Effect of confectionery solutes on the rheological properties of fish (Oncorhynchus mykiss) gelatin

Abstract

In this study, gelatin was extracted from the skin of rainbow trout (Oncorhynchus mykiss) and gelation performance was studied with confectionery solutes at different concentrations (0, 10, 20, 40, 60 g/100 mL) as an alternative to mammalian gelatin. Rheological measurements were used to characterise the gelling and melting temperature and the gel modulus. Sorbitol and sucrose addition positively affected the gelation, texture, thermal and rheological properties due to changes of structural properties of the gelatin investigated by FTIR analysis. Addition of sugar or polyol enhanced the formation of triple helix structure and more junction zones were formed between proteins. Notably, gel strength increased from 828 Pa to 2317 Pa and 1996 Pa with the addition of 10 g/100 mL sorbitol and sucrose, respectively. Sorbitol had more significant effects than sucrose, probably due to its higher conformational degrees of freedom. Melting temperature increased from 17.5 degrees C to 22 degrees C and 22.1 degrees C by sorbitol and sucrose addition, respectively. These data suggested that the addition of sorbitol and sucrose triggered the formation of more junction zones which caused to increase in hardness and chewiness values. The enhanced properties of fish gel solutions with confectionery solutes showed the potential for use of this fish gelatin in gummy like candies.