| Kiwi fruit juice is the main deep-processing products, It is a favorite drink, The rapid detection of the main chemical composition of the fruit juice is of great significance for the producing and quality control. The thesis analyzed the ingredients difference among the different kiwi fruit varieties through the determination of the carbohydrate,organic acids and phenolic substances of six varieties of 60 samples,which are developed on the main producing areas of Kiwifruit in Meixian County and Zhouzhi County,Shaanxi, in 2005 / 2006 and 2006/2007; A rapid detection method of carbohydrate and organic acids in the kiwi fruit juice via the Near-infrared spectra was established. The main results of this paper are as follows:1. Polyphenols is detected in kiwifruit juice of the five varieties (Hayward, Qin mei, Yate, Xu xiang and Red yangtao) through HPLC,the results showed that : Kiwi fruit juices contain the protocatechuic acid, chlorogenic acid, epicatechin, caffeic acid and hyperin. Of which : Hayward's caffeic acid content is the largest, reaching 2.423 mg/L; Qin mei's chlorogenic acid is the most, reaching 2.627 mg/L; Ya te's caffeic acid is the largest, reaching 2.763mg/L; Red yangtao's caffeic acid is the largest, reaching 3.738 mg/L; Xu Xiang's chlorogenic acid is the most, reaching 3.186 mg/L.2. Total phenol in kiwi fruit juice is 441.82 ~ 729.55mg/L, caffeic acid and chlorogenic acid are as the main polyphenol substances, Their contents are in 2.319 ~ 3.738mg/L and 1.072 - 3.186mg/L respectively; Epicatechin and hyperin. content are in second which are of 0.894 ~ 2.533mg/L and 0.688-1.319mg/L respectively; protocatechuic acid content is relatively low that is just 0.337 - 0.916mg/L.3. Using Ion chromatography to analyze carbohydrate of fruit juice of six varieties (Hayward, Qin mei, Ya te, Xu xiang, Red yangtao and 95 -1) the results showed : glucose and fructose are the main suger for kiwifruit juice, Their contents are in 19.49 ~ 52.91g/L and 10.65 ~ 14.81g/L respectively; followed by sugar, the content is 3.97~30.44g/L. Of which : Hayward, Qin mei, Xu xiang ,95-1 contains more glucose , followed by fructose, sucrose is lest; glucose in Ya te is the largest, followed by sucrose, fructose minimum; Red yangtao contains highest sucrose, glucose and fructose are smaller.4. Using Ion chromatography to analyze organic acid of kiwifruit juice of six varieties (Hayward, Qin mei, Ya te, Xu xiang, Red yangtao and 95 -1) the results are as follow : citric acid content is the largest which is of 65.97 ~ 729.68mg/L, malic acid is in second , the content is of 47.9~194.91mg/L,tartaric acid content is at least,it is 12.66~ 54.75mg/L.5. Using Near Infrared Spectrum to determine the content of the glucose, fructose, sucrose, malic acid, tartaric acid and citric acid in kiwi friut. The results show that partial least squares (PLS) method of quantitative analysis, Spectra pretreatment methods and spectrum options for the chemical constituents are different. For glucose using a derivative + straight deduction, Spectral range is of 6098 ~ 11995.4cm-1; For fructose used less in a straight line. Spectral range of 4242.8~5450-1 and 6098 ~11995.4cm-1; sucrose used for a less linear, spectral range of 7498.1~9746.8cm-1; malic acid used for vector normalization method, spectral range of 7498.1~9746.8 cm-1; tartaric acid for use of a vector to the law, spectral range of 7498.1~9746.8cm-1; citric acid used for a less linear, spectral range of 7498.1~9746.8cm-1;6.Based on the Near Infrared Spectra , a rapid detection method of carbohydrate and organic acids in the kiwi fruit juice is establashed. Using the Near-Infrared spectroscopy , rapid detection of glucose, fructose, sucrose, malic acid, tartaric acid and citric acid are achieved .
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