Abstract: In this study, the proximate nutrient composition and flavor substances of Chinese toon (fresh young leaves and buds of Toona sinensis) from different growing areas of Henan province were investigated. The contents of total proteins, total saponins, total alkaloids, and total flavonoids were determined by routine methods. Amino acid composition was determined by using an amino acid analyzer. Volatile compounds were determined by gas chromatography-mass spectrometry (GC-MS). The results showed that Chinese toon from Luoyang exhibited the highest contents of total proteins, total saponins, total alkaloids and total flavonoids among the four areas. A total of 17 amino acids were detected, including 7 essential amino acids. Chinese toon from Luoyang showed the highest contents of both total amino acids and essential amino acids, which were 274.82 and 86.09 mg/g, respectively. A total of 75 aroma compounds were identified, 52, 48, 47 and 46 of which were detected in Chinese toon from Yuanyang, Zhongmou, Anyang and Luoyang, respectively. Terpenes were present as the dominant compounds in all four samples, and the number of terpenes detected in Chinese toon from Luoyang was the largest. Thus, Chinese toon from four growing areas have significant differences in proximate composition and flavor substances. All the above results suggested that the quality of Chinese toon from Luoyang was better. The geographical origin of Chinese toon should be taken into account when processing it into various products.

Key words: different growing areas, Toona sinensis, nutrients, flavor substances