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Modified Atmosphere Packaging (MAP) has been widely used as an effective way to preserve foods. Fresh produce, meat and meat products, seafood, and dairy products can benefit from modified gaseous atmospheres, which are usually achieved by reducing oxygen and increasing carbon dioxide concentrations, within limits, defined by product tolerances. MAP of fresh produce is particularly challenging because products are living and respiring. Respiration rates depend on several factors including temperature, oxygen, and carbon dioxide concentrations. Balancing package permeation with respiration is challenging, often due to limited selection of practical packaging materials. Failing to remain within tolerance limits of products leads to rapid quality loss. Gas barrier properties of packages determined rate of gas exchange with the external environment and is a critical factor for achieving tolerable levels. Availability of packaging materials that meet requirement of specific produce is essential. Relative permeability of common films to carbon dioxide is about 3 to 6 times of that to oxygen, often leading to package collapse for package atmospheres that benefit from carbon dioxide. Films often fail to provide desired oxygen transmission rates, high carbon dioxide to oxygen selectivity and desired mechanical properties simultaneously. Despite advances, minimal availability and high cost of selective barrier films limit applications of MAP for fresh produce packaging. Therefore, active packaging components and films are being developed and designed to overcome these limitations. Inserts or films that contain active mixtures as gas emitters and/or scavengers are now commercially available. "Clean label" trends are motivating alternative approaches using active packaging components. [ABSTRACT FROM AUTHOR]

Effects of postharvest oxalic acid (OA) application on chilling injury (CI) in harvested mango fruit (Mangifera indica L.) were investigated using 'Tommy Atkins' fruit from Florida and 'Zill' fruit from Panzhihua. TheOAwas applied to harvested fruit as a 5 or 10 mM drench for 10 or 15 minutes at 25 °C. 'Tommy Atkins' fruit typically develop external CI symptoms while 'Zill' develops internal symptoms. Development of CI symptoms was significantly reduced in OA-treated 'Tommy Atkins' fruit stored for 18 days at 5 °C as was the rate of softening upon transfer to 25 °C for 4 days. However, OA treatment did not substantially control fruit decay. For 'Zill', CI development was significantly reduced in OA-treated fruit during storage at 10 °C for 49 days and subsequently for 4 days at 25 °C. In addition, membrane integrity was enhanced and the activities of the antioxidant system enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were elevated, although there were decreases in both hydrogen peroxide (H2O2) content and superoxide radical production in OA-treated fruit. The activities of some enzymes of the energy cycle were also elevated in the OA-treated fruit, including succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), H+-adenosine triphosphatase (H+-ATPase), and Ca2+- adenosine triphosphatase (Ca2+-ATPase). Thus, OA may enhance CI tolerance in mango fruit by maintaining membrane integrity associated with enhanced antioxidant activity and regulation of energy metabolism. Application of 5 mM OA appears to be beneficial in controlling postharvest CI in mango fruit. [ABSTRACT FROM AUTHOR]

Huanglongbing (HLB), a citrus disease, has caused >70% decline in Florida citrus production over the past decade. Fruit from HLB-affected trees are small, lopsided, uneven colored, with bitter and acidic taste, making them undesirable for the fresh market. 'Tango' mandarin is fairly tolerant to HLB, but achieving acceptable peel color under Florida conditions is challenging. Therefore, preharvest foliar-applied mineral nutrients (K + Ca, K + B, and Ca + B) applied to HLB-affected 'Tango' trees followed by postharvest degreening were evaluated for their effects on fruit quality and storage life. In addition, degreening followed by thiabendazole fungicide and storage conditions (4 ± 1 °C or 24 ± 1 °C) were evaluated. The K + B treatment resulted in fewer HLB-symptomatic fruit, as well as greater fruit weight and diameter, and better peel color development. Degreening fruit allowed marketable color to be achieved. Compression forces for both healthy and HLB-affected fruit, and peel puncture resistance forces for healthy fruit were higher in cold storage than ambient storage. Thiabendazole-treated fruit had less storage decay incidence than non-treated fruit at room temperature, and no decay was observed in cold storage. Overall, preharvest K + B spray and degreening, alone or in combination, are potent tools for achieving marketable peel color of 'Tango' fruit from HLB-affected trees. • K + B treatment increased fruit size in HLB-affected 'Tango' trees. • K + B treatment initiated uniform peel color formation in HLB-affected 'Tango' fruit. • Fruit from K + B treatment followed by degreening attained marketable peel color. • Degreening achieved acceptable peel color in fruit grown in CUPS and open field. • Fertilization strategies and degreening may need to be changed in the HLB-era. [ABSTRACT FROM AUTHOR]

• Identification of senescence-associated genes in postharvest senescence. • The identified candidate genes could serve as markers for broccoli senescence stages. • Understanding function of Senescence-Associated Genes supports shelf-life extension. We used genomic tools to understand senescence and molecular signaling events in harvested broccoli florets stored at 25 or 4 °C to test the hypothesis that genetic markers can be used to identify the stage of senescence or physiological age of plant tissue. The RNA-sequencing approach provided key insights into the gradual changes in transcriptome during postharvest storage in broccoli. We found that 4279 and 4143 transcripts were differentially expressed after 3 and 5 days of storage at the two storage temperatures, respectively. We then performed genome-wide comparisons at 25 and 4 °C and illustrated the temporal and spatial-specific genes in stored broccoli. By using quantitative Real-Time PCR and transient tobacco assay, we validated our RNA-sequencing experiment. We further performed comparative analysis of Arabidopsis and broccoli to disclose conserved senescence genes. Concurrently, we found that 43 genes were senescence-specific genes that are common senescence-associated genes (SAGs) regardless of tissue-specific expression. Interestingly, we observed 73 transcription factors (TFs) within this group that might form a core transcriptional regulatory circuitry to control the onset and progression of senescence. Moreover, we also identified new molecular players involved in postharvest senescence including brassinosteroids (BR) perception genes, BIK1 (Brassinosteroid-Interacting Kinase1), BRL1 (BRI1-like 1), BIR1 (BAK1-Inteacting Receptor-Like Kinase 1), stomatal patterning gene SPCH , and circadian clock genes CCA1. Those genes could serve as 'freshness-indicators' for the stage of senescence or relative freshness of the product. This report identified the SAGs that are essential for tissue-specific senescence and provided fundamental insights into signaling events during postharvest senescence in Brassica plants. [ABSTRACT FROM AUTHOR]

Apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf. ('Gala', 'Delicious', 'Granny Smith' and 'Fuji')], pretreated or nontreated with 1-methylcyclopropene (1-MCP, 0.6 to 1.0 µL·L-1 for 18 hours at 20 °C), were stored in controlled atmosphere (CA, 1 to 1.5 kPa O2; 1 to 2 kPa CO2) or in regular atmosphere (RA) for up to 8 months at 1 °C. Firmness, titratable acidity (TA), soluble solids content (SSC), and volatile abundance were analyzed every month directly or after transfer to air at 20 °C for 1 week to determine effect of 1-MCP, storage atmosphere and storage time on apple quality immediately after cold storage and after simulated marketing conditions at 20 °C. The 1-MCP ± CA treatments delayed ripening and prolonged storage life as indicated by delayed loss of firmness and TA in all four cultivars during storage. The 1-MCP ± CA also slightly delayed loss of SSC for 'Gala' but had no effect on SSC levels for the other cultivars. There were differences among treatments for firmness and TA content [(1-MCP + RA) > CA] for 'Gala', 'Delicious', and 'Granny Smith' apples, but not for 'Fuji'. These differences were generally exacerbated after transfer of fruit to 20 °C for 1 week. A combination of 1-MCP + CA was generally best [(1-MCP + CA) > (1-MCP + RA) or CA] for maintaining 'Delicious' firmness and TA. However, the treatments that were most effective at retaining TA and firmness also retained the least volatiles. The results indicate that the efficacy of 1-MCP and CA in maintaining apple quality factors is cultivar dependent and that 1-MCP + RA may be a viable alternative to CA for optimal eating quality for some cultivars. [ABSTRACT FROM AUTHOR]

• Thyme oil inhibited in vitro mycelial growth of C. gloeosporioides. • 1% chitosan plus 400 μL l -1 thyme oil effectively controlled C. gloeosporioides in mango fruit. • 1% chitosan plus 400 μL l -1 thyme oil reduced naturally occurring decay in mango fruit. • 1% chitosan plus 400 μL l -1 thyme oil boast defence enzymes in mango fruit. Anthracnose caused by Colletotrichum gloeosporioides is a severe postharvest mango disease. Postharvest application of fungicides is necessary to effectively control this disease, however, many of these fungicides are not allowed in many countries. In this study we aimed to investigate the combined effect of 1% chitosan plus 400 μLL−1 thyme oil to control anthracnose and improve shelf life of mango fruit (cv. White Chaunsa). We found that 400 μL L-1 thyme oil can completely inhibit in vitro mycelial growth of the fungus C. gloeosporioides. However, the combined application of 1% chitosan plus 400 μL L−1 thyme oil was more effective than thyme oil (400 μL L-1) alone in controlling the disease in artificially inoculated mango fruit. Furthermore, this combined treatment significantly (P ≤ 0.05) decreased naturally occurring decay. A mechanism related to promotion of fruit resistance by stimulation of phenolic metabolism is suggested by elevated phenylalanine ammonia-lyase (PAL) and peroxidase (POD) activities as compared to both the control and the synthetic fungicide Prochloraz. In addition, retention of physicochemical properties such as titratable acidity, total soluble solids, firmness, weight loss, color, and higher scores for sensory perception confirmed the efficacy of the treatment. This study demonstrated that the application of 1% chitosan plus 400 μL L-1 thyme oil more effectively controlled mango anthracnose as compared to synthetic fungicide; however, the commercial efficacy of the treatment needs to be tested. [ABSTRACT FROM AUTHOR]

• Muscadine berries treated with controlled atmosphere remained firmer during storage than berries in normal air. • Decay control was greatly improved by increasing the CO 2 concentration compared to the control berries. • Ethylene production was significantly decreased in the regular controlled atmosphere and extreme CO 2 treatment. • Storage in controlled atmosphere prevented the decline in anthocyanins than occurred in regular air. Muscadine grape (Vitis rotundifolia Michx) is a non-climacteric fruit that rapidly loses quality during storage. This study aimed to assess the effect of controlled atmosphere (CA) on quality parameters and muscadine grapes decay. Berries of two muscadine grape cultivars, Triumph, and Supreme, were stored at 4 °C with 95 % relative humidity in either regular air (AIR), regular CA (RCA) (6 % O 2 + 10 % CO 2), or CA with extreme CO 2 level (ECA; 4 % O 2 + 30 % CO 2) for up to 42 d. Treated berries with either RCA or ECA provided better control of weight loss. Both CA treatments reduced decay incidence, but there was no decay in ECA berries after 42 d for both cultivars and no evidence of CO 2 injury. The results showed that berry softening was significantly delayed by RCA and ECA, which had a lower ethylene production rate than berries exposed to AIR. Application of RCA and ECA also retained greater total antioxidant activity, total phenolic compounds, and firmness compared to AIR. These results demonstrate that maintaining CA conditions postharvest leads to improved preservation of compositional quality and delayed softening and decay of harvested muscadine grapes compared with AIR storage. [ABSTRACT FROM AUTHOR]

• Major anthocyanins in Taoxingli: cyanidin 3-o-glucoside and cyanidin 3-o-rutinoside. • 1-MCP maintained the quality of chemical attributes in 'Taoxingli' plum fruit. • 1-MCP regulated the expression of anthocyanin synthesis genes and PsMYB10. • 1-MCP delayed in accumulation of anthocyanin in 'Taoxingli' plum fruit during storage. The effects of 1-methylcyclopropene (1-MCP) treatment on the quality attributes of 'Taoxingli' plum fruit, particularly on whole fruit anthocyanin content via anthocyanin biosynthesis during storage at the non-chilling temperature of 10 °C were investigated. The results showed that 1-MCP treatment effectively reduced weight loss and better maintained soluble solids content (SSC) and titratable acidity (TA), resulting in increased contents of fructose, glucose, sorbitol, and malic acid, and reduced decay during storage. Furthermore, major anthocyanins, including cyanidin 3- O -glucoside and cyanidin 3- O -rutinoside, were detected. 1-MCP treatment delayed increases in total anthocyanins along with the major individual anthocyanins during storage, which was attributed to its effect in suppressing the expression of synthesis-related structural genes and the transcription factor PsMYB10 early in storage, enhancing their expression later in the storage period. Thus, 1-MCP treatment was beneficial for retaining the quality of 'Taoxingli' plums, particularly the chemical attributes, and extending the storage life with low economic loss during storage. [ABSTRACT FROM AUTHOR]

Vegetable grafting has primarily been used in the commercial production of high-value crops in the Solanaceae and Cucurbitaceae families. In this study, we explored the feasibility of making a novel graft between pac choi (Brassica rapa L. var. chinensis) and daikon radish (Raphanus sativus L. var. longipinnatus) to create a plant with harvestable pac choi leafy vegetable above-ground, and a daikon radish taproot below-ground. 'Mei Qing Choi' pac choi (scion) was grafted onto 'Bora King' daikon radish (rootstock). Grafted pac choi–daikon radish plants did not show a decrease in SPAD value, canopy size, leaf number, leaf area, or above-ground weight compared with self-grafted pac choi plants. However, taproot formation was reduced in grafted pac choi–daikon radish plants, as shown by decreased taproot length, diameter, fresh weight, and dry weight compared with non- and self-grafted daikon radish plants. Surprisingly, grafting with radish increased the photosynthetic rate of the pac choi. This pilot study demonstrated the potential of creating a new pac choi–daikon radish vegetable product to help save growing space and minimize waste at consumption, as pac choi roots are not eaten and radish leaves are usually discarded. The inter-generic grafting between B. rapa var. chinensis and R. sativus var. longipinnatus could also provide a unique model system to help elucidate scion-rootstock synergy and above- and below-ground sink competition in horticultural crops. [ABSTRACT FROM AUTHOR]

Temperature control of produce in the retail environment is essential to reduce food safety risks, maintain quality, and reduce food waste. Previous studies have demonstrated that retrofitting or replacing open display cases doors results in better control of temperature and humidity. However, there are no studies to date that comprehensively evaluate temperature profiles in cases with and without doors in actual retail store environments. Twenty-five open and closed refrigerated display cases in ten retail stores in five states were monitored for temperature and humidity over 9 months. Sensors recorded data every 2 min at eight positions (top, middle, bottom and under the bottom bin, in the front and back locations of each shelf). There were significant differences between open and closed cases, retailers, and sensor position in display cases on temperature and relative humidity (p < 0.0001). Seven display cases were retrofitted with doors and, as a result, temperature variations were significantly minimized (p-value <0.0001). Cases with doors maintained temperatures significantly lower (4.7 °C, p-value <0.0001) than cases without doors, and the top front position in the cases had both the highest temperature (5.7 °C) and abuse due to high temperature (>5 °C) for the longest duration (35.7% of total time observed) of allow locations measured. Temperatures and abuse conditions above 5 °C were not significantly different between front and back positions in the cases. The range of temperature and RH variability was reduced following door installation. With changes in display case technology over the past five years, this study provides updated data on operational temperatures in display cases before and after retrofitting with doors. It also provides evidence of the importance of temperature monitoring within display cases to ensure abusive conditions do not persist. • Significant difference between retailers observed in display cases. • Behavior and technology differences between retailers. • Display cases retrofitted with doors improved temperature and humidity control. • Performance monitoring of display cases provide food safety information. [ABSTRACT FROM AUTHOR]

Retail display of highly perishable foods behind glass doors ensures uniform product temperatures below the FDA Food Code threshold of 5 °C, resulting in better-preserved foods while reducing energy costs. However, only a handful of studies have evaluated the effect of repeated door openings on product temperatures and energy consumption with contrasting reports. In this paper, we evaluated the effects of two frequencies (doors opened every 5 or 15 min) and four durations (doors held ajar for 5, 15, 30 or 60 s) on product simulator temperatures in a display case installed in our research supermarket. At ambient conditions (19.6–20.9 °C, 63% RH), with a case thermostat setting of 0.6 °C and a daily 30-min defrost cycle, the only statistically significant fluctuation in product simulator temperatures was found for the most aggressive opening schedule where the door was opened every 5 min for 60 s at each opening. Pairwise comparisons demonstrated that this treatment resulted in product simulator temperatures (up to 6.6 °C during defrost cycle) that were significantly higher (p < 0.001) or somewhat significantly higher (p < 0.03) compared to product exposed to all other combinations. Product exposed to all other treatment combination resulted in temperatures that either never exceeded 5 °C or briefly exceeded it only during the single 30-min defrost cycle. As a result, we selected an average opening sequence (every 10 min for 12 s) to perform an energy consumption assessment of the case. Energy consumption was determined to be 66% lower than that compared to an open-retail display case (same model, mark, size, operating schedule and thermostat setting). Even with the most extreme schedule where three of the six doors remained open continuously, there was still a measured 45% reduction in energy consumption as compared to that of the open-retail display case. • Enclosed refrigerated display cases support compliance with US Food Code. • Typical door opening regimes do not impact product temperature uniformity in display cases. • Typical door opening regimes still provide significant energy savings compared to an open display case. [ABSTRACT FROM AUTHOR]

Muscadine grapes ( Vitis rotundifolia Michx.) are delicate in nature with short shelf life. Postharvest technologies like modified atmosphere packaging (MAP) with reduced oxygen (O 2 ) and elevated carbon dioxide (CO 2 ) could increase the postharvest storage life with better quality. In the current experiment, physical and biochemical quality attributes of black and bronze cultivars of muscadine grapes ('Supreme' and 'Granny Val', respectively) were evaluated in active MAP. Fruit were packed in plastic trays, sealed with impermeable film, and CO 2 was introduced into the package. The MAP was created by a rigid microperforated plastic patch coated with a proprietary semipermeable resin, which was applied over a hole in the tray; packages with the same size hole without a patch were the control. Fruit were stored at 4°C for 42 days (6 weeks). MAP resulted in significantly lower decay incidence and better retention of fruit firmness for up to 28 days of storage in both cultivars as well as reducing color changes in 'Supreme' fruit. Although MAP did not affect the biochemical quality of muscadine grapes, total antioxidants increased initially and then decreased during storage, irrespective of packaging treatments. A significant linear increase in total phenolic content was also found during storage, regardless of treatments applied. Overall, the results of the current study demonstrate that MAP can be an affective technology to increase storage duration of muscadines with better retention of physical quality, without affecting the biochemical attributes., Competing Interests: The authors declare no conflict of interest to disclose., (© 2024 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Background: Achieving a larger berry size accompanied with even ripening are demanded by producers in growing muscadine cultivars. The current study aimed to evaluate the impact of fruit thinning on berry size and quality in two muscadine grape cultivars, 'Triumph' a bronze-fruited cultivar bearing hermaphrodite flowers, and 'Supreme' a dark black-fruited cultivar bearing female flowers. Thinning was performed before bunch closure and only one cluster per cane was retained., Results: Results indicated a significant interaction of treatments and cultivars on berry weight and berry diameter. In 'Supreme,' berry weight and berry diameter were significantly increased where thinning was performed, and difference in plant yield between thinned and not thinned vines was not significant. For 'Triumph,' thinning had no significant impact on berry weight and diameter, but yield was ultimately reduced. Other physico-chemical characters were not affected by fruit thinning. However, differences were observed between both cultivars for these characters. The values of antioxidant scavenging activity (ASA) and total phenolic content (TPC) were 62.7% and 21.7% higher in 'Supreme' as compared to 'Triumph,' irrespective of the thinning treatments. Being a colored cultivar, 'Supreme' berries have higher anthocyanins than 'Triumph,' which has a negligible amount of anthocyanins. The ASA exhibited a strong positive correlation with TPC and anthocyanin content of muscadine grapes. There was also a significant positive correlation between TPC and anthocyanins., Conclusion: Cluster thinning of some muscadine grape cultivars may improve individual berry size without affecting overall plant yield or the fruit color, firmness, biochemical attributes and bioactive compounds. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

The appropriate selection of rootstock-scion combinations to improve yield and fully realize grafting benefits requires an in-depth understanding of rootstock-scion synergy. Toward this end, we grafted two determinate-type scions [grape tomato ('BHN 1022') and beefsteak tomato ('Skyway')] onto four rootstocks with different characteristics to examine plant growth, yield performance, biomass production, and fruit mineral nutrient composition. The study was conducted during two growing seasons (spring and fall plantings in Florida) under organic production in high tunnels with the non-grafted scions as controls. Rootstocks had previously been designated as either "generative" ('Estamino') or "vegetative" ('DR0141TX') by some commercial suppliers or had not been characterized ['RST-04-106-T' and 'SHIELD RZ F1 (61-802)']. Also, 'Estamino', 'DR0141TX', and 'RST-04-106-T' had been described as more vigorous than 'SHIELD RZ F1 (61-802)'. In both planting seasons (with low levels of soilborne disease pressure), the "vegetative" and "generative" rootstocks increased marketable and total fruit yields for both scions except for the beefsteak tomato grafted with the "vegetative" rootstock in fall planting. Positive effects of 'RST-04-106-T' on fruit yield varied with scions and planting seasons, and were most manifested when grafted with the beefsteak tomato scion in fall planting. 'SHIELD RZ F1 (61-802)' led to similar yields as the non-grafted controls except for grafting with the grape tomato scion in fall planting. For vegetative and fruit biomass, both the "vegetative" and "generative" rootstocks had positive impacts except for the beefsteak tomato in fall planting. For fruit mineral composition, the "vegetative" and "generative" rootstocks, both highly vigorous, consistently elevated fruit P, K, Ca, Zn, and Fe contents on a dry weight basis, whereas the other rootstocks did not. Overall, although the more vigorous rootstocks enhanced tomato plant productivity and fruit minerals, the evidence presented here does not support the suggestion that the so-called "vegetative" and "generative" rootstocks have different impacts on tomato scion yield, biomass production, or fruit mineral contents. More studies with different production systems and environmental conditions as well as contrasting scion genotypes are needed to further categorize the impacts of rootstocks with different vigor and other characteristics on plant biomass production and their implications on fruit yield development., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gong, Brecht, Koch, Hutton and Zhao.)

Previous studies of tomato rootstock effects on fruit quality have yielded mixed results, and few attempts have been made to systematically examine the association between rootstock characteristics and tomato fruit quality. In this study, grape tomato ('BHN 1022') and beefsteak tomato ('Skyway') were grafted onto four rootstocks ['Estamino' (vigorous and "generative"), 'DR0141TX' (vigorous and "vegetative"), 'RST-04-106-T' (uncharacterized), and 'SHIELD RZ F1 (61-802)' (mid-vigor, uncharacterized)] and compared to non-grafted scion controls for two growing seasons (Spring and Fall in Florida) in organically managed high tunnels. In both seasons and for both scions, the two vigorous rootstocks, regardless of their designation as "vegetative" ('DR0141TX') or "generative" ('Estamino'), exhibited negative impacts on dry matter content, soluble solids content (SSC), SSC/titratable acidity (TA), lycopene, and ascorbic acid contents. Similar effects on fruit dry matter content and SSC were also observed with the 'RST-04-106-T' rootstock, although little to no change was seen with grafting onto 'SHIELD RZ F1 (61-802)'. Further studies are needed to elucidate the impact of rootstock vigor on tomato volatile profiles and consumer sensory acceptability in order to better determine whether any of the documented effects are of practical importance. On the other hand, the evident effects of scion cultivar and planting season on fruit quality were observed in most of the measurements. The scion by rootstock interaction affected fruit length, firmness, pH, and total phenolic content, while the planting season by rootstock interaction impacted fruit firmness, pH, total antioxidant capacity, and ascorbic acid and lycopene contents. The multivariate separation pattern of planting season, scion, and rootstock treatments as revealed by the canonical discriminant analysis further indicated that the influence of scion cultivar and planting season on tomato fruit quality could be much more pronounced than the rootstock effects. The fruit color ( C * and H °), length and width, SSC, pH, total antioxidant capacity, ascorbic acid, and lycopene contents were the main attributes distinguishing different scion-planting season groups., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gong, Brecht, Hutton, Koch and Zhao.)

Background: 'Vegetative' and 'generative' tomato rootstock types have been proposed based on their different effects on tomato scion growth performance; however, their impacts on fruit quality have not been characterized. No study has been conducted in which the effects of rootstock on grape tomato quality attributes were assessed using sensory and instrumental methods of evaluation. Here, we conducted two experiments to examine the influence of 'DR0141TX', 'Estamino', and 'Multifort' rootstocks (vegetative, generative, and uncharacterized, respectively) on fruit quality properties of determinate and indeterminate grape tomato scions under organic production in high tunnels, including color, size, firmness, dry matter content, soluble solids content (SSC), titratable acidity (TA), pH, and consumer sensory attributes., Results: In both experiments, grafting 'Sweet Hearts' indeterminate grape tomato onto 'DR0141TX', 'Estamino', or 'Multifort' increased fruit size and led to negligible effects on sensory attributes and instrumental measurements of fruit quality attributes. For 'BHN 1022' determinate grape tomato, rootstocks did not exhibit any major impact on fruit quality attributes in Experiment 1. However, fruit quality was compromised by grafting per se and rootstocks, especially 'Multifort', in Experiment 2, as reflected by reduced SSC, TA, and SSC/TA and lower scores for overall appearance, overall acceptability, tomato flavor, overall texture, and sweetness., Conclusion: In general, 'vegetative' and 'generative' rootstocks showed comparable effects on sensory evaluations and instrumental measurements of grape tomato quality attributes for both indeterminate and determinate scions. More research is needed to better characterize rootstock effects on fruit quality, including the flavor-related compounds under different growing conditions. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Storage at the putative chilling threshold temperature (CTT) to avoid chilling injury still limits postharvest handling of tropical fruit like banana in that ripening may occur at the CTT. To determine whether chilling injury (CI) symptoms would develop in mature green (MG) banana fruit if the CTT exposure was extended by inhibiting ethylene action and thus ripening, 1-methylcyclopropene (1-MCP) was applied. Individual 'fingers' from multiple 'clusters' of MG bananas were either immersed in water or 50 μg L -1 1-MCP (a.i.) solution and each treatment was divided into three subgroups for storage at 5.0°C (severe CI), 13.0°C (mild CI), or 14.0°C (CTT) ± 0.1°C. 1-MCP delayed ripening in terms of color change for 10 days for fruit stored at the CTT. Ethylene production by fruit at 5.0°C remained around 0.04 ng kg -1 s -1 with no obvious increase during 31-day storage. Ethylene production at 14.0°C (-1-MCP/+1-MCP) increased on Day 33 while increasing on Day 38 for 13.0°C fruit without 1-MCP and on Day 39 for fruit with 1-MCP. Peak climacteric ethylene occurred on Days 44 and 39 for 13.0 and 14.0°C fruit without 1-MCP, respectively, and on Days 59 and 51 for 13.0°C and 14.0°C 1-MCP-treated fruit, respectively. As hypothesized, longer exposure of MG banana fruit to the CTT of 14.0°C without onset of ripening as was allowed by prior 1-MCP treatment allowed CI to develop at that normally non-chilling temperature. Vascular browning was the first visual and most sensitive CI symptom in the experiment and was observed on Day 4 at 5.0°C, Day 10 at 13.0°C, Day 19 at 14.0°C without 1-MCP, and on Day 28 at 14.0°C with 1-MCP. Using a 1-MCP pre-treatment to remove the influence of ethylene from bananas stored at 13°C or 14°C also resulted in slight reduction in vascular browning severity. In conclusion, a putative safe temperature may become a CI temperature if the shelf-life-limiting factor is removed, allowing longer exposure. Chilling at the CTT caused relatively mild injury on fruit, and vascular browning is a sensitive indicator of CI status, while the light-adapted quantum yield of photosystem II [Y(II)] could be a non-destructive indicator of early CI stress in MG banana. Fruit at 13.0/14.0°C developed CI symptoms slightly later with 1-MCP than without 1-MCP. This suggests that ethylene might be involved in early CI symptom development., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chang, Sargent, Kim and Brecht.)

The efficacy of the signaling molecule melatonin for alleviating chilling injury (CI) in mango ( Mangifera indica L.) fruit was studied to investigate the potential role of membrane integrity, energy charge, and ripening-related changes in the development of CI, and its management by melatonin. 'Langra' and 'Gulab Jamun' cultivar mango fruit was immersed in 100 μM of melatonin before storage for 28 days at 5°C with weekly transfers to shelf life at 25°C. CI symptom development was associated with compositional and enzymatic aspects of textural changes, cell membrane deterioration, and chemical energy status. Melatonin-treated 'Langra' fruit exhibited very low CI (5 vs. 21%) while 'Gulab Jamun' fruit exhibited higher CI (36 vs. 38%) during 28 days of storage at 5 ± 1°C. Higher chilling tolerance in melatonin-treated 'Langra' was associated with lower softening, ascribed to lower cell wall degrading exo- and endo- polygalacturonase, pectinesterase, and endo-1,4-β-D-glucanase. In addition, lower membrane deteriorating-phospholipase D and lipoxygenase activity in melatonin-treated 'Langra' corresponded to lower palmitic and stearic acids and higher oleic, linoleic, and linolenic acids accumulation, thus, higher unsaturated/saturated fatty acids ratio. Additionally, there was a higher intracellular energy supply with melatonin, represented by a higher adenylate energy charge (AEC) arising from higher ATP and ADP and lower AMP accumulation, related to higher H + -ATPase, Ca 2+ -ATPase, succinate dehydrogenase, and cytochrome c oxidase activities. This study for the first time provides evidence, suggesting that melatonin alleviation of CI is related to the preservation of membrane integrity, thereby protecting the intracellular energy supply, and preserving cell wall integrity via impeding cell wall degrading enzyme activities., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Bhardwaj, Aghdam, Arnao, Brecht, Fawole and Pareek.)

In recent decades, increasing attention has been paid to food safety and organic horticulture. Thus, people are looking for natural products to manage plant diseases, pests, and weeds. Essential oils (EOs) or EO-based products are potentially promising candidates for biocontrol agents due to their safe, bioactive, biodegradable, ecologically, and economically viable properties. Born of necessity or commercial interest to satisfy market demand for natural products, this emerging technology is highly anticipated, but its application has been limited without the benefit of a thorough analysis of the scientific evidence on efficacy, scope, and mechanism of action. This review covers the uses of EOs as broad-spectrum biocontrol agents in both preharvest and postharvest systems. The known functions of EOs in suppressing fungi, bacteria, viruses, pests, and weeds are briefly summarized. Related results and possible modes of action from recent research are listed. The weaknesses of applying EOs are also discussed, such as high volatility and low stability, low water solubility, strong influence on organoleptic properties, and phytotoxic effects. Therefore, EO formulations and methods of incorporation to enhance the strengths and compensate for the shortages are outlined. This review also concludes with research directions needed to better understand and fully evaluate EOs and provides an outlook on the prospects for future applications of EOs in organic horticulture production., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chang, Harmon, Treadwell, Carrillo, Sarkhosh and Brecht.)

Controlled postharvest stresses were used to induce the synthesis of carotenoids in tomato fruit. The accumulation of carotenoids was observed by the change of color of the tomato fruit from green to red. This change of color was monitored by the a* value and hue of the CIELAB* color coordinates in which the a* value increased following a sigmoidal curve and hue decreased in a similar trend. This sigmoidal curve marked the transition from chloroplasts to chromoplasts; in other words, the change of color tracked the disorganization or degreening, which was simultaneously accompanied by chromoplast biogenesis or red color development when tomatoes were at the Turning stage of development. The color data and photographic images provides information on how heat stress affected the synchronicity of chloroplast disorganization and chromoplast biogenesis in the early developmental stages of tomato ripening., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article., (© 2021 The Author(s). Published by Elsevier Inc.)

The global demand for pomegranate has led to increasing research and improvement of cultivars that produce higher antioxidant compounds. The current study was carried out to evaluate the bioactive constituents and physical properties of fourteen pomegranate genotypes grown in the subtropical region of Florida. There were differences in aril color among genotypes. The highest total anthocyanin content was found in 'Ariana', 'Molla Nepes', and 'Parfianka' genotypes. Furthermore, total anthocyanin content in peel ranged from 2.14 to 10.86 mg/100 g dry weight. Total phenolic content in the pomegranate fruit juice differed significantly among genotypes, varying from 365.71 to 1167.40 mg/L. Moreover, total phenolic content in the fruit peel ranged from 1313.08 to 1700.07 mg/L. Total phenolic compounds and reducing power activity in peel tissues were greater than in pomegranate juice. Reducing power activity and titratable acidity were positively and significantly correlated with total anthocyanin content., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Tree-ripe mangoes are of a better quality than the more commonly marketed mature-green fruit. However, the postharvest life of tree-ripe mangoes at the chilling threshold temperature for mature-green fruit of 12 °C is insufficient to allow long distance transport for international marketing. Because the chilling sensitivity often decreases as fruit ripen, lower temperatures (5 and 8 °C) in combination with a controlled atmosphere of 5 kPa O 2 plus 10 or 25 kPa CO 2 were tested to determine whether the quality of tree-ripe mangoes could be maintained longer without chilling injury (CI)., Results: Tree-ripe 'Tommy Atkins' and 'Keitt' mangoes were stored for 14 or 21 days, respectively, in air or controlled atmosphere (CA) at 5 or 8 °C. Respiration rates were below 10 mL kg -1 h -1 during CA storage and increased three-fold during a 3-day shelf life period at 20 °C. Ethanol synthesis of fruit stored in 25 kPa CO 2 , but not 10 kPa CO 2 , increased during storage and remained high during shelf life, indicating physiological stress. Elevated electrolyte leakage and 1-aminocyclopropane-1-carboxylic acid concentrations in both cultivars stored in 25 kPa CO 2 also indicated that mesocarp tissues were injured by the higher CO 2 level. No CI symptoms were observed in air or CA at either 5 or 8 °C., Conclusion: Storage of tree-ripe mangoes in 5 kPa O 2 plus 10 kPa CO 2 at either 5 or 8 °C best maintained the quality of Tommy Atkins and Keitt fruit for 14 or 21 days, respectively, without evidence of either atmosphere injury or CI. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: Reducing the negative effects of chilling injury (CI) in tomatoes after harvest is essential to ensure good quality and to minimize losses. CI is a postharvest disorder associated with the generation of reactive oxygen species (ROS) in the fruit. Therefore, antioxidant accumulation can counteract ROS, alleviating CI symptoms. In this sense, it has been confirmed that a brief hot-water (HW) immersion promotes the synthesis of antioxidants., Results: HW treatment at 52 °C for 5 min significantly reduced chilling-associated decay, from 66.7% to 17.2% in breaker turning (BT) and from 55.8% to 9.8% in mature green (MG) 'BHN-602' tomatoes stored at 5 °C for 2 weeks and from 26.7% to 6.7% in BT tomatoes stored at 5 °C for 1 week. Also, HW treatment significantly increased lycopene content by 17% in BT tomatoes stored at 5 °C for 2 weeks, as well as ascorbic acid by 11%, lipophilic phenolics by 18% and total phenolics by 6.5% in BT tomatoes stored at 12.5 °C for 1 week. Despite the increase of antioxidants, HW treatment did not enhance the sensory aromatic profile, color and antioxidant capacity. Interestingly, HW treatment reduced ripening time by 3 days in MG tomatoes stored at 5 °C for 2 weeks or at 12.5 °C for 1 week., Conclusion: HW treatment applied to MG or BT 'BHN-602' tomatoes can alleviate the development of some CI symptoms, particularly decay, possibly by increasing antioxidants that scavenge ROS. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

The subtropical peach cultivar UFSun grafted on five different rootstocks ('Flordaguard', 'Barton', 'MP-29', 'P-22', and 'Okinawa') was investigated in terms of the pomological and biochemical parameters of the fruit. Significant differences in fruit weight and size, soluble solids content, titratable acidity, and firmness were found among some rootstocks. The fruit length and diameter were different between the 'MP-29' and other rootstocks. It was also found that firmness of 'UFSun' fruit was affected by the rootstock. The highest firmness value was found when 'UFSun' was grafted on 'Flordaguard'.' 'MP-29' fruit had the highest soluble solids content, but there were no differences among the other rootstocks. 'UFSun' fruit from trees grafted on 'MP-29' were smaller and had the most intense color compared to 'UFSun' fruit from other rootstocks. Rootstock had a significant influence on total fruit phenolic compounds, anthocyanin content, and total antioxidant activity, with fruit from 'UFSun' on 'MP-29' having the highest values in all of them. A high correlation between fruit total antioxidant activity and total phenolic content was found. Overall, the results showed that 'MP-29' seems to induce the highest fruit quality, showing higher contents of total soluble solids, total titratable acidity, total phenolic compounds, total antioxidant activity, and total anthocyanin content. Selecting the right combination of the rootstock and cultivar is important for optimizing fruit quality parameters., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Designing modified atmosphere packages (MAPs) for fresh produce requires respiration rate (RR) data. A steady-state (SS) approach is widely used but is expensive, tedious, and time-consuming. Unsteady-state (USS) methods mitigate shortcomings of the SS approach, but comparisons between the two approaches have not been done to verify the design outcomes of MAPs, especially those with microperforations. RR measurement methods for grape tomatoes and blueberries were compared. Data were then used to design microperforated MAP packages to compare predicted design specifications created from RR data with observed shelf life. Results show that the USS method provides similar magnitudes of RR and predicts similar numbers of perforations as the SS method. Observations of packages produced using 100 µm perforations, using measured respiration data, suggest that both methods underestimated what might have been deemed correct by about one microperforation. PRACTICAL APPLICATION: Designing packaging for fresh produce requires the knowledge of produce respiration. Steady-state methods are conceptually simple, but time-consuming. Unsteady-state methods are rapid. This work compares methods on design of packages., (© 2020 Institute of Food Technologists®.)

Background: Nitrogen is a key component of crop production and is commonly related to increases in yield and fruit size. The N fertilization rates used for low-chill peach cultivars were adapted from other peach production regions, where environmental and soil conditions are different. The growth and production as well as the effect on fruit physical and compositional attributes of two low-chill peach cultivars - 'TropicBeauty' (TB) and 'UFSharp' (UFS) - with five different N fertilization rates (0 (N0), 45 (N1), 90 (N2), 179 (N3) and 269 (N4) kg ha -1 applied each year from 2011 to 2017) were examined., Results: Peach trees under higher N rates had higher pruning weights compared to the lower N0 or N1 rates. Yield was only affected in 2017 for the two cultivars tested. Physical attributes were inconsistently affected by N. Fruit from the higher N rates had lower a* value (more green) than fruit from the trees under low or zero N. While fruit firmness was not affected by N, fruit from trees under zero/low N had higher total soluble solids in some years., Conclusion: Considering that N is recycled in the trees, being retained and reused each season to resume growth, it is important to address peach orchard fertilization based on peach tree N status. The results of this experiment show that an increase in N beyond what is required for tree maintenance does not increase yield. In addition, reducing N does not strongly affect fruit quality, although the color and soluble solids results suggest that lower N rates may advance fruit maturation. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: The market demand for seedless watermelon has been continuously increasing because of consumer preference. Grafting is a useful tool to manage soilborne diseases in watermelon production, but the use of squash rootstocks may negatively affect watermelon fruit quality. Currently, most research has focused on seeded cultivars, while grafting effects on seedless watermelons remain largely unknown. This multi-season study was conducted to assess the effects of squash rootstocks, including both Cucurbita maxima × C. moschata and C. moschata cultivars, with intact or excised and regenerated roots, on fruit quality of seedless watermelon 'Melody' using both instrumental and sensory measurements under different production scenarios. The grafted watermelon plants were also challenged by field inoculation with Fusarium oxysporum f.sp. niveum., Results: A combination of instrumental measurements and consumer sensory analyses suggested that fruit quality of the seedless watermelon 'Melody' was not impacted by the use of the squash rootstocks used in this study, which included soluble solids content, titratable acidity, pH and most fruit sensory properties. Watermelon flesh firmness was increased by grafting but the grafting effect on lycopene content was inconclusive. Root excision and regeneration did not influence the grafting effect, whereas the grafting effect on flesh firmness varied among the rootstocks under Fusarium inoculation., Conclusion: Overall, grafting with squash rootstocks did not reduce fruit quality attributes of 'Melody' but improved texture. Our results support incorporating grafting into integrated management programs for seedless watermelon production. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Kiwifruit (Actinidia deliciosa cv. Bruno) fruits were sprayed with 5mM oxalic acid (OA) at 130, 137, and 144 days after full blossom, and then harvested at commercial maturity [soluble solid content (SSC) around 10.0%] and stored at room temperature (20 ± 1 °C). Pre-harvest application of OA led to fruit with higher ascorbic acid content at harvest, slowed the decreases in fruit firmness and ascorbic acid content and increase in SSC during storage, and also decreased the natural disease incidence, lesion diameter, and patulin accumulation in fruit inoculated with Penicillium expansum, indicating that the OA treatment increased quality and induced disease resistance in kiwifruit. It was suggested that the increase in activities of defense-related enzymes and in levels of substances related to disease resistance might collectively contribute to resistance in kiwifruit against fungi such as P. expansum in storage., (Copyright © 2015 Elsevier Ltd. All rights reserved.)