Storage and Drying Time Effects on Digestibility and Amino Acid Composition of Dried Smoked Horse Mackerel (Trachurus trachurus) Fillets

摘要

This study assessed the effect of storage on the amino acid composition of dried horse mackerel fillets. Dried horse mackerel (Trachurus trachurus ) fillets were prepared by smoking brined horse mackerel fillets in a traditional improved kiln for 4 hours at 60-70℃. The fillets were later oven-dried at 65-70℃ for 0, 2, 4, 6, and 8 hours. There was a significant difference (p < 0.05) in-vitro protein digestibility (IVPD) of dried fillets over the 8 hours of drying (from 99.44% in control sample to 95.02% for the 8 hour dried sample), while storage decreased the IVPD of the samples from a range of 99.44 - 94.07% in control sample to 95.02 to 89.60 % in the 8 hour dried sample. Drying reduced the amino acid composition of the horse mackerel fillets from 47.10 g/100g protein in control sample to 27.14 g/100g protein in 8 hour dried. The results also showed that the total amino acids significantly reduced (p < 0.05) from the range of 47.10 to 27.14 g/100g protein on the 0 day to 27.42 -14.58 g/100g protein on the last (30~(th)) day of storage. Essential amino acids reduced from the range of 25.40 - 14.01 g/100g protein on the 0 day to 14.64 - 7.42 g/100g protein while the non essential amino acids also decreased from a range of 21.71 - 13.13 g/100g protein on the 0 day to 12.78 - 7.16 g/100g protein on the last day of storage. In conclusion, both drying and storage affected the IVPD and the amino acid composition. However, results showed that they could still meet the amino acid requirement of an adult (70 kg) man.