Effect of different gums addition on technological and rheological proporties of fish gelatin

Gels created from fish gelatin tend to be less stable and have weaker rheological properties, so they are not suitable for direct use in the food industry and should be modified. With this study, gelatin was produced from fish skins to evaluate industrial waste materials. The change in technological and rheological properties of fish gelatin was determined with different gum additions (xanthan gum, gellan gum, agar-agar, locust bean gum, carrageenan, guar gum, gum arabic). The pH value of 5 for beef and fish gelatin increased to 5,08 for Carob added fish gelatin, and it was determined to drop to 4,78 pH in other mixtures. While the ash content of beef was 3,75%, it was determined as 6,80 in fish gelatin. Gellan gum and Carrageenan mixtures were determined as 7,02 and 8,21% protein ratios, respectively, and it was determined that the protein ratio in other mixtures fell below 6,80. G' value and G'' values increase with the addition of gum to the fish gelatin solution. It has been determined that its elastic structure becomes stronger and shows a significantly higher gel property (G '> G''). It was determined that the addition of gum arabic adversely affected the structure of fish gelatin, causing a decrease in gel strength and a more viscous structure. The highest gel strength value was achieved by adding gellan gum (7,50%) to fish gelatin. With the addition of all gums except gum arabic, the gel strength and consistency index of fish gelatin were increased. Regarding the effect of gums on gelatin kinetics and strength of fish gelatin, gellan gum affected Kgel, G 'and gel strength more positively than other gums. As a general trend, G ', gel strength, and kgel values also increased with the increase in gum concentration. The melting temperatures of fish gelatin were increased by gum arabic other than gum arabic. In this study, where we aimed to eliminate the low melting point, which is one of the biggest deficiencies of fish gelatin, with the addition of different hydrocolloids, addition of 5,00% xanthan gum to fish gelatin was reached to 15,93ᵒC which is the highest melting temperature. In similarly, increase of the melting point was detected in the control sample with the addition of gellan gum, agar-agar, carrageenan, and carob. The melting point of bovine gelatin (29,74ᵒC) could not be reached at the optimum concentrations of the gums which were tested. Bloom value was determined as 247.16 for beef gelatin and 31.29 for fish gelatin. This value in the mixture with gellan gum; While it increased to 409,363, it changed between 8,11-131,08 in other mixtures. Water holding capacity (STK) was found to be 784,36% in bovine gelatin, 35,14% in fish gelatin. And xanthan gum (232,5%) has the highest STK value in mixtures. While Fat Binding Capacity (YBK) was 190,87% in bovine gelatin, 148,43% in fish gelatin, the highest YBK was found in sample which was added gellan gum (166,33%). When the hydrocolloids used within the scope of the study were evaluated, it was determined that the best results were obtained with the addition of gellan gum.