Collagen extraction from tuna fish skin (Thunnus sp.) and its application in citrus honey tea drink (yujacha)

Abstract

One of the challenges in the tuna processing industry is waste management. Tuna skin is a byproduct rich in protein and has great potential for collagen. This study aimed to extract collagen from tuna skin waste (Thunnus sp.) and apply it in citrus honey tea (yujacha) beverage as a functional food product. Collagen extraction was carried out using the hydro-extraction method. Characterization included proximate analysis collagen content (using Fourier Transform Infrared test), antioxidant activity (using the Ferric Reducing Antioxidant Power method), and amino acid composition (using high performance liquid chromatography). The production of collagen drinks was carried out with four treatments of collagen concentration (0, 1, 2, and 3%) to assess its effect on viscosity, pH, and hedonic quality. The results showed that the collagen produced had a high protein content (86.55%), low moisture content (7.02%), and ash content (0.67%), which was in accordance with SNI standards. The collagen exhibited high antioxidant activity, measuring 151.65 pmol Fe? gi. The amino acids content was dominated by glycine, proline, and arginine. The application of collagen in yujacha beverages increased viscosity (26.11-38.60 cP) and pH (3.26-4.26), although there was a decrease in sensory receptivity to aroma and taste with an increased collagen concentration. This study concluded that collagen from tuna skin waste has a great potential as an innovative raw material for functional food products, especially beverages. In addition to increasing the added value of fishery waste, these results support the development of high economic value and sustainable products in the food industry.