Production of protein hydrolysate from silverfish (Atherina boyeri risso, 1810) and determination of its functional and bioactive properties

Transforming invasive fish species that live outside their natural habitats and damage the ecosystem into valuable products has significant potential to reduce environmental damage and contribute to the economy. In this thesis, protein hydrolysate was produced from the invasi ve sand smelt(Atherine boyeri) in the Yamula Lake in Kayseri and the Hirfanlı Dam Lake in Kırşehir using alcalase, flavorzyme, and bromelain enzymes for comparati ve purposes. The physicochemical, functional, and bioacti ve properties of the produced hydrolysate were in ve stigated. The degree of hydrolysis was determined as 10.90%, 11.60%, 7.61%, 9.74%, 11.04%, and 6.66% in the HGalc, HGbro, HGfla, YGalc, YGbro, and YGfla samples, respecti ve ly. Among the functional properties, the highest emulsion capacity (EAI) value was 99.49±0.48 m2/g, and the highest emulsion stability (ESI) value was 49.02±0.804 min. It belonged to the HGbro sample. The highest foaming capacity and stability values were obtained in the HGalc sample as 114.84±2.82% and 76.65±1.51%, respecti ve ly. The highest oil binding capacity was obser ve d in the YGfla sample, which had the lowest degree of hydrolysis, and was calculated as 3.75±0.12 mL/g. The hydrolyzates had consistently high solubility at various pH values, between the lowest HGfla (79.82%) and the highest HGalc (97.69%). In conclusion, the solubility, emulsifying, foaming and oil binding properties of the hydrolyzates have a potential application as food additives.