The ancient medical book recorded:" If eat crab with perimmons together, it can make people suffer from diarrhea." The reason is that the crab includes the abundent protein, and persimmons contain a lot of tannic acid, the two eat together, will solidify and harden. In addition, the crab and persimmons all belong to the cold and cool things, at the same time can easily cause to uncomfortable if take it excessively (Da Zha, 2004).
Factors cause the crab and persimmons combination choice:
1. Taking persimmons before or after crab meal, especially during Chinese New Year.
2. Taking persimmon as appetizer and follow by a meal with crab.
3. Drink persimmon juice with crab meal.
5. Taking persimmon cake follow by a chili crab meal.
Crab contains the abundent protein and persimmons contain a lot of tannic acid. The tannic acid from persimmons inhibits the secretion of the digestive acids required for protein digestion. One tannin molecules binds two or more peptide groups, by formation of cross-link between the protein chains. The level of cross-linkage depends upon the number and accessibility of protein carbonyl groups per protein molecule and the relative concentration of the tannin. Tannin reacts with protein will form turbidity and a medium, coagulate the protein. The protein-tannin coagulate form will accumulate in stomach (D.K.Salunkhe, 1990).