Improvement of technofunctional properties of sour cherry seed protein by different glycation methods

Plant based proteins are expected to be important protein sources of the future in terms of sustainability and health. However, the use of plant proteins as functional ingredients in the food industry is reasonably limited due to their lower foaming and emulsifying properties than animal based proteins. A promising approach to overcome these limitations is the glycation of plant proteins via the Maillard reaction. The covalent bonding formed between protein and polysaccharide through the first stage of the Maillard reaction can improve the technofunctional properties of the protein. In this context, within the scope of the study, sour cherry seed protein; Gum arabic was conjugated with carboxymethyl cellulose and pectin polysaccharides by wet heating glycation, microwave-assisted glycation and ultrasound-assisted glycation methods. Optimization was carried out with response surface methodology (RSM) to determine the most suitable process parameters in microwave and ultrasound-assisted glycation. While power (Watt) and processing time (min) were defined as independent variables for microwave-assisted glycation, amplitude (%) and processing time (min) were defined as independent variables for ultrasound-assisted glycation, the degree of glycation was defined as the dependent variable. Characterization of Maillard conjugates obtained at optimum points was carried out by glycation degree, FTIR, and SEM analyses. The conjugation process improved the techno-functional properties of sour cherry seed protein namely solubility, water retention/oil binding, foaming capacity/stability and emulsion activity/stability. However, this development varied depending on the different polysaccharide type/glycation method. By microwave-assisted glycation, conjugates with a higher degree of glycation were obtained with a shorter processing time. To evaluate the emulsification properties of protein and Maillard conjugates in food systems, the created emulsions were exposed to environmental stresses namely different temperature, pH and salt concentrations, and freeze-thaw process. The results showed the emulsifying properties of the conjugates prepared in the presence of carboxymethyl cellulose and pectin were prominent compared to the conjugate prepared in the presence of Gum arabic. Among the glycation methods, conjugates obtained by microwave-assisted glycation exhibited the best technofunctional properties. In this context, patty analog production was carried out with conjugates obtained by microwave-assisted glycation for application to the food industry. Patty analogue formulated with sour cherry seed protein was used as a control. Patty analogues were examined for physicochemical properties, morphological structure, in vitro digestibility and sensory analysis. The results showed the patty analogue containing carboxymethyl cellulose-glycated conjugate in its formulation was the best.