The content of heavy metals in vegetable products exceeds a certain amount and is also detrimental to human health. Therefore, the enrichment of heavy metals is also one of the important contents of the sanitary quality of vegetables. The allowable amount of heavy metals in vegetable products is shown in Table 9-2. Table 9-2 Permissible heavy metals in vegetable products (mg/kg) Heavy metal indicators Standard Source Mercury (Hg) ≤ 0.01 GB2762-94 Lead (Pb) ≤ 0.2 GB 14935-94 As (As) ≤ 0.5 GB 4810-94 Chromium (Cr) ≤ 0.5 GB 14961-94 Copper (Cu) ≤ 10 GB 15 199-94 Cadmium ( Cd) ≤ 0.05GB15201-94 Zinc (Zn) ≤ 20GB13106-91 The allowable amount of pesticides in vegetables has been stipulated by the country. The limit standards are: 666 ≤ 0.2 mg/kg; DDT ≤ 0.1 mg/kg; dichlorvos ≤ 0.2 mg/kg; dimethoate ≤ 0.1 mg/kg; malathion, parathion and phorate are not detectable Out; fenitrothion ≤ 0.4 mg/kg; fenthion ≤ 0.05 mg/kg. Deltamethrin: leaf vegetables ≤ 0.5 mg/kg; fruits and vegetables ≤ 0.2 mg/kg. (To be continued) Combined Nd Ib Eds H9N2 Killed Vaccine Killed Vaccine For Chicken,Four Combination Vaccine,Combined Nd Ib Eds Ai Vaccine,Combined Nd Ib Eds H9N2 Killed Vaccine Shangqiu Meilan Biological Engineering Co.,Ltd , https://www.melanvaccine.com
With reference to the daily allowances for nitrate intake set by the World Health Organization and the UN Food and Agriculture Organization of the People's Republic of China, the allowable nitrate content of vegetables in China is calculated to be 432 mg/kg fresh weight. If the salt and cooking losses are added at 45% and 70%, respectively, this limit can be expanded to 785 mg/kg and 1440 mg/kg, which raises the degree of nitrate pollution and health assessment standards for vegetables in China ( Table 9-1).
Table 9-1 Pollution degree of nitrate in vegetables and health assessment standard grade Nitrate content (mg/kg fresh weight) Pollution degree Hygiene evaluation 1 ≥ 432 Mild permissible raw food 2 ≥ 785 Moderate unacceptable raw food, allowed salted, cooked food 3 ≥1440 height should not be eaten raw, salted, allowed cooked food 4≥3100 not allowed to eat
Relationship between vegetable quality and fertilization (2)
2. Hygienic quality The hygienic quality of vegetables is also called safety quality. It mainly refers to the degree of chemical pollution and biological pollution. During the period of mass application of human excrement, the sanitary quality of vegetables is dominated by biological contamination such as pathogens and parasite eggs; under the conditions of using chemical fertilizers, pesticides and sewage irrigation, the sanitary quality of vegetables is nitrate accumulation and heavy metal enrichment. Sets and pesticide residues as the main content. All these health quality countries have corresponding standards or indicators.