Study On Extraction And Physical Properties Of Isolated Almond Protein

Sweet almonds of Xinjiang was used as material In this study, the alkali fusion and acid precipitation theory were employed to extract the isolated protein, the extraction conditions were optimized,and the performance and composition of isolated protein from sweet almonds were analyzed, the main results are as follows:Extracting almond isolated protein again form The residue of Sweet almonds extracted by alkaline extraction,Single factor experiment and orthogonal design experiment are carried out to achieve the optimum extraction conditions of both extraction,the results showed that the optimized conditions of the first extraction are: temperature 50℃, pH 8.5, solid-liquid ratio 1:30, and the extraction time 70 min. The extracting ratio is 84.3% under this condition; the optimized conditions of the second extraction are: temperature 50℃, pH 9.5, solid-liquid ratio 1:15, and the extraction time 60 min. Finally, the total extraction rate was 84.3%, and the purity of protein was 63.21%.The determination on the basic components of almonds indicated that,The fat content is the highest in the basic components of almonds, reaching 50.2%, next came the protein as 25.86%. The analysis of amino acid of Almond showed that it contains 18 kinds of amino acids, of which eight is essential amino acids for the human body. Tryptophan is the first limiting amino acid of Sweet almond.Effects of the pH value,the heating time and the extraction temperature on the holding water capacity,the holding oil capacity and the emulsion stability of separated almond protein were investigated respectively, research showed that:Research on the holding water capacity shows that:the holding water capacity of the isolated protein extracted from sweet almonds or almond meat are all better than other protein Under Different Temperature Condition;but the holding water capacity of the isolated protein extracted from soy were affected greatly by pH values Under Different pH Condition,also shows better capacity than other protein, in all, the holding water capacity of the isolated protein extracted from sweet almonds are all better than soy protein relatively。Research on the holding oil capacity shows that:the holding oil capacity of the isolated protein extracted from soy bean are higher than other protein. But those three isolated protein shows little difference in holding oil capacity with the prolonging of heating time and temperature,all are about 200%。Research on the emulsion activity shows that: the holding water capacity of the isolated protein extracted from sweet almonds or almond meat are all better than other protein both on the emulsion activity and the emulsion stability, and the emulsion stability is proportional to the emulsion activity.