Digestibility and availability of nutrients in bee pollen applying different pretreatments

Abstract

Bee pollen is characterized by its high nutritional value that could be used in human diet, specifically for its value in protein and antioxidant capacity. Different studies emphasize that pollen shows a restriction in nutrient absorption caused by its complex external cell wall, being not easily digestible by monogastric species as bees and humans. The objective of this study was to apply different pretreatments: enzymatic, alkaline, dry thermal and wet thermal. In order to evaluate the effect of each pretreatment, protein by Bradford method, in vitro digestibility, antioxidant capacity and total phenols were quantified. Protein estimated by Bradford method decreased in pretreated pollen, due to the breakage of peptide bonds, and the digestibility raise from 62% in untreated pollen to 85-98% in pretreated pollen. In relation to antioxidant capacity, it showed a non-representative decrease regarding other vegetable matrices, with the exception of a raise in phenols for some pretreatments. Such results coincide with microstructural changes observed in pretreated pollen micrographs. Finally, the variables assessed by principal component analysis showed differences for every pretreatment.