| As the third largest drupe in yield, the apricot takes an important role in fruit market ofthe world and has great nutritional value. Because of the short shelf life and the difficulty instorage transportation, the apricot products are mainly traded in the form of concentratedapricot pulp around the world. The export of apricot pulp in China has been at the forefront ofthe world in recent years, and Xinjiang province has the largest share. However, the sale profitof apricot pulp is very low and its market demand is so unstable that the export has to sufferrestriction. In addition, the domestic consumers don’t like eating jam and traditionally thinkthat eating too many apricots is unhealthy. To solve the problem of production and marketingradically, it is necessary to deeply investigate the apricot processing technology to increasethe added value of apricot.There are many types of alpha hydroxy acids with highly physiological activity in theapricots which play an important role in the metabolic system of our body. They could beapplied in many fields, such as cosmetics, medicine and some other areas. Extraction of thehigh purity alpha hydroxy acid from apricot pulp will be a new breakthrough in apricotindustry and a new direction in the field of alpha hydroxy acid. The main research contentswere as follows:(1) The types and contents of alpha hydroxy acids in the concentrated apricot pulp fromXinjiang were detected with high liquid chromatography method. There were eight alphahydroxy acids in the apricot pulp. The contents of malic acid, lactic acid and citric acid were59.83%,21.39%and15.50%, respectively.(2) Viscozyme L can effectively improve the juice yield and the clarity of concentratedapricot pulp. The results showed that the juice yield of apricot pulp was58.9±0.79%at thecondition of1:2(w/w) solid-liquid ratio,40~45℃and2h for Hydrolysis. And, transmittancewas91±0.28%, the soluble solids content was10.2±0.1°Brix, total sugar content was86.15±1.04g/L, total acid content was16.94±1.32g/L and the extraction rate of AHA was92.29±1.32%.(3) In the present study, in regards to the higher decoloration rate and the lower acid lossrate, compared with other seven decolorants, powdered activate carbon was selected as theoptimum decolorant. The results showed that the optimum decoloring conditions were theaddition of activate carbon1.2g/100mL,70℃and60min, and the decoloration rate was93.01±1.22%, the acid loss rate was5.89±0.14%.(4) To select the best adsorbent for isolation and purification of alpha hydroxy acid in theapricot pulp, static adsorption and desorption experiments were carried out. And the ionexchange resin SQD56was selected as the optimum resin among seven resins. Here weoptimized the adsorption of alpha hydroxyl acids by experiments at different conditions, theadsorption quantity reached as high as up to135.81±1.33mg/g of the resin SQD56at samplesolution concentration of16g/L, temperature of20℃and flow rate of3BV/h. And weoptimized the elution rate by experiments at different conditions. The results showed that theoptimum elution conditions were the ammonia concentration of4%, temperature of40℃, flow rate of3BV/h and elution volume of6BV, and the elution rate was76.52±1.88%.(5) The types and contents of alpha hydroxy acids extracted from the apricot pulp weredetected with high liquid chromatography method. The contents of malic acid, lactic acid andcitric acid were62.12%,22.05%and14.21%, respectively. The result was similar with thefront result, the extraction technology was useful.(6) To investigate the anti-aging activity of alpha hydroxy acids, aging model wereestablished by injected D-galactose into mice. The results showed that alpha hydroxy acidsolution could effectively delay skin-aging both at low concentration (5%) and highconcentration (10%). The histomorphology of skin tissue of the high-dose group manifestedthat the layers of skin tissue were clear, the thickness of epidermis and dermis layer increasedand collagenous fibers were aligned tightly and regularly. The SOD vigor and contents of Hypand total protein were significantly increased while the contents of MDA were decreasedsubstantially. The alpha hydroxy acid at10%concentration had a better anti-aging activity. |
PDF Full Text Request