Chlorophyll fluorescence for classification of tomato fruits by their maturity stage

Classification of tomato fruit and control of post-harvest maturation based on the stage of maturity at harvesting, are necessary to ensure the highest possible quality and marketability of the final ripe product. A method of sorting tomatoes to assess the degree of their maturation based on the control of their chlorophyll fluorescence induction is proposed. Tomatoes (Black baron) at five different stages of maturity were used. Variance analysis (ANOVA) was performed and the Duncan’s mean values were compared at a significance level of p ≤0.05. In addition, the correlation between the chlorophyll fluorescence induction parameters and the maturity of the same fruit was carried out using the statistical software SPSS 20.0. The general pattern of fluorescence induction analysis was revealed; as the fruit matures, the value of both maximum fluorescence induction (Fm ) and the coefficient of specific photosynthetic activity of tomatoes (Kf ) decreases. Both Fm and Kf exhibited a statistically significant difference (p ≤0.05) between stages of maturity. A very strong negative correlation between slow chlorophyll fluorescence induction parameters (Fm and Kf) and maturity were observed. Moreover, there is a strong positive correlation between Fm and Kf . In conclusion, the slow induction of chlorophyll fluorescence is a good indicator of the degree of maturity of tomato fruits and the proposed method had better reflected the actual ripening process of fruit per maturity stage.