Isolation and Characterization of Neutral Lipids of Desilked Eri Silkworm Pupae Grown on Castor and Tapioca Leaves

Abstract

The neutral lipid of desilked eri silkworm pupae (Samia cynthia ricini) grown on two different host plants, castor (Ricinus communis Linn.) and tapioca (Manihot utilizsima Phol.) leaves, was extracted with hexane. The oil content in pupae was estimated to be in the range of 18-20% (dry basis). The pupal oil was found to be enriched with alpha-linolenic acid (ALA) with palmitic acid as the second major fatty acid. The level of ALA in the oil of silkworm pupae was found to be significantly higher (P < 0.001) when grown on tapioca (58.3%) as compared to those grown on castor (42.9%). Other chemical parameters such as percent free fatty acid, peroxide value, phosphorus content, percent unsaponifiable matter, and composition of sterols were also determined in both of the oils and compared. Reversed-phase high-performance liquid chromatography analysis of triacylglycerol molecular species showed that the pupal oil is rich in molecular species with equivalent carbon numbers (ECN) C36, C40, C42, C44, and C48. There was a significantly higher level (P < 0.001) of trilinolenin (C36) in the oil of tapioca-based silkworm as compared to castor-based silkworm pupae. Regiospecific analysis of the oil showed a higher level of ALA at the sn-2 position of silkworm pupae grown on tapioca (60.2%) as compared to those grown on castor (47.3%) oil. Thus, the presence of a large amount of ALA and their predominance at the sn-2 position make the eri pupal oil highly nutritious, provided that the oxidative stability is ensured.

Eri silkworm: a source of edible oil with a high content of α‐linolenic acid and of significant nutritional value

“…Developmental stages of the insect appear to have a bearing on the fatty acid content as stearic acid increased from 3.91 to 5.61% as the worm transformed from the pre‐pupae stage to the pupae stage with concomitant decrease in the linoleic acid content. Palmitic acid and α‐linolenic acid were the major fatty acids comprising 69–72% of the total fatty acids, which is similar to that reported earlier for eri pupae fat by Shanker et al 15 Total saturated fatty acids of 32% in eri silk worm pupae oil in the present investigation was comparable to 33.2% in spent silkworm ( Bombyx mori ) pupae oil reported by Rao 9. The total unsaturated fatty acids of eri silkworm pupae oil (67–69%) and spent silk worm pupae oil (66.8%)9 were also comparable but vegetable oils like perilla,16 with substantial α‐linolenic acid content had higher levels of total unsaturated fatty acids (87.3%).…”

Supercritical Carbon Dioxide Extraction of the Oak Silkworm (Antheraea pernyi) Pupal Oil: Process Optimization and Composition Determination

“…Shanker et al . [30] also demonstrated that the fat content and its composition are influenced by species, season, geographical regions, age, and process methods. α-linolenic acid in the diet can prevent disorders such as atherosclerosis, coronary heart disease and high blood pressure [31].…”

Sex Differences in the Relationship of Dietary Fatty Acids to Cognitive Measures in American Children

“…Although their bodies have significant amounts of ALA obtained from plants, their nervous systems contain little or no DHA (Jerde et al, 1975; Fontaneto et al, 2011); instead they use mainly ALA (Stark et al, 1993; Shanker et al, 2006). Their inability to convert alpha-linolenic to DHA may limit the complexity of their nervous systems.…”