ANALYSIS OF SAMPLES OF FREEZING SLICES OF FRUIT OF CHINESE HAWTHORN(CRATAEGUS L.) AND ITS NUTRIENT EVALUATION
低温冷冻干燥山楂果片的分析研究和营养评价

Owing to the abundant nutrients and specific function for health protection and medical treatment, Crataegus fruit is widely cultivated in North China and the output has been ever increasing in recent years. To further develop and to protect the resource of Crataegus, a new processing method,, the freeze-drying me-thod, is adopted to dry Crataegus slices under the condition of natural low tem-perature by utilizing the rule of the phase change of water instead of the traditional heat-drying process. It has been shown that the efficiency of the freeze-dried fruit slices by this method is much higher than that of the heat-dried pieces. The aim of this paper is to make a chemical analytical comparison in some respects between the freezing-dried slices and the heat-dried pieces. It is shown that the nutrients such as the pectine, the total acid, the total carbohydrates, the flavone and Vitamins C, B1, B2, E etc., especially Vitamin C in the freeze-dried slices is retained much more than those in the heat-dried pieces. And, by analy-zing the rate of preservation of nutrients it is shown that the loss of nutrients in the freeze-dried slices is much less than that in the heat-dried pieces; especially the rate of loss of the flavone in the freeze-dried slices accounts only 2%, while that in the heat-dried piece reaches 80%.