Analysis of proximate composition and consumer preference of three reef fish species
D.M.A. EDIRISINGHE, P.R.T. CUMARANATUNGA, K.RADAMPOLA and P.T. KIRINDEARACHCHIGE
Reef fishery plays a very important role in the coastal fishing of Sri Lanka and also there is a belief that some reef fishes provide special health benefits. However, the information available on chemical composition of reef fish is very limited. This study is based on the consumer preference survey conducted through an interview of 60 consumers at three retail markets in Sri Lanka namely Dondra, Matara and Weligama. Proximate composition was also analyzed for three highly consumer preferred reef fish species. A total of 34 fish, representing at least 11 specimens from each of the three fish species were analyzed for moisture, protein, lipid, ash and the total energy content. Gonado-somatic index (GSI), hepato-somatic index (HSI) and condition factor (K) were also calculated from January to April 2012.
It was revealed that consumers highly preferred Lethrines olivaceus (Long–face emperor) (27%) whereas preference for Epinephelus merra (Honey comb grouper) and Lutjanus rivulatus (Blubber-lip snapper) were 17% and 9% respectively. Two way ANOVA showed no significant difference in the moisture and ash content among three species, but there was a significant difference (p<0.05) in protein and fat content. Highest protein content was in E. merra (89%), while its lipid content was 5-8% (of the dry weight). Three species had condition factors above 1.7, which indicates their relative healthiness, with respect to food and space within the southern coastal waters of Sri Lanka. E. merra had the highest GSI values while L. olivaceus and L. rivulatus had the lowest and intermediate values respectively, which can be related to their gonadal development stage. The HSI was negatively related to total energy of females of E. merra and L. olivaceus, which could be due to energy reservation in liver than in muscles for their reproduction, while in L. rivulatus such a trend was not evident possibly due to prominent lipid storage structures within their body cavity. E. merra had the highest energy content (5.82 kJg-1) and consumers expressed their belief on its suitability for consumption with a view to reduce cholesterol level (80%).
Keywords: Serranidae, Lethrinidae, Lutjanidae, condition factor, gonado-somatic index, hepato-somatic index