Physicochemical Characterization of Oil and Chitosan Extracted from Cross Breed and Bivoltine Hybrid Silkworm Pupae: A Comparative Analysis

Abstract

The oil and chitosan were extracted from silkworm pupae and analysed its physicochemical properties. Oil content in silkworm pupae ranged from 26 to 28 % on a dry weight basis. Notably, female pupae had a higher oil content (27.99 %) compared to males (27.03%). Further, bivoltine hybrids exhibited a slightly higher oil content (27.65 %) than cross breeds (27.30 %). In comparison to edible oils like groundnut oil and sunflower oil, the pupal oil showed favourable results in terms of moisture content, iodine value and saponification values, indicating quality similar to edible oils. However, acid value of silkworm pupal oil (1.570 mg KOH/g oil) was lower than that of groundnut oil (3.125 mg KOH/g oil). The acid value and peroxide value were found to be lower than three in pupal oil samples, revealed that pupal oil is good for edible purposes and indicates good oxidative stability. Among the samples, Chitosan content was higher 2.526% in the cross breed (PM × CSR2) than bivoltine hybrid 2.308%. Male silkworm pupae had a higher chitin content (3.242%) compared to female pupae (3.013%) and chitosan content was also higher (2.430%) in male pupae than in female pupae (2.345%). Pupal chitosan shows better solubility (99 %), degree of deacetylation (>85%) and ash content (<1%). These physicochemical properties were achieved the desired level for utilizing the silkworm pupal oil and chitosan as commercial utilization.