Soybean seeds and its by-product okara as sources of dietary fibre. Measurement by AOAC and Englyst methods

The composition of soybean seeds and its by-product okara has been studied in this work. Dietary fibre was analysed by Englyst et al. method, by enzymatic–gravimetric methods of AOAC and by the quantification of the monomers obtained from the AOAC residues after acid hydrolysis (AOAC plus hydrolysis). Total dietary fibre by the enzymatic–gravimetric methods of AOAC in okara (55.48 g/100 g dry matter) is more than twice that of soybean seeds (24.37 g/100 g dry matter). The proportion IF/SF is 11 in okara and 6 in soybean seeds. Dietary fibre results from enzymatic–gravimetric AOAC methods are higher in okara and soybean seed samples than those from the Englyst method (okara: 41.14 g/100 g dry matter; soybean seeds: 15.05 g/100 g dry matter), and AOAC plus hydrolysis (okara: 44.91 g/100 g dry matter; soybean seeds: 16.38 g/100 g dry matter). In the case of the insoluble fibre from both samples, AOAC plus hydrolysis gives significantly (p < 0.001) higher values than the Englyst method, whilst for soluble fibre the opposite occurs (p < 0.001). The main monomers in soybean seeds and okara fibre are glucose, galactose, uronic acids, arabinose and xylose. The proportion of each monomer is similar in soybean seeds and okara, so the healthy properties of soybean seeds fibre are also claimed for okara.     

Cholesterol-lowering effect of phytosterol-containing lactic-fermented milk powder in hamsters

Male hamsters were fed six different diets for 4 weeks. Group 1, fed with control diet of regular rodent chow. Group 2, fed with high-fat-high-cholesterol diet containing cholesterol and corn/coconut oil mixture. Group 3, the positive control fed with high-fat-high-cholesterol diet containing 0.74% (w/w) phytosterols. Groups 4–6 were the high-fat-high-cholesterol diet mixed with phytosterol-containing lactic-fermented milk powder (PSFMP) which contains 0.37%, 0.74% and 1.85% (w/w) of phytosterols, respectively. Results demonstrated that PSFMP could significantly decrease (P < 0.05–P < 0.001) the levels of total cholesterol (serum cholesterol), serum triacylglycerol, liver lipids and atherogenic index (LDL-C/HDL-C), while it could also significantly (P < 0.001) increase the level of fecal cholesterol. The pronounced hypolipidemic effects of PSFMP might be attributed to its ability to enhance cholesterol excretion. These results suggest that PSFMP could be used as a potential cholesterol-lowering ingredient in the management of hypercholesterolemia.     

Effects of diet enriched with restructured meats,containing Himanthalia elongata, on hypercholesterolaemic induction,CYP7A1 expression and antioxidant enzyme activity and expression in growing rats

Meat and pork consumptions are very high in Spain. Seaweeds are rich in fibre, minerals, and bioactive substances. Due to the growing demand for healthier meats, this work studied the effect of diets containing restructured pork (RP) enriched with Himanthalia elongata (Sea Spaghetti) on: (1) cholesterolaemia; (2) liver cytochrome P450 7A1 (CYP7A1) expression; (3) liver antioxidant enzyme activities and gene expression; (4) the liver antioxidant substrate concentrations. Four groups of 10 Wistar rats each were fed a mix of 85% AIN-93 M rodent diet and 15% freeze-dried RM for 35 days. The control group (C) consumed control RP; the Sea Spaghetti (SS) group, RP with 5% Sea Spaghetti. Animals on added cholesterol diets (CholC and CholSS) consumed their basal C and SS diets enriched with cholesterol and cholic acid as hypercholesterolaemic agent. Food intake was significantly affected by the alga × cholesterol interaction and by dietary cholesterol (both p < 0.001). Plasma cholesterol was significantly affected by the cholesterol × alga interaction (p < 0.05). CholC rats showed significantly higher plasma cholesterol (p < 0.001) than did their C counterparts, whilst serum cholesterol of CholSS was significantly lower (p < 0.05) than that of CholC. The glutathione peroxide (GSSG) concentrations and all mRNA expressions were significantly affected by the cholesterol × alga interaction (at least p < 0.05). SS vs C group showed significant (at least p < 0.05) increases in superoxide dismutase (Mn-SOD and Cu,Zn-SOD), glutathione peroxidase (GPx) and decrease of glutathione reductase (GR) expressions, and increased GR activity, GSSG and the redox index. CholSS vs CholC showed significant (at least p < 0.05) increases of CYP7A1, GR and Cu,Zn-SOD expression but decreases in catalase, Mn-SOD and GPx expression, and increase of GR activity. In conclusion, Sea Spaghetti could be widely used in RP design. Its addition to non-cholesterol enriched RP diet reduced oxidation mechanisms. SS-RP partially blocked the effect of the hypercholesterolaemic agent, giving rise to a new balance of the antioxidant enzyme expression.     

Taurine alleviates dyslipidemia and liver damage induced by a high-fat/cholesterol-dietary habit

Eight male hamsters per group were assigned randomly to one of the following diets: chow diet (Control); high-fat/cholesterol diet (HFCD); HFCD supplemented with 1% Tau (HFCD/1% Tau); HFCD supplemented with 2% Tau (HFCD/2% Tau). Tau supplementation improved (P < 0.05) serum lipids and cholesterol profile in the high-fat/cholesterol-dietary hamsters. Although hepatic cholesterol/triacylglycerol in the high-fat/cholesterol-dietary hamsters were not (P > 0.05) changed by Tau supplementation, faecal cholesterol and bile acid outputs were increased (P < 0.05). Two percent Tau supplementation unregulated (P < 0.05) HMG-CoA reductase and cholesterol 7-α hydroxylase (CYP7A1) expressions in the high-fat/cholesterol-dietary hamsters. Besides, Tau supplementation also increased (P < 0.05) LDL receptor mRNA expressions in high-fat/cholesterol-dietary hamsters. Tau supplementation also reduced serum GPT and GOT values and C-reactive protein (CRP) levels in the high-fat/cholesterol-dietary hamsters. Results clearly indicated that Tau could alleviate blood lipids and hepatic damage induced by a high-fat/cholesterol-dietary diet.     

Amaranth protein presents cholesterol-lowering effect

This study describes amaranth’s protein cholesterol-lowering effect and investigates its mechanisms hypercholesterolaemia was induced in male hamsters through diet rich in casein (300 g/kg diet) containing regular levels of cholesterol (0.5 kg/g) fed during 3 weeks. Animals were divided into three groups and fed ad libitum diets for 4 weeks containing as the sole source of protein: casein (control), amaranth protein isolate or, casein + amaranth protein isolate. Plasma concentrations of cholesterol and triacylglycerols were measured at four different points: at the beginning of the study, after hypercholesterolaemia was induced, in the first week and then at the end of the experimental diet period. The reduction of the total plasma cholesterol concentration at the end of experimental period for animals fed on diets containing amaranth protein isolate pure and with casein were 27% (P < 0.05) and 48% (P < 0.05), respectively, being the non-HDL fractions the most affected. Digestibility of protein as well as excretion of cholesterol and bile acid, were investigated as the possible mechanisms for this significant hypocholesterolaemic effect. Cholesterol excretion was related to the hypocholesterolaemia but could not explain all the observed reduction. Our findings suggest that amaranth protein has a metabolic effect on endogenous cholesterol metabolism.     

Pea pod, broad bean pod and okara, potential sources of functional compounds

Disposal of by-products generated by plant food processing represent an important problem in the industry, but these by-products are also promising sources of compounds which may be used for their technological or nutritional properties, and today they are considered as a possible source of functional compounds. This work has contributed to the knowledge of three legume by-products, pea pod (Pisum sativum L.), broad bean pod (Vicia faba L.) and okara from soybean (Glycine max L.). These three by-products have in common that their major fraction is dietary fibre (pea pod: 58.6 g/100 g; okara: 54.3 g/100 g; broad bean pod: 40.1 g/100 g). Sucrose, glucose and fructose are the most important soluble sugars in both pods; however α-galactosides (stachyose and raffinose) are in greater concentration in okara. Protein is also a considerable component, although in higher amount in okara than in pods. Okara presents a large quantity of fat however both pods show similar low contents. Linoleic acid is the most important fatty acid; oleic acid is remarkable in okara and pea pod and linolenic acid in broad bean pod. Mineral amount is major in by-product pods than in okara, and the most important minerals are potassium, calcium and iron.     

Cardiovascular protection of deep-seawater drinking water in high-fat/cholesterol fed hamsters

Cardiovascular protection of deep-seawater (DSW) drinking water was assessed using high-fat/cholesterol-fed hamsters in this study. All hamsters were fed a high-fat/cholesterol diet (12% fat/0.2% cholesterol), and drinking solutions were normal distiled water (NDW, hardness: 2.48 ppm), DSW300 (hardness: 324.5 ppm), DSW900 (hardness: 858.5 ppm), and DSW1500 (hardness: 1569.0 ppm), respectively. After a 6-week feeding period, body weight, heart rates, and blood pressures of hamsters were not influenced by DSW drinking waters. Serum total cholesterol (TC), triacylglycerol (TAG), atherogenic index, and malondialdehyde (MDA) levels were decreased (p < 0.05) in the DSW-drinking-water groups, as compared to those in the NDW group. Additionally, increased (p < 0.05) serum Trolox equivalent antioxidant capacity (TEAC), and faecal TC, TAG, and bile acid outputs were measured in the DSW-drinking-water groups. Hepatic low-density-lipoprotein receptor (LDL receptor) and cholesterol-7α-hydroxylase (CYP7A1) gene expressions were upregulated (p < 0.05) by DSW drinking waters. These results demonstrate that DSW drinking water benefits the attenuation of high-fat/cholesterol-diet-induced cardiovascular disorders in hamsters.     

Effects of casein,sweet white lupin and sweet yellow lupin diet on cholesterol metabolism in rats

The effect of lupin seed protein on rat cholesterol metabolism has been studied with diets high in fat (20% by weight) and containing cholesterol (1%). The proteins used were characterised by their lysine/arginine ratios (sweet white lupin (SWL) 0·5; sweet yellow lupin (SYL) 0·4; and casein 1·8), because the lysine/arginine ratio is one of the parameters suspected to decrease or increase plasma cholesterol depending on the ratio; the diets were also characterised by their total fibre content (casein diet 5%; SWL 22%; SYL 17%) because chronic fibre intake could improve glucose tolerance and modify glucoregulatory hormone levels. Methionine content of diets was balanced. Differences among the total serum cholesterol levels of rat groups fed these diets for 28 days were not significant. But, compared to the casein diet, both lupin diets increased plasma glucagon levels and faeces. Compared to casein and SYL diets, the SWL diet significantly decreased plasma triglyceride levels and the insulin/glucagon ratio, as well as unesterified liver cholesterol and plasma LDL triglycerides levels. The SYL diet significantly increased plasma glucose and insulin, as well as liver total cholesterol compared to the casein and SWL diets. The total fibre content of the diets could indirectly modulate the effect related to the insulin/glucagon ratio on cholesterol metabolism and explain the differences observed between the SWL and SYL diets. © 1998 SCI.     

Hypolipidemic study of xylanase-modified corn bran fibre in rats

In order to understand the regulatory effect of xylanase-modified corn bran fibre (XMF) on lipid homeostasis, detailed influences, following the ingestion of XMF and its original form (corn bran dietary fibre, CDF), on serum, liver and faecal lipids were studied in Sprague–Dawley rats. In both CDF and XMF groups, serum total cholesterol (TC), triacylglycerol (TG) and low-density lipoprotein cholesterol (LDL-C) were significantly lowered after 4 weeks (p < 0.05). By the end of week 6, data in the XMF group showed that serum LDL-C was lowered further and high-density lipoprotein cholesterol (HDL-C) was significantly increased (p < 0.05); liver TC, TG and fat were significantly lower (p < 0.05), while the excretions of faecal fat, TC and bile acids were significantly higher (p < 0.05). The decrease of liver and serum lipids in the XMF group was consistent with the improved excretion of faecal lipids and bile acids. Other related mechanisms are also considered.     

Cholesterol‐Lowering Properties of Whole Cowpea Seed and Its Protein Isolate in Hamsters

ABSTRACT: Hypercholesterolemic hamsters were fed for 4 wk on diets rich in saturated fatty acids and cholesterol, differing only in protein source (20 %): casein (control group, HC), whole cowpea seed (HWS), and cowpea protein isolate (HPI). Hamsters fed on HWS and HPI presented significant reductions in plasma total cholesterol and non‐HDL cholesterol. HPI and HC presented similar protein digestibility, which were significantly higher than that of HWS. Animals fed on HWS presented significantly higher levels of bile acids and cholesterol in feces than did the animals fed on casein or HPI diets. Histological analyses of the liver showed that HC diet resulted in steatosis widely distributed throughout the hepatic lobule, while HWS and HPI diets promoted reductions in liver steatosis. The effectiveness of HWS for modulating lipid metabolism was greater than that of HPI, as measured by plasma cholesterol reduction and liver steatosis.     

Sorghum distillers dried grain lipid extract increases cholesterol excretion and decreases plasma and liver cholesterol concentration in hamsters

Grain sorghum is a rich source of phytochemicals. In this study, male hamsters were fed AIN-93M diets supplemented with a hexane-extractable lipid fraction from sorghum distillers dried grains with solubles (DDGS). Diets contained 0.0%, 0.5%, 1.0%, and 5.0% (w/w) DDGS lipid extract. After 4 wk, the 5.0% DDGS lipids group had significantly lower plasma non-HDL cholesterol and liver esterified cholesterol concentration. Faecal neutral sterol (i.e., cholesterol) excretion was significantly higher in the 5.0% DDGS lipids group compared to the other treatments (66% higher compared to controls). Bile acid excretion was not affected by DDGS lipid intake. Faecal cholesterol excretion was negatively correlated with liver cholesterol concentration (r = ?0.97, P = 0.026), and liver cholesterol concentration was directly correlated with plasma total cholesterol concentration (r = 0.96, P = 0.041). Thus, lipid extract of sorghum DDGS exhibited cholesterol-lowering properties due, at least in part, to increased cholesterol excretion from the body and could provide health benefits when incorporated into human diets.     

Prepartum nutrition alters fatty acid composition in plasma, adipose tissue, and liver lipids of periparturient dairy cows

The fatty acyl profile of phospholipids (PL) determines the fluidity of cell membranes and affects cell function. The degree to which long-chain fatty acid (LCFA) composition of PL and triacylglycerols (TG) in liver and total lipids in adipose tissue can be altered by prepartum nutrition in peripartal dairy cows is unclear. Multiparous Holsteins (n = 25) were assigned to 1 of 4 prepartal diets: 1) CA, the control diet fed to meet 120% of energy requirements; 2) CR, a control diet fed to meet 80% of requirements; 3) S, a diet supplemented with mostly saturated free fatty acids (47% 16:0, 36% 18:0, 14% cis-18:1) and fed to meet 120% of requirements; or 4) U, a diet similar to S except that cows were abomasally infused with soybean oil so that the diet plus infused fat would meet 120% of requirements. Diets were fed for 40 d prepartum; all cows received a lactation diet postpartum. Groups CR and U had lower prepartum intakes of dry matter and net energy, but glucose concentrations in plasma were similar among treatments. Cows fed S, U, or CR had greater nonesterified fatty acids in plasma prepartum, but cows fed U had decreased β-hydroxybutyrate postpartum. Postpartal concentrations of total lipids and glycogen in liver tissue were similar among treatments. Cows in group U had a greater percentage of 18:2 but less 16:0, 18:0, and 20:4 in plasma total lipids than cows fed S. Treatment U increased 18:2 and 18:3 and decreased 18:1 in subcutaneous adipose tissue at 1 d postpartum. Across diets, percentages of 16:0 and trans-18:1 were increased, and 18:0, 20:3, and 20:5 were decreased, in hepatic PL at d 1 postpartum. Significant treatment × time interactions indicated that treatment U increased 18:2 in hepatic PL at the expense of 18:1, 20:3, 20:4, 22:6, and 24:0 on d 1 postpartum, but changes were normalized by d 65 postpartum. The unsaturation index of hepatic PL was lower at d 1 than at d −45 or 65, which implies that hepatic membrane fluidity decreased around parturition. The unsaturation index at d 1 was greater for cows fed S than those fed CA or U. Percentages of 16:0, 18:1, and 22:0 were increased, and 18:0, 20:3, 20:4, 20:5, 24:0, and 26:0 were decreased, in hepatic TG at d 1. Prepartal feed restriction modestly affected tissue LCFA profiles. The LCFA profile of adipose tissue, liver PL, and liver TG can be altered by dietary LCFA supply prepartum; changes in liver are normalized by 65 d postpartum.     

Sequential extraction of polysaccharides from enzymatically hydrolyzed okara byproduct: Physicochemical properties and in vitro fermentability

Okara, a byproduct of soymilk production, has been upgraded through the use of an enzymatic treatment with Ultraflo L® to give a product (okara^ET) which has a higher content of soluble dietary fibre and an enhanced ratio of soluble: insoluble fibre than is found in okara without treatment. Polysaccharides were isolated from okara^ET by sequential extraction to yield soluble fractions in water (22%), CDTA (8.7%), alkali (37.7%) without and NaClO₂ (9.1%) and the cellulosic residue represents a (22.5%). The physicochemical properties of okara^ET were improved due to the enzymatic treatment: oil retention capacity (6.94 g/g), water retention capacity (10.76 g/g) and swelling capacity (13.85 g/g) were higher than in okara that had not undergone enzymatic treatment. The gelation capacity (8%) and the cation exchange capacity (8.96 mEq/kg) of okara^ET were lower than that of other byproducts. Short chain fatty acid production during in vitro fermentation of okara^ET by a pure culture of Bifidobacterium bifidus was mainly represented by acetic acid, followed by propionic and butyric acids. In addition, the decreases in pH and substrate consumption demonstrated the bifidogenic capacity of okara^ET.     

Effects of dietary broccoli fibre and corn oil on serum lipids, faecal bile acid excretion and hepatic gene expression in rats

To determine the effects of broccoli fibre and corn oil on lipid metabolism, male Sprague-Dawley rats were fed diets containing high (30%) or low (5%) corn oil, in combination with either 7.5% broccoli fibre or cellulose, for 4 months. High corn oil groups had significantly lower serum cholesterol and triglycerides than had low corn oil groups (p < 0.001). Broccoli fibre also lowered serum cholesterol and triglyceride levels compared to cellulose fibre. Faecal bile acid concentrations were higher in high corn oil-fed rats than in low corn oil-fed rats, with broccoli fibre inclusion in high corn oil diets resulting in higher faecal bile acid concentrations. Regardless of corn oil level, broccoli fibre supplementation in the diet resulted in an increase (p = 0.018) in hepatic cytochrome P450, family 7A1 (CYP7A1) expression. High corn oil feeding resulted in reduced expression of fatty acid synthase (FAS) and increased expression of carnitine palmitoyl transferase 1a (CPT1a) and 3-hydroxy-3-methyl-coenzyme A reductase (HMGCR) (p < 0.05). Our findings suggest that high dietary corn oil and broccoli fibre have beneficial effects on lipid metabolism. Corn oil lipid-lowering effects may be due to alteration of hepatic expression of genes involved in lipid synthesis and increased rate of cholesterol catabolism to bile acids. Broccoli fibre may also act via its physical properties to reduce enterohepatic bile acid recycling and intestinal lipid absorption, and increase luminal binding of bile acids, resulting in increased faecal bile acid excretion.     

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.     

Effects of different levels of trans fatty acids and oxidised lipids in diet on cholesterol and cholesterol oxidation products formation in rabbit

The objective was to assess the effects of trans fatty acids and oxidised lipids, present in dietary fat by-products used in feeds, on cholesterol and oxycholesterols in meat, liver and plasma of rabbits. A palm fatty acid distillate, before and after hydrogenation (trans fatty acid trial), and a sunflower–olive oil blend (70/30, v/v), before and after use in a commercial frying process (oxidised lipid trial), were used in experimental feeds (at 3%, w/w). High trans fatty acid and oxidised lipid diets caused significantly higher cholesterol and oxycholesterol levels in all tissues of rabbit (0.01 < p ? 0.05). The content of oxycholesterols in rabbit meat, liver and plasma obtained from trans fatty acid experiments varied from 9 to 34 μg/100 g, 24 to 61 μg/100 g and 60 to 138 μg/dl, respectively, from low to high levels. In the oxidised lipid experiments, content of oxycholesterols varied from 16 to 52 μg/100 g, 14 to 108 μg/100 g and 52 to 269 μg/dl in meat, liver and plasma, respectively. As a consequence, meat products from rabbits fed a diet containing higher levels of trans fatty acids or oxidised lipids may result in higher intakes of cholesterol and oxycholesterols by humans.     

Plasma total,lipoprotein cholesterol,organs cholesterol and growth performance in rats fed dietary gum arabic

Thirty two male Wistar rats with initial body weight ranging from 45 to 55 g were randomly assigned to four dietary treatments. Rats were fed with ad libitum access diets containing 7.5% as cellulose or gum arabic with or without 1% added cholesterol for five weeks. Final body weight, body weight gain and feed efficiency ratio were comparable in all groups. Within cholesterol-fed groups, the cholesterol concentration of plasma was significantly lower in rats fed diet supplemented with gum arabic compared with those fed cellulose. Among cholesterol-fed groups, liver cholesterol was significantly higher in the group fed diet supplemented with gum arabic compared with those fed cellulose. In rats fed cholesterol-free diets, the cholesterol levels of plasma, LDL, HDL and liver were comparable.     

Effects of a black rice extract (Oryza sativa L. indica) on cholesterol levels and plasma lipid parameters in Wistar Kyoto rats

This study was designed to evaluate the efficacy of an anthocyanin pigmented rice (e.g. black rice) to mitigate the onset of hypercholesterolemia in rats-fed atherogenic diets. Male Wistar (n = 10/group) rats were fed with atherogenic diets containing 0.5% cholesterol in the presence and in the absence of bile salt (e.g. 0.05% cholic acid) along with a standardized black rice extract (BRE) (e.g. 3%, w/w). All animals were individually housed in stainless steel cages and fed with the experimental diets during a 12-h period for 10 weeks. Body weights of rats were measured every week of the experiment. After 10 weeks fed on experimental diets, rats were sacrificed and plasma total cholesterol, HDL and LDL cholesterol and triacylglycerols were measured immediately. The total cholesterol (TC) content in the liver, heart and aorta, and the concentration of triacylglycerol (TAG) were measured after lipid extraction using Folch method. Rats fed with 0.5% cholesterol containing diets which also included bile salt exhibited a considerably more severe hypercholesterolemia than counterparts fed diets containing only 0.5% cholesterol. The inclusion of the BRE in diets significantly (p < 0.05) decreased the level of TC, LDL–TC and TAG in plasma of rats-fed control diets that either contained or were absent in bile salt (p < 0.05). There were no differences in HDL-level. Liver crude lipids and total cholesterol levels were also significantly (p < 0.05) decreased in experimental groups relative to the control group in both experiments. Thus, supplementation of atherogenic experimental diets with BRE effectively decreased lipid levels in hypercholesterolemic rats. In lieu of the mixture of bioactive components present in BRE, it is possible that more than one mechanism underlying this reduction in lipids is involved.