| Maca (Lepidium meyenii) is a crucifer plant belonging to the Brassicaceae family. It grows in Andes at altitudes between 3500 m and 4500 m. Since 2008. maca was planted in Lijiang, Yunnan province. It was approved as a new resource food in 2011 in China. The components in Maca from Yunnan and Peru were analyzed systematically in this thesis. Simultaneous extraction of alkaloid and polysaccharide was researched. High-purity maca polysaccharides were obtained by grade preparation and their antioxidant activities were investigated. Finally, anti-fatigue function and safety of maca and its combination with traditional Chinese medicine were evaluated by animal studies. The main results obtained in this paper are as follows:(1) Component analysis of maca from Yunnan and PeruA comprehensive analysis of nutrients, secondary metabolic products, minerals, trace element and heavy metals was conducted. Results showed that maca from Yunnan contained more protein (16.32% to 12.49%), adenosine (214.88 μg/g to 25.49 μg/g) and amino acid (14.68% to 11.46%) than those from Peru, especially the contents of arginine (1.71% to 1.17%), polysaccharide (9.51% to 9.42%), alkaloid (0.126% to 0.083%) and macamide (0.06% to 0.05%), these all related to fertility and anti-fatigue are higher than those from Peru. In addition, the time-variant content of adenosine in maca was found for the first time.(2) The alkaloid and polysaccharide prepared by simultaneous extraction and scaled upThe orthogonal array test was used to determine the optimal extraction conditions, which were as follows:extraction twice,90 min each time, pH 4.5, solid to liquid 1:10, and the extraction recovery of alkaloid and polysaccharide reached 82.91% and 85.73% respectively. Then different drying methods such as vacuum, freeze and spray drying were investigated, and finally the spray drying conditions were as follows:the density 1.07 g/mL, inlet temperature 165℃ and feed rate 400 mL/min. Retention rate were 93.30% and 94.10% respectively for alkaloids and polysaccharides.(3) Grading preparation of maca polysaccharides and their antioxidant activitiesThe polysaccharides were deproteinized by Sevage method. Then amylase and glucoamylase were added in order to remove starch. Four kinds of maca polysaccharides (LMP-60、LMP-70、LMP-80 and LMP-90) were obtained by changing the ethanol concentration in the precipitation. All of the LMPs were composed of rhamnose, arabinose, glucose and galactose (1.81:6.85:1:3.21,2.18:9.47:1:5.21,1.49:6.87:1:3.5,0.83:2.68:1: 1.32). There was a positive correlation between the purity of LMPs and antioxidant activities. The scavenging rates for superoxide radical were higher than that of maca extract (the rate was 33.0%) with 85.88%、70.15%、60.03%、37.64% for LMP-60、LMP-70、 LMP-80 and LMP-90, respectively.(4) Anti-fatigue of maca extractTotal of 160 healthy male mice were randomly divided into 4 groups to examine load swimming time, BUN, HG, and BLA, respectively. Results showed that compared with control group, load swimming time and the content of HG in different dosage groups increased, while the content of urea nitrogen and lactic acid decreased. Therefore, maca extract powder could alleviate physical fatigue.(5) Safety evaluation of maca extract and epimedium extract combinationThe acute toxicity test by oral administration in mice, three terms of genetic toxicity test and the 30 day feeding test in rats were used to evaluate the safety of maca extract and epimedium extract combination. No obvious toxic symptoms and death were found during the 2 week observation. Negative results were observed in the three terms of genetic toxicity test. Dosages of sample, which were corresponding to 100,50,25 times daily dosage in human respectively, were fed to the rats for 30 days. Compared with the control group, indexes of weight, weight gain, food intake, food utilization, blood routine index, blood biochemical indicators, viscera weight and viscera/weight ratio in the three dose groups were not significantly different (P>0.05).(6) Anti-fatigue of maca extract and epimedium extract combinationMale mice were used to test the anti-fatigue of maca extract and epimedium extract combination, maca extract and epimedium extract with different doses for 30 days. The result showed combination group had better effect than that of the single extract group with the same dosage. The former could prolong the swimming time, accelerate BLA clearance, promote HG storage, and reduce the content of BUN. |
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