Effect of Grass Carp Skin Protein Hydrolysates on the Retrogradation Tendency of Gelatinized Rice Starch in the Presence of Non‐Ionic and Ionic Hydrocolloids During Cold Storage

Abstract

Gluten‐free (GF) goods produced from rice starch (RS) are the most preferred products for consumers with celiac disease. But these foods lack essential amino acids and are prone to retrogradation, which are the barriers related to rice starch‐containing GF foods. The objective of this work is to study the synergistic impact of grass carp skin protein hydrolysates (GCSPHs) in the presence of xanthan (XT) and guar gum (GG) on the retrogradation tendency of gelatinized rice starch (GRS). During 14‐day storage at 4 °C, texture profile analysis revealed that combined GCSPHs and XT can significantly reduce the hardness from 1181.8 to 249.3 g, which has a more suppressive effect on retrogradation than that of all the other gel samples. The physical phenomena underlying the reduced retrogradation of GRS based on differential scanning calorimetry, X‐ray diffraction, attenuated total reflectance fourier transform infrared, low‐field 1H nuclear magnetic resonance, and scanning electron microscopy are characterized and it is shown that GCSPHs in GRS/XT gel can remarkably decrease the double helices localized inside crystallites of retrogradation, increase the amorphous region, immobilize the transversal relaxation time, lock the water in the GRS system and form a more homogeneous continuous phase, which can play a significant role in mitigating the retrogradation of GRS. These findings suggest that the synergism of GCSPHs and anionic hydrocolloids (XT) is more effective for inhibiting the retrogradation of GRS and improving the quality and nutrition of RS‐containing GF foods.