| Chaya,as "the ideal food and medicine"of Maya Indians,has many functions. However, after introduction and cultivation, Chaya's ecological environment has undergone tremendous changes, thus it is necessary to conduct systematic studies of it. To lay the foundationgs for the utilization of Chaya as new food resources or health food raw materials anti-nutritional factors and the main anti-nutritional components of the introduction of new resources Chaya were studied.Using the national standard or commonly used laboratory assay, the quantitative determination of the existence of anti-nutritional factors have been researched,after the qualitative analysis characterization of the types of anti-nutritional factors by systemic pre-test.The main anti-nutritional factors oxalic acid, tannin and cyanogenic glycosides and their content in the different processings have been studied prioritizely. The results are as follows:1 Qualitative analysis of anti-nutritional factors of Chaya:Chaya contained cyanide glycosides, organic acids, saponins and alkaloids, tannins, contains tannins and cardiac glycosides possibly and didn't contain glucosinolates and cohesion. Further characterization of alkaloids showed Chaya might contain toxic lentil base, veratridine, landlocked base, quinine, and scopolamine.2 Quantitative analysis of anti-nutritional factors of Chaya:Comparing experimental results with similar anti-nutritional factors of common food raw materials, the content phytic acid and trypsin were 0.28% and 589.5TIU/g, much lower than 12% of pytate bean meal and soybean trypsin inhibitor 5146TIU/g; urease activity were△pH=0.02, and correspond to the consumption of soybean meal and health standards urease activity is△pH≥0.02;the content of oxalic acid were 0.62%,Chaya as much as spinach with high content of oxalic acid; the content of tannin were 0.49%, higher than that in astringent persimmon fruits (0.25%); the content of cyanogenic glycosides were up to 119.37mg/kg,which is almost with content of cassava tubers (100～140mg/kg). This shows the main anti-nutritional factors are cyanogenic glycosides, oxalic acid and tannin in Chaya.3 The results of major anti-nutrional factors affected by commonly used methods of cook process:according to the characters of anti-nutritional factors of plant, combining with popular way of cooking food processing, blanch treatment (boiling water, and 70℃hot water), microwave heating, drying at atmospheric pressure, and atmospheric pressure steam heating were choosen,to treat with Chaya leaves in different age growth.The results showed that blanching in boiling water for 15 times water (11 times) and microwave treatment were the best, followed by blanching treatment with 70℃hot water, atmospheric pressure steam treatment and blast dried.The content of cyanogenic glycosides in mature leaves decreased from 119.37mg/kg to 2.59 (6.82) mg/kg, 4.47mg/kg,28.97mg/kg,37.37mg/kg, and 48.57mg/kg, respectively. The content of cyanogenic glycosides in tender leaves decreased from 144.34mg/kg to 5.38 (5.35) mg/kg,3.00mg/kg, 12.91mg/kg,14.25mg/kg and 39.40mg/kg (90℃). The content of tannin in mature leaves decreased from 0.52%to 0.15 (0.16)%,0.24%,0.22%,0.33% and 0.28%(30℃). The content of tannin decreased from 0.31% to 0.05 (0.05)%,0.30%,0.21%,0.14% and 0.30%(30℃)in tender leaves. The content of oxalic acid in mature leaves decreased from 0.62% to 0.13 (0.21)%,0.34%,0.17%, 0.46%,0.28%(30℃). The content of oxalic acid in tender leaves were much lower.This displays that the effect of different cooking processings on the degradation of anti-nutritional factors in young leaves were better than that in mature leaves.4 The research on the main component of cyanogenic glycosides in Chaya and their dynamic changes during the processing:According to foreign literature, the main components of cyanogenic glycosides were analyzeed using HPLC and LC-MS. The results showed that the main component of cyanogenic glycosides were linamarin,79.21 mg/kg in mature leaves, and 75.58mg/kg in tender leaves,which account to 66.36% and 52.36% of cyanogenic glycosides respectively in Chaya.Chaya leaves in different ages were dealed with blanching in boiling water using 11times orl5times water, blanching in 70℃hot water, microwave heating, atmospheric pressure steam treatment and 50℃hot air drying. The results showed that the content of linamarin in mature leaves decreased from 79.21mg/kg to 5.38mg/kg,5.49mg/kg,13.70mg/kg,32.72mg/kg,35.63mg/kg and 32.82mg/kg by different processings, and retention rate of them were 6.79%,6.93%,17.30%,41.31%,44.98%, 41.43 respectively.The content of linamarin in tender leaves decreased from 75.58mg/kg to 5.26mg/kg,5.49 mg/kg,14.67mg/kg,29.20mg/kg,35.42mg/kg and 29.58mg/kg by different processings, and retention rate of them were 7.96%,7.26%,19.41%,38.63%,39.14%,46.86% respectively. That blanching treatment can effectively reduce the content of linamarin.
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