Broccoli seed germination enhances their nutritional composition, antioxidant, anticancer, and antimicrobial activities, and in vitro nutrient digestibility

Abstract

The present study aimed to investigate the effect of germination on the nutritional composition, antioxidant, antidiabetic, anticancer, and antimicrobial activities of broccoli seeds, as well as their in vitro nutrient digestibility. The five-day germination process resulted in a significant increase in the levels of crude fibre (p<0.05), methionine (p<0.01), calcium (p<0.01), beta-carotene (p<0.01), vitamin C (p<0.01), and free amino acids (p<0.01). However, it decreased (p<0.01) protein levels in sprouts compared to seeds. A notable improvement (p<0.01) was observed in the DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), and metal chelating activity in broccoli sprouts compared to seeds. The levels of total polyphenol (p<0.01) and flavonoid (p<0.05) were significantly higher in sprouts compared to seeds. Broccoli sprouts demonstrated increased levels of the anticancer agent glucosinolate (p<0.05) compared to seeds. Broccoli sprouts exhibited improved antidiabetic activity by significantly inhibiting α-glucosidase activity (p<0.05) compared to broccoli seeds. When compared to seeds, broccoli sprouts showed considerably higher (p<0.05) antibacterial capabilities against Gram-negative bacteria, including Salmonella typhimurium and Escherichia coli, while no effect was observed against Gram-positive bacteria. Germinated broccoli seeds showed significantly higher in vitro protein digestibility (p<0.01) as well as in vitro starch digestibility (p<0.01). Our findings indicate that the germination of broccoli seeds increases its nutritional and phytochemical contents and, therefore, can be considered a potent functional food with enhanced disease-prevention properties.