Valdemiro Carlos Sgarbieri

Physical, Chemical, and Nutritional Properties of Common Bean (Phaseolus) Proteins

Publisher Summary This chapter discusses that the family Leguminosae includes approximately 600 genera, with about 13,000 species. In legume seeds, the cotyledons form the bulk of the seed and synthesize most of the proteins. Research on identification and quantification of the storage proteins in beans (Phaseolus) goes back several decades. These investigators referred to three proteins in Phaseolus (phaseolin, phaselin, and conphaseolin). The chapter discusses that bean proteins were first studied by Osborne. He found that the extractable proteins were mostly globulins, a fact which was later confirmed and emphasized by other investigators, who found three globulins in Phaseolus seeds. The biological value of bean proteins in general is low as compared to most other food proteins. According to Boyd, hemagglutinating activity was first described by Stillmark in 1888 in extracts of castor bean (Ricinus communis) and the first plant lectin found to be blood group specific was from lima bean (Phaseolus lunatus). Proteins that inhibit a-amylases from animals and insects have been reported in a variety of plants. Common beans (Phaseolus vulgaris) are normally harvested with about 20% moisture in the seeds and dried to about 10% water content before storage or consumption. The chapter discusses that common beans contain from 18% to 35% protein, however, their biological value is much lower than expected on a protein and amino acid composition basis.

Propriedades fisiológicas-funcionais das proteínas do soro de leite

A B S T R A C T This article emphasizes the multifunctional properties of the bovine milk whey proteins, starting with the colostrum where these proteins occur in high concentrations and are reputed as responsible for the protection and passive immunization of the newborn babies. The same proteins found in colostrum in high concentrations are found in milk although at much lower concentrations. The utilization of the milk whey proteins in the form

Guar gum effects on food intake, blood serum lipids and glucose levels of Wistar rats

The effects of guar gum derived from the endosperm of Cyamopsis tetragonoloba (75% soluble fiber, 7.6% insoluble fiber, 2.16% crude protein, 0.78% total lipids, 0.54% ash and 9.55% moisture) on food intake, levels of blood serum cholesterol, triacylglycerols, glucose and LDL and HDL-cholesterol were studied. The effects of guar gum on indices of protein absorption and utilization were also investigated. Diets containing 0%, 10% and 20% (w/w) guar gum or 10% and 20% cellulose powder (reference) were fed to normal rats for 60 days. The rats fed the guar gum diets showed significantly (p ≤ 0.05) lower levels of blood serum cholesterol, triacylglycerols, reduced food intake and body weight gain. Furthermore, a concomitant increase in HDL-cholesterol with a substantial elevation of the HDL/LDL cholesterol ratio were noted. Guar gum decreased blood serum glucose only during the first month of the experiment, and no changes in the indices of protein absorption and utilization were found. The guar gum caused a 10% increase in the small intestine length and a 25% retardation in the intestinal transit. The results of this research suggested that guar gum could potentially be effective in the treatment of hypercholesterolemia and obesity in humans.

Efficacy of a Whey Protein Concentrate on the Inhibition of Stomach Ulcerative Lesions Caused by Ethanol Ingestion

The purpose of this research was to test the ability of a whey protein concentrate (WPC) to inhibit gastric mucosal ulcerative lesions caused by oral administration to rats of absolute ethanol. Acute administration (single doses) of WPC resulted in 41% inhibition of the ulcerative lesion index (ULI), and 73% inhibition was obtained with repetitive doses. In a 10-days subchronic treatment study, the inhibition was 64%, all relative to a saline treatment (negative control). Alkylation of sulfhydryl compounds by subcutaneous injection of N-ethylmaleimide essentially eliminated the WPC protection. Treating the rats with an intraperitoneal injection of butathionine sulfoximine, which inhibits glutathione synthesis, reduced WPC protection to 35% and 52% for single and double doses, respectively. Taken as a whole, the results indicate that WPC does protect gastric mucosa from ethanol damage and that the protection depends on sulfhydryl compounds present in the WPC, including its capacity to stimulate glutathione synthesis.

Nutritional and toxicological evaluation of yeast (Saccharomyces cerevisiae) biomass and a yeast protein concentrate

Brewers yeast was prepared by alkaline treatment for debittering, cell wall rupture and dehydration by spray drying. Yeast protein concentrate was prepared by centrifugation of the ruptured cell suspension, treatment of the supernatant with sodium perchlorate, precipitation of the protein at isoelectric pH (4.2) and neutralisation of the isoelectric protein to pH 6.5 with sodium hydroxide, prior to lyophylisation. Chemical characterisation was performed on the biomass and protein concentrate. Amino acid scores were 98.1 and 87.2% for the whole biomass and protein concentrate respectively, based on available lysine and compared with the FAO/WHO/UNU reference standard. The growth-promoting property of the yeast biomass protein was roughly 85% of casein and was significantly better than for the yeast protein concentrate. No difference in growth was found between 15 and 30% dietary protein for all three sources, ie casein, whole yeast biomass and yeast protein concentrate. When tested for subchronical toxicity at 15 and 30% protein concentration, no evidence of toxicity was found for the whole yeast biomass, compared with casein, after 45 and 90 days of feeding. Retarded growth and discrete liver steatosis were observed in rats fed the yeast protein concentrate at both dietary levels. © 2000 Society of Chemical Industry

Composição centesimal e valor protéico de levedura residual da fermentação etanólica e de seus derivados

Este trabalho teve por objetivo promover a autolise e o fracionamento da levedura (Saccharomyces sp.) para producao de autolisado e extrato, bem como para producao de concentrado proteico fosforilado, a partir da levedura residual das destilarias de alcool etilico. Foram estudados a composicao centesimal, o perfil de aminoacidos essenciais e o valor proteico dos tres derivados comparativamente a levedura integra nao processada. Proteina e carboidrato (fibra alimentar) foram os principais componentes da levedura integra e do autolisado. No extrato e no concentrado proteico predominaram proteina e minerais (cinzas). O autolisado e a levedura integra apresentaram os melhores indices de aminoacidos essenciais, seguidos pelo concentrado proteico e pelo extrato. A digestibilidade da proteina variou de 68% para a levedura integra a 91% para o extrato. Os indices de quociente de utilizacao liquida da proteina variaram de 2,1 para a levedura integra a 4,3 para a caseina (referencia). Nao houve diferenca estatistica no quociente de utilizacao liquida da proteina entre o autolisado (4,1), o extrato (3,9) e o concentrado proteico (4,2). O concentrado proteico promoveu o maior crescimento no periodo (21 dias), seguido do extrato e o autolisado. As celulas integras apresentaram a menor capacidade para promover crescimento em rato.

Anti-Ulcerogenic Effect of a Whey Protein Isolate and Collagen Hydrolysates Against Ethanol Ulcerative Lesions on Oral Administration to Rats

The effect of the administration of a whey protein isolate (WPI) and collagen hydrolysates on ethanol-induced ulcerative lesions was studied in rats. WPI and bovine or porcine collagen hydrolysate (BCH and PCH, respectively) were given to rats by gavage. In acute experiments, (single-dose) physiological saline (10 mL/kg of body weight) was used as the negative control, and carbenoxolone (200 mg/kg of body weight) was used as a positive control. Ethanol (1 mL per 250-g rat) was also given by gavage. These treatments reduced the ulcerative lesion index (ULI) in a range of 40-77%, depending on the dosage. Some mixtures of WPI with either PCH or BCH provided results that suggested synergisms between WPI and the collagen hydrolysates. For example, WPI/BCH (in the proportion of 375:375 mg/kg of body weight) decreased ULI by 64%. The mechanism for mucosal protection involved a decrease in plasma gastrin (approximately 40%), a significant increase (50-267%) in mucus production, and a reduction in ULI (percentage) when intragastric administrations were performed after in vivo alkylation by N-ethylmaleimide. Results suggest that gastrin, sulfhydryl substances, and some mechanisms related to mucus production are all involved in gastric ulcer protection against ethanol. The collagen hydrolysates (both PCH and BCH) presented a stronger effect on mucus production; on the other hand, the effect of WPI was also dependent on sulfhydryl compounds, resulting in a more protective effect when the two proteins were administered together.

Determinação do valor protéico de células íntegras, autolisado total e extrato de levedura (Saccharomyces sp.)

Clean and debittered yeast cells biomass and its derivatives, total autolisate and extract, after dehydration (spray dryer), were used in a bioassay with wistar rats for determination of protein nutritive value and evaluation of the impact of the yeast products on the blood serum levels of uric acid, triacylglycerols, total cholesterol and High Density Lipoproteins-cholesterol. Integral cells, total autolisate and yeast extract did not differ statistically (p £ 0.05) regarding Protein Efficiency Ratio and Net Protein Ratio, which were significantly lower than the casein value. The growth promoting capacity was higher for casein, followed by integral cells, yeast extract and total autolisate, in decreasing order of magnitude. Net protein utilization values confirmed the Protein Efficiency Ratio and Net Protein Ratio results. Yeast products protein nutritive value was statistically identical but inferior to casein value. On the whole, the nutritive value of the yeast products protein ranked between 80-85% of the casein value. Uric acid serum concentration increased in the rats fed the diets containing yeast products, but the values remained in the range considered of normality for rats. The diet containing yeast autolisate produced a reduction of the triacylglycerols content, which was not observed in the other diets. For total cholesterol and High Density Lipoproteins-cholesterol all three yeast diets were similar and did not differ from the casein diet.

In vitro impact of a whey protein isolate (WPI) and collagen hydrolysates (CHs) on B16F10 melanoma cells proliferation

BACKGROUND Porcine skin gelatine presented anti-tumoral effect on murine hepatoma cells (MH134), inducing programmed cell death (apoptosis). Whey proteins (mainly lactoferrin) have been investigated for cancer prevention and treatment. OBJECTIVE Investigation of the inhibitory capacity on melanoma cells (B16F10) proliferation and the influence on % distribution of cell cycle phases, in the presence of various concentrations of whey protein isolate (WPI), bovine collagen hydrolysate (BCH) or its fractions. METHODS The permeate fraction BCH-P1 (molecular mass, MM 2.5kDa) was further fractionated into five retentate fractions (R1-R5) by ultrafiltration membranes and into four fractions (F1-F4) by reverse phase chromatography. The permeate BCH-P1 and all its fractions were comparatively tested against a negative control (B16F10 cells+culture medium), and also against a positive control (B16F10+culture medium+WPI). RESULTS The inhibitory concentrations for 50% of B16F10 cells (IC(50)) ranged from 0.19 to 156.9 mg/mL for all these proteins evaluated. The most inhibitory fractions of the BCH hydrolysate were BCH-P1 and F1-F4 with IC(50) concentrations below 1mg/mL. Changes in cell cycle phases were characterized by a general decrease in the G2/M phase that emphasizes growth arrest, some increase in phase S (BCH-P1 and F4) but a strong increase in G0/G1 phase for BCH-P1 and F4. Caspase-3 expression increased significantly in all media containing F and R fractions, and also in the presence of BCH or WPI. Apoptosis was extremely high at low concentration (400 microg/mL) of the F1-F3 fractions. CONCLUSION It is suggested that a mechanism for tumorigenesis inhibition may involve the caspases cascade and apoptosis.

Impact of different dietary protein on rat growth, blood serum lipids and protein and liver cholesterol

The purpose of this research was to comparatively investigate the effect of whey protein concentrate (WPC), soy protein isolate (SPI) and casein on the growth and lipid concentration on rat liver and blood serum in a 45 days feeding experiment. Hypercholesterolemic diets containing 6% coconut fat plus 1% cholesterol and 20% protein from whey protein concentrate (WPC), soy protein isolate (SPI) and commercial casein (CC) were prepared. The remaining of the diets composition was identical with AIN (AIN-93G) recommendation. After 45 days of feeding CC and SPI diets promoted higher intake and better growth than the WPC diet. Blood serum and liver cholesterol was significantly higher (p < 0.05) for rats on the casein diet than for the rats on SPI and WPC diets. SPI diet was relatively more hypocholesterolemic than WPC diet. None of the dietary protein was able to maintain blood serum triacylglycerols at or near reference levels, with an increase of nearly two fold for all three dietary treatments. Blood serum total protein increased nearly two and a half fold, and no statistical differences were found among treatments.