Evaluation of Some Bioactive Nutraceutical Compounds in Agro-Industrial Waste Used as Animal Feed Additive

Abstract

Some parts of agro-wastes (pomace meal) are used for animal food containing variability in composition (proteins, dietary fibres, carbohydrates, polyphenols, minerals). This paper aims at evaluating some nutraceutical bioactive compounds from pomace meal for use as animal feed additives. Studied meals are pomace obtained from solid remains of grapes and sea buckthorn after juice pressing, as well as flaxseed and rapeseed after oil pressing. HPLC methods were used to determine some carbohydrates (glucose, fructose, sucrose, maltose), organic acids (oxalic, citric, tartaric, malic), flavonoids (catechin, epicatechin, rutin, quercetin, luteolin) and phenolic acids (gallic, vanillic, caffeic, p-coumaric, ferulic). The content of total polyphenolic compounds and the antioxidant activity (DPPH and ABTS assays) of the pomace meals were evaluated by spectrophotometry. The results obtained show that the carbohydrates quantities (mg/100 g) in pomace meals were between 2943.31 (grapeseed) and 3210.11 (rapeseed). Sea buckthorn contains the most important amount of total organic acids of 8078.89 mg/100 g. Also, the highest quantities (mg/100 g) of total polyphenolic compounds were found in grapeseed (10789) and flaxseed (8537), respectively. These findings indicate a good source of carbohydrates, organic acids and polyphenols (phenolic acids and flavonoids) therefore these meals can be used as animal feed additives.