Abstract: Purpose: To understand changes in nutrient and hazardous substances during the growth of unearthed bamboo shoots. Methods: The starting point of the growth period of bamboo shoots from selected bamboo forests under the same cultivation conditions was just before breaking through the soil. Unearthed bamboo shoots with different heights labeled on the same day were harvested and analyzed for their nutrients and hazardous substances. The results revealed that crude protein content basically tended to decrease during the growth of bamboo shoots and decreased by 0.017 mg/(kg·cm) with increasing height. The proportion of essential amino acids occupying total amino acids displayed a gradual increase. No obvious change in crude fiber content was observed. The maximum content of nitrate in bamboo shoots was 175 mg/kg. In the height range of 5 to 15 cm, both nitrite and nitrate contents were less than 10 mg/kg. Conclusion: The nutritional value of unearthed bamboo shoots increases with the extension of growth period, and a very small amount of nitrite is accumulated. Therefore, higher bamboo shoots are a nutritional and safe food.

Key words: bamboo shoots, growth period, nutrients, nitrate