Impact of Microwave Cooling on Resistant Starch and Digestibility in High-Carbohydrate Foods: A Meta-Analysis

Starch is extensively utilized in food processing for various functional purposes. However, the use of native starch is limited due to its incompatibility with specific processing conditions and final product characteristics. Microwave treatment has emerged as an efficient physical modification technique to enhance the content of resistant starch in food ingredients, offering lower energy consumption compared to conventional heating methods. Nevertheless, the impact of this method varies depending on the type of high-carbohydrate food, particularly in terms of resistant starch content, in vitro digestibility, include starch composition, amylose and amylopectin content, solubility, water absorption capacity, gelatinization, retrogradation, and starch digestibility. This meta-analysis aimed to evaluate the effect of microwave treatment combined with cooling on the resistant starch content of high-carbohydrate foods. A total of 23 studies were selected and analyzed following the PRISMA guidelines, from an initial pool of 3,663 articles. Data were analyzed using Hedges’d standardized mean difference (SMD) and confidence intervals (CI) via the OpenMEE software. The findings indicated that the microwave-cooling method had a statistically significant positive effect on resistant starch content in high-carbohydrate foods (SMD = 2.461; 95% CI: 1.652–3.270; P < 0.001). In conclusion, the microwave-cooling treatment significantly influences resistant starch content, in vitro digestibility, and physicochemical properties of high-carbohydrate foods, with strong statistical support at a 95% confidence level.