Identification of polysaccharides extracted from pea pod by-products and evaluation of their biological and functional properties

Abstract A three-variable Box-Behnken design was employed to obtain the best possible combination of extraction time, ratio (raw material/water) and extraction temperature to allow maximum extraction yield of polysaccharides from pea pod (PPP). The preferred extraction conditions were: extraction time 195 min, extraction temperature 70 °C and ratio of raw material/water 1/40. Under these conditions, the experimental yield was 16.21 ± 1.12%, which is in close agreement with the value predicted by response surface methodology model yield (16.08 ± 0.95%). The molecular weight distribution of PPP showed two peaks with M W of 5217 kDa and 50 kDa, respectively. The main monosaccharides in PPP were galactose, xylose and arabinose, whereas the major functional groups identified from FT-IR spectrum included CO, OH and CH. In addition, PPP had high 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and a moderate reducing power. The antibacterial activity of PPP was also observed against the tested microorganisms and at 50 mg/mL PPP could inhibit the growth of the Gram-negative and Gram-positive bacteria. Generally, these results suggest that the PPP has significant antioxidant activity and good antibacterial activity and can potentially be used as additive in food, pharmaceutical and cosmetic preparations.