, were 2.40 and 2.56, respectively; these values increased by about 10% when the protein of the dehulled lupin seeds were tested. The requirement for added methionine for maximum p.e.r. was 0.65 g/kg diet. When dehulled lupin seed was steeped in water for a day and boiled and included in the diet of rats, slightly superior growth and p.e.r. resulted. The two varieties of dehulled lupin seeds effectively supplemented the protein of barley meal in the diet of rats, especially when methionine supplements were added, but were less efficient in supplemental value than was casein.     

Cholesterol-lowering effect of whole lupin (Lupinus albus) seed and its protein isolate

This study describes the hypocholesterolaemic effect of whole lupin and its protein in hamsters. The diets were: casein (control group HC), lupin protein isolate (group HPI) and whole lupin seed (group HWS). Diets from HPI and HWS promoted a significant reduction of total cholesterol and non-HDL cholesterol in the hamsters’ plasma as compared with HC. The true digestibility of HPI and HC groups were similar and differed significantly from the HWS one, which in turn showed a significant difference in total sterol excretion as compared to the former groups. Histological analysis of the liver revealed that animals fed on HPI and HWS diets presented a low level of steatosis (level 1) as compared to the ones fed on HC diet (level 4). Our findings demonstrate that protein isolate from Lupinus albus from Brazil has a metabolic effect on endogenous cholesterol metabolism and a protector effect on development of hepatic steatosis.     

Ileal digestibility of defatted soybean,lupin and chickpea seed meals in cannulated Iberian pigs: I. Proteins

Five castrated male Iberian pigs (100 ± 2 kg body weight) fitted with T‐shaped cannulas at the terminal ileum were used to determine ileal digestibility of legume seed meals. The diets were based on defatted soybean, lupin or chickpea seed meals and contained similar levels of digestible energy (14.2–15.1 kJ g^?1) and protein (107 g kg^?1). Protein‐free and a hydrolysed casein diets were used to study endogenous ileal amino acid flows. Chromium oxide (10 g kg^?1 diet) was added to the diets as an indigestible marker. Ileal flows in pigs fed the hydrolysed casein diet were different (p < 0.05) in amino acid contents and composition from those on the protein‐free diet. Ileal sialic acid flows in pigs fed lupin‐ or chickpea‐based diets were higher (p < 0.05) than those of animals fed soybean or casein diets. Among essential amino acids, only the apparent ileal digestibilities of phenylalanine and valine in lupin meal were lower (p < 0.05) than those in soybean. Apparent ileal digestibilities of lupin aspartate and proline, together with chickpea aspartate, were also lower (p < 0.05) than those of soybean. True ileal digestibility of nitrogen in pigs fed lupin or chickpea meals, calculated according to values from animals fed the protein‐free diet, was lower (p < 0.05) than that for soybean or casein. Among individual essential amino acids, only the true ileal digestibility of phenylalanine in lupin was lower (p < 0.05) than that in soybean. True ileal digestibility of nitrogen calculated according to values obtained with pigs fed a hydrolysed casein diet was not different among soybean, lupin or chickpea meals. Among essential amino acids, only the true ileal digestibilities of isoleucine and lysine in chickpea were lower (p < 0.05) than those of soybean. It is concluded that true ileal nitrogen and amino acid digestibilities of lupin and chickpea meals are comparable to those of defatted soybean in Iberian pigs. The results with protein‐free diets tended to underestimate endogenous protein secretion in pigs fed on diets containing protein. Copyright © 2005 Society of Chemical Industry     

Lysine in cassava based diets: II. The nutritional evaluation of acetylated casein in maize meal,corn starch and cassava based diets

Casein was acetylated with sodium acetate/acetic anhydride and was found to be 98·5% acetylated by the FDNB available lysine method.The PER of maize meal and corn starch diets decreased with increasing amounts of acetylated casein. The PER of a maize meal—casein diet was 2·21 but this decreased to 2·13 and 1·60 when acetylated casein was incorporated at 5 and 10% levels, respectively. The same trend was observed for corn starch diets with a PER of 1·60 for a casein—corn starch diet but PERs of 1·28 and 0·91 when acetylated casein was added at 8 and 16% levels, respectively.In the presence of cassava, the nutritional value of acetylated casein was enhanced. Thus a meal made of 10% acetylated casein: 50% cassava: 25% maize meal had a PER of 2·06 compared to 1·60 for a diet consisting of 10% acetylated casein: 70% maize meal. At 16% acetylated casein: 70% cassava the PER was 1·75 compared to 0·91 in a 16% acetylated casein: 70% corn starch diet.A similar trend was observed for NPU, NPR and serum urea levels for the respective diets considered.Acetylated casein moderately elevated the activity of urine enzymes (LDH, GDH, alkaline and acid phosphatases) in corn starch based diets while cassava based diets appeared to depress the level of the enzymes.     

Composition of sweet and bitter lupin seed hulls with observations on the apparent digestibility of sweet lupin seed hulls by young rats

Seed hulls from both sweet and bitter varieties of lupins (Lupinus angustifolius) have been analysed for constituent polysaccharides. The hulls contained 15 to 32% oxalate-soluble pectic polysaccharide, excluding pentose, 12 to 14% hemi-cellulose, 44 to 51% cellulose, 0.3 to 0.4% lignin, 2.7 to 3.8% protein and 2% ash. “Crude fibre” was 54.9%. In agreement with the low lignin values all of the hemicellulose was extractable with alkali without prior delignification and 70 to 80% of the polysaccharide in depectinated hulls was hydrolysed by cellulase plus hemicellulase, likewise without delignification. Sweet lupin seed hulls, added to a complete basal diet up to 40%, did not depress growth of young rats significantly; compensatory increase in food consumption occurred. With 60% hulls in the diet growth and food efficiency were reduced. Ground hulls did depress food and protein digestibility in direct proportion to their amount in the diet, possibly because of physical entrapment in the excessive bulk in the gut. The digestibility of the “crude fibre” of the hulls was 33% when the diet contained 20% hulls; this decreased to 22% when the content of hulls in the diet was increased to 60%.     

Organs relative weight and plasma amino acid concentrations in rats fed diets based on whole legume (faba bean,lupin, chickpea,defatted soybean) seed meals or their fractions

The effects on organ relative weights (g per 100 g bw) and plasma amino acid concentrations of diets based in legume (faba bean (Vicia faba), lupin (Lupinus angustifolius), chickpea (Cicer arietinum) and soybean (Glycine max)) seed meals as the only source of protein were studied with growing rats using lactalbumin or casein as controls. Also, legume seed meal extracted globulins were included in control diets replacing lactalbumin to produce legume globulin‐based diets, and legume residue fractions, containing most of the starch and/or insoluble fibre (NSP+lignin) from the seed meals, were included in control diets to reach the same amounts present in whole legume seed meal diets. All experimental diets were formulated to contain the same amounts of protein (100 g kg⁻¹) and energy (15.5 kJ g⁻¹), and were supplemented with essential amino acids. Compared with lactalbumin, higher relative weights of gastrointestinal sections were determined in rats fed legume seed meals or their corresponding residue fractions. On the contrary, spleen relative weight was lower in rats fed diets containing lupin, chickpea or soybean meals or extracted globulins, while residue fractions had no effect on it. Thymus relative weight was also lower in rats fed whole chickpea seed meal or any of the extracted legume globulins. Except for chickpea meal, animals fed legume‐ or legume protein‐based diets had lower liver relative weights than controls. Lower proportions (mg g⁻¹ tissue) of glycogen, and lower total protein and RNA, were also determined in the livers of rats fed lupin seed meal. Free plasma concentrations (mM litre ⁻¹) of glycine, histidine and arginine were higher, and threonine, leucine and lysine were lower, in rats fed diets based in all legume seed meals of their respective globulin proteins. The possible reasons and implications of these results are discussed. © 1999 Society of Chemical Industry     

Temporal Changes in Serum Cholesterol Levels of Rats Fed Casein and Skim Milk Powdered Diets

The temporal cholesterolemic patterns to skim milk powder (SMP) and reprocessed SMP (RSMP) diets were compared to diets containing casein or laboratory rat chow over a 24-day period. SMP was hypocholestetemic relative to casein in rats fed a 1% dietary cholesterol. Reprocessing of SMP resulted in an apparent loss of the relative hypocholesterolemic reponse of native SMP. Amino acid analysis of SMP and RSMP, showed only marginally lower lysine levels than casein; however, the Iysine/arginine ratio was higher in SMP than either in casein or RSMP. Available lysine content in SMP was higher than in RSMP, suggesting occurrence of nonenyzmatic browning reactions. Although a similar cholesterolemic response was observed in casein and RSMP, the available lysine content of these two protein sources were markedly different, suggesting that reduced available lysine alone was not totally responsible for the lower cholesterolemic response of SMP, relative to casein.     

Comparison of sweet white lupin seeds with soybean meal as a protein supplement for lactating dairy cows

Data were from 45 Holstein cows (23 multiparous, 22 primiparous) assigned by calving date and parity within groups to one of two isonitrogenous (16% crude protein) diets. The diets were 50% forages (corn silage, alfalfa silage) and 50% concentrate, dry basis. In diet A, soybean meal supplied 34.2% of total crude protein; in diet B, ground sweet white lupin seeds provided 37.9% of total crude protein. Cows were fed once daily during the experimental period (d 4 to 116 postpartum). Cows fed lupins consumed significantly less dry matter, produced 1.8 kg/d less milk (but not significantly different), and had lower milk protein percent. Milk fat and total solids percents were similar. Reasons for reduced intake of cows fed lupins were not evident. Traces of alkaloids (.005% dry basis) were present in diet B. Combined results of in vitro continuous culture fermentation and in situ degradation measurements indicated that crude protein from lupins was more degradable than that of soybean meal. Poor performances of cows fed lupins could be partly due to a reduced true protein supply to the small intestine.     

The nutritional toxicity of sweet lupin (Lupinus angustifolius) seed proteins

The effects of raw sweet lupin (Lupinus angustifolius) meal on the growth and N utilisation of rats were determined in two ad libitum and two restricted‐feeding net protein utilisation (NPU) and five N balance experiments. Sweet lupin seed grown in Western Australia, obtained as meal, either unsupplemented (LMU) or fully supplemented with required amino acids (360 g kg⁻¹) (LMFS), was tested. Rats fed lactalbumin (130 g kg⁻¹) (LACT) were used as positive controls, while rats fed a non‐protein diet (NPC) were used as negative controls. In addition, seed protein, extracted at pH 7.0 with water and insoluble after dialysis at pH 7.0 (LPADI; 124 g kg⁻¹), was also used. The diets contained the same amounts of energy and protein and were supplemented with essential amino acids, vitamins and minerals to target requirements for rats. Inclusion of LPADI in the diet of growing rats caused urinary losses of N, almost all as urea, hypoproteinaemia and increase in body water that resulted in the lowest NPU values, N balance and growth rate as compared with other diets used. These rats developed atrophy of the spleen (low dry weight) and had a comparatively smaller thymus gland than those given raw meals. Furthermore, the LPADI fraction was shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) to contain three polypeptides with molecular weights between 30 and 36 kDa which are similar to lectins obtained from Phaseolus vulgaris, Abrus precatorius and Ricinus communis. It is possible that the toxic protein component in the sweet lupin, which has negligible in vitro haemagglutination properties and is extremely toxic in vivo, exerts toxicity by interfering with protein synthesis in the liver, while the immune responses are secondary to azotaemia (high level of urea in the blood) or cytotoxicity action on lymphocytes. The unusual depletion of fat from the body, however, was due to the failure of absorbed amino acids to assimilate as proteins, creating dietary protein restriction and leading to lipolysis. It is therefore tentatively suggested that sweet lupin seed contains a lectin‐like protein that is concentrated in this fraction. Further purification and biological evaluation to establish the exact nature of this protein may be important. © 2000 Society of Chemical Industry     

Nutritional potential and functional properties of sweet and bitter lupin seed protein isolates

Protein isolates were prepared from both sweet and bitter lupin seed flours by two different methods, i.e. by alkaline water extraction/isoelectric precipitation (P1) and by micellisation (MI), and studied with regard to nutritional quality and functional properties. Protein solubility of both lupin seed flours was increased as sodium chloride concentration increased up to 1.0 M, then decreased. The minimum protein solubility of bitter lupin seed flour was quite sharp at pH 4.5, while it exhibited a broad pH range of 4.3–4.9 for sweet lupin seed flour. No significant (P<0.05) differences were found between any isolates in their dry matter, fiber, lipids and moisture contents. Isolates-PI from both sources had significantly (P<0.05) higher crude protein and ash contents than their isolates-MI. Bitter and sweet isolates-PI had lower values of total essential amino acids and higher values of tyrosine, phenylalanine, threonine, tryptophan and valine than isolates-MI. There was no significant (P>0.05) difference between bitter isolates in their alkaloid contents, while both sweet lupin isolates were free of total alkaloids. Bitter lupin isolate-PI had significantly (P<0.05) lower tannins, but sweet lupin isolate-MI had a significantly (P<0.05) higher phytic acid content than other isolates. Isolates-MI from both sources had higher chemical scores than their isolates-PI. The first and second limiting amino acids were total sulfur amino acids and valine, respectively, for all types of isolates. Sweet lupin isolate-MI had a higher essential amino acid index and protein efficiency ratio than other isolates. The protein solubility index, fat absorption and emulsification capacities of both isolates-MI were significantly (P<0.05) higher than their isolates-PI. Both sweet lupin isolates had significantly (P<0.05) higher water absorption capacity than bitter lupin isolates. Sweet lupin isolate-MI had significantly (P<0.05) higher foam capacity and foam stability than other lupin isolates.     

Chemical, nutritional and sensory properties of bread supplemented with lupin seed (Lupinus albus) products

Sweet lupin Lupinus albus seed flour (SLSF), two sweet lupin protein isolates (SLPI-I and SLPI-II) and sweet lupin seed protein concentrate (SLSPC) were added to wheat flour (WF) in an amount of 3, 6, 9 and 12% of wheat flour. The effects of lupin products supplementation on physical dough properties were studied using a Brabender farinograph. Loaves were prepared from the various blends using the straight dough procedure and then evaluated for volume, crust and crumb colour, crumb texture, flavour and overall quality. Water absorption, development time and dough weakening were significantly (P < 0.05) increased as the lupin product levels increased in all doughs; however, dough stability decreased. Lupin products could be added to WF up to 9% level (SLPI-I and SLPI-II) and 6% level (for other lupin products), without any observed detrimental effect on bread sensory properties. No significant (P > 0.05) differences were recorded in loaf volume between control and breads containing SLPI-I and II (up to 9% level) and SLSPC (up to 3% level). Addition of lupin products increased the content of protein and total essential amino acids, especially lysine. The addition also improved in-vitro protein digestibility.     

Plasma lipid regulatory effect of compounded freshwater clam hydrolysate and Gracilaria insoluble dietary fibre

This study investigates the hypocholesterolemic effects of a diet containing freshwater clam hydrolysate (PX) and insoluble dietary fibre from whole Gracilaria (IDF). Freshwater clam meat and whole dried Gracilaria were separately extracted using hot water. The residual meat was hydrolysed at 50 °C by Protamex to obtain freshwater clam hydrolysate (PX). Levels of triacylglycerol and cholesterol in Sprague–Dawley (SD) rats were compared with those of rats fed diets containing casein and cellulose as a control. Plasma triacylglycerol levels decreased by 65.8%, 27.9%, and 44.3%, respectively, in PX10 (16.6% hydrolysate), IDF10 (13.0% IDF) and compounded PX10/IDF10 groups, while plasma total cholesterol levels decreased by 26.1%, 24.2%, and 17.1%, respectively. In the liver, triacylglycerol levels decreased by 27.6%, 21.0%, and 28.0%, respectively, while total cholesterol levels decreased by 50.0%, 38.5%, and 48.6%, respectively. The compound PX10/IDF10 diet group showed a higher excretion of faecal total cholesterol and bile acids levels than did the other groups.     

Sensory acceptability of white bread with added Australian sweet lupin (Lupinus angustifolius) kernel fibre and its glycaemic and insulinaemic responses when eaten as a breakfast

The aim of this study was to determine whether lupin kernel fibre (LKF) could lower the glycaemic and insulinaemic responses of bread without reducing palatability. Healthy adults (n = 21) consumed control (white) bread (2.7% total dietary fibre (TDF)) once and LKF bread (8.5% TDF) once, as 50 g available carbohydrate breakfasts, in random order on different occasions. Venous blood samples were taken fasting, then post‐prandially over 2 h and analysed for plasma glucose and insulin. Incremental areas under curves (IAUC) for glucose and insulin, glycaemic index (GI) and insulinaemic index (II) were calculated. Sensory acceptability of a control (white) bread (3.5% TDF) and two LKF breads (6.6 and 8.3% TDF) was determined (n = 54). A reduction of 18.8% (P < 0.05) was seen in IAUC for insulin of LKF bread compared with the control (white) bread breakfast. No significant differences were seen in the other glucose or insulin measures. Mean sensory ratings for all breads were ‘acceptable’, with no significant differences between the ratings of the breads. In conclusion, LKF can be formulated into palatable bread and beneficially influenced the IAUC for insulin. Further studies are required to determine unequivocally whether LKF has beneficial effects on blood glucose and insulin measures. Copyright © 2003 Society of Chemical Industry     

The Nigerian diets: Distribution of protein,carbohydrate, fat,fibre and minerals

Nigerian diets consumed by population groups in the Calabar Metropolis were analysed for protein, carbohydrate, fat, fibre and mineral constituents. The crude protein content ranged between 5·4% and 26·3% (dry weight), 9·5% and 24·4% and 7·2% and 25·5% for breakfast, lunch and dinner diets, respectively. The ranges of values for carbohydrate, crude fat, crude fibre and total cholesterol were 32–83%, 9–39%, 1·3–3·9% and 54·8–1046 mg (per 100 g dry weight) respectively, for breakfasts; 43–75%, 12–30%, 1·8–3·4% and 452–900 mg, respectively, for lunch diets and 47–78%, 11–28%, 1·5–3·5% and 98·5–863 mg, respectively, for dinners. Typical Nigerian diets provided 25% of total food energy from fat. The mineral analysis provided data on twelve minerals and their distribution in the diets.The results indicate that diets consumed in the Calabar Metropolis contain moderate protein, low fat and cholesterol, high carbohydrate and dietary fibre, but the diets of elite groups approximate those of western nations in composition.     

Effect of rumen-protected methionine and lysine on casein in milk when diets high in fat or concentrate are fed

To examine the effect of supplying methionine and lysine on milk N composition, isoenergetic, isonitrogenous diets containing 50:50 with 3.9% added fat or 25:75 forage to concentrate with no added fat were fed with or without rumen-protected methionine and lysine to four primiparous and four multiparous early lactation (36 d in milk) Holstein cows in two 4 x 4 Latin squares. Diets contained 1.7 Mcal NE1 and were fed for ad libitum intake. Periods were 21 d. Rumen-protected methionine and lysine increased total N and casein N percentage with the 3.9% fat, but did not increase total N and casein N percentage with the diet without fat. Whey N percentage was greater with the no fat than with the 3.9% fat diet. Whey N percentage was not affected by adding amino acids. Nonprotein N percentage was greater for the diet with the 3.9% fat than with no fat. Proportions of casein N or whey N to total N were unaffected by treatments. Adding methionine and lysine to diets did not increase yields of total N and casein N. The 3.9% fat diet increased proportions of long-chain (C18:0 and C18:1) and decreased proportions of short- to medium-chain fatty acids (C8 to C16) in milk fat. Plasma nonesterified fatty acids and triglyceride concentrations were greater with the 3.9% fat as compared to the no fat diet. Methionine and lysine decreased plasma triglyceride concentrations with the 3.9% fat diet. Milk yields, DM intakes, and plasma glucose concentrations were unaffected by treatment.     

Barley β-glucan is effective as a hypocholesterolaemic ingredient in foods

Barley contains high levels of soluble dietary fibre, including mixed linked 1→3, 1→4β-D -glucans (β-glucan). An extract of β-glucan from waxy, hulless barley containing 56% total dietary fibre (TDF) was incorporated into flour tortillas, cornstarch pudding and apple granola bars to provide 2 g soluble fibre as β-glucan per serving. The foods were tested for objective functional properties. Flour tortillas with β-glucan were incorporated into rat diets and compared to diets containing an equivalent amount of cellulose, to test the fibre effect on growth and lipid metabolism parameters. Rats fed β-glucan tortillas had lower feed consumption and body weight (P<0·05) compared to those fed the cellulose tortillas, although feed/gain ratios were not different (P>0·05). Plasma LDL-cholesterol of rats fed β-glucan was lower (P<0·05) than cellulose-fed controls, although total cholesterol and triglycerides did not differ (P>0·05). Rats fed β-glucan tortillas had higher (P<0·05) faecal fat excretion, suggesting impairment of intestinal fat absorption. Liver composition data showed lower (P<0·05) levels of total lipid and cholesterol in β-glucan-fed rats. The results suggest that the barley β-glucan concentrate has potential as a food ingredient to provide supplemental soluble fibre which may be beneficial in reducing plasma LDL-cholesterol in humans. © 1998 SCI.     

Response of insulin, glucagon, and growth hormone to intravenous glucose challenge in cows fed high fat diets

Effect of feeding high fat diets on peripheral plasma concentrations of immunoreactive insulin, glucagon, and growth hormone following intravenous glucose challenge (100 mg D-glucose/kg body weight) at 50 and 100 d of lactation in 16 multiparous Holstein cows was evaluated. The high fat diet contained 18.5% whole cottonseed on a dry matter basis as the source of extra dietary fat. Feeding the high fat diet had no apparent effect on energy balance. Basal plasma insulin and insulin:glucagon ratio were increased in cows fed the high fat diet relative to those of controls. Glucagon, insulin, and insulin:glucagon ratio response to glucose challenge were not affected by diet. Response of growth hormone to glucose challenge at 50 d of lactation was depressed in cows fed the high fat diet. Plasma glucose peaked at greater concentrations in cows fed the high fat diet. Feeding a high fat diet to dairy cows appears to increase basal insulin concentration and insulin:glucagon ratio, which has actions opposed to glucose synthesis. Thus, endocrine effects of a high fat diet appear to favor decreased milk production.     

Effect of high-fat diets supplemented with okara soybean by-product on lipid profiles of plasma,liver and faeces in Syrian hamsters

The main components of okara, a by-product from soybean, are dietary fibre and protein. In this study we fed okara based diets with different amounts of fibre, protein and isoflavones to determine their effect on the lipid profile in the plasma, liver and faeces of an animal model. Male golden Syrian hamsters were fed high-fat diets supplemented with okara for 3 weeks. The supplemented diets contained 13% or 20% of okara fibre (OK-13 and OK-20), low-protein okara with 13% of fibre (OK1-13), and isoflavone-free okara with 13% of fibre (OK2-13). Okara supplemented diets did not produce significant differences in the feed intake or body weight gain (p > 0.05). The plasma levels of triglycerides, VLDL- plus LDL cholesterol and total cholesterol in hamsters fed OK-20 decreased significantly (p < 0.05) with respect to the 20% control group (C-20). However, no significant differences (p > 0.05) were found in LDL- and HDL-cholesterol plasma levels in all experiments. Total lipids, triglycerides, total and esterified cholesterol concentrations in liver were reduced by OK-20 diet. Regarding the hamsters fed OK-13 diets, the mean values of the total lipid, triglyceride and cholesterol in the plasma and liver decreased as compared to the control (C-13), but the differences were not statistically significant. All of the okara diets assayed increased the faecal excretion of total lipids, triglycerides, free cholesterol and total nitrogen (p < 0.05) compared to their respective controls. Our results suggest that the main components of okara, dietary fibre and protein, could be related with the total lipids and cholesterol decrease in the plasma and liver, as well as with the faecal output increase in high-fat fed hamsters. Okara might play an interesting role in the prevention of hyperlipidemia and could be used as a natural ingredient or supplement for functional food preparation.