本研究依行政院衛生署公告之食品中漂白劑之機驗方法-二氧化硫之檢驗-暫行方法,同時參照日本衛生試驗法注解食品中漂白料之檢驗方法與日本食品中の食品添加物分析法,對產地金針中二氧化硫殘留檢驗方法加以探討。結果顯示金針菜中二氧化硫殘留可以以通氣蒸餾法檢驗,惟檢體細切之長度以5mm~10mm為宜。添加之磷酸濃度及加熱時間分別以l%以上與5~10分鐘即可。以不含二氧化硫之5g新鮮金針中添加0.5~30.0ml NaHSO3(以SO2計:1mg/ml),10%磷酸10ml,加熱時間10分鐘,其二氧化硫之回收率可達93%以上,變異係數介鈴0.5~1.7%之間。將產地加工廠洽購之乾製金針分別浸於25℃冷水中60分鐘或45℃溫水中20分鐘,其二氧化硫殘留去除率可達70%左右,是為一理想之去除二氧化硫方法。
According to the testing method for bleaching agents in food-a sulfur dioxide test published by Department of Health, Executive Yuan, R.O.C. 1983, and Referred to Standard methods of bleaching agents analysis for Hygienic Chemists by Pharmaceutical Society of Japan, Methods of bleaching agents analysis for food additives by Bureau of Environmentary Sanitation, Health Department, Japan. Methods of analysis of residual SO2 in dehydrated Day Lily from production farm were discussed. The assay of residual SO2 could be achieved by distillation with N2 gas. However, the length of sample should be cut in 5~10 mm long. The concentration of phosphoric acid and heating time should be 1% or over and 5~l0 minutes, respectively. 5 g of Day Lily were added with 0.5, 1.0, 2.5, 5.0, 10.0, 20.0, 30.0 ml NaHSO3 (SO2:1 mg/nil) respectively and under conditions of 10% phosphoric acid 10 ml, heating time 10 minutes. The recovery of SO2 could reach over 93%, with a coefficient of variation was 0.5~1.7%. Soaking of dehydrated Day Lily in 25℃ cold water for 60 minutes or 45℃ warm water for 20 minutes was able to reduce the residual SO2 about 70%. This may be a proper method for SO2 reduction of dehydrated Day Lily.