Characteristic of yellow tuna skin (Thunnus albacares) gelatin enriched with cinnamon (Cinnamomum zeylanicum) and roselle (Hibiscus sabdariffa) powder

Abstract

The current practice condition of fish processing will generate some amounts of byproducts such as skin waste. These fish processing by-products can be considered as an alternative raw material for the preparation of high protein ingredients such as gelatin. Gelatin extraction from the skin of yellowfin tuna (Thunnus albacares) was conducted by the acid process. Afterwards, the fish gelatin was mixed with cinnamon (GECP) and roselle powder (GERP) to enhance the physicochemical and functional properties of gelatin. The effects of the addition of cinnamon (GECP) and roselle powder (GERP) on the physicochemical and the functional properties such as tensile strength, hardness, viscosity, water holding capacity, oil holding capacity, total flavonoid, total phenolic, total antioxidant and flavor compounds of enriched gelatin (GECP and GERP) from tuna skin were evaluated and compared with control (without the addition of cinnamon and roselle powder). The gelatin exhibited excellent tensile strength, WHC, OHC, total flavonoid, total phenolic, and antioxidant in the presence of cinnamon and roselle powder rather than control (without addition) (p<0.05). The flavor analysis by using GC-MS showed more cinnamaldehyde as one important flavor compounds in GECP and where cyclohexanones can be identified as one important flavor compound in GERP. Thus, this study confirmed the improvement of physicochemical properties of gelatin enriched with cinnamon and roselle powder.