Study On The Preparation Technology

Maca(Lepidium meyenii Walp.), is a plant that can be used as food and medicine. Before 2000, it was used in Peru and it was unique for the improvement of human’s energy, sexual function and anti-cancer. At present, the products of maca were almost oral liquid and tablets whitch for high consumer groups, and few products for mass consumption. The situation led to a result that the maca products failed to take full advantage of the effect. In order to solve those problems, and fill the blank of the research of blanching and maca juice, the process of blanching, the preparation technology of maca raw juice, extracting juice, and cloudy juice were studied.① High temperature short time steam was used to blanch maca in this paper, response surface methodology(RSM) was employed. The optimization results showed that the optimum conditions were 133℃ of steam temperature and 170g of spheroniser load for 54s, relative activity of POD in maca was 4.9%. After 7d, the browning rate of unhandled maca was 52.66%, the loss rate of glucosinolates, alkaloid, Vc and total phenols were 45.68%,13.71%,20.27%and 15.13%. By comparing that the browning of maca could be effectively controlled, the nutrients could be well preserved.② The preparation technology of maca raw juice is that, at first, fresh maca was blanched, then juice was obtained by screw juice extractor and filtered, and it was clarified by chitosan. The optimization results showed that the optimum conditions were 0.22g/L of dosage and 39℃ of temperature load for 32min, the luminousness of maca juice was 98.36%. After clarification of the maca juice, the loss rate of pectin, water-soluble proteins, total phenols, glucosinolates, water soluble alkaloids, Vc and total sugar were 58.90%,42.93%,2.16%,0.56%,0.33%,0.34% and 0.89%. It showed that the nutrients could be well preserved by chitosan clarification. And the sanitary index is normal by detecting.③ The preparation technology of maca extracting juice is that, the optimization results showed that the optimum conditions were 4u/g of pectinase and 48.5℃ of temperature load for 32min, the content of glucosinolates was 0.3821mg/g in maca extracting juice. Extraction rate of glucosinolates, water soluble alkaloids, Vc, total sugar and total phenols were 70.37%,75.23%,89.91%,79.45%,84.45% and 87.93%. In the optimum extraction conditions, the effect of chitosan clarified maca extracting juice was studied, the optimal conditions were obtained by RSM were 0.21g/L of dosage and 45 ℃ of temperature load for 32min, the luminousness of maca extracting juice was 95.90%. After clarification of the maca extracting juice, the loss rate of pectin, water-soluble proteins, total phenols, glucosinolates, water soluble alkaloids, Vc and total sugar were 49.78%,30.91%,4.90%,2.63%,7.32%,5.17% and 0.97%. It showed that the cause of maca juice turbidity substances such as pectin, water-soluble proteins and phenols could be removed, and the nutrients could be well preserved by chitosan clarification. And last, the sanitary index in maca extracting juice is normal by detecting.④ The preparation technology of maca cloudy juice is that, the best condition were 0.09% of gum xanthan,280bar of pressure homogenised 2 times, the content of unstable suspended substance was 0.59. After 30d the maca cloudy juice in 4℃, leaching rate of glucosinolates, water soluble alkaloids, pectin, water-soluble proteins, Vc, total sugar and total phenols were 82.61%,67.86%,72.42%,70.78%,81.82%, 120.11%,81.42%. And last, the sanitary index in maca cloudy juice is normal by detecting.