Effect of Aloe vera gel coating enriched with Fagonia indica plant extract on physicochemical and antioxidant activity of sapodilla fruit during postharvest storage.

The effect of Aloe vera (AV) gel (at 50% or 100%) alone or enriched with Fagonia indica (FI) plant extract at 1% on physiological and biochemical responses of sapodilla fruit were studied during storage at 20 °C for 12 days. Sapodilla fruit treated with AV 100% and FI 1% significantly reduced weight loss, decay incidence, soluble solids concentration, and kept a high level of firmness and titratable acidity compared to the untreated fruit. FI 1% added to AV 50% or AV 100% efficiently maintained higher ascorbic acid, total flavonoids, total phenolics and radical scavenging activity of sapodilla fruit. The panelists did not detect any negative effect of AV gel and FI plant extract on the sensory attributes of sapodilla fruit. Therefore, the addition of FI plant extract to AV gel coating could be a promising approach to prolong the shelf life and preserve the quality of sapodilla fruit during storage.

Immobilization of pectin depolymerising polygalacturonase using different polymers.

Polygalacturonase catalyses the hydrolysis of pectin substances and widely has been used in food and textile industries. In current study, different polymers such as calcium alginate beads, polyacrylamide gel and agar-agar matrix were screened for the immobilization of polygalacturonase through entrapment technique. Polyacrylamide gel was found to be most promising one and gave maximum (89%) immobilization yield as compared to agar-agar (80%) and calcium alginate beads (46%). The polymers increased the reaction time of polygalacturonase and polymers entrapped polygalacturonases showed maximum pectinolytic activity after 10 min of reaction as compared to free polygalacturonase which performed maximum activity after 5.0 min of reaction time. The temperature of polygalacturonase for maximum enzymatic activity was increased from 45°C to 50°C and 55°C when it was immobilized within agar-agar and calcium alginate beads, respectively. The optimum pH (pH 10) of polygalacturonase was remained same when it was immobilized within polyacrylamide gel and calcium alginate beads, but changed from pH 10 to pH 9.0 after entrapment within agar-agar. Thermal stability of polygalacturonase was improved after immobilization and immobilized polygalacturonases showed higher tolerance against different temperatures as compared to free enzyme. Polymers entrapped polygalacturonases showed good reusability and retained more than 80% of their initial activity during 2nd cycles.