CHEMICAL COMPOSITION, NUTRIENT BIOAVAILABILITY AND CONSUMER ACCEPTABILITY OF CIRINA FORDA (WESTWOOD) LARVA-ENRICHED VEGETABLE SOUPS

Abstract

One of the public health concerns in developing countries is still protein-energy malnutrition and micronutrient deficiency. Some edible insects, especially Cirina forda (CF) larvae with high protein, minerals, and vitamins could serve as a source of these nutrients in traditional foods in most localities. However, there has been a steady decline in consumption of CF due to fear of toxicity and deforestation; hence, the need to investigate the nutrient bioavailability and food safety of the edible larva. This study examined the consumption pattern, nutrient bioavailability, toxicology, nutrient composition, and consumer acceptability of CF larva-enriched vegetable soups.

The cross-sectional design with an analytical component was adopted. Respondents which comprised five hundred and two from two urban and three rural wards in Iseyin and Saki East Local Government Areas of Oyo State (where the insect consumption was popular) were recruited through a four-stage random sampling technique. An interviewer-administered questionnaire which was pre-tested was used to collect data on socio-demographic and CF mode of consumption. Dried CF larvae from Nigeria, Ghana, and Burkina Faso were purchased from Iseyin, Bodija market, Bobo-Diollaso respectively.Four vegetable soups:(vegetable+larvae,vegetable(control), Vegetable+egusi+larvae and vegetable+egusi (control) ) were prepared using traditional method.Standard methods were used to analyze the chemical composition of the three larvae and four vegetable soups. Toxicological and nutrient bioavailability evaluations were done using Wistar rats following OECD guidelines, while the microbial assessment was done using the pour-plate method. Vegetable soups acceptability rating was conducted among 30 untrained panellists using a 9-point hedonic scale. Descriptive statistics, independent sample t-test and ANOVA were used to analyse data at α0.05.

Respondents’ age was 46.3±16.4 years and 11.8% had tertiary education. Most respondents (99.8%) were aware of and had consumed CF larvae, 35.4% consumed it as roasted/dried, 35.9% as boiled/fried and 74.9% as a condiment in soups. One hundred grammes of dried CF sample contained 3.8±0.35g moisture, 53.2±1.10g protein, 16.9±0.23g fat, 2.6±0.09g ash, 453.3±0.08kcal energy, 8.9±0.02mg iron, 633.3±0.01mg potassium, 270.6±0.01mg calcium, and 1.4±0.03mg zinc. There was no significant difference in haematological and serum chemistry values of rats fed with control and CF-supplemented diets at 20% inclusion level, but significant weight gain was noticed in rats fed with CF-supplemented feeds (37.3g) compared to the control (29.5g), with an increase in alkaline phosphatase at 80% inclusion level indicating a negative effect of the rat liver. Serum protein (5.1±0.14g/dL), ferritin (26.0±0.55mg/dL), vitamin A (40.2±0.99µg/dL) and zinc (5.6±0.44mg/dL) concentrations of the experimental diets were significantly higher than that of basal diet at 4.1±0.14g/dL, 22.4±1.37mg/dL, 31.1±0.48µg/dL and 3.1±0.49mg/dL respectively. Larvae-enriched vegetable soups had higher nutrient content than plain vegetable soups and were more suitable in terms of aroma, colour, taste and texture. Total heterotrophic microflora counts (25.3-39.2×105) of dried CF were within the acceptable limit after 180 days of storage.

Cirina forda larva is rich in macro and micro-nutrients which are bioavailable. Its consumption posed no health hazard in rats, hence, its consumption is recommended for human, as it has the potential to reduce protein-energy malnutrition and micronutrients deficiencies among consumers.