Extraction Of Avocado Oil And Protein Extraction And Properties Analysis Of Avocado Dregs

Avocados are one of fruits,which contains plenty of unsaturated fatty acids and has nutritional value.Gradually avocado becomes a new raw material of high quality vegetable oil. Avocados pulp which oil removed can be a good source of protein and carbohydrates.In order to improve the utilization value of avocados, increasing the study of its various by-products is very necessary. Using avocado pulp as raw material, this paper studies its nutrients, using aqueous extraction method to extract the best extraction process of avocado oil and the best extraction condition of avocado protein extracted from avocado pulp were detected, and then after avocado oil removed,the solubility, emulsification and emulsion stability of the pulp were studied. The experimental results showed that:(1) An analysis of basic compositions from fresh avocados pulp: water content is75.56%, crude fat content is 16.70%, protein content is only 1.64%, ash content is1.05%, carbohydrate content is 4.18%。(2)The optimal condition for avocado oil extracting by aqueous extraction was found as follows: material/liquid ratio is 1:6(g/m L); extraction duration is 3h;extraction temperature is 25℃ and centrifugal speed is 4400r/min. Under the optimal extraction conditions, the extraction rate of avocado oil is 72.86%.The oil is of high quality. As for the physical and chemical indexes, acid value is 0.62 mg/g, iodine value is 47.20g/100 g, saponification value is 197.80mg/g, peroxide value is6.40mmol/kg, which reached the national standard. Oil extracted by aqueous extraction from avocado was detected for fatty acid analysis.The result showed that avocado oil contain 19 kinds of fatty acids, and the unsaturated fatty acids are the main. In addition, 9c18:1, 11c18:1, 9c12c18:2n-6, C16:0 and 9c16:1 are the main fatty acids of avocado oil.(3) Based on the experimental results, alkali-solution and acid-isolation was chosen as the optimal protein extraction method. And the optimal conditions for extracting proteins from this material were determined to be: material/liquid ratio is1:15(g/mL); pH is 10; extraction duration is 2h; and extraction temperature is 40℃. A protein extraction rate of 49.13% was obtained under the optimal extraction conditions. In addition, isoelectric point of avocado pulp is 4.6.( 4) Also studying on the solubility, emulsifying and emulsion stability of avocados dregs after aqueous extraction of oil under different pH and temperature.The results showed that functional properties were changed with the change of pH and temperature. At isoelectric point of avocado protein around 4.6, it showed low solubility. Amino acid composition analysis results showed that avocado protein contains 17 kinds of amino acid. There are seven kinds of essential amino acid:threonine, valine, methionine, leucine, isoleucine, lysine and phenylalanine.