1988 Research Article Received: 20 May 2011 Revised: 29 November 2011 Accepted: 30 November 2011 Published online in Wiley Online Library: 30 January 2012 (wileyonlinelibrary.com) DOI 10.1002/jsfa.5572 Eri silkworm: a source of edible oil with a high content of α -linolenic acid and of significant nutritional value Thingnganing Longvah, * Korra Manghtya and Syed S Y H Qadri Abstract BACKGROUND: The study was undertaken to provide value addition to spent eri silkworm as an alternative source of edible oil for the food and feed industry by carrying out a short-term nutritional and toxicological evaluation of eri silkworm pupae oil using Wistar NIN rats. RESULTS: Growth performance of rats fed either sunflower oil (Control) or eri silkworm pupae oil (Experimental) was comparable. Histopathological examination of the various tissues showed no signs of toxicity even after feeding the eri silkworm oil for 18 weeks. Serum cholesterol and triglyceride was significantly reduced (P < 0.05) while high-density lipoprotein cholesterol was significantly increased (P < 0.05) which is attributed to the high α-linolenic acid content of eri silkworm oil. CONCLUSION: The study showed that eri silkworm pupae oil is safe and nutritionally equivalent to commonly used vegetable oils. Eri silkworm pupae can be harvested to provide a cost effective alternative edible oil that can be used to nutritional advantage in the food and feed industry. Therefore eri silkworm and its host plants offer an excellent example of multiple product crops and of sustainable agricultural practice with excellent opportunity for economic and nutritional benefits. c  2012 Society of Chemical Industry Keywords: eri silkworm (Samia ricinii) oil; fatty acid composition; nutritional; toxicological evaluation INTRODUCTION Eri silkworm (Samia ricinii) is one of the important non-mulberry silk produced primarily in north-east India. Eri silkworm is polyfagus and grows on a wide range of plants such as castor (Ricinus communis), tapioca (Manihot utilizsima), kissaru (Heteropanax fragrans), payam (Evodia flaxinifolia), barpat (Ailanthus grandis), papaya (Carica papaya), jatropha (Jatropha curcus) and barkesseru (Ailenthus excels). 1 Eri silk is a staple fibre, darker and heavier than other silks. Eri silk blends well with cotton, wool, jute or mulberry silk to create a new range of fabrics which is in great demand. Therefore, eri culture was introduced in many states outside north- east India, wherever the host plants are being cultivated on large tracts of land, in order to not only increase eri silk production but also to improve the economic status of the marginal farmers growing the host plant. The population in north-east India uses a variety of insects as food, one of which is the eri silkworm (Samia ricinii). The spent eri silkworm pre-pupae and pupae are considered a delicacy and is always in great demand in local markets. 2 Nutrient composition and protein quality evaluation of eri silkworm pre-pupae and pupae has shown that it is an excellent source of good quality protein. 3 Some insects are also known to secrete toxic metabolites or sequester toxic chemicals from plant foods. 4–7 However, the long history of human use suggests that insects harvested for human consumption may not pose any significant health problem. In 2009–2010, India imported 10.1 million tons of edible oil as against the domestic production of 8.2 million tons. The demand for imported oil remains strong due to growing consumption and the constraints on supply. 8 Therefore, the government of India is exploring alternative sources of edible oil to augment the increasing shortage in order to meet the growing demand and save precious foreign exchange. Silk production in India reached 19 600 metric tons in 2009–2010. Pupae, which accounts for 60% of the cocoon weight, is discarded as waste material. Silkworms such as Samia ricinii, Bombyx mori and Antheraea pernyi have been reported to contain good amounts of fat. 3,9,10 With the introduction of eri culture outside north-east India the production of eri silk has increased substantially, with a concomitant increase in the production of eri pre-pupae and pupae. Harvesting oil from spent silkworm could help augment the acute shortage for edible oil in the food and feed industry in the country. Therefore the study was undertaken to provide value addition to spent eri silkworm pre-pupae and pupae by carrying out short- term nutritional and toxicological evaluation of the eri silkworm pupae oil. ∗ Correspondence to: Thingnganing Longvah, National Institute of Nutrition, Ja- maiOsmaniaPO,Hyderabad – 500007,AP, India.E-mail: tlongvah@gmail.com National Institute of Nutrition, Jamai Osmania PO, Hyderabad – 500 007, AP, India J Sci Food Agric 2012; 92: 1988–1993 www.soci.org c  2012 Society of Chemical Industry