The paper indicates that the yellow and purple cabbage recognize food

The borax detection kit in the food of Hue students is cheap, easy to use and especially the very simple "process" of production, everyone can do it.

With the desire to protect health for oneself, family and community, Duong Thi Ha Mi, Nguyen Phan Tuan Anh and Nguyen Phan Bao Loc, Huynh Thuc Khang Secondary School, Hue city, Thua Thien Hue province, have studied Successful directives for the discovery of food in food .

The paper indicates the use of yellow and purple cabbage.

Welding is the salt of boric acid used to preserve food from the first half of the twentieth century onwards. Today, science has proven that borax is toxic to humans. Welding can cause chronic poisoning, affect the liver, kidneys cause anorexia, body weakness. If using borax, although small in size, in a long time will affect health and is one of the causes of cancer.

Duong Thi Ha Mi shared, to make a color indicator paper, first cut absorbent paper into a length of 1-1.5cm, wash it in 96 degree alcohol solution. Then rinse with distilled water, dry or dried. Soak the absorbent paper into yellow turmeric extract or purple cabbage extract for 1 hour and dry, repeat 3 times, store in a sealed container.

In your experiment, when dip the color indicator paper into the borax solution by 1%, 2%, 3%, yellow turmeric paper will turn orange to reddish brown, cabbage purple paper will turn gray to blue. Yellow turmeric paper and purple cabbage paper do not change color in porcelain cups containing distilled water.

Nguyen Phan Bao Loc explained that the borax is alkaline, so when it comes to yellow paper, it makes the paper turn from yellow to orange to reddish brown. The indicator for purple cabbage is purple, in the alkaline environment will change from purple to gray to blue.

Also according to Bao Loc, clear and fast color changing directives, cheap prices, easy-to-make materials, easy-to-implement processes and easy to use. The authors hope that this handy "kit" will be widely applied in practice to ensure food hygiene and safety, and protect each person's health.