Rainbow trout (Salmo irideus) produced in Finland VI. Prolongation of the keeping quality rainbow trout by antioxidants

Abstract

The transportation of fresh rainbow trout in good condition from the fisher to the consumer or to the fish industry presents a difficult problem. The fat of rainbow trout, like the fat in fish in general, contains plenty of unsaturated fatty acids and turns for that reason very easily rancid. According to Hansen (1964), the season and the sex of the fish influence the keeping quality of rainbow trout. Treatments that prevent the fish from coming into contact with the air (vacuum, glazing, dipping) The purpose of this study was to test BHA as an antioxidant in the storage of fresh rainbow trout. Ascorbic acid, the synergist of BHA, was also tested in the experiment. Material and methodsThe tested fish consisted of two-year-old male rainbow trouts weighing 300 grams. With the exception of the first experiment, the fish were brought alive to the laboratory, where they were killed, rinsed and filleted. They were then divided into four groups: 1) Control group, 2) 0.02 % BHA, 3) 0.01 % BHA, and 4) ascorbic acid.The fish fillets were packed in polyethylene bags. BHA, mixed in sunflower oil, was added to the bags. In the fourth group the fish fillets were dipped before packing for 2 minutes in 0.2 per cent ascorbic acid solution. The fish were stored at -f 4°C in ice which was changed daily.