The physico-chemical and microstructural changes of “Rojo Brillante” persimmons in two maturity stages (S1 and S2) were evaluated during air drying. The maturity stage influences moisture loss. A Moisture level of approximately 50%, a limit at which persimmons are considered semidried, was reached after 21 and 28 days for S1 and S2, respectively. Shrinkage resulting from water removal led to secondary epidermis formation concomitantly to internal flesh gelling, which was related to moisture loss and water activity changes of each fruit part. The thicker epidermis and the lower volume of gelled area inside the S1 fruits led to harder fruit compared to the S2 fruits. The microstructural study revealed parenchyma degradation during drying in both the outermost area (secondary epidermis) and internal flesh, and this process was faster in S1 than in S2. The second peel presented hollows, generated by water outflow, which were bigger in S1 and explained the faster internal dehydration in S1. During drying, slight browning occurred, as reflected in the declining color parameters (L*, h* and C*). Water removal led to soluble solids tannin reduction to non-astringency values on day 28.

This study aimed to evaluate the concentrations of the main macroelements in leaves and fruit grown following organic and conventional practices, and to relate them to physico-chemical parameters during commercial fruit harvests. Three samplings were carried out during fruit maturation. Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined in leaves and in two fruit flesh areas: basal and apical. Weight, color, firmness, soluble tannins (ST), and total soluble solids (TSS) were also evaluated in fruit. During the study period, the lowering leaf N concentration was accompanied by its increment in flesh. Leaf P and K lowered but did not imply changes in these concentrations in fruit. N, P, and K concentrations were higher in the apical area than in the basal flesh. No changes in Ca concentration occurred in leaf, but Ca translocation from the basal to the apical area was detected in fruit. Management affected the concentrations of leaf K and Mg and the fruit N, P and Ca. The agronomic efficiency of the macronutrients in the organic crops was superior to that in the conventional crops. The Ca and Mg and the N/Ca and Ca/(K+Mg) ratios were closely related to color, firmness, TSS, and ST content.

Today, the ‘Rojo Brillante’ persimmons undergoing prolonged storage are treated with giberellic acid, which allows the delay of the harvesting to November-December. Although during this period the fruit maintained high commercial firmness, practical experience indicates very different behavior during the posterior cold storage, depending on the harvest moment. To explain what leads to these differences, an in-depth study of the physicochemical and microstructural changes occurring in the fruit during five commercial harvest times from November to December was carried out. During this period, slight variations in firmness occurred, ranging from 48 to 40 N. Nevertheless, the fruit behavior under cold storage was strongly influenced by the harvest date, which was explained by the degradation of cell wall, cell membrane and tonoplast, mainly noted in fruit from the latest harvests. Therefore, the fruit harvested with firmness close to 48 N had a highly structured cell, which maintained firmness during cold storage for up to 90 days. The fruit harvested with 43 N presented a more degraded structure, while the fruit with initial firmness around 40 N underwent major ultrastructure cell wall and membranes modifications, which led to greater firmness loss. Therefore, the fruit firmness at harvest is decisive for its storage potential.

This study investigated the effect of preharvest 1-MCP treatment on maintaining ‘Rojo Brillante’ persimmon firmness. Early in the season, preharvest 1-MCP was applied 1, 7 and 10 days after ethephon treatment. The fruit firmness was evaluated during three different harvests and after the commercialization period of 3 d at 3 °C, plus 6 d at 20 °C. Late in the season, 1-MCP was applied 3 days before harvest in the fruit treated with gibberellic acid (GA) and then cold-stored for up to 60 days, plus a 6-day shelf life at 20 °C. The results showed that preharvest 1-MCP delayed the fruit softening induced by ethephon during the harvest period, and was the most effective treatment when performed 1 day after ethephon application. Therefore, preharvest 1-MCP extended the harvest period of ethephon-treated fruit. At the end of the season, preharvest 1-MCP had the same effect on maintaining the fruit firmness as the commercial postharvest application.

This study evaluates mineral concentrations, biocomponents contents and fruit quality attributes in ‘Rojo Brillante’ persimmon grown under organic and conventional managements. During two seasons, the concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and boron (B) were determined in leaves and fruits. Weight, color, firmness, and total soluble solids (TSS) were also evaluated in fruits. Moreover, in the second season, organic acids (citric, succinic, and fumaric acids), main sugars (sucrose, glucose, and fructose), carotenoids (β-carotene, β-cryptoxanthin, violaxanthin, lutein, and zeaxanthin), phenolic compounds (gallic and ρ-coumaric), and ascorbic acid concentrations were determined in fruit flesh. The crop yield in the conventional plots was bigger than that for organic crops. Nevertheless, the highest agronomic efficiency was found in organic management. In general, the greater nutrient supply in the conventional compared to in the organic system did not result in higher concentrations of macro- and microelements in leaves and fruits. The organic fruit had higher color values and lower firmness values than the conventional fruit. The concentrations of malic acid, β-cryptoxanthin, and ascorbic acid were higher in the organic compared to in the conventional fruit, while no crop system effect was found in the other evaluated biocompounds.