Rojo Brillante Research Articles

Phenotypic and Gene Expression Analysis of Fruit Development of ‘Rojo Brillante’ and ‘Fuyu’ Persimmon (Diospyros kaki L.) Cultivars in Two Different Locations

Fruit development and maturation rely on intrinsic genetic programs involving hormone biosynthesis and signalling and environmental cues, integrating phenological cycles and climatic issues encompassing abiotic stresses and climate change. In persimmon trees, environmental inputs strongly influence fitness and agricultural performance, and fruit yield can be severely compromised by them. We have grown two persimmon accessions (‘Rojo Brillante’ and ‘Fuyu’) under contrasting meteorological conditions of two locations in Spain and Japan. Fruit size, colour change, and firmness parameters were followed during fruit development from 30 days after fruit set until commercial ripening, and the expression of genes related to ethylene production and signalling, gibberellin response, carotenoid biosynthesis, cell wall dynamics, and oxidative stress were reported. Genes depending on intrinsic developmental programs (ethylene and ripening variables, mostly) showed common expression trends in both cultivars and locations, whereas gibberellin and abiotic stress-related genes mimicked reduced fruit growth and abiotic stress associated with higher summer temperatures (>35 °C) and lower rainfall reported in the Spanish location. The expression pattern of these genes is consistent with a growth–defence trade-off that explains fruit differential growth through hormonal and stress tolerance mechanisms.

The effect of pretreatments on the drying of persimmon with infrared energy

AbstractThe effects of various pretreatments, including edible coatings, on drying kinetics and some physical quality parameters of persimmon varieties (Fuyu and Rojo Brillante) and differences between varieties were investigated. The experiments were conducted at an infrared radiation intensity of 1210 W m−2 and air velocity (v) of 1.5 m s−1. Drying time differed depending on pretreatments and varieties. Pretreatments generally shortened the Fuyu variety's drying time and increased the Rojo Brillante variety's drying time. Lower specific energy consumption and higher diffusion coefficient values were recorded for the Rojo Brillante variety compared to the Fuyu. In terms of quality parameters, the Fuyu variety generally obtained lower values for shrinkage. Rehydration rate was higher for the Rojo Brillante variety. Total color change was lower in the Rojo Brillante variety. Based on the pretreatments applied, xanthan gum gave better results in terms of operational parameters. In terms of quality parameters, ascorbic acid had better results for rehydration rate and shrinkage. For total color change, better results were obtained in arabic gum pretreatment. As a result, when an evaluation is made regarding variety differences and pretreatments applied, the Rojo Brillante variety can be recommended for drying.Practical applicationsPersimmon is a popular fruit in appearance, flavor, and rich nutritional content. The high moisture and sugar content in the fruit increases spoilage in a short time, making it difficult to consume in all seasons. For this reason, different preservation methods are being investigated to extend the shelf life. Sun drying and other drying methods developed as an alternative to these methods have many disadvantages. Different pretreatments prevent the negativities that occur in other drying methods. Especially, edible coatings can increase product quality by preserving color and appearance as well as controlling mass transfer, flavor, and aroma losses. This study investigated the effects of various pretreatments, including edible coatings, on drying kinetics and some physical quality parameters of persimmon varieties, as well the differences between varieties. Based on variety differences and pretreatments applied, the Rojo Brillante variety can be recommended for drying in terms of both processing and drying characteristics.

Influence of temperature on ‘Rojo Brillante’ persimmon drying. Quality characteristics and drying kinetics

A physico-chemical characterization and drying kinetics study was performed for whole ‘Rojo Brillante’ persimmon subjected to hot-air drying at 35 ᵒC, 40 ᵒC and 45 ᵒC. Fruit was dried until a moisture content of 30 g water/100 g product, which is required to be considered dried persimmon. This moisture value was obtained after 12, 8 and 7 d when the drying process was applied at 35 ᵒC, 40 ᵒC and 45 ᵒC, respectively. All the drying treatments caused flesh structure changes, shrinkage and secondary epidermis formation. The final product's quality characteristics especially the texture, strongly depended on drying temperature. The fruit dried at 35 ᵒC exhibited a gelatinous internal texture and a thin secondary epidermis, similarly to that obtained during a natural drying process. The drying treatment at 40 ᵒC resulted in fruit having more rubbery flesh. However, the fruit dried at 45 ᵒC had a corky texture, with a very thick secondary epidermis that resulted in excessively tough fruit for commercialization purposes. The differences in flesh structure were revealed in the microstructural study by Cryo-FESEM. In all cases, soluble tannins content lowered to non-astringency values. Hot-air drying technology proved to be a good alternative to valorize discarded ‘Rojo Brillante’ persimmon.

Ionomic Concentration and Metabolomic Profile of Organically and Conventionally Produced ‘Rojo Brillante’ Persimmon

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.

Astringent and non‐astringent persimmon cremogenates made with different thickeners

SummaryDue to the surplus in the production of ‘Rojo Brillante’ persimmon in Spain, there is great interest in developing products made from this fruit that can take full advantage of production peaks. However, heat treatment can reverse the astringency, limiting the diversity of products derived from persimmon. The aim of this study was to characterise physicochemically astringent and non‐astringent persimmon cremogenates subjected to pasteurisation and elaborated with different thickeners (guar gum, sodium alginate and pectin). Several aspects were specifically analysed: the evolution during the storage of the soluble solid content, water, total phenols, antioxidant capacity, optical and mechanical properties, as well as the microbiological stability. The sensory acceptability of the selected cremogenates was also evaluated. The results showed that the final colour of the samples depended on the initial level of astringency of the raw material; the non‐astringent persimmons were much darker (L* ≈ 40–50) than astringent persimmons (L* ≈ 65–70), and the type of thickener used had no effect and led to no difference. Furthermore, the cremogenate was harder (F ≈ 20–120 N) when astringent persimmons were used. In astringent cremogenates the thickeners evaluated help in reducing the total phenol content after 3 months of storage in 40% when compared to the control. The heat treatment applied (70 °C, 30 min) did not reverse the astringency, so this type of cremogenate could be a commercial outlet for the waste or surplus of this fruit. In this regard, non‐astringent persimmons with pectin would be recommended for the preparation of cremogenates from this fruit since they were also those that the scored best in the sensory analysis.

Estimation of Macro and Micronutrients in Persimmon (Diospyros kaki L.) cv. ‘Rojo Brillante’ Leaves through Vis-NIR Reflectance Spectroscopy

The nutritional diagnosis of crops is carried out through costly elemental analyses of different plant organs, particularly leaves, in the laboratory. However, visible and near-infrared (Vis-NIR) spectroscopy of unprocessed plant samples has a high potential as a faster, non-destructive, environmental-friendly alternative to elemental analyses. In this work, the potential of this technique to estimate the concentrations of macronutrients such as nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg), and micronutrients such as iron (Fe), manganese (Mn) and boron (B), in persimmon (Diospyros kaki L.) ‘Rojo Brillante’ leaves, has been investigated. Throughout the crop cycle variable rates of N and K were applied to obtain six nutritional status levels in persimmon trees in an experimental orchard. Then, leaves were systematically sampled throughout the cropping season from the different nutritional levels and spectral reflectance measurements were acquired in the 430–1040 nm wavelength range. The concentrations of nutrients were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) for P, K, Ca, Mg, Fe, Mn and B after microwave digestion, while the Kjeldahl method was used for N. Then, partial least squares regression (PLS-R) was used to model the concentrations of these nutrients from the reflectance measurements of the leaves. The model was calibrated using 75% of the samples while the remaining 25% were left as the independent test set for external validation. The results of the test set indicated an acceptable validation for most of the nutrients, with determination coefficients (R2) of 0.74 for N and P, 0.54 for K, 0.77 for Ca, 0.60 for Mg, 0.39 for Fe, 0.69 for Mn and 0.83 for B. These findings support the potential use of Vis-NIR spectrometric techniques as an alternative to conventional laboratory methods for the persimmon nutritional status diagnosis although more research is needed to know how the models developed one year perform in ensuing years.

Evaluation of Removed and Recycled Mineral Nutrients in Italian Commercial Persimmon Orchards

Persimmon is a typical fruit crop of the Mediterranean region and, since it is considered a minor species, little information is available on its nutrients need. In the present experiment, it was estimated the quantity of removed and recycled nutrients by Kaki Tipo and Rojo Brillante, the two main varieties of persimmon grown in Emilia-Romagna region (Po Valley, Italy). Plants from ten mature orchards were selected and harvested; organs (leaves in summer, fruits at harvest, abscissed leaves, roots and skeleton) biomass and mineral composition were determined. The yearly uptake of macronutrients was similar for the 2 varieties, accounting for (kg ha−1): N 89-91, P 10-11, K 79-91, Ca 132-162, Mg 22-26 and S 9. While K was mostly found in fruits, Ca and Mg were mainly partitioned to leaves. Among micronutrients, Mn and Fe showed the highest values (1.1–1.3 and 1.2–2.1 kg ha−1, respectively), followed by B (370 g ha−1), while Cu and Zn showed the smallest amounts (less 100 g ha−1). Nitrogen, Ca, Mg and S were those more recycled than removed, while K showed an opposite trend; among the microelements, the annual recycled fractions of B and Mn were higher than that removed.

Dynamics of ethanol and its metabolites in fruit: The impact of the temperature and fruit species

The objectives of this study were to: i) determine the effect of temperature on the ethanol vaporization rate, ii) determine the effect of temperature on the uptake rate of fruit species and cultivars, iii) understand the relationship between the temperature that ethanol is applied, ethylene metabolism, and respiration rate of fruit, and iv) evaluate the interaction between temperature that fruit are submitted to ethanol treatment on the metabolites produced by them as a response to ethanol treatment. The ethanol vaporization rate was performed in an empty container experiment at 2, 10, and 20 °C. Four experiments were conducted to identify the ethanol uptake rate in ‘Maxi Gala’ and ‘Cripps Pink’ apples, ‘BRS Isis’ table grapes, and ‘Rojo Brillante’ persimmons at 2, 10, and 20 °C. The metabolites produced by the fruit as a response to the ethanol treatment were determined using HS-SPME-GC/MS analysis. Our findings showed that the ethanol vaporization rate increases exponentially with the temperature and has a linear relationship with time. Moreover, the temperature and fruit species/cultivar affected the ethanol uptake rate, with the highest uptake rate at 20 °C. Furthermore, ethanol vapor uptake rate was positively correlated to respiration rate when all fruit species/cultivars were evaluated together, showing that fruit metabolism affects ethanol uptake rate. The temperature impacted the metabolite produced by fruit from ethanol application, evidencing the possibility of managing the volatile compounds produced from ethanol based on the ethanol treatment temperature. The fruit species has a decisive impact if ethanol is esterified or transformed to acetaldehyde, being predominantly esterified in apples and grapes, and converted to acetaldehyde in persimmons. Ethanol vapor treatment reduced the ethylene metabolism in apples at 20 °C, although ethanol increased ethylene in persimmons at 2 °C. Moreover, the respiration rate was generally unaffected or reduced in ethanol-treated fruit compared to untreated fruit of the same species/cultivar.

Evaluation of the Bioactive Compounds, and Physicochemical and Sensory Properties of Gluten-Free Muffins Enriched with Persimmon 'Rojo Brillante' Flour.

Because of the nutritional need of patients with celiac disease, producing quality gluten-free diet food is important. This study evaluated the use of persimmon flour on the properties of muffins. Persimmon flour obtained from the astringent variety 'Rojo Brillante', which is often discarded due to its characteristic astringency, was added to muffins replacing corn flour (10%, 20%, and 30%). Despite the height differences between the control muffin and the muffins with persimmon flour, similar mechanical parameters were obtained. As the percentage of persimmon flour increased, the muffin color was darker, turning toward a more reddish hue, mainly because of the intensification of nonenzymatic browning reactions. The sensory results showed high scores for taste attributes, the texture attributes were similar to the control, and astringency was hardly detected when persimmon flour was used. The content of tannins and carotenoids and their antioxidant activity increased significantly with an increasing amount of persimmon flour. After in vitro digestion, high recovery index values of soluble tannins and carotenoids were obtained in muffins with added persimmon flour. This study shows that the use of persimmon flour as a functional ingredient offers an opportunity to develop quality gluten-free muffins that reduce agricultural losses. Astringent varieties can be used, without applying a de-astringency treatment, as the astringency is removed during muffin baking due to tannins' insolubilization.

Determining transpiration coefficients of ‘Rojo Brillante’ persimmon trees under Mediterranean climatic conditions

There is scarce knowledge on what are the actual water requirements of persimmon trees (Diospyros kaki). Research on this topic is required to better adjust irrigation water supplies to the actual crop water needs. This study aimed to determine the transpiration coefficients (Kp) of persimmon ‘Rojo Brillante’ trees and assess how transpiration and Kp are influenced by environmental factors and the atmospheric demand under Mediterranean climatic conditions. This was done over the course of three growing seasons by means of sap flow measurements calibrated with whole canopy gas exchange chambers. Irrigation was applied aiming to avoid water limiting conditions for trees. This was verified by monitoring the trees’ water status across the growing seasons. Sap flow measurements were linearly and highly correlated (p < 0.001) with canopy transpiration (Ep) obtained with the whole canopy chambers, but either overestimated or underestimated it. Ep increased from April until June-July in response to canopy development and increased midday canopy light interception. There was a positive linear relationship between daily Ep, reference evapotranspiration (ETo) and solar radiation. However, a non-linear relationship was obtained between Ep and vapor pressure deficit (VPD). A positive non-linear relationship (p < 0.01) was observed between Kp (Ep / ETo in non-limited water conditions) and VPD, illustrating the low stomatal regulation that persimmon trees exhibit in response to air dryness. Kp varied over the growing seasons following the ETo pattern although showing comparatively a slighter decrease during the last part of the growing season. From June to September, Kp of persimmon ‘Rojo Brillante’ trees with a midday photosynthetically active radiation (PAR) intercepted of ~30 % ranged from 0.45 to 0.56. A strong relationship was obtained between Kp and percentage of midday intercepted PAR that can be used to estimate Kp of persimmon ‘Rojo Brillante’ trees with a range of ground canopy covers. This information is useful for deriving specific water use models for persimmon trees to be implemented in decision support systems. The monthly transpiration coefficients here provided will be useful for optimizing irrigation scheduling decisions in persimmon orchards and therefore irrigation water management.

DRIS Norms and Sufficiency Ranges for Persimmon ‘Rojo Brillante’ Grown under Mediterranean Conditions in Spain

The aim of this study was to establish DRIS (Diagnosis and Recommendation Integrated System) norms and Nutritional Optimal Ranges (NOR) for ‘Rojo Brillante’ Protected Designation of Origin (PDO) ‘Ribera del Xúquer’. The database contained 800 leaf samples collected in different crop phenological stages [after flowering (AF), fruit enlargement (FE), fruit colouring (FC), and harvesting HV)]. DRIS norms (78) were established for macronutrients: N, P, K, Ca, Mg and S; micronutrients B, Cu, Fe, Mn, and Zn and salinity elements: Na and Cl. The Nutrient Balance Index (NBI; the absolute value of the sum of the DRIS indices) was used to determine the optimal sampling period. Fruit enlargement was the period during which persimmon trees were more nutritionally balanced regardless of sprout origin (vegetative or floral) and irrigation type (drip or flood) in orchards

Effect of Preharvest 1-MCP Treatment on the Flesh Firmness of ‘Rojo Brillante’ Persimmon

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.

Slight Changes in Fruit Firmness at Harvest Determine the Storage Potential of the ‘Rojo Brillante’ Persimmon Treated with Gibberellic Acid

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.

Leaf and Fruit Nutrient Concentration in Rojo Brillante Persimmon Grown under Conventional and Organic Management, and Its Correlation with Fruit Quality Parameters

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.

An in vitro digestion study of tannins and antioxidant activity affected by drying “Rojo Brillante” persimmon

This study focuses on the evaluation of soluble and insoluble tannins and their antioxidant activity in fresh and dehydrated “Rojo Brillante” persimmon after in vitro digestion. Persimmon and its derived products contain a high amount of tannins with high antioxidant activity. An inversely proportional relationship between soluble and insoluble tannins was observed marked by the deastringency and hot air-drying treatments. Furthermore, the antioxidant activity after the hydrolysis of insoluble tannins was greater compared to soluble tannins. After small intestine in vitro digestion, the recovery of soluble tannins was higher in samples dehydrated at 40 and 60 °C, and insoluble tannins remained intact. Therefore, soluble tannins could be absorbed in the small intestine and insoluble tannins could reach the colon microbiota, both indicating potential health-promoting properties. Therefore, hot air drying and freeze-drying are alternative treatments to develop dehydrated persimmon snacks or powdery ingredients to improve nutritional properties of new foods.

Detection of Invisible Damages in 'Rojo Brillante' Persimmon Fruit at Different Stages Using Hyperspectral Imaging and Chemometrics.

The main cause of flesh browning in ‘Rojo Brillante’ persimmon fruit is mechanical damage caused during harvesting and packing. Innovation and research on nondestructive techniques to detect this phenomenon in the packing lines are necessary because this type of alteration is often only seen when the final consumer peels the fruit. In this work, we have studied the application of hyperspectral imaging in the range of 450–1040 nm to detect mechanical damage without any external symptoms. The fruit was damaged in a controlled manner. Later, images were acquired before and at 0, 1, 2 and 3 days after damage induction. First, the spectral data captured from the images were analysed through an algorithm based on principal component analysis (PCA). The aim was to automatically separate intact and damaged fruit, and to detect the damage in the PC images when present. With this algorithm, 90.0% of intact fruit and 90.8% of damaged fruit were correctly detected. A model based on partial least squares—discriminant analysis (PLS-DA), was later calibrated using the mean spectrum of the pixels detected as damaged, to determine the moment when the fruit was damaged. The model differentiated fruit corresponding correctly to 0, 1, 2 and 3 days after damage induction, achieving a total accuracy of 99.4%.

Hydroxypropyl Methylcellulose-Based Edible Coatings Formulated with Antifungal Food Additives to Reduce Alternaria Black Spot and Maintain Postharvest Quality of Cold-Stored ‘Rojo Brillante’ Persimmons

Composite edible coatings based on hydroxypropyl methylcellulose (HPMC), as a polymeric phase, and oleic acid (OA) or beeswax (BW), as a hydrophobic phase, were formulated with different food additives as antifungal ingredients. HPMC–OA coatings containing 2% (w/v) sodium benzoate (SB), 1% ammonium carbonate (AC), 1% potassium carbonate (PC), 1% potassium bicarbonate (PBC), 1% sodium bicarbonate (SBC), 1% potassium silicate (PSi), 0.1% sodium methyl paraben (SMP) or 0.1% sodium ethyl paraben (SEP), and HPMC–BW coatings containing 2% sodium propionate (SP), 2% PBC, 2% SB or 0.1% SEP were evaluated for the control of Alternaria black spot (ABS) on Diospyros kaki Thunb. ’Rojo Brillante’ persimmons artificially inoculated with Alternaria alternata. After 14 days of incubation at 20 °C, HPMC–OA coatings formulated with PBC, PC or SEP were the most effective to reduce ABS incidence (61, 54, and 36% reduction, respectively, concerning uncoated control fruit) and severity (28, 12 and 22% reduction, respectively), while only HPMC–BW coatings formulated with SEP significantly reduced ABS incidence (50% reduction) and severity (36% reduction). HPMC–OA and HPMC–BW coatings containing 2% PBC or 0.1% SEP were selected to evaluate their effect on the weight loss, firmness and respiration rate of healthy ‘Rojo Brillante’ persimmons cold-stored at 1 °C and 90% relative humidity (RH) for 15 and 30 days, followed by 7 days of shelf life at 20 °C. HPMC–BW coatings were more effective in reducing fruit weight and firmness losses than HPMC–OA coatings, while all antifungal coatings significantly reduced fruit respiration. Overall, the HPMC–BW edible coating that contains SEP could be a promising postharvest treatment to control ABS and maintain the quality of cold-stored ‘Rojo Brillante’ persimmons.

Natural Drying of Astringent and Non-Astringent Persimmon "Rojo Brillante". Drying Kinetics and Physico-Chemical Properties.

Persimmon (Diospyros kaki L.f.) crop has markedly increased in Spain, and “Rojo Brillante” persimmon is the main cultivated variety. This astringent cultivar requires de-astringency treatment before commercialization, which may involve an extra cost. Its short commercial season implies handling large volumes of fruits with consequent postharvest losses. Therefore, the development of derived added-value products is of much interest. In this study, astringent and non-astringent “Rojo Brillante” persimmons were dehydrated by following a natural drying method used in Asia. The drying kinetics and physico-chemical properties were analyzed for 81 days. The results indicated subsequent reductions in weight, water content, and water activity throughout the drying process, and the equatorial diameter decreased. All the employed thin-layer mathematical models were suitable for representing the drying characteristics of both products with similar behavior. The effective water diffusivity values were 5.07 × 10−11 m2 s−1 and 6.07 × 10−11 m2 s−1 for astringent and non-astringent persimmon samples, respectively. The drying treatment significantly decreased the soluble tannins content, and the astringent samples obtained similar values to those obtained for the non-astringent samples in 20 days. The external and internal flesh of the astringent fruit remained orange through the drying period, while brown coloration in the non-astringent fruit was observed after 57 drying days. Therefore, prior de-astringency treatment would not be necessary.

Application of a new wax containing ethanol as a method to remove persimmon astringency during cold storage.

Nowadays the treatment based on applying high CO2 concentrations to fruit is the main method used in astringent persimmon prior to being commercialized, but it can cause quality problems for fruit during cold storage. The aim of this study was to evaluate the effectiveness of a recently patented astringency removal method based on applying a new wax whose formulation includes ethanol before commercial packaging. During two seasons, three treatments were evaluated in cv. Rojo Brillante and Triumph: (1) CO2- standard treatment; (2) waxed and packed in plastic film according to the patented method; (3) packed in plastic film without any treatment. During a third season, the new method's effectiveness in removing astringency was evaluated under industrial conditions. After treatments fruit was stored at 0°C for 15, 21 and 30days before being transferred at 20°C to simulate a 5-days shelf-life. All the fruit treated with the new wax completely lost astringency after 30days at 0°C, and commercial firmness was maintained. At the end of the storage, fruit quality was substantially higher in fruit submitted to the new treatment. CO2-treated fruit, manifested internal browning after 30 storage days and shelf-life, while this disorder was not detected in waxed fruit.

Formation and evaluation of the genefund of subtropical cultures in the Nikita Botanical Gardens

The article presents the stages of formation and the results of the study of the genefund of persimmon, ziziphus, olives and figs in the Nikita Botanical Gardens. Based on the results of many years research, the best cultivars have been selected that are donors of economically valuable characteristics. Among the cultivars of foreign selection, the following cultivars are selected according to the best complex of economically valuable characteristics: persimmons (Fuyu, Kiara, Hiakume, Hachia, Rojo Brillante, Sharon, Batumsky II, etc.), ziziphus (Zhu-Tau-Zao, Chinese 2A, Chinese 93, Ta-Yan-Zao, Ya-Zao), olives (Ascolano, Tiflis, Coreggiolo, Della Madonna, Otur, etc.), figs (Randino, Grosse Violette de Bordeaux, Castle Kennedy etc.). As a result of directed interspecific and intraspecific hybridization of the best foreign cultivars, a significant hybrid fund was formed and new cultivars were bred, which surpass foreign cultivars in a number of characteristics. Among them are persimmon cultivars: Stella, Zolotistaya, Zvezdochka, Mechta, Nikitskaya Bordovaya, Yuzhnaya Krasavitsa, Ukrainka, Suvenir Oseni, Rossiyanka, etc., cultivars of ziziphus Koktebel, Meteor, Tavrika, Yalita, Sinit, Radoslav, Konfetny, etc., cultivars of olives: Manita, Skorospelaya, Violetta, Nikitskaya, Krymskaya Prevoskhodnaya, etc., fig cultivars: Yantarny, Sukhofruktovy Nikitsky, Podarok Oktyabru, Sabrucia Rozovaya, etc.