Seasonal variation in the proximate composition of sardine (Sardinella gibbosa) from Thoothukudi coast

Abstract

Seasonal variation in the proximate composition (moisture, protein, fat, carbohydrate and ash) of sardine (Sardinella gibbosa) was analysed for one year (June 2013 to May 2014). In addition, the fatty acid profile and protein fractions (sarcoplasmic, myofibrillar and stoma proteins) of the sample collected in the month of May 2014 were also analysed. Protein, fat, carbohydrate and ash content were varied significantly (P<0.05) from 15.43 to 22.76%, 1.25 to 6.77%, 0.47 to 0.89% and 1.78 to 3.21% respectively. Lipid content of sardine was high during November 2013 to January 2014 (6.21 – 6.77%) and least in the month of May 2014 (1.25%). Sardine sample collected in May 2014 was rich in PUFA especially EPA (C20:5) and DHA (C22:6). Analysis of protein fraction in sardine collected in the month of May 2014 showed that the sardine muscle contains 23.81% sarcoplasmic, 71.97% myofibrillar and 3.20% stroma proteins. The results showed no marked the variation in the protein, carbohydrate and ash contents, whereas, greater seasonal variation in the lipid content of the sample. Lipid content increased from the month of June 2013, reaching a maximum of 6.77% in November 2013, was almost stable in December 2013 (6.33%) and January 2014 (6.21%), after where it decreased as low as 1.25% in May 2014.