고령친화형 젤리푸드 개발을 위한 동 · 식물성 단백질의 농도별 젤 형성능 및 경도

Abstract

Purpose: This study was performed to evaluate the physicochemical properties of animal and plant heat-induced protein gels. The obtained results could serve as a fundamental database for future development of high-protein senior-friendly jelly foods. Methods: A total of nine food protein powders were used to manufacture heat-induced gels: pork skin gelatin, porcine myofibrillar protein, blood plasma protein, casein, whey protein concentrate, egg white protein, concentrated soy protein, isolated soy protein, and pea protein. The protein powders were mixed with distilled water at concentrations ranging from 6-20% (w/w), at 2% intervals. Mixtures were heated in a 90℃ water-bath for 30 min, at a heating rate of 3.80℃/min. The pH, moisture content, and protein content of the protein powders were determined, and the gel-forming ability, cooking yield, and hardness of the heat-induced protein gels were evaluated. Results: Gel formation was observed at all concentrations (6-20%, w/w) for pork skin gelatin, blood plasma protein, and egg white protein, whereas whey protein concentrate, concentrated soy protein, and isolated soy protein required over 10% (w/w) protein concentration for attaining heat-induced gels. The cooking yield of various proteins was over 96% for all concentrations examined, except porcine myofibrillar protein and casein. A dose-dependent increase was observed for hardness of the heat-induced protein gels, wherein proteins (excluding casein) showed linear regression between hardness and protein concentration (R2 > 0.9). Based on the regression equations, we predicted the protein concentrations corresponding to texture grades of Korea senior-friendly food standard. Conclusion: Whey protein concentrate and egg white protein presented higher protein content and cooking yield compared to other protein powders, and were therefore potentially useful ingredients for producing senior-friendly jelly foods. Further studies are required to develop the processing technique, for manufacturing soft hardness along with high protein concentration in jelly foods.