Sulfites are used as preservatives, bleaching agents, color retention agents, bulking agents, reducing agents, etc. in the food and drug industry, and have excellent food modification effects. However, long-term excessive intake of sulfites can cause various toxicity, such as destroying vitamin B1, affecting growth and development, and susceptible to polyneuritis; causing gastrointestinal dysfunction and causing severe diarrhea, headaches, and liver damage. In addition, some people may be allergic to sulfites, especially asthma patients. Experiments have proved that sulfite has a certain reproductive toxicity to rats.
Based on the understanding of the toxicity of sulfite, the allowable daily intake (ADI) of sulfite proposed by the International Committee on Food Additives (JECFA) is 0-0.7mg/kg body weight (based on SO2 content). The food and drug regulatory authorities of various countries (regions) have different regulations on sulfite. EP stipulates that the SO2 content shall not exceed 50ppm. The limit of JP is 60ppm. The limit of USP is 40ppm. The limit of the 2000 version is 200ppm, while the standard of my country GB6783-94 stipulates A-grade edible gelatin. This index shall not exceed 40ppm, the B grade is 100ppm, and the C grade is 150ppm. The light industry standard QB2354-2005 of medicinal gelatin stipulates that the sulfite content shall not exceed 50ppm. my country's food additives use hygiene standards also stipulate that the content of biscuits, sugar, vermicelli, and cans shall not exceed 50ppm, and other varieties shall not exceed 100ppm. Among them, the EU has relatively strict restrictions on SO2 content. Not only does it stipulate that it is lower than 50ppm in EP, the EU pointed out in relevant regulations in 2005 that products with SO2 content higher than 10ppm are products containing allergens and need to be indicated on the label. The sulfite limit of the CP 2010 version of "Gelatin Hollow Capsules" and "Gelatin for Capsules" is 100ppm, which is gradually approaching the international advanced level.