Modification of functional properties of tuber flour and starch by Lactic acid bacteria fermentation

Starches and flours derived from tubers generally exhibit good gel-forming properties. However, their solubility, water-absorbing ability, and stability are limited. Notably, these functional weaknesses can be mitigated by fermentation, either spontaneous or controlled fermentation using lactic acid bacteria (LAB) as a starter. This review contributed to provide the studies related to modification by fermentations in various tubers (including cassava, potatoes, sweet potatoes, taro, and others), and their effects on functional properties, pasting, crystallinity, granule morphology, and their applications. Modification begins with the initiation of fermentation, with or without specific microorganisms. Subsequently, microorganisms begin fermentation using the existing starch substrate. Microorganisms hydrolyze starch by producing enzymes, which hydrolyze starch into shorter polymers or sugars. Further fermentation converts sugars into organic acids, so that the functional and physicochemical properties of starch change. Modification by fermentation could change the characteristics, but the results obtained vary depending on the type of tuber, starter used, and fermentation conditions. This critical review serves as a foundation for further research. Furthermore, information regarding the various characteristics of starch and flour from fermented tubers serves as a reference to determine their applications in the food industry and other fields.