Study On Preparation And Function Of Peony Seed Oil And Protein

In this paper, preparation of peony seed oil and protein were studied, and theircharacteristics were determined. At first, peony seed oil was prepared by solventextraction, and fatty acid composition of peony seed oil that was prepared underoptimum condition was detected and analyzed. Oxidation stability of peony seed oilwas determined, and the influence of storage conditions on the oxidative stability ofpeony seed oil was studied. Secondly, process conditions that peony seed protein wasprepared by both method that alkali-soluble and acid precipitation and glucoamylaseassisting. The purity of peony seed protein that was prepared by two methods wascompared. At last, peony seed protein was hydrolyzed by alkaline protease. The effectof different degrees of hydrolysis on functional properties and amino acidcomposition of peony seed protein was studied. Its functional characteristicscompared with soy protein. Amino acids of peony seed protein with different degreeof hydrolysis were compared. The main research results were as follows:1. The optimum conditions of peony seed oil was prepared by solvent extractionwas that extraction time was240min, moisture content was4.0%, solid-liquid ratiowas1:4.5, temperature was50℃. Residual oil rate of peony seed meal was0.98%under this condition. Seven kinds of fatty acids were found in peony seed oil, and thecontent of unsaturated fatty acid was92.754%, the content of saturated fatty acid wasjust7.246%. Studies have shown that peony seed oil can be stored longer under thecondition of absence of air and light and low temperatures.0.05%VE and0.01%TBHQ were added in peony seeds oil, antioxidant of peony seeds oil was best.2. Purity of peony seeds protein as indicator, peony seeds protein was preparedby alkali extraction and acid precipitation and glucoamylase assisted. Optimalconditions for the preparation by alkali extraction and acid precipitation was that pHof alkaline extraction was9.5, solid-liquid ratio was1:10, extraction time was120minand extraction temperature is50℃. Optimal condition for the preparation byglucoamylase assisted was that enzyme action time was30min, the amount of enzymewas0.03%, pH of alkaline extraction was9.5, pH of enzymatic reaction was4.0, andsolid-liquid ratio was1:10. Two methods of preparing peony seed protein wascompared, purity of peony seed protein was prepared by glucoamylase assisted washigher. It can reached requirement of protein isolate.3. With the increase of hydrolysis degree of peony seed protein, solubility increases. When degree of hydrolysis of30.11%, the solubility was70.23%, solubilitywas greater than solubility of SPI. With the increase of hydrolysis degree of peonyseed protein, water retention was increased firstly, then decreased. When the degreeof hydrolysis was23.52%, water retention was27.05g/g, water retention was greaterthan water retention of SPI. With the increase of hydrolysis degree of peony seedprotein, oil absorption increased firstly, then decreased. When the degree ofhydrolysis was23.52%, oil absorption was27.05g/g, oil absorption was greater thanoil absorption of SPI. With the increase of hydrolysis degree of peony seed protein,emulsification increased firstly, then decreased, and the stability of the emulsionincreased. When the degree of hydrolysis was27.43%, emulsification was36.94m2/g.When the degree of hydrolysis was30.11%, the stability of the emulsion was1061min. Emulsification and stability of the emulsion was greater than SPI’s underoptimal conditions. With the increase of hydrolysis degree of peony seed protein,foaming increased. When the degree of hydrolysis was30.11%, foaming was92.50%.With the increase of hydrolysis degree of peony seed protein, foam stability wasdecreased. When the degree of hydrolysis was15.13%, foam stability was93.33%,foaming and foam stability were greater than SPI’s under optimal condition.