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Abstract: The objective of this study was to evaluate the use of an ethanol vapor release pad and a saprophytic yeast Cryptococcus infirmo-miniatum (CIM) to reduce decay and maintain postharvest quality of intact or fresh-cut sweet cherries (Prunus avium) cv. Lapins and Bing. Intact or fresh-cut fruit were packed in perforated clamshells (capacity 454g) and stored at 1, 10 or 20°C for up to 21, 14 and 8d, respectively. For ethanol treatment, a pad made with silica gel powder containing 10g ethanol and covered with perforated film, which allows ethanol vapor to diffuse gradually, was attached to the upper lid of the clamshells. Ethanol treatment caused accumulation of ethanol in the packaging headspace, about 10μLL−1 with little change within 14d at 1°C, 23μLL−1 at d 1 and decreased to 15μLL−1 at d 10 at 10°C, and 26μLL−1 at d 1 and decreased to 13μLL−1 at d 3 at 20°C. Ethanol content in fruit was less than 9mgkg−1 in all the control fruit, and increased to 16, 34 and 43mgkg−1 in ethanol-treated fruit at 1, 10 and 20°C, respectively. Nonetheless, a sensory taste panel did not perceive any flavor difference from the ethanol treatment. The ethanol treatment retarded softening, darkening, and acid decrease in fruit as well as discoloration of the stems, and extended shelf-life of intact cherries. Ethanol reduced brown rot (Monilinia fructicola) in fresh-cut cherries stored at 20°C, but not at 1 and 10°C. A pre-packaging dip in CIM completely controlled brown rot in inoculated fresh-cut cherries stored at 1°C, and in naturally infected cherries at 20°C. [Copyright &y& Elsevier]

Abstract: Mango fruit (Mangifera indica L.), cv. ‘Cogshall’, ‘Kent’ and ‘Keitt’ were harvested at different maturities (61–115d past flowering and 80–307averageg fresh weight for ‘Cogshall’) and at different sizes (364–1563 and 276–894averageg fresh weight for ‘Keitt’ and ‘Kent’, respectively). Immediately after harvest (green) or after 1 week of ripening at room temperature (ripe), fruit were homogenized or left intact and evaluated by electronic nose (enose) or by gas chromatography (GC) for aroma and other volatiles as well as for soluble solids and acids. Volatile data from the different harvest maturities and ripening stages were discriminated by using multivariate statistics (discriminant factor analysis). Both the enose and GC were able, in most cases, to separate fruit from different harvest maturities, especially for ‘Cogshall’ mangoes, at both the green and ripe stages as well as discriminate green from ripe fruit and fruit from the different varieties within a maturity stage. Solids and acids data indicated that later harvest maturities resulted in sweeter fruit and later-harvested fruit had a different volatile profile from earlier-harvested fruit. Mango fruit volatiles may be useful as maturity markers to determine optimal harvest maturity for mango fruit that results in full quality upon ripening. [Copyright &y& Elsevier]

• 21 papaya accessions were evaluated, including large-fruited and solo types. • Yield, fruit size, soluble solids, and titratable acidity varied among accessions. • 124 volatiles were detected, and 25 had odor activity by GC-O. • A few papaya accessions have potential for commercial production in Florida. Papaya (Carica papaya L.) is a globally popular tropical fruit that can either be used in an unripe, "mature green" state in savory dishes, or consumed when ripe and sweet. In recent years, commercial papaya growers in southern Florida have favored large-fruited accessions often destined for the mature green market. Increased cultivation of papayas for the dessert fruit market, especially varieties with superior fruit quality may facilitate growth of the industry. Therefore, a study was designed to identify varieties that perform well in southern Florida, as well as accessions possessing useful characteristics for future breeding work. A total of 21 papaya accessions were assessed for yield components, plant height, and ripe fruit quality traits with an emphasis on aroma. In general, small fruited solo-type papayas were among the tallest accessions at first harvest reaching up to 244 cm tall for 'Kapoho #1' and with first fruit insertion heights up to 152 cm for 'Kapoho #2'. N08–75, 'Sunrise #2', and 'Sunset' had higher average fruit numbers (43, 45, and 37 fruit per plant, respectively) than some of the larger fruited accessions like Saipan Red #1 (7 fruit per plant) throughout a six-month harvest period. The accessions with the highest fruit weights ranged from 1.48 to 2.13 kg for Brash Panama, HAES 7836, N07–24, Saipan Red #1, and Saipan Red #2. There were significant differences among the accessions for fruit quality traits including pH (4.55–5.13), titratable acidity (0.10–0.23%), and total soluble solids (8.9–14.5%). Quantification of 112 putatively identified and 12 unknown volatile compounds revealed terpenes as the most abundant components in 18 accessions, with linalool typically at the highest concentration. Gas chromatography-olfactometry (GC-O) revealed 26 volatiles that may contribute to aroma. Several of these compounds including butanoic acid, methyl butanoate, octanoic acid, and (E)-citral varied greatly in abundance among accessions. The variability observed for important fruit quality and agronomic traits suggests potential for improvement through plant breeding, as well as expanded cultivation of currently available varieties for the dessert fruit market in southern Florida. [ABSTRACT FROM AUTHOR]

• A large variation in total oil content was found among14 avocado genotypes. • Oleate, palmitate and linoleate were the major fatty acid components in all genotypes. • Acetaldehyde, C-6 aldehydes and mono/sesquiterpenes were the major VOCs. • '35707' and 'PA-6206' were rich in total oil content and unsaturated fatty acids. Worldwide avocado consumption is growing due to potential health benefits. Most research has been focused on 'Hass', which does not perform well in Florida. Fatty acids and volatile organic compounds (VOCs) were evaluated in 14 avocado genotypes grown in East-Central Florida conditions and compared to 'Hass'. Two saturated and five unsaturated fatty acids were detected. Total oil content (TOC) was 11–25%, with 58.2–71.5% unsaturated fatty acids (UFA). 'FL Hass' contained 20% TOC, near the average for genotypes tested, but with a low UFA of 61.9%. 'PA-6206' (a 'Hass' x 'Bacon' seedling) and '35707' (a 'Catalina' seedling) had higher TOC and UFA than other genotypes, while the mostly West Indian types such as 'Simmonds', 'Day', 'Pflume' and 'Miguel' had low TOC. Detected VOCs were acetaldehyde, hexanal, (E)-2-hexenal, limonene, α-cubebene, α-copaene, and β -caryophyllene. Most genotypes contained most of the VOCs. 'Monroe' lacked C6 aldehydes, and 'Pflume', 'Bernecker-43', 'Lula' and '35707' lacked some or all sesquiterpenes. [ABSTRACT FROM AUTHOR]

Tomato fruits exposed to chilling temperatures suffer aroma loss prior to visual chilling injury (CI) symptoms. Methyl salicylate (MeSA) and methyl jasmonate (MeJA) treatments were reported to alleviate the development of visual CI; however, it is unknown if the treatments alleviate internal CI in the form of aroma loss. In this research, ‘FL 47’ tomatoes at breaker stage were treated with MeSA or MeJA vapor prior exposure to chilling temperature. The chilling treatment did not result in visual CI; however, for internal CI it generally suppressed production of oxygen-containing heterocyclic compounds, ketones, sulfur- and nitrogen-containing heterocyclic compounds, alcohols, and aldehydes, including 13 important aroma contributors to tomato fruit. MeJA had no impact on sensory evaluation in spite of resulting in slightly altered volatile profile; however, MeSA alleviated the CI-induced reduction of a number of volatile compounds, and thereby enhanced tomato aroma. [ABSTRACT FROM AUTHOR]

Guava ( Psidium guajava ) fruit are valued for their rich, tropical aroma, but fruit quality data are lacking for many important cultivars. Guava is native to warm-climate areas of the Americas and is grown commercially in southern Florida, USA. Varieties relevant to south Florida display a high level of morphological diversity, including fruit color and shape. Fruit are commercially available at either a mature green stage which are harvested prior to full aroma development, or as mature yellow fruit which possess a full aroma profile. We sampled 27 guava accessions growing at the University of Florida’s Tropical Research and Education Center for aroma at immature, mature green, and mature yellow fruit developmental stages. Variability in pulp pH (3–4.6) was not indicative of fruit maturity, but titratable acidity (0.17–3.6%) did decrease throughout fruit development. Aroma profiles showed significant differences among accessions. Some volatiles including hexanal, ( E )-caryophyllene, and ( E )-2-hexenal were common across guava accessions and were present at all developmental stages. Other compounds including ( Z )-3-hexenyl acetate, ethyl butanoate, and ethyl octanoate had the greatest abundance only at the mature yellow stage of fruit development. Limonene, ( E )-cadina-1,4-diene, and β-ionone were abundant in some accessions and not detected in others (21, 10, and 14 out of 27 accessions, respectively). This work describes the comparative diversity of guava fruit quality for a large number of accessions through fruit development for the first time. Furthermore, these fruit quality data could support future breeding work towards the genetic improvement of guava flavor. [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate whether an electronic tongue (e-tongue) could differentiate “taste” profiles of full ripe tomato fruit of different cultivars, harvest maturities, and exposure to refrigeration or blanching. The four cultivars included: two common commercial cultivars, ‘Tygress’ and ‘FL 47’, with round shape and firm texture; ‘Tasti-Lee’, a hybrid with high lycopene content due to the crimson gene for the premium tomato market; and ‘Cherokee Purple’, an heirloom cultivar that consistently ranked very high in taste tests. Commercially, tomatoes are often harvested at the mature green (MG) stage for the fresh fruit and food service markets, and traditional vine-ripe harvested tomatoes are generally sold directly at farmer’s markets. To assess the effect of harvest maturity on fruit flavor once the fruit are fully ripened, fruit were harvested at six maturities from MG to full red. ‘Tygress’, ‘FL 47’, and ‘Tasti-Lee’ fruit all had similar total soluble solids (TSS) and titratable acidity (TA) content regardless of harvest maturity. Nonetheless, ‘Cherokee Purple’ had much higher TSS and TA at all but the MG harvest stage. E-tongue tests not only confirmed the differences detected in TSS/TA data, but also differentiated between the three commercial cultivars, and six harvest maturities. Both refrigeration and blanching are common kitchen practices and they were tested on ‘Tasti-Lee’ fruit for which some changes in the taste profiles were found by e-tongue, especially for the refrigeration treatment. E-tongue sensors ZZ, JE, BB, HA, and JB data correlated to TSS and TA, with significantly high correlations with TSS. E-tongue profiles not only significantly related to TSS, but successfully predicted TSS. [ABSTRACT FROM AUTHOR]

Citrus greening or huanglonbing (HLB) is thought to be caused by Candidatus Liberibacter asiaticus ( C Las) and is devastating the citrus industry worldwide. One symptom of HLB disease is excessive pre-harvest fruit drop. Recently, higher incidence of Lasiodiplodia theobromae ( Diplodia ) was found in HLB-symptomatic orange calyx abscission zones (AZ-C) than in non-symptomatic fruit, and the infection was positively correlated with the reduction in fruit detachment force (FDF), suggesting that Diplodia infection may be involved in the HLB-related pre-harvest fruit drop. To verify the hypothesis, we conducted two experiments. Experiment 1 was conducted by shaking HLB-affected ‘Hamlin’ and ‘Valencia’ orange trees during the harvest season (twice for ‘Hamlin’ and once for ‘Valencia’). The fruit that dropped from trees upon shaking were collected (D), and the fruit retained on trees after shaking were harvested (R). Fruit ethylene production was measured, and the levels of Diplodia and C Las in AZ-C of D and R fruit were analyzed. The results revealed significantly higher levels of Diplodia in D compared with R fruit; and ethylene was produced from more than half of the D fruit but none of the R fruit. Ethylene production was positively correlated with Diplodia level in D fruit. In experiment 2, a preliminary trial on the effect of fungicide (Quadris Top) application on incidence of Diplodia infection and fruit drop was investigated. The experiment was conducted in a commercial grove with essentially 100% of the trees being HLB-symptomatic, and included five citrus cultivars (‘Early Gold’ orange, ‘Midsweet’ orange, ‘Murcott’ tangor, ‘Navel’ orange and ‘Ray Ruby’ grapefruit). Diplodia levels were lower and FDF significantly higher in fungicide-treated compared to non-treated ‘Early Gold’, ‘Midsweet’ and ‘Murcott’ fruit, and consequently, the fruit drop was reduced by 45%, 30% and 46% that of non-sprayed controls, respectively. For ‘Navel’ or ‘Ray Ruby’ fruit, there was no significant change between sprayed and non-sprayed controls in the level of Diplodia , FDF or fruit-drop. The results consistently showed a positive correlation between Diplodia infection and fruit drop in HLB-affected fruit, indicating the possible involvement of the fungus in HLB-related excessive fruit drop. This suggests that control of Diplodia fungal infection in the field may reduce HLB-associated pre-harvest fruit drop. [ABSTRACT FROM AUTHOR]

• Six SHB blueberry cultivars were observed for 2 years, 2 harvests, 2 storage weeks. • Indigocrisp and Keecrisp were the firmest and maintained firmness in storage. • Indigocrisp was the sweetest with highest blueberry flavor among cultivars. • Sensory firmness and sourness were highly correlated with instrumental measures. • Indigocrisp maintained its quality independent of environmental variables. Blueberry (Vaccinium spp.) is a specialty crop with expanding production and consumption worldwide. Southern Highbush Blueberries (SHB) require few chilling hours and include early-ripening cultivars which can be harvested in an early market window making the crop more profitable for growers in sub-tropical regions. To expand the marketability of the crop, fruit breeders are seeking to meet the current demand for fruit quality. To this end, this study gathered sensory measurements (firmness, sweetness, sourness, blueberry flavor, green flavor and off-flavors), chemical (pH, titratable acidity and soluble solids concentration), and physical attributes (compression force) on six SHB cultivars, in order to understand how fruit quality traits are affected by environmental conditions such as storage duration, year and harvest date. Differences across environmental conditions for all attributes were observed. Indigocrisp and Keecrisp were the firmest cultivars and maintained firmness over time in storage. Additionally, Indigocrisp was the sweetest and had the most blueberry and green flavors among the cultivars. On the other hand, Arcadia was the softest, as measured by sensory and compression force, but varied with year and harvest. Arcadia and Emerald were the least sweet and most sour of the cultivars, and Endura and Patrecia were intermediate for all sensory attributes. In general, sensory descriptors were well explained by instrumental measurements. Variations across seasons and storage were inconsistent among cultivars, but Indigocrisp was the most stable cultivar for the quality traits evaluated. In the end, all fruit quality traits assayed in this study were influenced by environmental conditions throughout the season. [ABSTRACT FROM AUTHOR]

• Citrus x Poncirus hybrids have poor eating quality due to the Poncirus parent • In this study, three such hybrids had composition analysis similar to citrus fruit • Two hybrids had volatile composition closer to that of Poncirus trifoliata fruit • One hybrid had a flavonoid aglycone profile similar to that of pure Poncirus • A pattern of inheritance of Poncirus chemical traits could be seen Citrus breeders have made numerous hybridizations that included Poncirus trifoliata L.Raf. (P. trifoliata), a relative of the genus Citrus , in their pedigree to produce hybrids that are cold- and disease-resistant. Initial hybrids of Citrus × P. trifoliata typically produce fruit that have unacceptable flavor, but more advanced hybrids with greater proportions of Citrus in their pedigrees have various degrees of off-flavor and taste. This study reports the volatile constituents, as well as nonvolatile limonoids and flavonoids, in the juice of six Citrus hybrids containing P. trifoliata in their pedigrees, compared to two hybrids derived solely from Citrus. Secondary metabolite profiles reflected the complex genetic backgrounds of those hybrids. Hybrids 6_23−20 and US 119 had juice composition most similar to that of P. trifoliata , with more volatiles, and in particular, more esters and sesquiterpenes with higher amounts in total. Furthermore, hesperidin concentration in US 119 was low (10 μg g−1) in comparison with other hybrids (125−326 μg g−1) while concentrations of narirutin and isosakuranetin-7-O-rutinoside were unusually high (135−211 μg g−1 and 304−182 μg g−1, respectively) in comparison with the other hybrids (5−60 μg g−1 and 10−75 μg g−1, respectively), which is in agreement with the composition of pure P. trifoliata. Juice of P. trifoliata derived hybrids 5−18-24, 5−18-31, 1−76-100, and 1−77-105 presented secondary metabolite compositions closer to those of pure Citrus hybrids. Based on volatiles, limonoids, and flavonoid profiles, we conclude that it is possible to generate advanced Citrus hybrids including P. trifoliata in their pedigrees that approach the quality of common Citrus types. [ABSTRACT FROM AUTHOR]

• A HW applied on MG tomatoes induced higher antioxidant capacity when ripe. • High-temperature ethylene treatment promoted phenolics compounds. • HW synergized with high temperature ethylene treatment to promote antioxidants. • High temperature ethylene treatment delayed ripening of tomatoes. Controlled postharvest stresses were used to induce the synthesis of antioxidants in tomato fruit. In this study, a hot-water (HW) treatment of 52 °C for 5 min promoted higher total oxygen radical absorbance capacity (ORAC) compared to fruit immersed in 25 °C water for 5 min. Whereas, ethylene treatment at high temperature, particularly at 35 °C for 24, 48 or 72 h, induced higher content of total phenolics and ferric reducing ability of plasma (FRAP) than fruit treated with ethylene at 20 or 30 °C. In combination, there was synergy between the treatments, and this was most notable by the increase of total phenolics in HW-treated tomatoes exposed to ethylene at 35 °C for 24, 48 or 72 h. There was also a significant increase of total ORAC in HW-treated fruit exposed to ethylene at 30 °C for 72 h or 35 °C for 24, 48 or 72 h. This increase in antioxidant capacity was observed in the hydrophilic fraction of HW-treated fruit exposed to ethylene at 30 °C for 72 h or 35 °C for 24 or 48 h and in the lipophilic fraction of HW-treated tomatoes exposed to ethylene at 35 °C for 24, 48 or 72 h. Moreover, The HW-treatment especially maintained the level of total carotenoids and ascorbic acid when exposed to ethylene at 30 °C for 72 h or 35 °C for 48 or 72 h. Nevertheless, the high temperature ethylene treatment reduced the a* value of tomato peel regardless of the application of HW treatment. In conclusion, application of a HW treatment of 52 °C for 5 min followed by exposure to ethylene at 35 °C for 48 h was most effective in synergistically improving the antioxidant capacity and composition of tomatoes without severely impairing color development. [ABSTRACT FROM AUTHOR]