PUFA Content of silages prepared from tuna cannery wastes

Ensiling as one of the best methods for utilization of tuna wastes was investigated. docosahexaenoic acid [DHA C۲۲:۶(n-۳)]- rich products were obtained from the wastes (viscera and dark meat) of four tuna species, namely longtail, skipjack, yellowfin and kawakawa by a procedure involving ensiling in organic acids followed by neutralization. Identification of fatty acids in the samples was performed by comparison with chromatograms of fatty acids standard. Total lipid content of silages varied from ۱۰.۴۱% in skipjack dark meat silage to ۲۲.۰۱% in kawakawa viscera silage, but all lipids contained high percentages of DHA and EPA [eicosapanteoneic acid C۲۰:۵(n-۳)]. The highest DHA ratio (۱۵% of total lipids) was found in the lipid of skipjack viscera silage and the highest ratio of EPA (۱۱% of total lipids) belonged to the lipids of kawakawa dark meat silage. ANOVA test results indicated that DHA ratio was significantly high before silage preparation and linolenic acid [C۱۸:۳(n-۳)] content significantly differed between the species (p<۰.۰۵).

Keywords:

Silage , PUFA , Tuna wastes , DHA , EPA , Persian Gulf