Musthofa Lutfi, Chakra Herlaut, N. Wahyunanto Agung
Nowadays many methods have been developed for non-destructive sorting system such as detecting aroma and fruit color but those methods was rarely used in the society because of the lack knowledge of people how to use those tools. Hence another method for non-destructive sorting system being developed by created a tool that using an alternative approach which are by giving a knock on the fruit skin and determining the ripeness of one fruit based on the sound frequency from the knocking. The fruit that used on this research was Juan Canary melon with an assumption that fruits from the Cucurbitacea family have a special characteristic on their skin, which the skin will get harder or softer when it comes to ripe. The aim of this research are to explain the theory of fruit ripe assessment by knocking on the fruit skin, created a simple tool that can be used to determining a fruit ripeness without injuring the fruit by using the knocking method on the fruit skin and to know the range of sound frequency from the fruit knocking on each harvesting age. From the tool test result that have been created, it was proved that the Juan Canary melon skin are going softer when its come to ripe, which is represented by the decreased value of the sound frequency. The sound frequency range from each harvesting age are 4.00 - 4.49 kHz for harvesting at 55th day; 2.38 - 2.91 kHz for harvesting at 60th day; 1.62 - 1.78 kHz for harvesting at 65th day; 1.61 - 1.62 kHz for harvesting at 70th day and 0.94 - 1.05 kHz for harvesting at 75th day. The sound frequency can be used to determining the quality (brix) of Juan Canary melon, the value of brix form the test was increasing day by day, thus make the relation between sound frequency and brix value was inversely proportional.
Department of Agricultural Engineering, Brawijaya University, Malang, Indonesia
