What foods are incompatible with preserved eggs (pidan)?
Preserved eggs (pidan) may contain alkaline substances along with duck or chicken eggs, and may interact negatively with foods such as beer, honey, tofu, persimmons, and brown sugar. Detailed explanations are as follows:

1. Beer
Consuming preserved eggs with beer may lead to interaction between the carbon dioxide in beer and the alkaline components in preserved eggs, potentially accelerating the absorption of indigestible substances from the preserved eggs in the gastrointestinal tract. This may increase the burden on the digestive system, and long-term excessive intake could adversely affect the liver and kidneys.
2. Honey
The organic acids and enzymes in honey may react with the alkaline substances in preserved eggs, causing protein denaturation. This may not only reduce nutritional value but also irritate the gastrointestinal tract, causing discomfort.
3. Tofu
Consuming preserved eggs with tofu may result in the combination of proteins in tofu and alkaline components in preserved eggs, potentially forming compounds that are difficult for the human body to absorb. This may interfere with nutrient absorption and easily cause indigestion.
4. Persimmons
Consuming preserved eggs with persimmons may be problematic because persimmons contain large amounts of tannic acid. When tannic acid encounters proteins and alkaline substances in preserved eggs, it may easily form indigestible precipitates, increasing the burden on the digestive system and, in severe cases, causing gastric stones.
5. Brown Sugar
Consuming preserved eggs with brown sugar may cause acid-base imbalance. Preserved eggs are alkaline, while brown sugar is acidic. When both enter the body simultaneously, they may undergo acid-base neutralization reactions, producing substances that are harmful to health and potentially affecting nutrient absorption.
However, the above foods are not absolutely prohibited from being consumed with preserved eggs. They can also be appropriately combined in daily diets to maintain dietary diversity. If discomfort occurs after consuming certain food combinations, prompt medical consultation is advised.