Changes in the chemical composition, antioxidant and α-glucosidase inhibitory activities of shrimp paste (Ka-pi) following in vitro simulated gastrointestinal digestion

Shrimp paste is a traditional fermented condiment made from shrimp, widely produced in southern Thailand, particularly in Trang Province. During digestion, its chemical composition undergoes significant changes. This study aimed to analyze how digestion affects the chemical composition, antioxidant activity, and anti-diabetic properties of four shrimp paste samples (ka-pi) from different areas of Trang Province: Koh Kiam (Kp1), Koh Libong (Kp2), Had Yao (Kp3), and Tha Kham (Kp4). The physical and chemical characteristics of the samples were evaluated. Water content ranged from 38.24 to 48.25 %, while water activity (Aw) varied between 0.56 and 0.75. Salt concentration was measured at 6.78–10.65 %, and Brix content ranged from 7.40 % to 9.87 %. Nitrogen content was found to be between 6.22 % and 7.21 %. Among the samples, Kp4 had the highest protein content (49.21 %), followed by Kp2 (42.57 %), Kp3 (35.74 %), and Kp1 (34.24 %). Texture analysis showed firmness values between 1020.05 and 1473.21 g, toughness from 13,267.88 to 20,710.84 g s, and hardness ranging from 35.86 to 113.34 g. Simulated in vitro gastrointestinal digestion revealed notable alterations in the chemical composition, antioxidant properties (DPPH and ABTS), and α-glucosidase inhibitory activity (maltase and sucrase). All changes were statistically significant (p < 0.05). The findings suggest that Trang shrimp paste retains its protein content and offers potential health benefits, making it a nutritious and flavorful seasoning choice for consumers.