Effect of faba beans coat with different phenolics content on the use of protein by rats

The aim of the study was to determine the content and biological activity of phenolic compounds of three faba bean genotypes - a coloured flowered Nadwiślański variety, a coloured flowered "self-ending" Tinos variety and white flowered Caspar variety. Comparing the white flowered Caspar variety containing 0.34% of phenolic compounds in the seed coat, in this proantho- cyanidins made from 0.04%, the Polish Nadwiślański and Tinos variety were characterised as having a higher phenolic compound content in the seed coat, i.e. 8.70% and 11.75%, respectively. The proanthocyanidins content, being 6.54% and 8.32% respectively, is in accordance with the lower values determined in the seed coats of many European high-tannin faba bean varieties. Seed coats containing a higher level of polyphenols, added to casein diets in amounts of 15%, highly significantly lowered the digestibility and protein efficiency. Depending on the variety of seed coat, TD protein coefficients amounted to: Caspar — 85.4%, Nadwiślański — 71.3%, Tinos — 69.3%. For these same diets the NPU index was 71.2, 59.3 and 49.4, and the PER index was 2.63, 2.23 and 2.16, respectively. It was also found highly significant decrease of Ca, Fe, and Zn apparent digestibilities in casein diets with faba bean seed coats of a high polyphenolic content.Celem pracy było określenie zawartości i aktywności biologicznej związków fenolowych trzech genotypów bobiku — kwitnącej kolorowo odmiany Nadwiślański, kolorowo kwitnącej odmiany "samokończącej" Tinos oraz biało kwitnącej odmiany Caspar. Okrywa nasienna porównywanych odmian zawierała ok. 5.5% białka ogółem, 0.15% tłuszczu surowego oraz od 73.1% do 80.6% włókna pokarmowego (tab. 2). Czynnikiem w największym stopniu różniącym okrywę nasienną porównywanych odmian bobiku była zawartość związków fenolowych, a głównie proantocyjanidyn (tab. 3). W porównaniu z odmianą Caspar, zawierającą w okrywie 0.04% proantocyjanidyn, odmiany Nadwiślański i Tinos wyróżniały się dużą, charakterystyczną dla odmian wysokotaninowych, zawartością proantocyjanidyn w okrywie nasiennej; odpowiednio 6.54% i 8.32% (tab. 3). Okrywy o większej zawartości proantocyjanidyn, dodawane do standardowych diet kazeinowych w ilości 15%, wysokoistotnie obniżały strawność i wykorzystanie białka diet (tab. 4). Współczynnik strawności rzeczywistej białka zmalał z 95.9% w grupie kontrolnej do 85.4% lub do 71.3% i 69.3%, jeżeli do diety kazeinowej wprowadzono 15% okrywy nasiennej bobiku o małej lub dużej zawartości proantocyjanidyn. Stwierdzono również wysokoistotne obniżenie współczynników strawności pozornej Ca, P, Mg i Zn z diet kazeinowych z udziałem okrywy nasiennej bobiku o większej zawartości polifenoli (tab. 5)

Physiological influence of chokeberry phenolics in model diet

Seven groups of Wistar rats (8 males in each) were fed for 4 weeks diets with chokeberry products. Chokeberry juice was added every day to diets at a dose of 1.5, 3 and 6 ml per rat (corresponding to the intake of about 0.5, 1 and 2 l of juice by an adult person) or diets were supplemented with polyphenolics extract to reach the same level of phenolics. The addition of juice or extract did not affect food intake and body gain. Chokeberry juice increased stomach pH from 3.44 (control group) to 3.69–3.85, and ileal pH from 6.16 to 6.23–6.46. Alkalisation of digesta was less distinct with diets containing polyphenolics extract. Both chokeberry products decreased the concentration of caecal ammonia, especially at medium and high doses. The highest dose of chokeberry juice increased microbial α-glucosidase, decreased β-glucosidase and had no effect on β-glucuronidase activities in the caecal digesta. To compare with the control group, the highest dose of chokeberry juice and extract numerically decreased triglycerides (from 265 to 211 and 219 mg dl−1, respectively) and significantly decreased total cholesterol level in the serum (from 133 to 118 and 114 mg dl−1, respectively) and increased content of butyrate in short-chain fatty acids sum of caecal digesta. Indices of the antioxidant status of rats were similar in all treatments. Physiological results of applying relatively low amount of phenolic extract in the diet were similar as when applying high doses of chokeberry juice