Postharvest of Fruit and Vegetables

The effect of pre- and postharvest applications of 200 and 400 μgL^-1 aqueous solutions of 1-methylcyclopropene (1-MCP) on yellow pitahaya (maturity stage 3) was assessed. Changes in respiratory rate, color, firmness, soluble solids content, titratable acidity, maturity index, weight loss and commercial preservation were measured. Results showed that the preharvest application of 400 μgL-¹ 1-MCP enhanced fruit color, preserved firmness, and reduced weight loss and maturity index of fruits. It is suggested that these results were explained by the reduction of available membrane receptors able to bind ethylene, thus increasing ethylene sensitivity and response magnitude. The preharvest application of 1-MCP could potentially be used to accelerate pitahaya fruit ripening. The preharvest application of 200 μgL^-1 1-MCP resulted in smaller changes in color and titratable acidity vs. control. Total soluble solids and pH were not significantly affected by the treatments. The postharvest application of 1-MCP maintained the texture of fruits by three additional days when compared to the untreated control.

 
 
Navel oranges were subjected to high-temperature forced-air (HTFA) treatment to evaluate the effect on quality and sensory attributes as well as flavor volatiles of a treatment protocol designed to disinfest citrus of Anastrepha spp. fruit flies. The treatment consisted of heating the fruit to a core temperature of 44 °C and then holding it there for 100 min, after which the fruit were placed into storage for 4 weeks. The fruit were removed from storage and evaluated for surface injury, soluble solids concentration (SSC), titratable acidity (TA), and then judged for sensory characteristics by a semiexpert panel. In a separate experiment, fruit were removed at 30-min intervals from the treatment chamber and sensory quality as well as flavor volatiles determined to obtain an estimate of when the flavor changes occurred. It was found that the HTFA treatment caused a significant loss in flavor quality that was most closely linked to a loss in the fresh flavor of the fruit. The HTFA-treated fruit were also determined by panelists to be less sweet, although the SSC/TA ratio was increased by treatment. Neither storage nor waxing after treatment appeared to alter the HTFA effect, although waxing before treatment greatly enhanced the negative effect on flavor. Flavor began to be significantly affected during the final 30 min of treatment. The flavor changes occurred at the same time as large increases in the amount of four esters, two of which were present in concentrations exceeding aroma thresholds and are likely involved in the loss in flavor quality induced by HTFA treatment.

The combined effect of sulfur dioxide (SO₂) fumigation and different carbon dioxide (CO₂)-enriched atmospheres (3% O₂ + 3, 6, 12, or 24% CO₂) on quality attributes, postharvest decay, phytochemical content, and antioxidant capacity of eight fresh blueberry cultivars (Vaccinium corymbosum L.) was determined. The SO₂ treatments did not harm berry quality, but did significantly reduce decay incidence, especially when it was followed by storage in elevated CO₂ atmospheres (>6%). However, very high CO₂ atmospheres (24%) induced fruit softening and ‘off-flavors’. Botrytis and Alternaria spp. were the dominant fungal pathogens causing decay of blueberries during storage, but differences in the species of decay microorganisms were found among cultivars. Postharvest strategies that included SO₂ fumigation and/or enriched CO₂ atmospheres did not negatively affect phytochemical content or antioxidant activity of the fruit; however, the polyphenolic content and total antioxidant activity varied greatly among cultivars. Overall, SO₂ fumigation followed by controlled atmosphere storage (3% O₂ + 6 or 12% CO2) is a promising postharvest strategy for fresh blueberries to reduce decay, extend market life, and maintain high nutritional value.

El objetivo del presente trabajo fue determinar el efecto del almacenamiento en Atmósferas Controladas (AC) sobre la calidad poscosecha y el contenido nutricional de tomate (Solanum lycopersicum L.) "Imperial". Frutos de tomate en estado de madurez comercial fueron almacenados en refrigeración (aire ambiental, AIRE) o en AC (4 kPa O₂ + 96 kPa N₂) a 12 °C por 21 días antes de ser transferidos a un almacenamiento en aire a 23 °C por 12 días. Se retiraron tres frutas por cada tratamiento después de cero, cuatro, ocho y 12 días de maduración a 23 °C para evaluar el color externo, la firmeza, el contenido de sólidos solubles, las velocidades de producción de CO₂ y etileno y el contenido de ácido ascórbico, β-caroteno y licopeno. El almacenamiento en AC disminuyó la pérdida de firmeza y la degradación de ácido ascórbico. También disminuyó la producción de CO₂ y etileno y la síntesis de β-caroteno y licopeno; además, retrasó el desarrollo del color rojo y la maduración. Los resultados indican que el almacenamiento de tomate bajo condiciones de AC prolonga la vida de anaquel y el periodo de comercialización comparado con el sistema tradicional de refrigeración.

 
A considerable amount of tomato is damaged after harvest every year (20-30% annually) which has impact on the total vegetable production in Bangladesh. Gamma irradiation doses of 250, 500 and 750 Gray (Gy) were analyzed compared to those of unirradiated ones on 1st, 8th and 13th day of irradiation stored at 4, 12 and 25°C to observe whether it could combat the loss. Radiation did not affect colour of tomato and it did not differ significantly with dose as well. However, storage time had effect on colour at 12 and 25°C at some aspect whereas no effect at 4°C in both irradiated and unirradiated tomatoes. Significant firmness was lost in irradiated tomatoes stored for 13 days at 4°C while no such significant differences in firmness was observed at 12 and 25°C. Immediate firmness loss was observed in irradiated tomatoes stored at 25°C and firmness decreased more in 500 and 750 Gy treated tomatoes than 250 Gy treated ones at 4 and 25°C whereas no such difference was observed between irradiation doses at 12°C. Radiation had no effect on percent sugar. Highest percentage of tomato loss was found at 25°C in both irradiated and unirradiated tomatoes but 750 Gy treated tomatoes showed promising result at all storage temperatures. Considering firmness loss,Total Soluble Solid (TSS) (%sugar) and damage during storage, a dose of 750 Gy and storage temperature 12°C stood out as ideal combination for BARI Hybrid-3 tomato in Bangladesh to combat annual post harvest loss.

The ‘Empire’ is a major apple variety in the northeastern United States, especially in New York, that is grown for both domestic and export markets. The cultivar is also favored for its fresh cut slice quality because of maintenance of texture and slow browning. Market demand for ‘Empire’ apples is high and the industry would like to store the fruit for at least 10 months. However, a number of physiological disorders limit the controlled atmosphere (CA) storage life for this variety. The main ones are external CO₂ injury, firm flesh browning (chilling injury), soft flesh browning (senescent breakdown), and core browning.

External CO₂ injury is a serious problem, but we now know that this injury can be prevented by treatment of fruit with diphenylamine (DPA), an antioxidant used for control of superficial scald, or by use of low CO₂ levels in CA, especially during the earlier storage periods (Razafimbelo et al., 2006; Watkins and Nock, 2007).

Common food additives (sodium bicarbonate (SB), sodium carbonate (SC), and potassium sorbate (PS)) were compared to the fungicide fludioxonil for the control of gray mold on California-grown ‘Wonderful’ pomegranates artificially inoculated with Botrytis cinerea and stored at 7.2 °C in either air or controlled atmosphere (CA, 5 kPa O₂ +15 kPa CO₂) conditions. Fludioxonil was superior to other treatments. PS was the most effective additive. Synergistic effects between antifungal treatments and CA storage were observed. After 15 weeks of storage at 7.2 °C, the combination of PS treatment (3 min dip in 3% solution at 21 °C) and CA storage was as effective as the combination of heated fludioxonil (30 s dip in 0.6 g L⁻¹ of active ingredient at 49 °C) and air storage. Mixtures of PS with SB or SC did not improve the efficacy of either treatment alone. In tests conducted in commercial facilities, decay development and external and internal fruit quality were assessed on naturally infected pomegranates stored in either air or CA after application of a selected postharvest antifungal combined treatment (CTrt) integrating PS, SB + chlorine, and fludioxonil. CTrt was effective in controlling natural gray mold after 6 weeks of storage at 8.9 °C, but lacked persistence and it was not effective after 14 weeks. CA storage greatly enhanced decay control ability of CTrt. Skin red color was better maintained in CA-stored than in air-stored fruit. Juice color and properties (SSC, TA, and pH) were not practically affected by either postharvest treatment or storage condition. The integration of PS treatments with CA storage could provide an alternative to synthetic fungicides for the management of pomegranate postharvest decay.

 
 
Purpose of review: This article reviews research based on the evaluation of postharvest control methods alternative to conventional chemical fungicides for the control of citrus green and blue moulds, caused by the pathogens Penicillium digitatum and P. italicum, respectively. Emphasis is given to advances developed during the last few years. Potential benefits, disadvantages and commercial feasibility of the application of these methods are discussed.
Findings: Substantial progress has been accomplished in selecting and characterising new effective physical, chemical and biological control methods. However, their widespread commercial implementation relies, in general, on the integration of different treatments of the same or different nature in a multifaceted approach. For satisfactory penicillium decay control, this postharvest approach should be part of an integrated disease management (IDM) programme in which preharvest and harvest factors are also considered.
Limitations: The lack of either curative or preventive activity, low persistence, high variability, inconsistency or excessive specificity are general limitations associated with the use of alternatives to synthetic fungicides as stand-alone treatments. Furthermore, the risk of adverse effects on fruit quality, technological problems for cost-effective application, or the availability of new conventional fungicides for traditional markets are additional reasons that may hinder the broad commercial use of such treatments.
Directions for future research: As we learn more about the fundamental basis underlying host-pathogen interactions and how they are influenced by direct or indirect protective effects of existing or new single alternative treatments, more effective methods of applying and combining complementary approaches for additive or synergistic effects will emerge. Research should provide appropriate tools to tailor the application of these nonpolluting postharvest control systems and, further, the complete IDM strategy for each specific situation (ie, citrus species and cultivar, climatic and seasonal conditions, destination market, etc).

Frutos de aguacate 'Hass' fueon tratados térmicamente (38ºC y 40ºC por 360 min y 120 min respectivamente) y almacenados a 4ºC por 42 dias. La mayor calidad externa fue por el tratado a 40ºC. En calidad interna, no observándose diferencia entre control y tratados. Los frutos que desarrollaron mayor daño por frío externo fueron los tratados a 40ºC, seguidos por los controles y finalmente tratados a 38ºC. En la evaluación de daño por frío interno no se observaron diferencia entre los lotes. No existió diferencia entre los parámetros de color evaluados (a*, b*, L*, hº y C*) entre control y tratados. La pérdida de peso no demostró diferencia entre control y tratamientos. La firmeza del control fue la menor (15.93N), seguido por el tratamiento a 40ºC (41.69N) y el tratamiento a 38ºC (61.10N). Los triacilglicéridos evaluados (trilinoleina, 1,2-Dilinolein-3-Oleil-glicerol, 1,2-Dioleil-3-Esterail-glicerol), demostraron que el control presentó un comportamiento similar en todos los triacilglicérios. Los tratamientos incrementaron su concentración una vez finalizado el tratamiento térmico y posteriormente disminuye. El tratamiento a 38ºC mostró un incremento en 4 de los triacilglicéridos, no así el tratamiento a 40ºC.