Extraction optimization, antioxidant, and hypoglycemic activities in vitro of polysaccharides from broccoli byproducts

Broccoli is a health-promoting food and its enormous byproducts, such as leaves and stalks, are a promising source of valuable components. In this study, extraction optimization, antioxidant, and hypoglycemic activities in vitro of polysaccharides from broccoli byproducts (PBB) were investigated. Plackett–Burman design, response surface methodology were applied to optimize the extraction of PBB. The optimal extraction conditions with a yield of (16.59 ± 0.04) % for extraction of PBB were determined as extraction temperature 82°C, extraction time 212 min and ratio of water to raw material 26 mL/g. And, PBB-1obtained from deproteinization and decolorization of PBB was separated into two fractions: PBB-1a and PBB-1c by DEAE-Sepharose. PBB-1c exhibited better bioactivities than PBB-1and PBB-1a, including antioxidant, -amylase, and -glucosidase inhibitory activities. Overall, these data suggest significant potential for the antioxidant and hypoglycemic activities of PBB-1c indicating the need for their further exploration as functional food ingredients or complementary medicine. Practical applications Byproducts from broccoli industrial processing represent between 60 and 70% of the broccoli plant weight, but they are also a promising source of valuable components. Currently, polysaccharides have attracted extensive attention due to their various biological and pharmacological activities, including antioxidant, hypoglycemic, and anticancer. Therefore, the present study aimed at optimizing the extraction process to extract polysaccharides from broccoli discarded waste having in view applications in food and pharmaceutical industries.