Effect of Acid Pretreatment on PhysicoChemical, Optical, Functional, Thermal, and Morphological Characteristics of Unripe Plantain and Banana Flour

Abstract

Utilization of unripe plantain and banana flour can play a substantial role in economic sustainability and minimizing postharvest losses. Organic acids can play an essential role in preventing enzymatic browning and improving the properties of banana flour. Present work was conducted to study the effect of citric acid pretreatment on the physicochemical, functional, antioxidant, ther-mal, and morphological characteristics of unripe plantain (Bagner variety) and banana (Grand Naine variety) flour. Unripe plantain flour was found to have higher starch content than green banana flour. Citric acid treatment resulted in a decrease in the moisture content of dehydrated slices. Low moisture content indicates better storage quality and microbial stability. The Bagner variety had a higher swelling capacity than Grand Naine, possibly due to the higher starch content. Functional properties, namely water absorption capacity and swelling power, improved significantly after citric acid treatment. It also led to an improvement in total phenolic content and antioxidant activity. Citric acid treatment increased the gelatinization temperature and lowered peak viscosity. This might be due to the depolymerization of starch. Banana starch is observed to have a B-type crystal structure, a significant portion of which is resistant to digestion and thus can be used in developing various functional foods with a low-glycemic index.