Multivariate analysis of structural and functional properties of fbres from apple pomace using diferent extraction methods

Abstract

In recent years, diets rich in fbres have become more popular due to their well-documented benefcial health efects. This has driven exploration of novel dietary fbres from various bioresources. Apple pomace, an industrial waste rich in fbres was used in this study to extract the insoluble dietary fbres. The efect of various extraction methods (hot water, acid, and alkali) on the physico-chemical, structural and functional properties, and prebiotic activity of dietary fbres was evaluated. Hot water extraction resulted in highest yield of dietary fbres in comparison to other methods (p<0.05). All the fractions resulted in diferent organization of fbrous components as depicted by scanning electron micrographs, Fourier Transform Infrared spectroscopy (FTIR), X-Ray Difraction (XRD) pattern and Thermo Gravimet ric Analysis (TGA). The acid extracted fbre fraction was observed to be amorphous with loose and porous structure whereas the alkali extracted fraction was more thermal stable based on TGA profle. Among the functional proper ties, acid extracted dietary fbres fraction possessed highest water and oil holding capacity (p<0.05). The hot water extracted dietary fraction resulted in maximum increase in viable cell count of standard probiotic strains Lactobacillus sporogenes and Streptococcus faecalis. The Principal Component Analysis revealed that acid extracted fraction pos sessed better functional activity which also correlates with the structural properties whereas for prebiotic activities, the fbre obtained from hot water extraction method served the best method. These results indicate that dietary fbres extracted through hot water can be employed as a potential prebiotic substrate for the probiotic cultures and could be further explored in foods to improve textural, functional, and bioactive properties of foods.