Impact of different processing methods on physico-chemical characteristics and antioxidant activity of peanut milk

Peanut milk was prepared by different processing methods like fresh, blanching, soaking, roasting and germination methods and analyzed its physico chemical properties like pH, TSS, acidity, viscosity and colour value and also analyzed its antioxidant activity in both the selected local and CO 6 peanut varieties and studied the effect of processing methods on physico chemical properties, organoleptic characteristics and antioxidant activity.

Local and CO 6 peanut variety were selected for preparation of peanut milk by five different processing methods like fresh, blanching (121°C 15 psi for 2 mins), soaking for 3 hrs, roasting (roasting for 5 mins followed by soaking 3 hrs) and germination (8 hrs) pretreatments were done. Then grinded (1:3 ratio of kernel to water), filtered by using muslin cloth, slurry was separated. Then the peanut milk was homogenized for 5 mins and double pasteurized (85°C for 15 mins).

The present study results reported that physico chemical properties of peanut milk (local and CO 6 variety) pH value varied between 6.3–6.9, TSS 11–13°Brix, viscosity 4.80–5.00 (Cp/100 ml), acidity 0.04–0.08 (g%), colour value L*a*b was higher (91.02, 0.97, 12.47) in control peanut milk from both the local and CO 6 variety respectively. Antioxidant activity was significantly higher in peanut milk developed from roasting method (roasting for 5 mins followed by soaking 3 hrs) in both the peanut varieties. Antioxidant activity of the peanut milk is also important for maintaining the shelf life of the product and prevent oxidative damage in human being.