Investigation of some protein properties extracted from tuna waste

Fish proteins have many applications due to their properties such as water holding capacity, fat absorption, emulsifying and foaming properties and can be used as a food additive. Amino acids, which have a high nutritional value and are often used as flavorings in the food industry, can be easily recovered from waste. In this study, protein from fish waste was extracted by alkaline dissolution and precipitation at an isoelectric point and some of its properties were investigated. These characteristics can determine its role. In this study, Thunnus tonggol, which is a widely used species in food industry and tuna factories, was used. After extracting the protein, some of its properties were examined .To evaluate some functional properties of the isolated protein, it was first placed in a freeze dryer for ۴۸ hours .The studies performed included foaming stability, emulsifying properties, water adsorption and protein fat adsorption . Knowing the properties of the protein determines the type of application in different industries. According to the results, the ability to absorb water in the isolated protein was calculated to be ۱.۵ g / g and the ability to absorb fat was ۰.۴۱ g / g. The volume of foam formed in zero minutes was ۱۸ ml, which decreased by ۳ ml after ۶۰ minutes. Foam stability was expressed as the volume of the remaining foam after ۳۰ and ۶۰ minutes. Foam stability was calculated to be ۸۳.۳%. Turbidity measurement method was used to measure emulsifying properties and casein protein was used as a standard protein for comparison. To calculate the emulsion stability, the absorption of protein solution was calculated at ۰ min and at ۱۰ min at ۵۰۰ nm. The emulsion stability of the protein was calculated ۸۶.۵۴% .The emulsion stability of the isolated protein was higher than that of casein. Alkaline and acidic dissolution methods can be used to recover proteins from tuna factory waste. By optimizing, higher yields and better performing proteins can be extracted. Although the functional properties of the extracted protein make it suitable for use in a variety of industries, much research is needed to use the waste protein for food or pharmaceutical purposes or other purposes.

کلیدواژه ها:

alkaline dissolution ، isoelectric point ، freeze dryer