Proximate composition of the edible part of purple passion fruit and santol and in vitro prebiotic activity of crude polysaccharide extracts

Abstract

This study aimed to evaluate the functional and prebiotic properties of the edible portions of certain tropical fruits in Thailand, passion fruit and santol. The proximate composition of passion fruit and santol were analysed which total carbohydrate was the major component in both samples. Total dietary fibre of passion fruit and santol was 44.81 and 26.82% (w/w), respectively, with the majority of insoluble dietary fibre. Soluble dietary fibre of both fruits was extracted by hot water and water-extractable polysaccharide was yielded at 16.47% and 25.24% (w/w) for passion fruit and santol, respectively. The functional properties of fruit fibre were informed, with the satisfactory oil holding capacity of santol polysaccharide. The effect of both fruit polysaccharides on proliferation number at 24 hrs was not different from inulin. Prebiotic activity score of fruit polysaccharide was calculated from the growth of Lactobacillus acidophilus and Bifidobacterium longum compared with the growth of the enteric pathogen, Escherichia coli corresponding to-0.25 and-0.23 for passion fruit and 0.10 and-0.01 for santol, respectively. In conclusion, both passion fruit and santol polysaccharide showed a distinct effect on the supportive growth of probiotic bacteria which may be potential candidate ingredient incorporated in probiotic food. From this evidence, the development of fruit-based synbiotics from passion fruit and santol migh be affordable.