Model for evaluation of maturity index of durian fruit (Durio zibethinus Murray 'Monthong')

Abstract

Durian is one of the most popular and famous seasonal fruits in Southeast Asia. However, the fruit has more problem on maturity detection than any other fruits. A major problem in exporting Thai durian is that a large percentage of immature fruit. Reliable maturity indices have not been fully developed. Based on sensory tasting of unripe durian pulp., panelists could significantly rank the stages of maturity and this correlated well (R =0.8) with the ranking of the harvesters using the external characteristics of the fruit. Panelists and harvesters ranked the maturity into 5 levels from level of 50%, which is the immature fruit to 90%, which is fully mature. Objective detection of maturity index was developed through assessment and measurement of some biochemical changes at different stages of maturity from three different years. It was found that dry matter content was significantly correlated to the maturity level and could separated the critical stage of immature fruit of 60% level from the minimum acceptable mature stage of 70%. However, dry matter values differed each year. Therefore, appropriate maturity indices are developed from mathematical models and combinations of various quality factors.