Sun YL, Tang YF, Wang L, Li MZ, Chen ZX. Sodium caseinate medium promotes the in vitro digestion of starch: An insight into the macromolecular crowding effect.
Food Chem 2024;
436:137763. [PMID:
37857200 DOI:
10.1016/j.foodchem.2023.137763]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 10/07/2023] [Accepted: 10/13/2023] [Indexed: 10/21/2023]
Abstract
The macromolecular crowding effects of polysaccharides can alter the activity of digestive enzymes; however, whether protein crowding affects the digestive properties of starch remains unknown. Herein, the interaction of sodium caseinate (NaCas) with starch and pig pancreas α-amylase (PPA) and their effects on enzyme activity and starch digestion were studied. NaCas delayed gelatinization and reduced the leaching amount of amylose and increased the relative content of easily digestible starch. The ratio of the ordered structure (α-helix and β-sheet) to disordered structure (β-turns) of PPA increased with NaCas concentration, indicating that NaCas maintained the conformational stability of the enzyme and thereby accelerated the rate of enzymatic hydrolysis. This study demonstrates the detailed mechanism of NaCas-induced enhancement of starch digestibility and suggests a nonnegligible macromolecular crowding effect should be considered when evaluating the function of food macromolecules.
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