Whether for baozi or jiaozi, the common fillings are limited to a few types. The animal-based sources include pork, beef, lamb, eggs, and shrimp, while plant-based sources are chives, cabbage, celery, fennel, and carrots. These ingredients are highly nutritious on their own, and their combination is beneficial for a balanced diet. However, in practice, to make the filling rich and flavorful, people tend to use more meat and less vegetable to avoid a dry, "tough" texture. Additionally, it is traditional to squeeze the juice out of the vegetables during preparation, a process that causes a significant loss of soluble vitamins and nutrients like potassium. According to the principle of balancing acid and alkaline in the diet, "acidic" meats, eggs, and refined white flour should be balanced with "alkaline" vegetables. For instance, a reasonable combination for a filling would be one part meat to three parts unsqueezed vegetables.
Sea Kelp and Wood Ear Mushrooms are Best for Fillings
To achieve a smooth, soft, and juicy filling, large amounts of fatty meat, animal fat, and vegetable cream are often added. The meat used in fillings is typically at most 70% lean, with a fat content usually exceeding 40%. Even fillings made with low-fat fish and shrimp have animal fat added to improve the texture. This introduces a large amount of saturated fat and calories, which is detrimental to health. To achieve true nutritional balance in filled foods, one must start with the ingredients: reduce the amount of fatty meat and animal oil, and increase the proportion of vegetables. Meat fillings should be paired generously with vegetables rich in dietary fiber, supplemented with foods high in soluble fiber, such as shiitake mushrooms, wood ear mushrooms, tremella, and various mushrooms, as well as seaweeds like kelp and wakame. These can improve the texture, help reduce the absorption of cholesterol and fat, and control the rise in blood lipids after consuming meat fillings. Bamboo shoots also have a fat-absorbing effect. Various soy products and fish can also be used as fillings to replace a portion of the meat, which helps lower the fat content. It is also important to note that when eating these filled foods, one should avoid high-fat dishes and instead pair them with light, cold-dressed vegetables.
Vermicelli Should Not Be a Primary Filling
In comparison, vegetarian fillings based mainly on eggs and vegetables are healthier. The fat in these comes from vegetable oil, and the proportion of vegetables is relatively high. Since eggs are high in phosphorus, these fillings should be paired with green leafy vegetables rich in calcium, potassium, and magnesium, as well as ingredients like dried shrimp and seaweed to promote acid-base balance. Pure starch materials like vermicelli have low nutritional value and should not be used as the primary ingredient in fillings. From a cooking perspective, filled foods with a high vegetable content and little meat are high in moisture and prone to falling apart ("散"). Boiling them results in significant nutrient loss and a poor texture. Methods like pan-frying and steaming are better options. Conversely, filled foods with a high meat content are suitable for boiling and steaming, and it's best to minimize the use of oil-frying and deep-frying to avoid adding extra fat.