Farklı nişasta tiplerinin pisilyum lifi varlığında jelatinizasyon özelliklerinin in vitro sindirime etkisi

Starch's digestibility in foods strongly depends on the structure, other ingredients, and processing conditions used. It is essential to understand the relationship between food matrix and starch digestibility. The aim was to investigate the effect of psyllium fiber on gelatinization, crystallinity, and in vitro digestibility of starches with different crystalline structures (A, B, and C). Starches from various botanical sources (wheat, potato, and tapioca) with and without added psyllium fiber were heated at 90°C for 10 minutes at three different solid: water (w:v) ratios (1:1, 1:2, and 1:5). The added fiber content was 50% in the solid fraction for the fiber added samples. In vitro digestion analyses were conducted after the heating process. Structural changes were observed with Differential Scanning Calorimeter (DSC), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscope (SEM) analysis. Results showed that water content and psyllium fiber addition during cooking affected the structural, morphological, and digestion properties of wheat, potato, and tapioca starches. Psyllium addition decreased the rapidly digestible starch (RDS) fractions while increased the slowly digestible starch (SDS), and resistant starch (RS) fractions for all starch types. The effect of psyllium fiber addition was not limited to restricting the swelling and gelatinization of starch granules during cooking. Psyllium fiber also restricted the mobility of digestive enzymes during digestion. Understanding the relationship between psyllium and starch digestibility could assist in designing food formulations with lower starch digestibility. These in vitro data, however, should be confirmed by in vivo studies.