Quality and physiological responses of two late-season sweet cherry cultivars 'Lapins' and 'Skeena' to modified atmosphere packaging (MAP) during simulated long distance ocean shipping

The production and export of late season sweet cherry cultivars continues to increase in the US Pacific Northwest (PNW). Major postharvest quality deterioration during long distance ocean shipping include flavor loss, off-flavor development, skin darkening, pedicel browning, pitting, and decay. In this research, three modified atmosphere packaging (MAP) liners with varied gas permeability were evaluated for their effect on quality deterioration and physiological changes of ‘Lapins’ and ‘Skeena’ during a simulated transit of 6 weeks at 0°C. Results showed that MAP2 (O₂ 6.5–7.5%, CO₂ 8.0–10.0%) reduced ascorbic acid (AsA) loss and lipid peroxidation, maintained flavor by retarding titratable acid loss and bitter taste formation, and kept brighter color by retarding anthocyanin synthesis compared to the macro-perforated polyethylene liner after 4 and 6 weeks. In contrast, MAP1 (O₂ 12.0–13.5%, CO₂ 5.0–7.0%) had little benefit on maintaining fruit flavor and skin color. MAP3 (O₂ 0.5–1.5%, CO₂ ∼ 10%), on the other hand, showed greater benefits in most of the quality attributes; however, fruit exhibited anaerobic off-flavor from a significant accumulation of ethanol, especially in ‘Skeena’. All three MAP liners reduced pedicel browning and decay but did not affect pitting and splitting. In conclusion, only the MAP with the most appropriate gas permeability, which maintained O₂ 6.5–7.5% and CO₂ 8.0–10.0%, slowed down fruit senescence and maintained quality with respect to flavor and skin color of the late season sweet cherry cultivars after long distance ocean shipping.Keywords: Prunus avium L., Off-flavor, MAP, Flavor loss, Lipid peroxidation, Skin darkening, Postharvest disordersKeywords: Prunus avium L., Off-flavor, MAP, Flavor loss, Lipid peroxidation, Skin darkening, Postharvest disorder

Gas Chromatography–Olfactometry Analyses of Volatiles Produced by ‘Fallglo’ and ‘US Early Pride’ Tangerines

‘Fallglo’ is a popular tangerine (Citrus reticulata Blanco) cultivar with high eating quality. However, ‘Fallglo’ may contain as many as 30–40 seeds per fruit. ‘US Early Pride’ is a seedless mutation of ‘Fallglo’ with similar quality attributes. The objective of the current study was to determine if ‘Fallglo’ and ‘US Early Pride’ fruit differed in the composition or quantity of aroma-active volatiles produced over time. Fruit were harvested bi-weekly from October to December. Juice was carefully extracted from 50 fruit, and volatiles were analyzed using gas chromatography (GC). Two subjects evaluated the GC effluents by olfactometry in triplicate runs for each sample. Volatile identification was done by GC-mass spectrometry and confirmed by sniffing of authentic standards. The same 32 aroma-active compounds were perceived in ‘Fallglo’ and ‘US Early Pride’, of which 25 were identified. Compounds were classified in odor descriptor groups: fatty (10 compounds), plastic or rubber (seven compounds), fruity or citrus (four compounds), floral (four compounds), mushroom (two compounds), green (two compounds) and other (one compound). ‘Fallglo’ and ‘US Early Pride’ had similar aroma intensities for the three first harvests (26 Oct., 3 Nov., 17 Nov.), but ‘Fallglo’ had higher levels of two fruity odorous peaks (E-2-pentenal and the coeluting compounds E-2-hexenal and ethyl 2 methyl butanoate) than did ‘US Early Pride’ at the December harvest. The last harvest showed significantly higher aroma intensity for six peaks in each cultivar, with only two peaks in common in both cultivars

Effect of Huanglongbing or Greening Disease on Orange Juice Quality, a Review

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 or asymptomatic. Symptomatic oranges are small, asymmetrical and greener than healthy fruit. Furthermore, symptomatic oranges show higher titratable acidity and lower soluble solids, solids/acids ratio, total sugars, and malic acid levels. Among flavor volatiles, ethyl butanoate, valencene, decanal and other ethyl esters are lower, but many monoterpenes are higher in symptomatic fruit compared to healthy and asymptomatic fruit. The disease also causes an increase in secondary metabolites in the orange peel and pulp, including hydroxycinnamic acids, limonin, nomilin, narirutin, and hesperidin. Resulting from these chemical changes, juice made from symptomatic fruit is described as distinctly bitter, sour, salty/umami, metallic, musty, and lacking in sweetness and fruity/orange flavor. Those effects are reported in both Valencia and Hamlin oranges, two cultivars that are commercially processed for juice in Florida. The changes in the juice are reflective of a decrease in quality of the fresh fruit, although not all fresh fruit varieties have been tested. Earlier research showed that HLB-induced off-flavor was not detectable in juice made with up to 25% symptomatic fruit in healthy juice, by chemical or sensory analysis. However, a blend with a higher proportion of symptomatic juice would present a detectable and recognizable off flavor. In some production regions, such as Florida in the United States, it is increasingly difficult to find fruit not showing HLB symptoms. This review analyzes and discusses the effects of HLB on orange juice quality in order to help the citrus industry manage the quality of orange juice, and guide future research needs

Electronic Noses and Tongues: Applications for the Food and Pharmaceutical Industries

The electronic nose (e-nose) is designed to crudely mimic the mammalian nose in that most contain sensors that non-selectively interact with odor molecules to produce some sort of signal that is then sent to a computer that uses multivariate statistics to determine patterns in the data. This pattern recognition is used to determine that one sample is similar or different from another based on headspace volatiles. There are different types of e-nose sensors including organic polymers, metal oxides, quartz crystal microbalance and even gas-chromatography (GC) or combined with mass spectroscopy (MS) can be used in a non-selective manner using chemical mass or patterns from a short GC column as an e-nose or “Z” nose. The electronic tongue reacts similarly to non-volatile compounds in a liquid. This review will concentrate on applications of e-nose and e-tongue technology for edible products and pharmaceutical uses

Changes in Volatile and Non-Volatile Flavor Chemicals of “Valencia” Orange Juice over the Harvest Seasons

Florida “Valencia” oranges have a wide harvest window, covering four months after first reaching the commercial maturity. However, the influence of harvest time on juice flavor chemicals is not well documented, with the exception of sugars and acids. Therefore, we investigated the major flavor chemicals, volatile (aroma), non-volatile (taste) and mouth feel attributes, in the two harvest seasons (March to June in 2007 and February to May in 2012). Bitter limonoid compounds, limonin and nomilin, decreased gradually. Out of a total of 94 volatiles, 32 increased, 47 peaked mid to late season, and 15 decreased. Juice insoluble solids and pectin content increased over the season; however, pectin methylesterase activity remained unchanged. Fruit harvested in the earlier months had lower flavor quality. Juice from later harvests had a higher sugar/acid ratio with less bitterness, while, many important aroma compounds occurred at the highest concentrations in the middle to late season, but occurred at lower concentrations at the end of the season. The results provide information to the orange juice processing industry for selection of optimal harvest time and for setting of precise blending strategy

Soil Amendment and Storage Effect the Quality of Winter Melons (<i>Benincasa hispida</i> (Thunb) Cogn.) and Their Juice

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, volatile and nutritional compounds) properties were evaluated. Fruit juice extracted from ASD-grown fruit had greater magnitude of zeta potential than the control juice, indicating it was physically more stable than the juice obtained from the control conditions. ASD fruit juice had lower soluble solids content (SSC), and lower volatile compounds that contribute green, grass, and sulfur notes, and negatively influence flavor quality. ASD fruit juice had higher vitamin B5 and cytidine. Juice processed from 120 d stored fruit had less yield due to 12.4–15.6% weight loss. The non-soluble solids content was higher and particle size was larger, and the SSC and individual sugars decreased. However, titratable acidity (TA) increased primarily due to increased citric acid. Out of 16 free amino acids, 6 increased and only 1 decreased. However, three out of five nucleosides decreased; vitamins B1 and B6 increased; vitamins B2, B3 and C decreased. Overall, juice derived from fruit produced using ASD was physically more stable and had less SSC and off-odor volatiles than the control, while the fruit juice of those stored for 120 d had lower SSC and higher TA and nutritional profiles, comparable to freshly harvested fruit

Microencapsulation of Tangeretin in a Citrus Pectin Mixture Matrix

The objectives of this research were to microencapsulate tangeretin, and to evaluate the basic characteristics of the microcapsule products. Tangeretin is a polymethoxyflavone (PMF) which has been revealed to possess various health benefits and is abundant in tangerine and other citrus peels. Microencapsulation technology is widely employed in the food and pharmaceutical industries to exploit functional ingredients, cells, and enzymes. Spray drying is a frequently applied microencapsulation method because of its low cost and technical requirements. In this research, tangeretin dissolved at different concentrations in bergamot oil was microencapsulated in a citrus pectin/sodium alginate matrix. The resulting microcapsule powder showed promising physical and structural properties. The retention efficiency of tangeretin was greater at a concentration of 2.0% (98.92%) than at 0.2% (71.05%), probably due to the higher temperature of the emulsion during the homogenizing and spray-drying processes. Encapsulation efficiency was reduced with increased concentration of tangeretin. Our results indicate that tangeretin could be successfully encapsulated within a citrus pectin/sodium alginate matrix using bergamot oil as a carrier

Electronic Tongue Response to Chemicals in Orange Juice that Change Concentration in Relation to Harvest Maturity and Citrus Greening or Huanglongbing (HLB) Disease

In an earlier study, an electronic tongue system (e-tongue) has been used to differentiate between orange juice made from healthy fruit and from fruit affected by the citrus greening or Huanglongbing (HLB) disease. This study investigated the reaction of an e-tongue system to the main chemicals in orange juice that impact flavor and health benefits and are also impacted by HLB. Orange juice was spiked with sucrose (0.2–5.0 g/100 mL), citric acid (0.1%–3.0% g/100 mL) and potassium chloride (0.1–3.0 g/100 mL) as well as the secondary metabolites nomilin (1–30 µg/mL), limonin (1–30 µg/mL), limonin glucoside (30–200 µg/mL), hesperidin (30–400 µg/mL) and hesperetin (30–400 µg/mL). Performance of Alpha MOS sensor sets #1 (pharmaceutical) and #5 (food) were compared for the same samples, with sensor set #1 generally giving better separation than sensor set #5 for sucrose, sensor set #5 giving better separation for nomilin and limonin, both sets being efficient at separating citric acid, potassium chloride, hesperitin and limonin glucoside, and neither set discriminating hesperidin efficiently. Orange juice made from fruit over the harvest season and from fruit harvested from healthy or HLB-affected trees were separated by harvest maturity, disease state and disease severity