Optimization of the Manufacturing Process for Citric Acid-Thawed Sardine(Sardinops melanostictus) Canned in Chili Oil

This study examined the reduction of fishy odor by treating sardines(Sardinops melamostictus) with citric acid solution and the optimal blending ratio of chili oil for the preparation of canned sardine chili oil. The viable cell count, volatile basic nitrogen(VBN), and trimethylamine(TMA) of sardines thawed in citric acid solution decreased with increasing citric acid concentration. Sardines thawed in a 2% citric acid solution and stored for 72hours showed that the viable cell count remained stable at 1.43-1.52log CFU/g until 24hours, while VBN and TMA levels increased after 24hours. The independent variables for the central composite rotational design used in optimizing the sardine chili oil manufacturing process were chili oil(A), smoked flavoring(B), and capsicum(C). Using response surface methodology(RSM), the optimal values of the independent variables [X₁=A/(B+C), X₂=B/C] were determined based on volatile odor intensity(Y₁), amino acid nitrogen(Y₂), and overall acceptance(Y₃) of canned sardine chili oil. These optimal values corresponded to 98.0g of chili oil, 1.79g of smoked flavoring, and 0.21g of capsicum. When prepared with the optimal ratio, the actual results were as follows: volatile odor intensity(VOI) of 370.7±7, amino acid nitrogen of 201.2±5.2mg/100g and overall acceptance of 6.62±0.2 score. Based on these results, the optimal blending ratio for sardine chili oil was confirmed.