Normally, pistachio shells should be light yellow, but bleached pistachio shells will be extremely white. Many use prohibited bleaching agents such as hydrogen peroxide and sulfur, so everyone must be especially careful when purchasing.
I. Pistachios: Don't buy those with white shells and yellow kernels
Although bleached pistachios look good in color, their nutritional value is greatly diminished, especially with severe losses in vitamins, anthocyanins, and unsaturated fatty acids. Moreover, some are bleached to cover up surface mold spots.
Pistachio shells should be light yellow. Depending on the variety, some kernels are green and the skin is purplish-red, but this is not always the case. Bleached pistachios have one characteristic in common—the shells are excessively white, and in some cases, even the kernels are bleached.
According to national regulations, only a few types of bleaching agents are permitted for use in nuts, such as sulfur dioxide and sodium sulfite. However, many of the excessively white-shelled pistachios currently on the market use prohibited bleaching agents like hydrogen peroxide and sulfur. Therefore, be sure to pay close attention when purchasing, especially for children. Do not buy those with shells that are too white and kernels that are yellowish (as they may be bleached). It is best to choose unsalted ones (roasted salted pistachios should be eaten sparingly as they are high in salt), those without a moldy or strange odor, and those that are in small, sealed packages.
Note that nuts are rich in intestinal lubricants—fats and dietary fiber. People prone to diarrhea or with acute gastrointestinal infections should not eat too many.
II. The Efficacy and Effects of Pistachios
They are warm in nature, with a pungent and astringent taste. They warm the kidneys and spleen, tonify deficiency, regulate the middle jiao and promote qi circulation. They can help treat neurasthenia, edema, anemia, malnutrition, and chronic diarrhea.
1. Stress Relief and Lipid Reduction: Pistachios are rich in arginine, which not only helps prevent atherosclerosis and lower blood lipids, but also reduces the risk of heart attacks, lowers cholesterol, and alleviates acute stress responses.
2. Vision Improvement: The purplish-red skin of pistachios contains anthocyanins, a natural antioxidant. The emerald green kernels are rich in lutein, which not only has antioxidant properties but is also very beneficial for protecting the retina.
3. Weight Management: Eating 28 grams of pistachios daily, about 49 kernels, will not lead to weight gain and can even help control weight. This is because the feeling of fullness usually takes about 20 minutes to register. Shelling pistachios extends the eating time, creating a sense of fullness and satisfaction, which helps reduce food intake and control weight.
4. Anti-Aging: Pistachios are nutritious; their kernels contain about 20% protein and 15%-18% sugar, and they can also be pressed for oil. The kernels also contain vitamin E, which has anti-aging effects and can enhance physical fitness.
5. Bowel Regulation: Pistachios are rich in oil, which has a lubricating effect on the intestines, aiding in bowel movements and helping the body detoxify.