Effects of Starch on the Digestibility of Gluten under Different Thermal Processing Conditions

Abstract

Gluten and starch are the primary ingredients of wheat. The complex reaction between gluten and starch will occur during thermal food processing, which will affect digestibility. The effects of proteins on the digestibility of starch have been reported, but the effects of starch on the digestibility of proteins have not been well-researched. In this paper, the effects of starch on gluten digestion during the heating process were studied by the gluten−starch simulated system, and it was found that starch can enhance gluten digestion. When the complex of 1:1 gluten−starch is heated at 100 °C, the digestibility of gluten is higher and more low-molecular-weight peptides are produced. Results from the digestibility and digestion peptide mapping of the gluten−starch complex at different conditions showed that the addition of starch during processing enhanced the digestion performance of gluten. Meanwhile, the secondary structure, intrinsic fluorescence, and microscopic structure of the gluten− starch complex were investigated to understand the mechanism of the enhancement. The digestion performance is related to the secondary structure variation during the thermal processing caused by the hydration increase and disulfide bond reduction. The gluten−starch complex spatial structure is looser than gluten after heating, which could expose more protease cleavage sites. These results suggest that starch can protect gluten from aggregation in water and destroy the spatial structure of gluten with the assistance of heating, exposing more cleavage sites and enhancing gluten digestion.

Modification of Glutenin and Associated Changes in Digestibility Due to Methylglyoxal during Heat Processing

“…All measurements were conducted in triplicate. The extent of proteolytic hydrolysis (DH) was calculated using the following equation as previously described by Wenjun Wen et al: where h s is the concentration (mmol) of free amine groups per gram of protein in the sample, and h total is the concentration (mmol) of free amino groups per gram of protein, assuming complete hydrolysis of the protein (8.83 mmol/g protein). All measurements were made in triplicate.…”

Effect of methylglyoxal on the alteration in structure and digestibility of α‐lactalbumin, and the formation of advanced glycation end products under simulated thermal processing

“…The in vitro gastrointestinal digestibility of MG‐αLAs was determined according to the reported method (Wen et al., 2019). Briefly, 5 mg of MG‐αLA was added to 3.5 ml of simulated gastric fluid (the concentration of pepsin was 182 U/mg of protein) and then digested at 37°C for 1 hr.…”

Methylglyoxal Decoration of Glutenin during Heat Processing Could Alleviate the Resulting Allergic Reaction in Mice

“…The surface hydrophobicity index (H 0 ) of glutenin and its corresponding reaction product was determined by the method published in a former study [ 15 ]. The extent of proteolytic hydrolysis (DH%) was determined using methods previously described by Wenjun Wen et al [ 16 ]. All measurements were performed in triplicate.…”