Nuts are a great snack for tea time or after meals because they are fragrant, delicious, and highly nutritious, making them a natural delicacy. However, not all nuts are good for your health. You should stay away from the following six types of toxic nuts.
With a rancid smell.
Nuts contain a large amount of unsaturated fatty acids. Improper storage or prolonged storage can lead to rancidity, resulting in the "rancid" smell we often talk about. The danger of fatty acid rancidity in nuts is twofold: on one hand, it makes the nuts taste worse, producing a pungent, irritating taste. On the other hand, the products of oil rancidity in nuts, such as small molecule aldehydes and ketones, pose a threat to health. If consumed in large quantities, it can cause diarrhea in mild cases, and in severe cases, it may lead to liver disease. Nut vendors are generally reluctant to discard spoiled nuts. The best way to mask the "rancid" smell is to add large amounts of salt, Sichuan peppercorns, star anise, saccharin, essence, and other seasonings during processing. Therefore, spoiled nuts are often hidden in salty, five-spice, or creamy-flavored nuts. In comparison, the quality of plain or lightly roasted nuts is generally better.
Moldy.
Many nuts are susceptible to contamination by Aspergillus flavus, leading to mold and the production of a highly toxic substance—aflatoxin. This can cause fever and vomiting in humans, and in severe cases, it can be life-threatening. Aflatoxin also has powerful carcinogenic properties and causes great damage to human organs. Therefore, moldy nuts must not be eaten. If you detect a bitter, moldy, or pungent taste in the nuts in your mouth, spit them out immediately and rinse your mouth promptly.
Roasted until burnt.
Nuts contain large amounts of fat, protein, and carbohydrates. Ordinary heating is not enough to destroy them. However, when nuts are roasted until burnt, the temperature is already above 200°C. At this point, these originally beneficial nutrients begin to partially convert into carcinogenic substances such as benzopyrene, heterocyclic amines, and acrylamide. Therefore, burnt nuts are not suitable for consumption.
"Beautified" with paraffin.
On one hand, adding paraffin during nut processing makes the product look fresher and more appealing, and it also prevents them from becoming damp or soft. If you see nuts that are unusually shiny and "prettier" than ordinary nuts, they may have been treated with paraffin. On the other hand, some vendors add paraffin to nuts that have been in stock for a long time and have a poor color to "beautify" them and pass them off as higher quality. The industrial paraffin used by vendors is not of high purity and contains impurities such as heavy metals, which are harmful to health.
Too heavily flavored.
First, the stronger the flavor, the more salt is often added. Second, many heavily flavored and aromatic nuts have added substances like essence and saccharin during processing, and creamy-flavored nuts also contain artificial cream, none of which are good for your body. Finally, the heavier the flavor of the nut, the greater the possibility that it is spoiled.
Covered in dust.
Responsible vendors pay attention to the cleanliness of nut raw materials and the dust-proofing of their products. However, it's not uncommon to find products on the market with a lot of impurities like dust in the raw materials and no protection from dust during sales. Therefore, when purchasing, it's best to take a close look at the bottom of the container holding the nuts. Unclean nuts often leave a layer of dust at the bottom of the container.