Biological properties of water-soluble polysaccharides and hemicelluloses from almond gum

The aim of this work was to investigate the biological activities of almond gum polysaccharides (AGP) and almond gum hemicelluloses (AGH). Almond gum was first fractionated into AGP and AGH using hot water and alkaline solution, respectively. The antioxidant activities of both extracted polymers revealed interesting free radical scavenging activities through DPPH test (IC₅₀ AGP=4mg/mL, IC₅₀ AGH=6mg/mL), 2,2'-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) radical scavenging activity test (% inhibition ABTS=40.53±1.99% and 87.14±1% for AGP and AGH, respectively), reducing power capacity (RP_AGP=20mg/mL, RP_AGH=1.1mg/mL), and β-carotene bleaching inhibition (IC_50AGP=18.5mg/mL, IC_50AGH 0.8mg/mL). Antibacterial activities of both polymers were tested against pathogenic strains showing interesting growth inhibition. Moreover, AGP and AGH were also efficient to inhibit ACE; the angiotensin converting enzyme (at 1mg/mL, the ACE inhibitory activity was 75.81±1.53% and 90.86±2.47%, respectively). The results obtained in this study demonstrate the attractive biological properties of fractions obtained from almond gum and their potential to be used in numerous food and non-food applications.