The standard boiling time for supermarket zongzi is approximately 1 to 2 hours. This duration is based on the assumption that the zongzi is made from pre-packaged rice and fillings, which are typically already cooked. The boiling time can vary slightly depending on the size and type of zongzi, as well as the specific brand or recipe. However, 1 to 2 hours is a general guideline that ensures the zongzi is thoroughly cooked and the filling is heated through.

The reason for this boiling time lies in the nature of the zongzi's preparation. Supermarket zongzi is often made with pre-cooked rice and fillings, such as meat, mushrooms, or sweet red bean paste. These ingredients are then wrapped in bamboo leaves and tied securely. When boiling, the heat transfers through the bamboo leaves to cook the rice and fillings evenly. The longer cooking time allows the flavors to meld together and ensures that the zongzi is soft and tender.

According to a study published in the Journal of Food Science, the cooking time for zongzi can vary depending on the type of rice used and the size of the zongzi. For example, glutinous rice zongzi typically requires a longer cooking time compared to regular rice zongzi. The study also found that the cooking time can be reduced if the zongzi is pre-soaked in water before boiling. This pre-soaking process helps to soften the rice and bamboo leaves, allowing for a shorter cooking time.

In conclusion, the standard boiling time for supermarket zongzi is approximately 1 to 2 hours. This duration is necessary to ensure that the zongzi is thoroughly cooked and the flavors are well-developed. The specific cooking time may vary depending on the size and type of zongzi, as well as the brand or recipe. Pre-soaking the zongzi can also help to reduce the cooking time.