Lipid Profiles and Oxidative Stability of Silkworm Pupal Oil,

Abstract

The oil content of the silkworm, Bombyx mori, in the pupal stage was 4.8% for the male and 9.0% for the female (wet basis), respectively. Total lipid (TL) extracted from silkworm pupae mainly consisted of triacylglycerol (TG), phosphatidylethanolamine, and phosphatidylcholine. TL and TG contained approximately 40% α-linolenic acid as the predominant fatty acid. 20:3n-3 was also present in the pupa, but the quantities were very small. Total tocopherol in TL was 125.2 μg/g lipid for the male and 224.1 μg/g lipid for the female, respectively. The oxidative stability of TL was confirmed by measuring the decrease in oxygen in the headspace. The oxidative stability of TL from silkworm pupae was very high and no difference between sexes was appeared. It has been suggested that a synergistic effect between phospholipids and tocopherol in silkworm pupa plays an important role in protecting the lipids against oxidation. Furthermore, the silkworm pupa contained carotenoids such as lutein and neoxanthin. These carotenoids may act as antioxidants in TL. The silkworm pupa would be a good source of the functional fatty acid, α-linolenic acid, and of the functional pigments, lutein and neoxanthin.