My mother told me that the sesame seeds they grew in the countryside would not turn black when washed, so I used various methods to compare the sesame seeds I bought with the black sesame seeds grown in flower pots. , and found that it is more scientific to judge using the following method.

1. Look at the color. When the true black sesame seeds are not dried, the color is black, but after drying, the color of the black sesame seeds is dark gray, not dark black; the true black sesame seeds are usually mixed with white sesame seeds, yellow sesame seeds, and even some that have not been removed. The yellow sesame shells, while the dyed black sesame seeds look like they have no impurities, and the occasionally seen sesame stems are also dyed black. Without contrast in this method, it would be difficult for ordinary people to distinguish dyed and non-dyed sesame seeds by color.

2. Look at the hilum. There is a small dot at the tip of real black sesame seeds, which is gray-white in color. This is where the seeds germinate. All plant seeds have this obvious mark. The tips of dyed black sesame seeds are as black as the epidermis, and no white spots can be seen. This is because the hilum is also dyed black. This is the most critical point in judging true and false black sesame seeds. Therefore, you must carefully observe whether most black sesame seeds have hilum, and it is best to observe them in the sun, which will be more clear. However, today's black sesame seeds are usually mixed with half genuine and fake, dyed mixed with undyed. Usually some sesame seeds have hilum and most do not, so this method still cannot accurately tell whether it is dyed or not.

3. Scrape the skin. There is a layer of black skin on the outside of real black sesame seeds. After soaking, scrape it with your fingernails, and a layer of black skin will be scraped off; dyed sesame seeds will scrape out black powder, and when washed with water, only the sesame flesh will be left, and the black skin will disappear. But now Many sesame seeds are originally black sesame seeds, but merchants dye them to make them look darker and more beautiful. The scraped skin of black sesame seeds is also a layer of skin, so this is not the best way to identify them.

?4.? Soak in hot water. I think this method is the most reliable. The color of true black sesame seeds slowly precipitates after soaking in hot water, and finally it turns into light brown with a little light pink and purple. The color is clear and not turbid (see Figure 1); the color of dyed black sesame seeds precipitates immediately after brewing in hot water, and the water turns dark brown in the end. It is relatively turbid (see Figure 2); if you observe carefully, when the hot water is first poured into the bowl, you can still see some sesame seeds pulling out black smoke ribbons in the hot water. In addition, without kneading, after soaking dyed black sesame seeds, some of them will turn into white sesame meat or white sesame seeds (not kneaded sesame meat) for no reason. This will not happen with undyed black sesame seeds without kneading.

5. Fry in a pan. The dye used to dye sesame seeds melts easily when heated, so fry the sesame seeds over slow heat for a few minutes (be careful not to burn them). After the pot has cooled down, rub it with your fingers. If you dye sesame seeds, your hands will turn black. Wash your hands. The pot water is poured into the white porcelain bowl. The water is dark brown. However, natural undyed sesame seeds will not have such a situation, their hands will not turn black, and the water for washing pots will have no color. Some people say that the color of fried black sesame seeds will fade. I have done experiments and it turns out that they will not fade. The color of soaked black sesame seeds is the same as that of raw sesame seeds (picture 1). Therefore, that is a lie.

I compared the sesame seeds I grew with the sesame seeds I bought. After comparing more than 20 black sesame seeds, I finally found a natural sesame that is completely undyed. The sesame seeds there have hilums ( Small white dots), the color after soaking in water is exactly the same as home-grown black sesame seeds. Interested friends can communicate via private message. < /p>