Citrate and malate accumulation in banana fruit (Musa sp. AA) is highly affected by genotype and fruit age, but not by cultural practices

• Patterns of citrate and malate accumulation differed significantly among cultivars.
• Fruit age had a strong effect on accumulation of organic acids.
• Late harvested fruits had higher citrate and lower malate concentrations at maturity.
• Fruit load had no effect on accumulation of organic acids.
• Potassium fertilization had no effect on accumulation of organic acids.

Sourness and sweetness are major drivers of consumer preference for banana fruits and are mainly linked to the presence of citrate and malate. The objectives of the present work were to determine how agro-environmental and genotypic factors affect the concentrations of citrate and malate in banana pulp during growth and postharvest ripening. Changes in citrate and malate concentrations in the pulp during the development of the fruit were investigated in relation to fruit age, fruit load, and potassium fertilization in three cultivars of dessert banana presenting contrasted acidity at the eating stage. Major differences in the pattern of citrate and malate accumulation were found in the three cultivars both during growth and postharvest ripening. The fruit growth rate was greater when the fruit load was reduced, but this treatment had no effect on the accumulation of organic acids in any of the three cultivars. A high potassium supply increased fruit growth but had no effect on organic acid accumulation in any of the three cultivars. Late harvested fruits had higher citrate and lower malate concentrations in the pulp at the eating stage. Our results showed that the concentration of organic acids in banana pulp is mainly controlled by genotype and that this may be an interesting trait to target in breeding programs to improve the organoleptic quality of new cultivars. The physiological mechanisms likely to control the accumulation of citrate and malate during banana fruit development are discussed.