Adhering to the principle of "eating homemade to save money," I've always been a staunch advocate for bringing my own lunch. However, I recently discovered a rather critical issue: it turns out that many foods, when reheated, can become toxic and are unsuitable for the lunchbox crowd. What, you ask which foods are not suitable? Don't worry, just keep reading. Let's see which foods, when reheated, can lead to chronic poisoning.
1. Leafy Greens – Microwaving releases nitrites (which are carcinogenic)
Leafy greens contain varying amounts of nitrates. When microwaved or left for too long, the greens will turn yellow and spoil, and the nitrates will be converted by bacteria into toxic nitrites, which are carcinogenic.
2. Tremella (Wood Ear Mushroom) – Prolonged storage and reheating will convert it into nitrites
Whether cultivated indoors or on wood outdoors, tremella contains a significant amount of nitrates. If it's cooked and then left for too long, the nitrates will be converted into nitrites through bacterial action.
3. Cold Dishes – Prone to spoilage and should not be eaten overnight
Some people are in the habit of preparing the next day's bento box the night before. If you're one of them, you need to be especially careful not to put cold dishes into the box in advance. Cold dishes are more susceptible to contamination during preparation, and even when refrigerated, they are very likely to have spoiled by the next day!
4. Hairtail and Seafood – Nitrosamines can multiply several times overnight (damaging liver and kidney function)
Seafood also contains nitrosamines. After being left overnight, which means 8 to 12 hours later, the amount of nitrosamines can increase geometrically.
Editor's Tip: Cooking methods suitable for microwave reheating include steaming, braising, and stewing. Dishes cooked using these methods are less likely to change flavor or color when reheated in the microwave, whereas dishes that are deep-fried or stir-fried are clearly not suitable for reheating. It's worth reminding everyone that vegetables to be packed should be cooked to about 60-70% done to prevent further destruction of their nutrients when microwaved. Classic dishes like scrambled eggs with tomatoes and braised eggplant are quite suitable for the "lunchbox crowd."
These foods should not be reheated in the microwave repeatedly
1. Chicken
Reheating chicken in the microwave can be problematic because microwaves heat unevenly, causing some areas to get hot first. Chicken also has a higher protein density than other red meats, so when reheated, inconsistent protein breakdown can cause stomach upset. To ensure even heating, the chicken should be turned frequently.
2. Rice
The storage of rice is more important than reheating it. If stored at room temperature, it's very easy for bacteria to multiply, leading to toxin production that can cause vomiting or diarrhea. Reheating cannot eliminate these toxins.
3. Potatoes
Potatoes are popular, but they are tricky to store. If left at room temperature, especially when wrapped in foil which traps oxygen, they can easily grow Clostridium botulinum. Reheating cannot kill these bacteria, so they need to be stored in the refrigerator.
2. Rice
The storage of rice is more important than reheating it. If stored at room temperature, it's very easy for bacteria to multiply, leading to toxin production that can cause vomiting or diarrhea. Reheating cannot eliminate these toxins.
3. Potatoes
Potatoes are popular, but they are tricky to store. If left at room temperature, especially when wrapped in foil which traps oxygen, they can easily grow Clostridium botulinum. Reheating cannot kill these bacteria, so they need to be stored in the refrigerator.
4. Mushrooms
The protein in mushrooms is easily broken down by enzymes and other microorganisms. If stored incorrectly, reheating can cause stomach upset. However, if stored in the refrigerator for less than 24 hours, it is safe to reheat and eat as long as it is heated to above 70°C (158°F).
5. Spinach and Other Leafy Vegetables
Due to their growing environment, spinach and other leafy vegetables may contain high concentrations of nitrates. While nitrates themselves are not harmful, they can convert into carcinogenic nitrosamines. Nitrosamines can affect the blood's ability to carry oxygen and impact the health of young children. Therefore, it is not recommended to reheat spinach.