A standard way of grading pineapple in Thailand is as follows. The first step is to judge the optimum time for the harvesting of the fruit, which growers do by calculating the number of days until anthesis. After the crop arrives at the factory, graders subjectively sort the fresh pineapple into different maturity levels. The graders judge maturity based on the pitch of the sound that is produced when the fruit is tapped and also by assessing the weight of the fruit. According to the standards of pineapples for industrial processing in Thailand, the maturity is judged by the translucent yellow area of the flesh (Ministry of Agricultural and Cooperatives, 2000).