Fatty acids profile in canned tuna and sardine after retort sterilization and high pressure thermal sterilization treatment

Abstract

Fatty acid composition was asssessed for yellowfin tuna (Thunnus albacares) and sardine (Sardina pilchardus) canned in three different ways (brine, sunflower oil, olive oil) and subjected to two different sterilization treatments: retorting (as conventional treatment) and high pressure thermal sterilization (HPTS) (as alternative treatment). Impact of treatments on the fatty acid profile of the whole product was evaluated, particularly on the polyunsaturated fatty acids (PUFA) fraction since it is more susceptible to oxidation. Treatments were applied at pilot scale and the threshold for the sterilization factor was 7 min. HPTS treatment did not significantly affect the fatty acid profile of both canned tuna in brine and tuna in sunflower oil as compared with retorting. However, significant differences (p < 0.05) were observed in sardine in olive oil, where total PUFA content and the sum of eicosapentanoic acid and docosahexaenoic acid were nearly half in samples treated by HPTS. This work provides novel information on the impact of the combination of thermal treatment and high pressure as compared with classical retorting. Nevertheless, further investigation focused on the role of the prooxidants and antioxidants balance is necessary to confirm the oxidative effect of HPTS on PUFA content in oily fish species.