Blanching is a common process when cooking, but can you really blanch water? Which ingredients need to be blanched, cold or hot? Blanching water, do it right to be healthy and save your life, and if you do it wrong, the nutrition and taste will be greatly reduced~
In this article, we will take an inventory of the ingredients that need to be blanched and how to blanch them correctly.
Which ingredients need to be blanched?
1 Vegetables high in oxalic acid
Oxalic acid is an anti-nutrient found in many vegetables, but there are differences in content. Excessive intake of oxalic acid in the daily diet can form insoluble substances with calcium before absorption, hinder the absorption of calcium, and after absorption, it can form poorly soluble oxalate with calcium and other substances in the body, increasing the risk of stones. [1] Vegetables such as Chinese cabbage, small white radish, cabbage, mung bean sprouts, carrot tasseled and other vegetables have very low oxalic acid content, and can be eaten with confidence. whereas
Copyright pictures in the gallery, reprinting and using may cause copyright disputes
Fortunately, oxalic acid is easily soluble in water, and hot water blanching can remove most of oxalic acid. Studies have shown that when 180g of spinach is blanched in 1000ml of boiling water for 1 minute, 2 minutes, 3 minutes and 4 minutes, the removal rates of soluble oxalic acid are 43%, 50%, 54.7% and 58.9%, respectively. The removal rate of oxalic acid in spinach by oil stir-frying is not good, not more than 5%, even if the amount of cooking oil is increased, it has little effect. [1] In addition,
2 "Poisonous" vegetables
Some vegetables are raw and toxin-carried, and if not blanched or eaten raw, it may cause food poisoning, which can be fatal.
Certain ingredients in fresh yellow cauliflower can cause nausea, vomiting, dry mouth, and diarrhea when consumed. As for what this ingredient is, it is not yet clear. In the past, it was thought to be colchicine, but the latest research has put forward a different view of the "toxic component" in yellow cauliflower, believing that yellow cauliflower does not contain colchicine, but contains a co-outflow component of multiple compounds, soluble in water, and can be decomposed by steam and blanching,[4]
3 Vegetables high in nitrite
When it comes to "nitrite", many people think of "carcinogenic". In fact, nitrite itself is not carcinogenic, but after it is eaten by us, it will produce nitrosamines in the environment of stomach acid, nitrosamines are carcinogens, excessive intake will increase health risks.
Therefore, vegetables with high nitrite content must be blanched before cooking. Some researchers evaluated the health and safety level of vegetables in a suburban area of Shanghai, and found that the nitrite content in fresh vegetables was generally low, the highest nitrite content in leafy vegetables was 19mg/kg, the nitrite content of onions, garlic, melons, beans, aquatic and nightshade fruits was lower, and the nitrite content of some vegetables was less than 0.1mg/kg. [5] Although you can eat it with confidence, but
Someone bought 6 toon samples from farmers markets and supermarkets, the nitrite content is 100~500mg/kg, cleaning 3 times can remove more than 50% of nitrite, its nitrite content is 50~200mg/kg, blanching for 1 minute can remove more than 90% of nitrite, and its nitrite content is 10~50mg/kg. [6]
Therefore, do not eat the dipping sauce again, even if it is scrambled eggs, you must blanch it first.
Copyright pictures in the gallery, reprinting and using may cause copyright disputes
4 Vegetable aquatic plants that may be contaminated with parasites are likely to be contaminated with parasites, such as those we often eat
Blanch the water and then mix it cold to ensure the safety of eating.
5 Vegetables that are not easy to clean Some vegetables have uneven surfaces, more potholes, it is easy to hide dirt, and it is more likely to have pesticide residues. Like what
6 Food with blood stains or a special smell
Animal foods such as ribs, lamb, and pork intestines may carry blood stains or odors, and blanching water can reduce their effects and improve the quality of dishes. While blanching, you can add cooking wine, fragrant leaves, star anise and other spices to increase the flavor.
Things you must know before blanching
Blanching seems simple, it seems to be a matter of "boiling water + ingredients", but there are still many precautions in actual operation.
Meat foods need a pan under cold water to help skim away blood droplets. If the boiling water pot will denature the protein on the surface of the meat, the outermost layer is directly cooked, resulting in the blood and water inside not coming out, can not achieve the purpose of removing blood stains, and the taste is not good. Vegetables need to wait for the water to boil before cooking. Although cold blanching has a higher removal rate than hot blanching, but
It is recommended to blanch fish and shrimp in boiling water for 1~2 minutes and then take them out, which can not only remove the fishiness, but also maintain the tender taste.
It is best to flood the ingredients with water, so as to ensure that after adding the ingredients, the water in the pot can boil again in a short time, shortening the cooking time and reducing nutrient loss.
Copyright pictures in the gallery, reprinting and using may cause copyright disputes
Oxalic acid is soluble in water, and the longer it is blanched, the higher the content of oxalic acid in the soup.
If you don't know if the vegetables you want to eat need to be blanched, then simply make boiled dishes. Drain the vegetables after they are out of the pan, add steamed fish soy sauce or light soy sauce, and drizzle with sesame oil or flaxseed oil, and it's a delicious dish! Boiling belongs to low-temperature cooking, compared with stir-frying, frying, frying can retain more nutrients, but also avoid the production of harmful substances, is quite recommended!
Resources
[1] Xia Wei. The effect of cooking on oxalic acid in vegetables[D].Soochow University,2007.
[2] WU Nu, LIU Liqing, WU Xianhui, TIAN Yanji, PAN Bin. Differences in oxalic acid content in purslane at different picking stages by fresh blanching and different picking stages[J].Agricultural Products Processing,2016(23):52-54.DOI:10.16693/j.cnki.1671-9646(X).2016.12.014.)
[3] YANG Mingfang,CHEN Wei,YI Yanzhong,LU Zhenyu,HU Jun. Laboratory analysis of a four-season bean saponin poisoning incident[J].Chinese Journal of Health Laboratory and Laboratory,2018,28(12):1520-1522.)
[4] MA Wei,GAO Jie,XING Qian,ZHAO Dan,ZHENG Xiaonan,JIE Minchang. Safety analysis of chilled yellow cauliflower[J].Modern Food,2021(23):153-155.DOI:10.16736/j.cnki.cn41-1434/ts.2021.23.045.)
[5] ZHU Weifang, ZHAN Xiuping, SONG Jia, et al. Risk assessment of nitrate and nitrite content and dietary intake of vegetables in a suburban area of Shanghai[J].Agricultural Product Quality and Safety,2023(02):89-93.)
[6] Cong Yunxia, Ding Shijie, Yang Yang. Study on toon nitrite[J].Food Safety Guide,2021(19):74-75.DOI:10.16043/j.cnki.cfs.2021.19.053.
[7] YANG Yuexin. Chinese Food Composition Table, 6th Edition, Volume 1[M].Peking University Medical Press,2018