The inhibitory effects of the grape and apple pomace extracts on rat intestinal α-glucosidase activity. The α-glucosidase extract was prepared from rat intestinal powder. The enzyme activity was determined by measuring p-nitrophenol released from pNPG at 405 nm. The reaction was conducted at 37°C for 75 minutes. Results are expressed as mean ± standard deviation. Bars with different letters are significantly different (P < 0.05).