Effect of incorporating dietary fiber sources in bakery products on glycemic index and starch digestibility response: a review

Bakery products are eaten worldwide, and traditionally, they are prepared mainly based on wheat flour, fat, and sugar. It has a poor nutritional composition with high levels of easily digested starch due to refine wheat flour, sugar, butter, and low levels of dietary fiber (DF). With this composition, they are categorized as high-glycemic index (GI) food which leads to elevated blood glucose. This review was aimed at highlighting the strategies for enhancing the DF content and developing low-GI bakery products. Studies were searched from Scopus and ScienceDirect databases published between 2017 and February 2023, in English. Eventually, a total of 17 articles were selected for analysis. Non-wheat flour sources from whole grain, vegetables, legumes, fruits, and tubers were used to incorporate into bread, cakes, and biscuits. A significant increment in DF content, considerable low GI value, and slower starch digestibility were observed in most of the bakery products that have been incorporated with other plant flour compared with the control. The DF content of products depends on the fortification dosage and type of non-wheat plant flour used. In conclusion, based on this review, the GI value was affected by the DF content and type of carbohydrates. Most reviews indicated that bakery products can be claimed as high DF content with GI between low and intermediate. Therefore, it is possible to incorporate flour from other plants into bakery food as an alternative food with high DF and low GI, especially for diabetic patients.