熏蒸过的竹笋中二氧化硫的检测和卫生标准的探讨

Determination of SO_2 in Bamboo Shoots and Their Hygienic Standards

目的对用硫磺熏蒸过的竹笋样品SO2残留量进行测定和研究,为国家或地方重新制定竹笋的二氧化硫标准提出了数据和依据。方法竹笋分成散装干笋、散装水发竹笋和袋装浸泡竹笋。散装干笋与水按照1∶10和1∶20作浸泡试验,每12h更换一次浸泡液,测定每次竹笋样品和浸泡液中的SO2残留量;散装水发竹笋直接测定;袋装浸泡竹笋分别直接测定和按包装袋上的"食用方法"处理后测定。结果散装干笋的SO2残留量都大于0.05g/kg,但经浸泡48h后,样品中的SO2残留量都低于0.05g/kg;39.3%的水发竹笋和83.5%的袋装浸泡竹笋SO2残留量超过0.05g/kg。袋装浸泡竹笋经过按包装袋上"食用方法"处理后,仍有60.0%竹笋的SO2残留量超过0.05g/kg。结论建议散装水发竹笋和袋装浸泡竹笋的SO2直接测定,标准定为0.15g/kg为宜。

Objective To investigate SO2 residues in sulfur fumigated bamboo shoots and provide hygienic standards. Method There were dry unpacked bamboo shoots, soaked unpacked bamboo shoots and soaked pre-paeked bamboo shoots in markets. The dry samples were soaked in water with a ratio of 1 ： 10 and 1 ： 20, and changed water every 12 h. The SO2 residues in samples and soak solutions were tested. Results The SO2 residues in dry samples were more than 0.05 g/kg, but less than 0.05 g/kg after soaking in water for 48 h. The SO2 residues in 39.3 % of soaked unpacked samples and 83.5 % of packed soaked samples were more than 0.05 g/kg. After treating bamboo shoots with the methods on the package, the SO2 residues in 60% of pre-packed soaked bamboo shoots, were still greater than 0.05 g/kg. Conclusion It is suggested that the SO2 residues in water soaked bamboo shoots should be determined directly and assessed with a appropriate standard of 0.15 g/kg.