The pivotal role of phytohormones during fruit development and ripening is considered established knowledge in plant biology. Perhaps less well-known is the growing body of evidence suggesting that organic acids play a key function in plant development and, in particular, in fruit development, maturation and ripening. Here, we critically review the connection between organic acids and the development of both climacteric and non-climacteric fruits. By analyzing the metabolic content of different fruits during their ontogenetic trajectory, we noticed that the content of organic acids in the early stages of fruit development is directly related to the supply of substrates for respiratory processes. Although different organic acid species can be found during fruit development in general, it appears that citrate and malate play major roles in this process, as they accumulate on a broad range of climacteric and non-climacteric fruits. We further highlight the functional significance of changes in organic acid profile in fruits due to either the manipulation of fruit-specific genes or the use of fruit-specific promoters. Despite the complexity behind the fluctuation in organic acid content during fruit development and ripening, we extend our understanding on the importance of organic acids on fruit metabolism and the need to further boost future research. We suggest that engineering organic acid metabolism could improve both qualitative and quantitative traits of crop fruits.

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Modifications in Organic Acid Profiles During Fruit Development and Ripening: Correlation or Causation?

Blackberry (Rubus ulmifolius Schott): Chemical composition, phenolic compounds and antioxidant capacity in two edible stages.

Biochar is superior to lime in improving acidic soil properties and fruit quality of Satsuma mandarin

The concentrations of sugars and organic acids as well as the total soluble solid (TSS) in different parts of the strawberry fruit were characterized. The data were used to create simulated fruit juice jellies, in order to clarify how the sugar and organic acid levels affect the taste. Such an approach eliminates the influence of external factors such as size, color, and texture when using real fruits in sensory evaluations. Further, the use of a jelly allowed us to simulate the concentration differences between various parts of the fruit. In the strawberry fruit, the sugar content is higher in the apex than in the peduncle; however, the level of organic acids is the same throughout. It was revealed that the sweetness and sourness in the apex and peduncle could be sufficiently recognized by humans as tastes. Also, a layered jelly sample replicating the sugar and acid distribution in real strawberry was perceived as less sweet and more sour, compared to a homogeneous one with the same overall composition. The likely reason is that the sourness in the peduncle is accentuated by the low TSS level, which decreases the TSS/total organic acid ratio that affects the sweetness/sour perceptions. Based on these results, factors for the appropriate sensory evaluation of fresh fruits in general were considered. Specifically, the distribution of sugars and organic acids in the fruit should be analyzed first, and bite-sized parts with concentrations close to the average provide the most accurate evaluation results.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/fsn3.1109

Effects of distribution of sugars and organic acids on the taste of strawberries

Supplemental intracanopy far-red radiation to red LED light improves fruit quality attributes of greenhouse tomatoes

Fruit sugar and organic acid were significantly related to fruit Mg of six citrus cultivars.

The invention discloses special fertilizer capable of increasing the yield and improving the quality for fruit stabilizing period and fruit strengthening period of Guanxi honey pomelos and an application method thereof. The special fertilizer for the fruit stabilizing period and fruit strengthening period is prepared from nitrogen, phosphorus pentoxide, potassium oxide, magnesium oxide, humic acid, boron and molybdenum according to a certain proportion. The application method of the special fertilizer is characterized in that in the fruit stabilizing period of the Guanxi honey pomelos, i.e., the first ten-day of March in each year, the fruit stabilizing period special fertilizer is applied in one step in a furrow application mode at the application quantity of 2.5 to 3.5kg/plant; in the fruit strengthening period of the Guanxi honey pomelos, i.e., the last ten-day of July, the fruit strengthening period special fertilizer is applied in one step in a furrow application mode at the application quantity of 2.0 to 3.0kg/plant. The formula of the special fertilizer is reasonable; a series of problems of fertilizer application of the Guanxi honey pomelos in Pinghe county in Fujian province are solved; the yield of the Guanxi honey pomelos is improved; the quality of the Guanxi honey pomelos is improved. The special formula fertilizer application method is simple and reasonable; different fertilizer is applied in different periods.

Special fertilizer capable of increasing yield and improving quality for fruit stabilizing period and fruit strengthening period of Guanxi honey pomelos and application method thereof

The invention provides a fertilizer additive for reducing nitrate in outdoor vegetables and leaching loss of soil nitrate nitrogen. The fertilizer additive comprises 3, 4-dimethylpyrazole phosphate and chitin; a fertilizer is an inorganic fertilizer or a mixture of the inorganic fertilizer and an organic fertilizer; the addition amount of the 3, 4-dimethylpyrazole phosphate is 1% of N in the inorganic fertilizer; the addition amount of the chitin is 0.30%-0.62% of N in the inorganic fertilizer; chitosan is taken as the basis. According to the fertilizer additive, the content of the nitrate inthe outdoor vegetables and the leaching loss of the soil nitrate nitrogen can be effectively reduced, the quality of the vegetables is improved, and the environment stress is relieved.

He Weizhu

Papers

Fruit sugar and organic acid were significantly related to fruit Mg of six citrus cultivars.

Special fertilizer capable of increasing yield and improving quality for fruit stabilizing period and fruit strengthening period of Guanxi honey pomelos and application method thereof

Fertilizer additive for reducing nitrate in outdoor vegetables and leaching loss of soil nitrate nitrogen