The aim of the study was to compare the polyphenolic composition of extracts from different plant sources. Extracts from two new plants rich in polyphenols, i.e. chokeberries and honeysuckle, were compared with the well-investigated green tea polyphenols. All extracts obtained were characterised by a high content of polyphenols: green tea – 611 mg/g, honeysuckle – 633 mg/g and chokeberries – 714 mg/g. Honeysuckle and chokeberries extracts consisted mainly of anthocyanins (321.2 and 404.5 mg/g, respectively), whereas green tea extract contained mainly flavan-3-ols (587.9 mg/ g).
The aim of the study was to characterise caecal indices in rats fed diets supplemented with high doses (0.4, 0.8 and 1.2%) of a grapefruit commercial phenolic extract. Addition of the preparation caused an increase of wet mass of ceacal digesta. Dry matter content decreased from 22% to 7.0% and pH increased from 7.11 to 8.0 in the control group and experimental groups, respectively. Increased pH was a consequence of the lower concentration of volatile fatty acids in rats fed the extract (77 μmol/g in control animals versus 8-13 μmol/g in extract treatments). However, glycolytic microbiological activity, measured indirectly through the measurement of its enzyme activity, decreased only in rats fed a diet containing the lowest level of the preparation.
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.
W pracy scharakteryzowano skład chemiczny, jakość białka oraz strawność składników pokarmowych dwóch odmian bobiku (Bronto i Dino), wyróżniających się plonem nasion i białka wśród nowych odmian w Polsce. Nasiona ocenianych odmian zawierały charakterystyczną dla bobiku ilość podstawowych składników (w tym 28.6% białka w suchej masie) oraz substancji przeciwżywieniowych (polifenoli - ok. 1.46%, tanin skondensowanych - 0.07%, inhibitorów trypsyny - ok. 20 TUI/mg oraz galaktozydów - 3.40%). Nie stwierdzono znaczących różnic w składzie chemicznym oraz jakości białka obu odmian. Wskaźnik aminokwasów egzogennych wynosił 65.4 (Dino) i 65.6 (Bronto), a wskaźnik PER (przy dodatku 0.25% Dl-metioniny) odpowiednio 1.37 i 1.38. Obie odmiany charakteryzowały się wysoką strawnością białka dla świń (81-82%) oraz wysoką i nieistotnie zróżnicowaną strawnością energii (Dino - 84%, Bronto – 80%).