Effect of superfine grinding on physical properties, bioaccessibility, and anti-obesity activities of bitter melon powders.

BACKGROUND: Bitter melon is widely applied to the treatment of diabetes and obesity, but few studies focus on the processing procedure of bitter melon. The differences in physical properties, bioaccessibility, and anti-obesity activity of bitter melon powder (BMP) produced with or without superfine grinding were investigated to optimize an effective processing procedure. RESULTS: Results showed that superfine grinding could improve the physical properties of BMP, represented by greater bulk density, lower water-holding capacity, and higher bioactive compounds' solubilities. Superfine grinding remarkably affected the bioaccessibility of phenolics and the antioxidant capacity of bitter melon during in vitro digestion. Meanwhile, after a 4 week treatment, 25 µm BMP showed a greater anti-obesity activity with reduction in the serum insulin levels from 16.47 to 13.10 mIU L-1 , reversing high-fat-diet-induced glucose intolerance, decreasing levels of serum lipids and hepatic lipid accumulation compared with the high-fat diet group. CONCLUSION: In conclusion, superfine grinding was beneficial for improving the physical properties and bioaccessibility, simultaneously facilitating the anti-obesity activity of bitter melon, which will provide a reference for direct utilization of bitter melon as a health food to relieve symptoms of obesity. © 2022 Society of Chemical Industry.