Extraction Optimization and Analysis on Properties of Protein on Peony Seed Meal

In this study, an alkali solution and acid precipitation method were used to extract protein from peony seed meal. Solid-liquid ratio, pH, time, and temperature were selected to carry out a single-factor study and combined with the response surface method to optimize the optimal extraction process. The optimum process conditions were determined: The protein yield reached 23.81%±0.04% when the ratio of solid to liquid was 1:25 g/mL, pH10.6, the temperature was 55 ℃, and time was 130 min. The peony seed meal protein obtained under these conditions contained 18 kinds of amino acids. The water and oil retention of peony seed meal protein was 3.72 g/g and 3.67 g/g, respectively. Foamability and foam stability decreased significantly at pH2~4, and the lowest was at pH4. Between pH6 and 10, foamability continued to increase, while foam stability increased significantly and then decreased slightly. With the increase in pH, the emulsification and emulsification stability increased. The results were consistent with the variation trend of particle size and Zeta potential. This study provided a theoretical basis for the industrial production and comprehensive utilization of peony seed meal protein.