PROBLEM TO BE SOLVED: To continuously and highly accurately measure an air content (overrun) in line in the production of a food and drink containing bubbles and exemplified by ice cream and whipped cream.SOLUTION: The value of the overrun of a mix flowing through piping is calculated on the basis of a correlation between a measured value obtained by carrying out the measurement with a microwave densitometer for a food and drink containing the bubbles, the overrun of which is already-known, and the already-known value of the overrun and on the basis of a measured value obtained by measuring the mix flowing through the piping and containing the bubbles with the microwave densitometer in the production process of the food and drink containing the bubbles.
