Anne Plotto

United States Department of Agriculture | USDA · Agricultural Research Service (ARS)

Hybrids of Poncirus trifoliata L. Raf. with Citrus have shown degrees of tolerance to the deadly citrus greening disease, hence prompting interest as potential commercial varieties. Although P. trifoliata is known to produce fruit that is inedible, fruit from many advanced hybrid trees have not been evaluated for their quality potential. The sensor...

Along with orange and mandarin, grapefruit production in Florida has declined sharply due to Huanglongbing (HLB), or citrus greening disease, caused by Candidatus Liberibacter asiaticus (CLas). HLB affects the volatile profiles of juice and peel oil in oranges, but there is limited information on grapefruit. In this research, ‘Ray Ruby’ grapefruit...

Winter melon fruits were grown in the field using anaerobic soil disinfestation (ASD) and conventional fertilizer alone as the control treatment. Fruits were harvested and stored at 20 °C for 120 d, the juice was processed on day one and day 120, and the effects of soil amendment and 120 d storage on the juice’s physical and chemical (sugars, acids...

Fruit quality is of increasing importance for consumers but is a complex trait for growers, as it is affected by environment, genotype, and crop management interactions. Decision support tools, such as computer models that simulate crop growth and development can help optimize production but require further improvement to simulate quality aspects....

Diplodia stem-end rot (SER) caused by Lasiodiplodia spp. is an important postharvest decay on fresh citrus in Florida. Huanglongbing (HLB or Citrus Greening) significantly increases Lasiodiplodia preharvest infection, leading to increased postharvest Diplodia SER. An improved and effective control of Diplodia SER is needed to sustain Florida’s citr...

Carnauba wax nano and micro-sized emulsions and hydroxypropyl methylcellulose coatings, alone or combined with ginger essential oils (GEO) were applied on papayas and evaluated under several storage conditions. In a first experiment, storage parameters were: 6 days at 22 °C, and 9 days at 13 °C followed by 5 days at 22 °C. In a second experiment, s...

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 t...

Fresh fruits and vegetables are perishable commodities requiring technologies to extend their postharvest shelf life. Edible coatings have been used as a strategy to preserve fresh fruits and vegetables in addition to cold storage and/or controlled atmosphere. In recent years, nanotechnology has emerged as a new strategy for improving coating prope...

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...

The interactive effects of six maturity stages and refrigerated storage (chilling)/blanching (heating) treatments on the volatile profiles of ripe tomatoes were studied. A total of 42 volatiles were identified, of which 19 compounds had odor activity values equal to or greater than 1. Of those, “green” and “leafy” aroma volatiles were most abundant...

The objective of this research was to evaluate the use of a controlled-release carvacrol powder to delay storage decay and maintain the safety of blueberries. The controlled-release carvacrol powder was a microcapsule of carvacrol (11% (w/w) active carvacrol) surrounded by a pectin/sodium alginate matrix. The microcapsules were packed in an air-per...

Strawberries produce numerous volatile compounds that contribute to the unique flavors of fruits. Among the many volatiles, γ-decalactone (γ-D) has the greatest contribution to the characteristic fruity aroma in strawberry fruit. The presence or absence of γ-D is controlled by a single locus, FaFAD1 . However, this locus has not yet been systematic...

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...

The detrimental effects of Huanglongbing (HLB) on citrus are well known and so is the need for effective methods to combat this disease. Solar thermotherapy (ST), one of the management methods to help alleviate some of the negative effects of HLB, is the process of heating trees to therapeutic temperatures by encompassing the tree within a plastic...

A previous study using healthy “Valencia” orange fruit found that juicing extraction methods dramatically changed the orange juice (OJ) flavor and phytochemical profiles. The present study was conducted to confirm whether the same changes occur when Huanglongbing (HLB)-affected oranges were used. HLB has extensively spread to most OJ processing reg...

Florida orange trees have been affected by huanglongbing (HLB) for more than a decade. To alleviate disease-caused tree decline, maintain fruit productivity, and reduce disease transmission, enhanced foliar spray programs combining vector control and nutritional supplementation have been applied to healthy and diseased trees. The aim of this resear...

Descriptive analysis via trained sensory panels has great power to facilitate flavor improvement in fresh fruits and vegetables. When paired with an understanding of fruit volatile organic compounds, descriptive analysis can help uncover the chemical drivers of sensory attributes. In the present study, 213 strawberry samples representing 56 cultiva...

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...

Fresh-cut mango ( Mangifera indica ) slices and chunks garner an exotic image and are highly appreciated for their unique flavor and nutritional value. However, processors tend to use firm unripe mangoes to achieve shelf life of 10 to 14 days, which compromises eating quality. The post-processing life of ripe fresh-cut mangoes is limited by tissue...

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 fo...

Coatings are generally applied to fruit as microemulsions, but nanoemulsions are still experimental. ‘Nova’ mandarins ( Citrus reticulata ) were coated with shellac or carnauba ( Copernica cerifera ) microemulsions or an experimental carnauba nanoemulsion; these were compared with an uncoated control during storage for 7 days at 20 °C. Coatings wer...

Reducing the negative effects of chilling injury (CI) in tomatoes after harvest is essential to assure 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...

Mandarins (or tangerines) are mainly consumed as fresh fruits due to the ease of peeling and desirable flavor. Sweetness, acidity, and flavor of mandarin are the most important criteria for consumer preference. The objective of this study was to evaluate the effects of harvest date on sensory and chemical components of four mandarin cultivars (Murc...

Plants are constantly exposed to abiotic and biotic stresses, inducing the generation of reactive oxygen species (ROS). In response, the synthesis of antioxidants is upregulated to neutralize the deteriorating effects of ROS. We investigated whether promoting this response could enhance the nutritional and sensory quality of tomatoes. In preliminar...

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 fatt...

Huanglongbing (HLB) disease has reduced orange yield and flavor quality in Florida. Orange juice (OJ) and peel molasses (PM) compounds are “from the named fruit” (FTNF), and were tested for their effects on HLB-affected OJ taste. These and other “target” compounds, reportedly found in citrus, were spiked into off-flavored, HLB-affected reference ju...

Citrus greening disease or huanglongbing (HLB) is associated with excessive pre-harvest fruit drop. To understand the mechanisms of the HLB-associated fruit abscission, transcriptomes were analyzed by RNA sequencing of calyx abscission zones (AZ-C) of dropped “Hamlin” oranges from HLB-diseased trees upon shaking the trees (Dd), retained oranges on...

Water loss is one of the major causes for the food loss and waste of small fruits, both in the retail market and at the consumer level. A modified humidity (MH) one-pound (˜454 g) clamshell was designed for small fruit packaging and was compared to a typical commercial (COM) clamshell for several small fruits held in cold (0–6 °C), refrigerated she...

Strawberry is a fragile commodity highly susceptible to postharvest decay. With antifungal activity, thymol is a potential candidate for postharvest decay prevention. A coating consisting of whey protein isolate (WPI) (1% w/v) with 0.05, 0.1 and 0.2% thymol, was sprayed on strawberries cv. Radiance using an airbrush. Fruit were air dried and repack...

Background Valencene is a major sesquiterpene in citrus oil and biosynthesized by valencene synthase (Cstps1; EC: 4.2.3.73) from the 15-carbon substrate farnesyl diphosphate. It is abundant in juice of some mandarins (e.g. Citrus reticulata Blanco cv. Fortune), however, it is undetectable in others (e.g. C. reticulata Blanco cv. Murcott), We have d...

The biocontrol agent (BCA) Candida sake CPA-1 has proven to be effective against Botrytis cinerea, the fungus causing grey mold in many fruits. The performance of this yeast could be improved if applied in combination with edible coatings. Several combinations of starch derivatives and cell protectants were tested to obtain water-dispersible granul...

Huanglongbing (HLB) or citrus greening is the most severe citrus disease, currently devastating the citrus industry worldwide. The presumed causal bacterial agent Candidatus Liberibacter spp. affects tree health as well as fruit development, ripening and quality of citrus fruits and juice. Fruit from infected orange trees can be either symptomatic...

Lactic acid bacteria (LAB) have been shown to prevent the growth and activity of several postharvest pathogen fungi in fruit and vegetables, because of their ability to produce antimicrobial metabolites. Edible coatings (EC) can be used as carriers of LAB and could provide an alternative natural preservation method. The effectiveness of Lactobacill...

Fragaria vesca is a diploid strawberry species that produces gourmet, aromatic fruits with only limited commercial production because of its relative obscurity. Most F. vesca research focuses on genetics and fruit aroma, but yield and fruit quality data across diploid accessions are lacking. Sixteen F. vesca accessions were grown in replicated fiel...

Two major winter melon (Benincasa hispida) cultivars, waxy ‘Large Round’ and non-waxy ‘Southern Dark Skin’ were used for comparison of the physical, chemical and sensory properties of processed juice. Two types of juice were processed by using non-waxy fruits: non-waxy juice without peel (NW) and non-waxy juice with peel (NWP). For waxy fruit, the...

Orange trees affected by huanglongbing (HLB) exhibit excessive fruit drop, and fruit loosely attached to the tree may have inferior flavor. Fruit were collected from healthy and HLB-infected (Candidatus liberibacter asiaticus) ‘Hamlin’ and ‘Valencia’ trees. Prior to harvest, the trees were shaken, fruit that dropped collected, tree-retained fruit h...

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 t...

Citrus greening disease, also known as Huanglongbing (HLB), compromises the quality of citrus fruit and juice, causing increased bitterness, metallic taste, astringency and a burning mouthfeel. The chemical basis responsible for these changes remains largely unknown other than the roles of the bitter limonoids, limonin and nomilin, and of flavonoid...

Background Methyl anthranilate (MA) contributes an attractive fruity note to the complex flavor and aroma of strawberry (Fragaria spp.), yet it is rare in modern cultivars. The genetic basis for its biosynthesis has not been elucidated. Understanding the specific genes required for its synthesis could allow the development of gene/allele-specific m...

‘Valencia’ orange trees from groves with 90% infection by Candidatus liberibacter asiaticus ( C Las), the presumed pathogen for citrus greening or huanglongbing (HLB) disease, were treated with insecticide ( I) , a nutritional spray ( N ), and insecticide plus nutritional spray ( I + N ). Controls ( C ) were not treated. Fruit were harvested in Mar...

A 3-year study was undertaken to establish the effect of field nutritional sprays, combined with insecticide treatments or not against Asian Citrus psyllid, on the fruit quality of ‘Valencia’ orange trees affected by the greening disease Huanglongbing (HLB). Four replicated plots were harvested, juiced, and pasteurized. Nine to twelve trained panel...

Background: Citrus fruit flavor is an important attribute prioritized in variety improvement. This study compared juice volatiles compositions from 13 selected citrus genotypes, including six mandarins (Citrus reticulata), three sour oranges (C. aurantium), one blood orange (C. sinensis), one lime (C. limonia), one clementine (C. clementina) and o...

Avocado (Persea americana Mill.) is a high-value fruit that continues to increase in consumer demand. A population of ‘Hass’–‘Bacon’ hybrids was planted at USDAARS, Fort Pierce, as part of a study to find selections with good horticultural and postharvest quality traits for Florida. Extensive phenotypic data on quality were collected over 3 years....

A controlled-release chlorine dioxide (ClO 2) pouch was developed by sealing a slurry form of ClO 2 into semipermeable polymer film; the release properties of the pouch were monitored in containers with or without fruit. The pouch was affixed to the inside of a perforated clamshell containing grape tomatoes, and the effect on microbial population,...

Citrus greening or huanglonbing (HLB) is thought to be caused by Candidatus Liberibacter asiaticus (CLas) 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...

This chapter discusses the sensory quality and biochemical constituents involved in creating the unique flavor of different citrus fruit species, including oranges, mandarins, grapefruit, and lemons. It focuses on describing the flavor attributes of fresh citrus fruit and essential oils, but not of processed juices. For further information regardin...

Volatile composition of commercial orange pulp (from Brazil and Florida, U.S.A.) was analyzed by gas chromatography-mass spectrometry (GC-MS) and GCOlfactometry (GC-O). In both samples 72 volatiles were detected, of which 58 were identified. Odor-active compounds with a high frequency of detection (�5 out of 9) or intensity characterizing the aroma...