Nutritional Comparison of Fresh and Pressure-Cooked Yellowfin Tuna (Thunnus albacares) Stomach Waste

Abstract

Yellowfin tuna is a leading commodity in the capture fisheries sector and has high economic value in the global market. High tuna production results in large amounts of waste, including stomach waste that is not yet optimally utilized. This study aims to analyze changes in the chemical composition of stomach waste from yellowfin tuna. The sample consisted of 9 individuals and the proximate results were analyzed using the t-test and described descriptively in narrative form. Analysis of five parameters: water, ash, fat, protein, and carbohydrate content. The study found a water content of 78.350 ± 0.200% for fresh and 75.267 ± 0.208% for pressure-cooked. Ash 1.700 ± 0.040% for fresh and 2.530 ± 0.044% for pressure-cooked. Fat 8.020 ± 0.017% for fresh and 7.083 ± 0.065% after pressure-cooked. Protein 11.507 ± 0.309% for fresh and 10.733 ± 0.064% for pressure-cooked. Carbohydrate 0.423 ± 0.168% and 4.387 ± 0.216 for pressure-cooked. The results of the proximate test on the gastric waste of yellowfin tuna in fresh condition and after the pressure-cooked process for all parameters showed significant differences (p<0.05). The decrease in water content is caused by evaporation during heating, while the decrease in fat and protein occurs due to oxidation, decay, denaturation and dissolution of organic compounds in the cooking medium. Conversely, ash content increased as a result of the relative concentration of minerals after the loss of volatile components. Carbohydrate content also increased relatively, as a result of the reduction in other nutrients. These changes indicate that the pressure-cooked process functions as a method of softening the tissue and modifying the nutritional value of the waste fish organs. These findings are important to support the use of fish stomach waste as an alternative raw material in the animal protein-based feed or functional food industry.