Acid Silage from Nile Tilapia (Oreochromis niloticus) Byproducts as a Potential Biostimulant of Bread Wheat (Triticum aestivum) Sprouts
摘要
In this study, the potential of an aqueous phase recovered from the centrifuged acid silage made of tilapia (Oreochromis niloticus) byproducts using a mixture of citric and phosphoric acids (both at 2.5% of total mass) was analyzed as a biostimulant for the growth of wheat sprouts (Triticum aestivum), and the content of phytochemicals and their in vitro antioxidant capacity was evaluated. Additionally, the biochemical composition and molecular-weight and amino acid profiles of the acid silage were characterized. The acid silage was characterized by a high concentration of low-molecular-weight peptides (< 1.35 kDa) and 44.45% of total amino acids being essentials. When the silage was applied to the wheat seeds (269 mg SP/mL), a significant increase in the growth of the cotyledons (96.3%), hypocotyls (40%), and roots (53.5%) was observed relative to a control group, but similar to the effect of a commercial fertilizer used as positive control. The application of both silage and commercial fertilizer (concentration > 26.9 mg SP/mL) increased the flavonoid content in the sprouts from 0.08 to 0.16 mg of quercetin equivalents/g, which was correlated with an increase in the in vitro antioxidant capacity, as evaluated by DPPH and ABTS tests. These results suggest that the bioactive peptides present in the silage, together with free amino acids such as Arg and Glu, stimulate plant physiological processes, such as germination and growth. The antioxidant capacity of the treated sprouts suggests the potential for the production of functional foods with properties that benefit human health.