Abstract: The present invention relates to a method for monitoring the quality of red pepper powder, comprising the steps of: estimating at least one of a first particle size and a first moisture content of a first red pepper powder, based on the spectroscopic image data of the first red pepper powder obtained in or before and after at least one of the grinding process, filtration process and sterilization process of red pepper powder; calculating a second spicy level, based on at least one of the first particle size and the first moisture content, and the spectroscopic image data; and estimating a third spicy level of a first mixed red pepper powder in the mixing process, based on at least one of the first particle size and the first moisture content, the second spicy level, and an input amount of the first red pepper powder.