Sulu ortamda glike edilen soya proteinlerinin fizikokimyasal özelliklerinin incelenmesi

On a lab-scale, glycation is generally a lengthy process which if replicated on an industrial scale, would be costly. In this study, a simplified method for glycating soy protein isolate has been developed. Soy proteins were glycated with allulose, fructose and glucose in the presence of water. The protein-water ratio was changed from ½ to 1 (w/w) and glycation was conducted at 100°C and 130°C for 15 minutes, and samples were also dried at 50°C, 55% relative humidity for 1 day. The physicochemical properties of these proteins were analysed including free amino groups by OPA method, protein solubility by Lowry method, browning index, reducing sugar concentration using HPLC, structural changes via Fourier Transform Infrared (FT-IR) spectroscopy and hydration behavior using Time Domain Nuclear Magnetic Resonance (TD-NMR) relaxometry through T2 relaxation time measurements. The results showed that proteins could be glycated under these simple conditions and with minimal control. It was found that high temperatures are not favorable for glycation and lower temperatures could be preffered. At high temperatures, proteins become more denatured and less soluble as shown through the Lowry method for protein solubility and TD-NMR results. Higher browning was seen at higher temperature, especially when allulose and fructose were used for glycation. Proteins glycated with glucose were observed to be lighter in color. The highest glycation was obtained with glucose while allulose and fructose showed the lowest reactivity under the proposed conditions. Proteins with low solubility had longer T2 relaxation times, indicating the presence of more free water and weaker water-binding capability.