Biokemistri Nigerian Society for Experimental Biology ISSN: 0795-8080 Vol. 13, Num. 1, 2003, pp. 37-41

Biokemistri, Vol. 13, No.1, Jan, 2003, pp 37-41                 

The lipid profile of the pallid emperor moth Cirina forda Westwood (Lepidoptera: Saturniidae) caterpillar

Adeolu.T. ANDE

Department of Biological Sciences,University of Ilorin, P.M.B. 1515, Ilorin. Nigeria.
 E-mail:  andeolu@yahoo.com

Received  17 November 2002

Code Number: bk03006

Abstract

The phospholipid, cholesterol and triglyceride levels, as well as, the fatty acid profile of the caterpillar of Cirina forda, a pallid emperor moth, known for its popularity as a food insect in Nigeria, were elucidated and compared with other popular sources of lipids. C. forda had 554.96mg/100g, 201.01mg/100g and 244.03mg/100g of phospholipid, cholesterol and triglyceride, respectively. It proved to be a rich source of unsaturates, surpassing other popular lipid sources as a source of polyunsaturates. It is rich in fatty acids such as Linolenic acid (33.84%), Linoleic acid (7.81%) and Oleic acid (12.93%). The possible nutritional implications of the consumption of C. forda caterpillar on the human nervous system are highlighted.

Key words: lipid profile, Cirina forda, caterpillar

INTRODUCTION

The pallid emperor moth, Cirina forda Westwood (Lepidoptera: Saturniidae) caterpillar, is a lesser known but readily acceptable food insect in kwara state, Nigeria (Fasoranti and Ajiboye, 1986; Ande, 1991). Like other animal sources, such as fish, shellfishes and beef (Jay, 1978), C. forda has a desirably high crude protein content of 64.49% on dry weight basis (Ande, 2002), hence it is a reliable protein food source to peasants. Lipid quality varies widely in plants and animal foods (Swaminathan, 1986). In insects it ranged from 10% in Honeybees (Apis mellifera) to 58% in wax moth caterpillars (Galleria mellonella) (Dierenfield, 1993). Dunkel (1998) observed that insects have a good fatty acid content and low cholesterol level and concluded that they may be a better nutritional source to man. A commendable ether extract proportion of 21.45% (dry weight basis) was recorded in C. forda caterpillar (Ande, 2002), but its quality has not been reported. This dearth of information has been standing in the way of the utilization of this relatively rich lipid source to the benefit of man and the assessment of the extent to which thelipidcomponent fits into the human dietary requirements. This study therefore attempts to determine the phospholipid, cholesterol and triglyceride levels, as well as, the fatty acid profile of the lipid available in C. forda caterpillar, and to compare these values with reports on other popular plant and animal lipid sources.

MATERIALS AND METHODS    

Dried processed C. forda caterpillar procured from Ipata market, Ilorin, Nigeria were pulverized and sifted through a 20-mesh size sieve. 1.5g of each sample were weighed into a 25ml test tube and 20ml of Chloroform: Methanol (2:1v/v) was added (Folch et al., 1957). The extraction was done in three replicates. The tubes were corked and shaken intermittently and left overnight at room temperature. The extracts were purified using the method described by Amenta (1964). The phospholipid and cholesterol levels were quantified using the method of Abell et al. (1958).Triglyceride values were calculated by difference as: 100 – (phospholipid + cholesterol). The fatty acid profile was determined using the Gas Liquid Chromatographic technique. The Capillary Gas Chromatograph (Schimadzu GC-14B) fitted with fused Silica Capillary Column (2.5m x 0.25m ID) with GREA integrator was used. The fatty acid quantity and quality were obtained by comparing their retention time with those of standards obtained from Nocheck preparation, USA.

RESULTS AND DISCUSSION 

C. forda Westwood caterpillar had a phospholipid, cholesterol and triglyceride composition of 554.96mg/100g, 201.01mg/100g and 244.03mg/100g, respectively. The relatively higher phospholipid content is understandable, as this forms a basic constituent of cell membranes, and lipoproteins, which are abundant in animal samples (Swaminathan, 1989). The cholesterol content (201.01mg/100g) though higher than anticipated, is comparable to values in beef, pork, liver and butter, but lower than that of egg yolk, and it falls in the range described as good (Swaminathan, 1989).

Ritter (1990) observed that sterol composition of insect tissues might change when they feed on a different diet. Thus the cholesterol level of C. forda may be modified by offering a special diet wherein Δ5-sterols are replaced with Δ7-, Δ5,7- or Δ0-sterols (Ritter, 1984). The encouragingly high triglyceride composition of C. forda may be the resultant effect of the need for the mature larva/prepupa to store energy for metabolism during the prolonged 9-month pupal duration, which is devoid of feeding activity (Ande, 1991).       

Although plant oils are generally richer in unsaturates (Alais and Linden, 1999), C. forda oil proved to be richer than all animal sources considered in Table 1, as well as, palm oil; a plant source.  The relative proportion of unsaturates to saturates in C. forda is approximately 1:1. As a source of polyunsaturates (PUFA), C. forda surpasses all except soybean in which 85% has been reported (Elegbede, 1998) and melon oil (Table 1). Going by the rating suggested by Swaminathan (1989), C. forda is a rich source of Essential Fatty Acid (EFA), with 41.65% unsaturates. Of particular interest is Linolenic acid (33.84%), which is essential for the functioning of the retina and nerve formation and whose occurrence along with Linoleic acid presupposes a balanced fatty acid diet. The considerably higher Linolenic acid value may however inhibit transformation of Linoleic acid into Arachidonic acid (Alais and Linden, 1999), another desirable EFA not found in C. forda. The occurrence of Oleic acid in C. forda may be an advantage, as it could be readily converted to either α-Linolenic or γ-Linolenic or both which are EFAs.

C. forda therefore is a good source of unsaturated fatty acids, particularly Linolenic acid. Thus it may be good in the diet of old people since the activity of 6∆desaturase enzyme falls with age. The oil can also find ready use in pharmaceutical and other industries apart from its food value.

AKNOWLEDGEMENT

The provision of a bench space and financial assistance by the Council for Scientific and Industrial Research (CSIR), India is acknowledged. 

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© 2003 Nigerian Society for Experimental Biology.

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