Impact of blanching treatments on the chemical composition, total dietary fiber, physicochemical, functional, and structural properties of underutilized cauliflower leaves ( Brassica oleracea var. botrytis )

Abstract

Cauliflower leaves have been underutilized and discarded by many consumers as feed for animals or household waste. It is interesting to utilize these residues in value addition in food products. In this study, the effect of hot water and steam blanching on the chemical composition, functional and structural properties of the cauliflower leaf powder were investigated. From the study, it was observed that steam blanching led to better retention of protein, dietary fiber and exhibited a greater reduction in moisture content than hot water blanching. Enhancement of brightness and greenness was observed in hot water blanched samples. Blanching had a significant effect on the functional properties and particle characteristics of leaf powder. The water and oil absorption capacity, solubility, and particle density decreased in the blanched samples, but bulk and tapped density exhibited the opposite tendency. Scanning electron microscope images revealed that blanching reduced compactness and the surface roughness of leaf powder. Practical applications Cauliflower leaves contain a high source of protein, dietary fiber, and minerals, but many tons of these leaves are discarded as waste during harvesting. The blanching treatments preserve these leaves by reducing moisture content, enhancing the nutrient content, and thereby increasing the shelf life of leaves. The blanched and dried leaves could be utilized in food products as a functional ingredient. Future studies can be conducted on dietary fiber production from cauliflower leaf powder and used as a food supplement.