Chokeberry polyphenols reduce prooxidative influence of oxidized fats in rat diets.

The aim of the study was to estimate nutritional and physiological consequences of combined supplementation of rat casein diets with a strongly oxidized mixture of fats and extract of polyphenols from chokeberry. The experiment was conducted on 80 young Wistar rats divided into 8 groups. The animals were fed diets supplemented with 8% of fresh or oxidized fats and 0.4, 0.8 and 1.2% of polyphenol extract together. Addition of the oxidized fats caused significant reduction in animal growth without a decrease in nitrogen digestibility. On the other hand, the extract of polyphenols suppressed nitrogen utilization; animal growth was however similar to the control group. Analysis of the variance showed negative influence of the oxidized fats on cholesterol and triacyloglycerol concentration in the blood of the experimental animals. Increased activity of both aminotransferases in the blood of rats fed diets containing the oxidized fats indicated on liver malfunction. There was no effect of the experimental factors on the antioxidant status of the blood, but a dose-dependent reduced content of malonylodialdehyde in the blood of rats fed diets supplemented with the extract of polyphenols suggested that the extract had a preventive effect against prooxidative activity of the oxidized fats.

Simple method of isolation and purification of alpha-galactosides from legumes.

A simple method for the isolation and purification of alpha-galactosides, raffinose family oligosaccharides (RFOs), from legumes has been developed. The method includes (i) imbibition of seeds, (ii) extraction with 50% ethanol, (iii) precipitation of RFOs, (iv) purification of RFOs on diatomaceous earth and charcoal, and (v) cation-exchange chromatography. The described method allows one to obtain high purity RFO preparations (90% for lentil and 80% for pea seeds, determined by HPLC-RI analysis) in the form of white, fine powder. Yields of alpha-galactosides isolated from 100 g of seeds of lentil and pea were 5.6 and 4.3 g, respectively.

Comparative study of the chemical composition and nutritional value of pumpkin seed cake, soybean meal and casein.

The chemical composition and nutritional value of pumpkin (Cucurbita pepo) seed cake (PSC) were studied and compared with those of casein and soybean meal. Crude protein and ether extract content in dry matter of PSC was 598.0 g/kg and 124.6 g/kg, respectively, and was higher than the percentage of these components (474.2 and 28.3 g/kg, respectively) in soybean meal used in this experiment. The main fatty acids in PSC cake were oleic acid (50.4%) and linoleic acid (29.9%). Protein found in PSC contained considerable quantities of tryptophan (1.54 g/16 g N); by contrast, the content of lysine (3.21 g/16 g N) and isoleucine (3.83 g/16 g N) was low. Small quantities of phenolic compounds (2.61 g/kg), low activity of trypsin inhibitors (1.33 TUI/mg) and small quantities of alpha-galactosides (19.9 g/kg) were found in PSC. Among antinutritive components only the content of inositol phosphates in PSC (40.5 mg/g) was higher than in soybean meal (10.8 mg/g). True digestibility coefficient (TD) of PSC protein was similar (83.1%), but protein efficiency ratio (PER) was lower (1.01) in comparison with soybean meal (83.5% and 1.50, respectively). After supplementation with lysine, TD (85.9%) and PER (1.43) in PSC were comparable with TD and PER to soybean meal. The PSC-soybean meal mix diet (protein ratio 1:1) had a higher PER value than the diet with soybean meal only (1.98 vs. 1.50).