Sensory Quality Of Fruits Research Articles

Effect of a cold quarantine treatment on physiological disorders and quality of cactus pear fruit

Despite Italy is second only to Mexico for fresh production of cactus pears worldwide, postharvest handling and treatments are quite simply, being fruit immediately marketed after harvest. However, as the demand for fresh fruit beyond the harvesting period is constantly growing, in the next future the cactus pear industry likely will have to adopt postharvest treatments and technologies that can widen the marketable window. Yet, the potential exploitation of new markets in countries where the introduction of pests like Mediterranean fruit fly are considered risky, can be achieved only if fruit are subjected to approved quarantine protocols. Of the three main cultivated varieties (‘Bianca’, ‘Gialla’ and ‘Rossa’) limited studies concerning cold storage have been done mainly on fruit of cv ’Gialla’, while knowledge on response to cold quarantine treatments lacks for all cultivars. Thus this study was undertaken to get knowledge on postharvest behavior of the three main Italian cultivated cactus pears varieties, i.e. ‘Bianca’, ‘Gialla’ and ‘Rossa’ subjected to a cold quarantine treatment followed by either a week of simulated marketing conditions at 20 °C or by two additional weeks of storage at 8 °C before transfer to simulated marketing conditions at 20 °C for three days. These storage conditions so far are not practiced by packing houses as fruit are directly marketed after harvest, but could be a typical protocol in case fruit should be sold in countries that require approved cold quarantine treatments. Results showed an abnormal increase in respiratory activity and ethylene production rates following transfer from cold storage to 20 °C, especially after the two additional weeks of storage at 8 °C. Peel disorders and decay incidence were slight at the end of storage at 2 °C or 8 °C, but severe peel disorders developed when fruit were moved to 20 °C. Peel injury, decay incidence, the loss of overall appearance upon transfer to 20 °C were more severe in fruit stored for two additional weeks at 8 °C. Among the three cultivars, susceptibility to chilling injury and decay was higher in cv ‘Bianca’. Nevertheless, cold storage seems not to affect the chemical and sensory quality of fruit, whose changes were similar in all cultivars.

Influence of thermosonication treatments on bioactive compounds and sensory quality of fruit (Haematocarpus validus ) juice

The main aim of the paper was to evaluate the quality attributes and consumer acceptability of blood fruit (Haematocarpus validus) juice treated by thermosonication (TS) process. The major process parameters, temperature, processing time, and power load were experimented and the treated samples compared with the conventional pasteurized and untreated juice sample. Results obtained showed the TS‐treated juice sample (TS‐7) at 55°C/5 min/1.4 W/ml gives the maximum inactivation of pectin methyl esterase (PME), peroxidase (PO), and polyphenol oxidase (PPO) enzymes, microorganism (total bacteria and yeast and mold), and also excellent sensory qualities. In addition to this, higher retention of ascorbic acid, polyphenols, flavonoids, antioxidant, flavonols, anthocyanins was noted, besides preserving the original color. This optimized TS technique can be employed in numerous beverages industries to produce high quality of fruits and vegetables juices, squash, cordial, and other products. PRACTICAL APPLICATIONS: Increased health consciousness dictates various lifestyles changes and the need for better quality product in terms of freshness, less or no addictive usage and longer shelf life is warrant. The paper presents such technique: thermosonication (TS) which when employed in beverage’s preparation gives the above‐stated attributes. TS is a novel and viable technique that is employed to replace the conventional thermal processing. This shall provide great assistance to the commercial beverage industries to cater the health conscious population or otherwise and nonetheless, produced healthier, more stable and quality products which can be of therapeutic used.

Sensory quality of fruits of papaya formosa tainung-01 stored in modified atmosphere

Sensory quality of fruits of papaya formosa tainung-01 stored in modified atmosphere

Sensory, chemical and morphological characterization of Cucurbita maxima and Cucurbita moschata genotypes from different geographical origins

Cucurbita spp. is one of the most important vegetable crops in the world. They are characterized by great polymorphism according plants and fruits traits. The fruits are consumed in different ways as boiled, baked, dried or processed in puree and juice. The aim of the study was to assess variation of fruit sensory, chemical and morphological characteristics of Cucurbita genotypes in order to find appropriate parental components for the future high quality breeding programme. During 2-year period nine winter squash (Cucurbita maxima Duch.) and three pumpkin (Cucurbita moschata Duch.) genotypes originating from different geographical regions were tested on their morphological characters, basic chemical components and sensory profile. Cluster analysis and Principle component analysis were applied in order to identify similarities of different genotypes. According to the fruit characteristics and plant habitus significant differences were recorded. Considerable variation in the content of dry matter, ascorbic acid, total sugars, total pigments, beta-carotene and sensory assessment of the boiled fruits was established. Accession Moskatna carotina had the best flavour and chemical composition. The studied Cucurbita genotypes are a good basis for performing a breeding program to improve the sensory quality of fruits and increase basic chemical components especially those with antioxidant effect.

The antioxidant, cytotoxic, and antigenotoxic effects of galangin, puerarin, and ursolic acid in mammalian cells

Phenolic compounds not only contribute to the sensory qualities of fruits and vegetables but also exhibit several health protective properties. Galangin, puerarin, and ursolic acid are commonly used plant phenolics in folk medicine. In this study, the antioxidant capacities of galangin, puerarin, and ursolic acid by the trolox equivalent antioxidant capacity (TEAC) assay and the cytotoxic effects by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in V79 cells were investigated. The genotoxic potentials of galangin, puerarin, and ursolic acid were evaluated by micronucleus (MN) and alkaline COMET assays in human lymphocytes and in V79 cells. Galangin, puerarin, and ursolic acid (10, 100, 500, 1000, 2000, 5000, 10 000, and 20 000 μM) were found to have antioxidant activities at the studied concentrations. IC50 values of galangin, puerarin, and ursolic acid in V79 cells were found to be 275.48 μM, 2503.712 μM, and 224.85 μM, respectively. Galangin, puerarin, and ursolic acid, at the all concentrations, have not exerted genotoxic effects and galangin, puerarin, and ursolic acid revealed a reduction in the frequency of MN and DNA damage induced by H2O2.

Uso de embalagem e da refrigeração no armazenamento de lichias “Bengal”

The objective of this study was to evaluate the effect of packaging and refrigeration on the storage of “Bengal” litchi. Different packaging types were selected: expanded polystyrene trays covered with polyvinyl chloride film (PVC) (T1), polyethylene terephthalate tray (PET) with lid (T2) and absence of packaging (T3). After the selection, the material was split into two lots, where one packaging group was stored at room temperature, 25 °C, for a period of six days and the other group was stored under refrigeration at 5 °C for a period of nine days. Chemical, physical and sensory evaluations were performed every two days (room temperature) and every three days (refrigerated storage), the chemical evaluations being: pH, titratable acidity (TA), soluble solids (SS), ascorbic acid content and SS/TA ratio; physical evaluations being: luminosity, chromaticity, hue angle and weight loss; and sensory evaluations being: appearance, purchase intention and consumer preference. PET packaging showed lower fresh weight loss for the fruits, in the temperatures tested throughout the experiment. PET and PVC packaging were efficient in preventing browning of fruits. The use of PET packaging and refrigeration in the storage of litchi provides better maintenance of the physical, chemical and sensory quality of fruits for up to 9 days.

Carbon dioxide enrichment: a technique to mitigate the negative effects of salinity on the productivity of high value tomatoes

The present study was conducted to determine the mitigating influence of greenhouse CO2 enrichment on the negative effects of salinity in Mediterranean conditions. Hybrid Raf (cv. Delizia) tomato plants were exposed to two salinity levels of the nutrient solution (5 and 7 dS/m) obtained by adding NaCl, and two CO2 concentrations (350 and 800 μmol/mol) in which CO2 enrichment was applied during the daytime according to a strategy linked to ventilation. Increasing water salinity negatively affected the leaf area index (LAI), the specific leaf area (SLA), the water use efficiency (WUE), the radiation use efficiency (RUE) and dry weight (DW) accumulation resulting in lower marketable yield. The high salinity treatment (7 dS/m) increased fruit firmness (N), total soluble solids content (SSC) and titratable acidity (TA), whereas pH was reduced in the three ripening stages: mature green/breaker (G), turning (T), and pink/light red (P). Also, the increase in electrical conductivity of the nutrient solution led to a general change in intensity of the sensory characteristics of tomato fruits. On the other hand, CO2 enrichment did not affect LAI although SLA was reduced. RUE and DW accumulation were increased resulting in higher marketable yield, through positive effects on fruit number and their average weight. WUE was enhanced by CO2 supply mainly through increased growth and yield. Physical-chemical quality parameters such as fruit firmness, TA and pH were not affected by CO2 enrichment whereas SSC was enhanced. Greenhouse CO2 enrichment did mitigate the negative effect of saline conditions on productivity without compromising organoleptic and sensory fruit quality.

Influence of 1-Methylcyclopropene and ULO Conditions on Sensory Characteristics of Apple Fruit Grown in Latvia

Abstract The aim of the study was to evaluate the influence of 1-methylcyclopropene (1-MCP) treatment and ultra-low oxygen (ULO) storage conditions on the sensory characteristics of apples. Two apple storage technologies were tested in this study: cold storage under traditional conditions in combination with 1-MCP treatment, and ULO storage with two different compositions of a gas mixture. Apples were stored for 6 months. After storage, the sensory characteristics were analysed. Sensory evaluation showed that storage technology affected the sensory characteristics and panelists’ acceptability. Distinctive differences were found between apples stored under controlled atmosphere and traditional conditions. Trained panelists highlighted that samples stored under controlled atmosphere had pronounced juiciness and color, while 1-MCP-treated apples stored in cold were sweeter and more aromatic. Apples of the autumn cultivar ‘Auksis’, was perceived considerably higher after harvest and before long-term storage, compared with other cultivars. During 6 months of storage in controlled atmosphere, the sensory quality of these apples remained intact. Also, the sensory quality of fruit of the winter cultivar ‘Sinap Orlovskij’ throughout 6 months of its storage in controlled atmosphere remained intact. Besides, it was noticed that apples stored in controlled atmosphere were juicier and more aromatic with intense color. There is a positive effect of 1-MCP treatment on maintenance of apple quality stored in normal atmosphere for 6 months. With regard to some quality parameters and sensory attributes, 1-MCP-treated apples stored under normal atmosphere are comparable to those stored under ULO conditions.

Influence of Post Harvest Calcium Chloride Treatment and Shrink Film Packaging on Storage Life of Pear Fruits

To enhance the storage life of pear cv. ‘Punjab Beauty ’, fruits were dipped in aqueous solution of calcium chloride (1.5 and 2.5%) for 5 min., packed in corrugated fibre board (CFB) boxes or shrinkfilm trays and stored at 0–1°C with 90–95% RH for 67 days. Untreated fruits were dipped in fresh water only and kept in CFB boxes. The weight loss was appreciably reduced in CaCl2 treated + shrink wrapped fruits. CaCl2 treatment @ 1.5% and shrink film tray packaging proved effective in maintaining the firmness and acid content of fruits. Maximum sensory quality of fruits was recorded after 45 days in fruits treated with CaCl2 @ 2.5% + CFB packing. Soluble solids content in fruit juice was highest after 60 day of storage in all the treatments. Combination of shrink film tray packaging + CaCl2 @ 1.5% treatment was effective in minimizing the physiological loss in weight of fruits and maintaining the fruit quality for 60 days under storage.

Raspberry fruit quality changes during ripening and storage as assessed by colour, sensory evaluation and chemical analyses

In order to identify the optimal harvest time and monitor changes in raspberry (Rubus idaeus L. cv. Glen Ample) fruit quality during ripening and storage, quality was assessed and compared by physical, chemical and sensory fruit quality criteria. Visual classification of fruit colour according to the Natural Colour System (NCS) chart and by physical measurement of fruit adherence to the receptacle or fruit compression resistance yielded parallel and highly significant results. The light red colour stage corresponding to NCS S code 3060-Y90R was identified as the optimal harvest stage for commercial fresh marketing of the ‘Glen Ample’ cultivar. Fruit harvested at this stage developed the same chemical and sensory qualities as in situ matured fruits and maintained high sensory quality after 8 days of storage in the dark at 2–3°C. As the fruits mature, the concentration of titratable acids decreases, whereas the concentrations of anthocyanins and the sugar:acid ratio increase in parallel with colour development. While correlation analysis revealed a correlation between sensory traits like sweetness and acidity with sucrose and the sugar:acid ratio, respectively, the overall fruit tastefulness was not strongly correlated with any specific phytochemical component, thus illustrating the complex nature of this sensory trait. Due to its ease of performance, picking raspberry fruits related to a standardised colour chart is recommended for picking raspberry fruits with optimal quality.

Investigating the use of gradient boosting machine, random forest and their ensemble to predict skin flavonoid content from berry physical–mechanical characteristics in wine grapes

Flavonoids are a class of bioactive compounds largely represented in grapevine and wine. They also affect the sensory quality of fruits and vegetables, and derived products. Methods available for flavonoid measurement are time-consuming, thus a rapid and cost-effective determination of these compounds is an important research objective. This work tests if applying machine learning techniques to texture analysis data allows to reach good performances for flavonoid estimation in grape berries.Whole berry and skin texture analysis was applied to berries from 22 red wine grape cultivars and linked to the total flavonoid content. Three machine-learning techniques (regression tree, random forest and gradient boosting machine) were then applied. Models reached a high accuracy both in the external and internal validation. The R2 ranged from 0.75 to 0.85 for the external validation and from 0.65 to 0.75 for the internal validation, while RMSE (Root Mean Square Error) went from 0.95mgg−1 to 0.7mgg−1 in the external validation and from 1.3mgg−1 to 1.1mgg−1 in the internal validation.

Hydroxypropyl methylcellulose-beeswax edible coatings formulated with antifungal food additives to reduce alternaria black spot and maintain postharvest quality of cold-stored cherry tomatoes

Edible composite coatings based on hydroxypropyl methylcellulose (HPMC), beeswax (BW), and food preservatives with antifungal properties were formulated and evaluated on cherry tomatoes during cold storage. Selected food preservatives included: sodium methyl paraben (SMP), sodium ethyl paraben (SEP) and sodium benzoate (SB). Cherry tomatoes artificially inoculated with Alternaria alternata were coated and stored up to 21 d at 5°C followed by 4 d of shelf-life at 20°C. All antifungal coatings reduced the incidence and severity of alternaria black spot on inoculated cherry tomatoes, being the SB-based coating the most effective. Analytical and sensory fruit quality was evaluated on intact and cold-stored tomatoes. In contrast to coatings containing SMP or SEP, the SB-based coating was effective to reduce weight loss and respiration rate and maintain the firmness of coated cherry tomatoes. Peel color, ethanol and acetaldehyde content of the juice, sensory flavor, off-flavors, and fruit appearance were not adversely affected by the application of the antifungal coatings. In conclusion, HPMC-BW coatings containing the food additive SB at 2% showed potential for industrial application, including the production and commercialization of organic cherry tomatoes.

The antioxidant and antigenotoxic properties of citrus phenolics limonene and naringin

Phenolic compounds not only contribute to the sensory qualities of fruits and vegetables but also exhibit several health protective properties. Limonene and naringin are the most popular phenolics found in Citrus plants. In this study, we investigated the antioxidant capacities of limonene and naringin by the trolox equivalent antioxidant capacity (TEAC) assay and the cytotoxic effects by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in Chinese hamster fibroblast (V79) cells. The genotoxic potentials of limonene and naringin were evaluated by micronucleus (MN) and alkaline COMET assays in human lymphocytes and V79 cells. Limonene and naringin, were found to have antioxidant activities at concentrations of 2–2000 µM and 5–2000 µM respectively. IC50 values of limonene and naringin were found to be 1265 µM and 9026 µM, respectively. Limonene at the concentrations below 10,000 µM and naringin at the all concentrations studied, have not exerted genotoxic effects in lymphocytes and in V79 cells. Limonene and naringin at all concentrations revealed a reduction in the frequency of MN and DNA damage induced by H2O2.

Effect of antifungal hydroxypropyl methylcellulose-beeswax edible coatings on gray mold development and quality attributes of cold-stored cherry tomato fruit

Edible composite coatings based on hydroxypropyl methylcellulose (HPMC), beeswax (BW), and food preservatives with antifungal properties, were evaluated on cherry tomatoes during cold storage. Food preservatives selected from previous research work included sodium propionate (SP), potassium carbonate (PC), ammonium phosphate (APh) and ammonium carbonate (AC). Cherry tomatoes artificially inoculated with Botrytis cinerea were coated and stored up to 15d at 5°C followed by 7d of shelf-life at 20°C. All antifungal HPMC-BW coatings significantly reduced gray mold development on inoculated and cold-stored cherry tomatoes, the SP-based coating being the most effective. Analytical and sensory fruit quality was also evaluated after cold storage and shelf-life. The AC-based coating was the most effective to control weight loss and maintain the firmness of coated cherry tomatoes. Respiration rate, firmness, color, sensory flavor, off-flavor, and fruit appearance were not adversely affected by the application of the antifungal coatings. Overall, the application of HPMC-BW edible composite coatings containing AC could be a promising treatment to extend the postharvest life of cherry tomatoes. Further studies should focus on the modification of some physical characteristics of the coatings in order to enhance the general performance and provide higher peel gloss.

Prestorage application of high carbon dioxide combined with controlled atmosphere storage as a dual approach to control Botrytis cinerea in organic ‘Flame Seedless’ and ‘Crimson Seedless’ table grapes

Pre-storage application of 40% CO2 at 0°C for 24 or 48h and controlled atmosphere (12% O2+12% CO2) storage at 0°C for up to eight weeks on decay control and quality of organic ‘Flame Seedless’ and ‘Crimson Seedless’ table grapes were studied as a postharvest disease control alternative. To simulate different potential field conditions, these organic treatments were applied to organic-grown grapes that were naturally infected (without inoculation), surface inoculated (berries inoculated by spraying with a conidia suspension), and nesting inoculated (clusters inoculated by placing in the middle an artificially infected berry) with the pathogen Botrytis cinerea, the cause of grape gray mold. Under these three conditions, a 40% CO2 for 48h pre-storage treatment followed by controlled atmosphere reduced the gray mold incidence from 22% to 0.6% and from 100% to 7.4% after four and seven weeks, respectively. High CO2 pre-storage alone limited botrytis incidence in both naturally and artificially infected grapes, but was more effective when combined with CA. These treatments did not affect visual or sensory fruit quality. Exposure to high CO2 for 24 or 48h effectively inhibited mycelial growth of B. cinerea in PDA plates incubated at 22°C for up to 72h. Conidia germination in PDA plates was reduced ∼60% after 12h incubation. In vitro studies demonstrated a fungistatic effect, but further studies on the mechanism of action could improve treatment performance. This novel high CO2 initial fumigation followed by controlled atmosphere during storage or transportation could be a commercially feasible alternative for postharvest handling of organic and conventional table grapes. Our results encourage validating this combined physical treatment in other cultivars and under commercial conditions.

Comparison of Sensory Qualities of Geographically Paired Organic and Conventional Red Wines from the Southwestern US with Differing Total Polyphenol Concentrations: A Randomized Pilot Study

Dietary polyphenols, or phenolic compounds, are numerous, diverse, and ubiquitous phytochemicals occurring throughout the plant kingdom. They are important components of the human diet because of their capacity to reduce the risk of chronic diseases such as cardiovascular disease and cancer. In plants, polyphenols contribute to resistance to pathogens due to their potent astringency and function as phytoalexins. As a result, organic grapevines grown with reduced pesticides may be more stressed by pathogens than conventionally grown grapevines and presumably produce more polyphenols. Since polyphenols also play an important role in the sensory qualities of fruits and wines particularly involving astringency and bitterness, there may be differences that affect sensory perceptions of wine. This establishes a conundrum where dietary polyphenols are healthful but potentially unpalatable.We recruited and randomized 18 female participants (21 - 50 y) to one of five groups (3 - 4 per group). Each group evaluated the sensory qualities of a geographically paired organic (OW) and conventional wine (CW) and an artificially colored white wine placebo (PW) with significantly differing total polyphenol concentrations (TP). Participants reported for three visits (one wine per visit) where they consumed 5 ounces (150 mL) of wine over 15 minutes while completing the sensory survey. Sensory evaluations based on a Likert-type scale included visual, aroma, and taste perceptions and overall impressions (scale 0 - 10). In two wine pairs, the OW contained significantly more TP (3.49 and 5.86 g/L) than the respective CW (2.63 and 4.63 g/L). In two other wine pairs both produced by sustainable viticulture, the CW (5.23 and 8.38 g/L) contained sig- nificantly more TP than OW (4.55 and 3.70 g/L) and in one set the amounts were equivalent (4.10 and 4.17 g/L). The five PW averaged 1.26 ± 0.20 g/L. Although there were significant differences in TP content of test wines, the results indicated that no significant differences in either intensity or quality for any of the sensory qualities were detected be- tween paired OW and CW wines but both scored significantly higher than the PW, with significantly lower TP. We conclude in this pilot study that a subset of OW from the Southwestern US is perceived similarly to CW produced by the same vineyard even with significantly differing TP concentrations.

Effect of Antifungal Hydroxypropyl Methylcellulose‐Lipid Edible Composite Coatings on Penicillium Decay Development and Postharvest Quality of Cold‐Stored “Ortanique” Mandarins

Edible composite coatings based on hydroxypropyl methylcellulose (HPMC), hydrophobic components (beeswax and shellac), and food preservatives with antifungal properties were evaluated on "Ortanique" mandarins during long-term cold storage. Selected food preservatives included potassium sorbate (PS), sodium benzoate (SB), sodium propionate (SP), and their mixtures. Intact mandarins or mandarins artificially inoculated with the pathogens Penicillium digitatum and Penicillium italicum, the causal agents of citrus postharvest green (GM) and blue (BM) molds, respectively, were coated and stored up to 8 wk at 5 °C + 1 wk of shelf-life at 20 °C. HPMC-lipid coatings containing food preservatives controlled better GM than BM on Ortanique mandarins. SB- and SB + SP-based coatings reduced the incidence of GM by about 35% after 4 wk at 5 °C. Among all coatings, only the SB-based coating reduced the incidence of GM (about 16%) after 6 wk at 5 °C. All coatings significantly reduced disease severity of both GM and BM after 6 wk at 5 °C. Analytical and sensory fruit quality was evaluated on intact mandarins. All coatings, especially the SB + SP-based coatings, were effective to control weight loss and maintain the firmness of coated mandarins. Internal gas concentration, juice ethanol and acetaldehyde content, sensory flavor, off-flavor, and fruit appearance were not adversely affected by the application of the antifungal coatings. Further studies should focus on the modification of some physical characteristics of the coatings to improve the gloss and visual aspect of treated mandarins.

Long-term response of tomato plants to changing nutrient concentration in the root environment—the role of proline as an indicator of sensory fruit quality

The aim of the trial was to investigate the time course of changes in content of proline and organic compounds affecting sensory quality of ripe red tomatoes after nutrient concentration had been changed. Tomato (Lycopersicon esculentum Mill. cv. Counter) plants were grown in nutrient solutions containing equal nutrient ratios at either low or high concentration (N1=standard solution; N2=5.5 times the standard concentration). Immediately after first harvest of ripe tomatoes, half of the plants of each treatment were transferred to nutrient solutions of higher (from N1 to N2) or lower (from N2 to N1) nutrient concentration. Proline content in leaves of plants transferred to higher or lower nutrient concentration adjusted to control levels (N2 and N1, respectively) within 2 weeks. Growing and ripe fruit reached the corresponding control levels within the same time or 1–5 weeks later. Similar time courses were observed for sugar concentration and titratable acidity in fruit. Apart from leaves, proline content of young growing fruit also increased with increasing radiation intensity at high nutrient concentration. However, in ripe fruit, proline content increased only with low to moderate radiation intensity and decreased when a certain stress level was exceeded. Similar results were found for osmolality and sugar concentration of ripe fruit, while titratable acidity remained rather unaffected by radiation. The role of proline as an indicator of sensory fruit quality is discussed.

MOLECULAR AND GENETIC REGULATION OF SENSORY QUALITY OF CLIMACTERIC FRUIT

The sensory quality of fruit has become a major criterion in making the purchasing decision by consumers. Breeding programs have mainly been directed, from the post-harvest stand point, towards improving shelf-life. Chance seedlings or mutants with improved agronomic traits and/or extended shelf-life have been used for introgressing the long shelf-life character and eventually improved sensory quality traits in commercial genotypes of apple, melon or tomato. Because the plant hormone ethylene plays a central role in both storability and ripening of climacteric fruit, the generation by biotechnology of ethylene-inhibited fruit has offered a powerful tool to better understand, at the molecular and genetic level, the interrelations between storability and sensory quality. In the melon, inhibition of ethylene synthesis results is a strong inhibition of the synthesis of aroma volatiles while the accumulation of sugars is not affected or is even improved. The softening of the flesh is strongly affected but not abolished. Mid or long shelf-life melons generated by classical breeding present the same behavior. The generation of recombinant inbred lines by crossing a typical climacteric melon (Cantaloupe Charentais of the cantalupensis group) with a non climacteric melon (PI161375 of the agrestis chinensis group) allowed to demonstrate that the climacteric character is conferred by 2 duplicated loci only, which are of great importance for the regulation of storability and sensory quality. Due to the importance of aroma volatiles in sensory quality and to the strong negative correlation between aroma production and ethylene synthesis, we have developed a research program aimed at isolating genes involved in the synthesis of aroma volatiles. We will report on the recent advances in the field with special emphasis on the characterization of genes responsible for the synthesis of esters, a family of compounds crucial for the flavor of many fruit.

Efficacy of Gaseous Chlorine Dioxide as a Sanitizer for Killing Salmonella, Yeasts, and Molds on Blueberries, Strawberries, and Raspberries

Gaseous chlorine dioxide (ClO2) was tested for its effectiveness in killing Salmonella, yeasts, and molds on blueberries, strawberries, and red raspberries. An inoculum (100 μl, 6.0 to 6.8 log CFU/g of fruit) that contained five serotypes of Salmonella enterica was deposited on the skin, calyx tissue, or stem scar tissue of blueberries, skin or stem scar tissue of strawberries, and skin of red raspberries, dried for 2 h at 22°C, then held for 20 h at 4°C and 2 h at 22°C before treatment. Sachets that contained reactant chemicals were formulated to release gaseous ClO2 at concentrations of 4.1, 6.2, and 8.0 mg/liter of air within treatment times of 30, 60, and 120 min, respectively, at 23 ± 1°C. Lethality of ClO2 to Salmonella, yeasts, and molds was measured when fruits were in an atmosphere that contained 75 to 90% relative humidity. Treatment with 8.0 mg/liter of ClO2 significantly (α = 0.05) reduced the population of Salmonella on blueberries by 2.4 to 3.7 log CFU/g. Lethality was higher to cells in inoculum placed on the skin compared with the stem scar tissue. Populations of Salmonella on strawberries treated with 8.0 mg/liter of ClO2 were reduced by 3.8 to 4.4 log CFU/g; a significant reduction of 1.5 log CFU/g of raspberries was achieved. Treatment with 4.1 to 8.0 mg/liter of ClO2 caused reductions in populations of yeast and molds on blueberries, strawberries, and raspberries of 1.4 to 2.5, 1.4 to 4.2, and 2.6 to 3.0 log CFU/g, respectively. Treatment with 4.1 mg/liter of ClO2 did not markedly affect the sensory quality of fruits stored for up to 10 days at 8°C. Results indicate that gaseous ClO2 has promise as a sanitizer for small fruits.