Effects Of Roasting Condition, Skin Inclusion And Storge Duration On The Quality Of Peanut Milk

Abstract

The purpose of this research work was to explore the effects of roasting conditions, skin inclusion and storage duration on the quality of peanut milk. Peanuts’ roasting conditions were screened and carried out to assess antioxidant activity, total phenolic content, color measurement and sensory evaluation for the best results. The chosen roasting temperature and time compositions were 210oC – 8’ with 3.98 ± 0.01 µmol TE/g dry solid and 0.76 ± 0.01 mg GAE/g dry solid for no-skin inclusion roasted peanut milk (Sa); and 230oC – 7’ with 2081.4 ± 5.6 µmol TE/g dry solid and 127.9 ± 0.1 mg GAE/g dry solid for skin inclusion roasted peanut milk (Sx). Three peanut milks were formulated to three samples including control, unroasted peanut (Co), no-skin inclusion roasted peanut (Sa), skin inclusion roasted peanut (Sx) and carried out to assess proximate components, physicochemical characteristics, antioxidant activity, inhibit of lipid oxidation products (thiobarbituric acid reactive substances [TBARS], and peroxide value [PV]), and sensory parameters for maintaining qualities and the shelf-life of samples for 1st, and 7th day of the storage period. Although all aspects were decreased after 7 days of storage due to the denaturation and oxidation, the nutrition and antioxidant values of both roasted peanut milk samples were remained and even significantly higher (p < 0.05) amount in skin-inclusion sample. Lower concentrations of PV, TBARS, were observed in no skin inclusion roasted peanut milk sample on days 1 and 7, compared to controls. Regarding sensory analysis, appearance, color, odor, taste, texture, and overall acceptability at all treatments were almost significantly higher than control, and there were not significantly different found in both roasted peanut milk samples. It was therefore concluded that peanut skin could be an excellent natural antioxidant addition or inclusion to synthetic antioxidants used currently peanut milk making.