Postharvest Storage Of Fruits Research Articles

The Effects of Edible Coatings on the Postharvest Quality of Citrus Fruits as Affected by Granulation

The world population is growing day-by-day, while the available natural resources for agricultural production, i.e., soil and water, are rapidly decreasing. Moreover, consumer preferences are highly affected by some quality characteristics of food products, which can be classified as external, internal, and hidden attributes. Among the internal quality attributes, granulation is a significant factor damaging the inner quality of citrus fruits and reducing the consumer attraction. The main symptoms of granulation (also known as section drying, crystallization, or scarification) in citrus are shrivelling in juice sacs due to gel formation, hardening, white colour, and low extractable juice content. A well-known result of the granulation is the reduction in soluble solid concentration (SSC), total sugar, and titratable acidity (TA). Granulation is known to affect the citrus fruit quality all over the world. Since citrus is one of the world’s most popular fruit species, it is highly important to identify and manage this physiological problem to help sustainable production throughout the world. Consumer’s preferences have also been moving towards the use of eco- and environmental-friendly alternative methods in postharvest fruit storage, including edible coatings. Edible coatings act as a barrier for the air and water transitions through the surface of fruits which results in retarding the deterioration of fruits, preventing and/or controlling the microbial decay, improving the fruit quality, and hence extending the storage duration. The mechanism of citrus fruit granulation is highly associated with the oxidative stress, and edible coatings have been reported to significantly reduce granulation and improve the quality of the fruits. In line with this information, this review article aimed to summarize the reasons, results, and managements of granulation of citrus fruits.

Influence of gamma radiation treatment on the profile of phenolic compounds and on the quality parameters of strawberries cv. Albion during storage

This study evaluated the effects of gamma radiation treatment on the profile of phenolic compounds and the quality parameters of strawberries irradiated during storage. The fruits were submitted to irradiation doses 0, 0.8; 1.6, and 2.4 kGy and stored for up to 9 days at 10°C. The levels of anthocyanins, ascorbic acid, and total phenolic compounds were evaluated, as along with the profile of these compounds and colorimetric and microbiological parameters. Our results show that the doses used preserved the studied phenolic compounds. The variation in ascorbic acid values may be due to post-harvest storage of fruits. The applied doses did not interfere in the characteristic red color of the strawberry. The irradiation dose of 2.4 kGy more efficiently controlled microorganisms and is the ideal dose to increase the shelf life of strawberries.

Antioxidant enzyme activity and physiological potential of Capsicum baccatum var. baccatum seeds as a function of post-harvest storage of fruit

Abstract: Post-harvest storage of fleshy fruit is a strategy used for improving seed quality. The aim of this study was to evaluate post-harvest storage of the fruit of C. baccatum var. baccatum (cumari pepper) and relate it to antioxidant enzyme activity and seed physiological potential. Red-colored fruit (65 days after anthesis) was gathered and stored at 20 °C for 0, 5, 10, 15, and 20 days. The seeds were removed and evaluated for moisture content, physiological quality, antioxidant enzyme activity, and protein content. The means were fitted to regression equations and then passed through multivariate analysis (PCA). Seed moisture and 100-seed weight decreased through post-harvest storage. The 5- and 10-days storage periods led to an increase in the germination. Electrical conductivity was greater for the 0- and 20-day storage periods. Dry matter and protein increased in the 5- and 10-days. Enzymes exhibited reductions of activity comparing 0 and 20 days. The post-harvest storage of C. baccatum fruit for 5 and 10 days improves seed physiological potential and is related to physiological maturity. The incomplete maturation of cumari seeds obtained from unstored fruit (0 days) is related to greater enzyme activity, greater oxidative stress, and low germination and vigor. The lack of post-harvest storage of fruit and storage of fruit for longer than 10 days contributes to a lower physiological potential of cumari pepper seeds.

Physiological maturity of Tabebuia aurea (Silva Manso) Benth. & Hook. f. ex S. Moore seeds

Abstract: The purpose of this research was to verify the efficiency of physical and biochemical indices in determining the physiological maturity of Tabebuia aurea seeds, as well as to evaluate the post-harvest storage of fruits with different maturation stages on germination and vigor. For this, 200 fruits were classified as dark green (stage I), light green (stage II), and light brown (stage III) epicarp. Freshly harvested fruits were evaluated for length, width, and weight and their seeds for length, width, thickness, thousand-seed weight, water content, electrical conductivity, and chemical composition. Subsequently, a factorial consisting of three maturation stages and four storage periods of fruits (0, 5, 10 and 15 days) were used, and water content, germination, germination speed index, root length, shoot length, and seedling dry matter were evaluated. Physical and biochemical indices can be used as maturation indicators in T. aurea seeds, except fruit length, seed thickness, electrical conductivity, and protein content. The maximum germination and vigor of T. aurea seeds were obtained in fruits at stages I (dark green) or II (light green) associated with post-harvest storage of fifteen days.

Effect of Chitosan Coating on Physiological Responses and Nutritional Qualities of Tomato Fruits during Postharvest Storage

This experiment was conducted to evaluate the effect of chitosan coating on physiological responses and nutritional qualities of tomato fruits at postharvest storage. There were four treatments of chitosan viz. T0 (control), T1 (0.10%), T2 (0.20%) and T3 (0.30%), and two storage conditions viz. in refrigerator (4°C) and room temperature (≈23-25°C). The matured light yellow tomato fruit samples were collected at 10, 20, 30 and 50 days after postharvest storage to assess physiological parameters viz. shelf life and weight loss as well as to determine lycopene and mineral constituents viz. Ca, Mg, P, S, Na and K. The mean weight loss of tomato fruits were 0.64, 1.28, 1.59 and 2.28% at 4°C, while it was 0.88, 1.84, 2.60 and 4.80% at room temperature at 10, 20, 30 and 50 days after postharvest storage, respectively. The shelf life of tomato fruits ranged between 58.3-100.0, 50.0-100.0, 33.3-75.0 and 16.7-66.8% at 4°C, while the ranges were 66.8-100.0, 50.0-100.0, 33.3-75.0 and 0.0-41.8% at room temperature at 10, 20, 30 and 50 days after postharvest storage, respectively. As regards to weight loss and shelf life, the study results inferred that chitosan coating with 0.2% solution is useful at postharvest storage of fruits. The study results revealed that storage temperatures (4°C and ≈23-25°C) had no effect on the total contents of different mineral element of tomato fruits but lycopene content reduced almost twice at refrigerated condition. On the other hand, the effect of chitosan coating on Ca, Mg, P, S, Na and K contents of tomato fruits at different days after postharvest storage were highly significant at both conditions. Finally, the study results concluded that 0.2% chitosan based coatings in tomato fruits proved to extend the shelf life by decreasing the decay incidence and weight loss, and refrigerated condition is better than that of room temperature.

Unveiling Kiwifruit Metabolite and Protein Changes in the Course of Postharvest Cold Storage.

Actinidia deliciosa cv. Hayward fruit is renowned for its micro- and macronutrients, which vary in their levels during berry physiological development and postharvest processing. In this context, we have recently described metabolic pathways/molecular effectors in fruit outer endocarp characterizing the different stages of berry physiological maturation. Here, we report on the kiwifruit postharvest phase through an integrated approach consisting of pomological analysis combined with NMR/LC-UV/ESI-IT-MSn- and 2D-DIGE/nanoLC-ESI-LIT-MS/MS-based proteometabolomic measurements. Kiwifruit samples stored under conventional, cold-based postharvest conditions not involving the use of dedicated chemicals were sampled at four stages (from fruit harvest to pre-commercialization) and analyzed in comparison for pomological features, and outer endocarp metabolite and protein content. About 42 metabolites were quantified, together with corresponding proteomic changes. Proteomics showed that proteins associated with disease/defense, energy, protein destination/storage, cell structure and metabolism functions were affected at precise fruit postharvest times, providing a justification to corresponding pomological/metabolite content characteristics. Bioinformatic analysis of variably represented proteins revealed a central network of interacting species, modulating metabolite level variations during postharvest fruit storage. Kiwifruit allergens were also quantified, demonstrating in some cases their highest levels at the fruit pre-commercialization stage. By lining up kiwifruit postharvest processing to a proteometabolomic depiction, this study integrates previous observations on metabolite and protein content in postharvest berries treated with specific chemical additives, and provides a reference framework for further studies on the optimization of fruit storage before its commercialization.

Inherent Resistance to 14α-Demethylation Inhibitor Fungicides in Colletotrichum truncatum Is Likely Linked to CYP51A and/or CYP51B Gene Variants.

Anthracnose disease, caused by Colletotrichum truncatum, affects marketable yield during preharvest production and postharvest storage of fruits and vegetables worldwide. Demethylation inhibitor (DMI) fungicides are among the very few chemical classes of single-site mode of action fungicides that are effective in controlling anthracnose disease. However, some species are inherently resistant to DMIs and more information is needed to understand this phenomenon. Isolates of C. truncatum were collected from the United States and China from peach, soybean, citrus, and begonia and sensitivity to six DMIs (difenoconazole, propiconazole, metconazole, tebuconazole, flutriafol, and fenbuconazole) was determined. Compared with DMI sensitive isolates of C. fructicola, C. siamense, and C. fioriniae (EC50 value ranging from 0.03 to 16.2 µg/ml to six DMIs), C. truncatum and C. nymphaeae were resistant to flutriafol and fenbuconazole (with EC50 values of more 50 µg/ml). Moreover, C. truncatum was resistant to tebuconazole and metconazole (with resistance factors of 27.4 and 96.0) and displayed reduced sensitivity to difenoconazole and propiconazole (with resistance factors of 5.1 and 5.2). Analysis of the Colletotrichum spp. genome revealed two potential DMI targets, CYP51A and CYP51B, that putatively encode P450 sterol 14α-demethylases. Both genes were identified and sequenced from C. truncatum and other species and no correlation between CYP51 gene expression levels and fungicide sensitivity was found. Four amino acid variations L208Y, H238R, S302A, and I366L in CYP51A, and three variations H373 N, M376L, and S511T in CYP51B correlated with the DMI resistance phenotype. CYP51A structure model analysis suggested the four alterations may reduce azole affinity. Likewise, CYP51B structure analysis suggested the H373 N and M376L variants may change the conformation of the DMI binding pocket, thereby causing differential sensitivity to DMI fungicides in C. truncatum.

Modulation of Enhanced Antioxidant Activity by Hydrogen Sulfide Antagonization of Ethylene in Tomato Fruit Ripening.

Ethylene (C2H4) and hydrogen sulfide (H2S) play important physiological roles in regulating fruit ripening and senescence. The mechanism of H2S in ethylene-induced tomato fruit ripening and senescence is still unknown. Here, we show that exogenous H2S reduced the production of superoxide anion (·O2-), malondialdehyde (MDA), and H2O2 in tomato fruit. Further, additional H2S was found to induce the activities of guaiacol peroxidase, catalase, ascorbate peroxidase, and superoxide dismutase compared with C2H4 treatment alone, whereas the activities of lipoxygenase, polyphenol oxidase, and phenylalanine ammonia lyase were adversely affected. Moreover, the expression of the antioxidant-encoding genes SlAPX2, SlCAT1, SlPOD12, and SlCuZnSOD was generally up-regulated with C2H4-H2S cotreatment, compared with their expression after ethylene treatment. Thus, the present results suggest that exogenous H2S acts as a fruit-ripening regulator by antagonizing the effect of ethylene, thereby providing a potential application for H2S in the postharvest storage of fruit.

Properties of New Strawberry Lines Compared with Well-Known Cultivars in Winter Planting System Conditions

In Southern Italy and Sicily, strawberry cultivation is dominated by international cultivars such as ‘Candonga Sabrosa’, ‘Florida Fortuna’, ‘Sabrina’ and ‘Sant Andreas’. The primary objective of our study was to compare the field performance of two experimental lines and four established cultivars in a Sicilian representative strawberry production area. The second objective was to compare the fruits physic-chemical nutraceutical characteristics of these genotypes in response to different postharvest fruit storage temperatures. A supporting genetic analysis, via SSR markers, was also performed in order to establish genotype correlations. Our study confirmed the high result of ‘Florida Fortuna’ in terms of earliness and productivity and the high performance of ‘Candonga Sabrosa’ in terms of total soluble content and fruit firmness. The new lines ‘PA1’ and ‘PA2’ showed satisfying results. However, the new line ‘PA2’, might deserve particular attention by growers involved in strawberry early fruit production in Mediterranean areas both for its yield performance and fruit quality characteristics. This study also showed that a 4 °C fruit storage temperature treatment for 36 hours positively affects the physical and chemical quality properties of strawberry fruits, whereas overall quality declines at 20 °C storage. According to the genetic characterization, ‘PA2’ was closely related to ‘Candonga Sabrosa’ and ‘Florida Fortuna’.

Mechanical Harvesting and Postharvest Storage of Two Southern Highbush Blueberry Cultivars Grafted onto Vaccinium arboreum Rootstocks

The profitability of the fresh market blueberry industry in many areas is constrained by the extensive use and cost of soil amendments, high labor requirements for hand harvesting, and the inefficiencies of mechanical harvesters. Vaccinium arboreum Marsh is a wild species that has wide soil adaptation and monopodial growth habit. It has the potential to be used as a blueberry rootstock, expanding blueberry production to marginal soil and improving the mechanical harvesting efficiency of cultivated blueberry. The objectives of this research were to compare yield, berry quality, and postharvest fruit storage of own-rooted vs. grafted southern highbush blueberry (SHB) cultivars (Farthing and Meadowlark) grown on amended vs. nonamended soil and either hand or mechanical harvested. Yields of hand-harvested SHB during the first two fruiting years were generally greater in own-rooted plants grown on amended soil compared with own-rooted plants on nonamended soil or grafted plants on either soil treatment. However, by the second fruiting year, hand-harvest yields of grafted SHB were ≈80% greater than own-rooted plants when grown in nonamended soil. Yields of mechanical-harvested SHB grafted on V. arboreum and grown in either soil treatment were similar to yields of mechanical-harvested own-rooted plants in amended soil the second fruiting year, and greater than yields of own-rooted plants in non-amended soil. In general, mechanical harvesting reduced marketable yield ≈40% compared with hand harvesting. However, grafted plants reduced ground losses during harvest by ≈35% compared with own-rooted plants for both cultivars. Mechanical-harvested berries had a greater total soluble solids:total titratable acidity ratio (TSS:TTA) than hand-harvested berries, and berries harvested toward the end of the harvest season had a greater TSS:TTA than those from early-season harvests. As postharvest storage time increased, berry appearance ratings decreased and berry softness and shriveling increased, particularly in mechanical-harvested compared with hand-harvested berries. Firmness of mechanical-harvested berries decreased during storage, whereas firmness of hand-harvested berries remained relatively stable. However, fruit quality at harvest and during postharvest storage was unaffected by V. arboreum rootstocks or lack of pine bark amendment. This study suggests that using V. arboreum as a rootstock in an alternative blueberry production system has the potential to decrease the use of soil amendments and increase mechanical harvesting efficiency.

Perspectives on Utilization of Edible Coatings and Nano-laminate Coatings for Extension of Postharvest Storage of Fruits and Vegetables

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.

The effects of temperature and wetness duration on the development of Guignardia psidii in guava fruit naturally infected

A survey conducted in SP state in 2005 and another in 2007 found that black spot (Guignardia psidii) incidence on guava reached 58 %. The aim of this study was to investigate the effects of temperature and wetness duration on the development of black spot symptoms in detached guava naturally infected under controlled conditions. Guava fruit cv. Kumagai from a production field with a history of occurrence of the disease were subjected to different temperatures (10, 15, 20, 25, 30 and 35 °C) with wetness periods of 6 and 24 h. Analyses of variance and nonlinear regression were employed to evaluate the combined effects of temperature and wetness duration on the disease incidence, the final disease severity, the rate of disease progression and incubation period. Black spot symptoms were observed at all temperatures, except at 10 and 35 °C. The first symptoms of black spot in guavas were observed 2 days after incubation at 25 and 30 °C with wetness duration of 6 h. All variables reached their maximum values close to 30 °C, regardless of wetness duration. This temperature combined with 24 h of wetness duration resulted in black spot incidence of 100 %, disease severity of 3.02 cm, progress rate of 6.9 mm/day and incubation period of 6 days, 10 days after incubation. The postharvest storage of fruits at 10 °C and other control methods based on low or high temperature can delay the black spot incidence on ‘Kumagai’ guavas and prolong the fruit shelf life.

Ethylene Removal by Bio-filters in order to Increase Storage Life of Bananas

Ethylene gas is the simplest plant hormone and cause a variety of physiological effects in plants. This hormone is known as the hormone of aging, due to the hormonal effect on fruit maturation, leaf loss and separation of the fruit from the branches, changing color as fruit maturation because of chlorophyll loss, fruit firmness. Increased ethylene in fruit storage media creates the right conditions for growth of microorganisms such as fungi and bacteria. The purpose of this study was to evaluate the removal of ethylene by bio-filters to extend the shelf-life of fruits was studied at laboratory scale. Samples were evaluated organoleptic (sensory) and after preparing the best filter, filter efficient were used scale of operation (used in fruit cartons). Removal of ethylene gas by Gas chromatograph system showed that the amount of gas passing through the column 4 substrates including active sludge, peat wood chips, humus with organic soil was 0.6528 ml (ethylene) / L (air) in comparison to the other columns, and control sample. Results showed that the bio-filters with isolated bacteria in this study can be used to the removal of ethylene gas and increase shelf life of fruit postharvest storage conditions.DOI: http://dx.doi.org/10.3126/ijls.v9i5.12696

BREEDING MUSCADINE GRAPES IN ARKANSAS, USA: A NEW INITIATIVE

Muscadine? grape is a United States native grape commonly grown in the southeast and southwest regions of the country. ?Muscadine? breeding has been ongoing for many years, but programs have been reduced or eliminated in the previous 20 years and activity in breeding is less than in prior times. There is much to be improved with muscadines, particularly in traits that contribute to greater consumer acceptance of the fruit. The University of Arkansas Division of Agriculture initiated a muscadine breeding program in 2006 to develop improved quality cultivars for the fresh market. Major traits of interest include firm, non-slipskin texture, reduced skin thickness, excellent flavor, fruit and leaf shape diversification, increased dry stem scar, improved vine winter hardiness, and disease resistance. An emphasis is also being placed on postharvest storage of fruit and a postharvest protocol has been developed to identify superior storage potential genotypes. As of 2013, over 10,000 seedlings have been planted for field evaluation, resulting in 117 selections. Although the program has not released cultivars, several advanced selections have been identified for potential release.

Regulatory control of carotenoid accumulation in winter squash during storage.

Storage promotes carotenoid accumulation and converts amylochromoplasts into chromoplasts in winter squash. Such carotenoid enhancement is likely due to continuous biosynthesis along with reduced turnover and/or enhanced sequestration. Postharvest storage of fruits and vegetables is often required and frequently results in nutritional quality change. In this study, we investigated carotenoid storage plastids, carotenoid content, and its regulation during 3-month storage of winter squash butternut fruits. We showed that storage improved visual appearance of fruit flesh color from light to dark orange, and promoted continuous accumulation of carotenoids during the first 2-month storage. Such an increased carotenoid accumulation was found to be concomitant with starch breakdown, resulting in the conversion of amylochromoplasts into chromoplasts. The butternut fruits contained predominantly β-carotene, lutein, and violaxanthin. Increased ratios of β-carotene and violaxanthin to total carotenoids were noticed during the storage. Analysis of carotenoid metabolic gene expression and PSY protein level revealed a decreased expression of carotenogenic genes and PSY protein following the storage, indicating that the increased carotenoid level might not be due to increased biosynthesis. Instead, the increase likely resulted from a continuous biosynthesis with a possibly reduced turnover and/or enhanced sequestration, suggesting a complex regulation of carotenoid accumulation during fruit storage. This study provides important information to our understanding of carotenogenesis and its regulation during postharvest storage of fruits.

Effect of olive storage conditions on Chemlali olive oil quality and the effective role of fatty acids alkyl esters in checking olive oils authenticity

The present paper accounts for the study of the storage of Chemlali olive fruits at two conditions of limited aerobiosis: in closed plastic bags and in open perforated plastic boxes for different periods before oil extraction. The ultimate objective is to investigate the effect of the container type of the postharvest fruit storage on the deterioration of the olive oil quality. The results have shown that the oil quality of Chemlali olives deteriorated more rapidly during fruit storage in closed plastic bags than in perforated plastic boxes. Therefore, the use of perforated plastic boxes is recommended for keeping the olives for longer periods of storage. The repeated measures analysis of variance of all parameters analyzed indicated that the olive oil quality is mainly affected by the olives storage conditions (containers type and storage periods). Finally, blends of extra-virgin olive oil and mildly deodorized low-quality olive oils can be detected by their alkyl esters concentrations.

Nondestructive Analysis to Monitor Potato Quality during Cold Storage

AbstractSamples of potatoes were harvested in 2007 in Friuli Venezia Giulia (Italy) and were stored at 6.5C for 6 months to assess quality characteristics, mainly related to the sprouting trend of tubers. The quality changes during cold storage were monitored using conventional measures (i.e., weight, visual appearance, morphological control, number and length of buds, °Brix) and nondestructive methods (fluorometry and colorimetry). Among 17 cultivars, seven were stored at a lower temperature (0C) for 4 months and then 10C for 15 days to verify the reversible interconversion between starch and sugar induced by the storage temperature. The most important results were given by fluorometric analysis, which provided useful information for predicting the sprouting trend of tubers, as well as other objective analytical tests: the quantum yield had in most cultivars the minimum value in predicting sprouting time. After the low‐temperature storage, the quantum yield was irreversibly reduced.Practical ApplicationsNondestructive techniques based on chlorophyll fluorescence measurements are used to monitor quality changes during post harvest storage of fruit and vegetables. Fluorometric values give indications not only about the chlorophyll amount, but also on the physiological state of photosynthetic apparatus. Even if potato tubers in good storage conditions don't produce chlorophyll, they possess a photosynthetic apparatus whose physiological state can be measured by fluorometry. Potatoes stored at low temperatures are subject to the sweetening process, but starch is synthesized again when potatoes are transferred to normal temperatures. The photosynthetic apparatus is damaged by low temperatures, as indicated by the decrease of fluorometric values, and this process is not reversible. The fluorometric indexes can be measured in order to check if potatoes were properly stored and evaluate differences of behavior in storage. The nondestructive method will enhance monitoring of potatoes quality during storage, thus minimizing both time and food wastages.

Comparative analysis of surface wax in mature fruits between Satsuma mandarin (Citrus unshiu) and ‘Newhall’ navel orange (Citrus sinensis) from the perspective of crystal morphology, chemical composition and key gene expression

Surface wax of mature Satsuma mandarin (Citrus unshiu) and ‘Newhall’ navel orange (Citrus sinensis) was analysed by crystal morphology, chemical composition, and gene expression levels. The epicuticular and total waxes of both citrus cultivars were mostly composed of aldehydes, alkanes, fatty acids and primary alcohols. The epicuticular wax accounted for 80% of the total wax in the Newhall fruits and was higher than that in the Satsuma fruits. Scanning electron microscopy showed that larger and more wax platelets were deposited on the surface of Newhall fruits than on the Satsuma fruits. Moreover, the expression levels of genes involved in the wax formation were consistent with the biochemical and crystal morphological analyses. These diversities of fruit wax between the two cultivars may contribute to the differences of fruit postharvest storage properties, which can provide important information for the production of synthetic wax for citrus fruits.

Backcross introgression of plastomic factors controlling chilling tolerance into elite cucumber (Cucumis sativus L.) germplasm: early generation recovery of recurrent parent phenotype

Environmental stresses such as chilling temperatures can decrease germination, emergence, flower and fruit development, marketable yield, and postharvest fruit storage longevity in cucumber (Cucumis sativus L.). While response to chilling injury in cucumber is controlled by simple plastidic (maternal) and nuclear (paternal) factors, no chilling tolerant U.S. processing varieties are commercially available. Furthermore, even though three single nucleotide polymorphic sites have been identified as plastid components associated with chilling tolerance in cucumber, it is not known how these factors interact with nuclear factors controlling economically important traits. Therefore, an experiment was designed to evaluate the rate of recovery of the chilling susceptible (cytoplasm) genotype during introgression backcrossing (IB), where it was used as a recurrent parent after the initial mating to a line possessing chilling tolerant cytoplasm (donor parent). Phenotypic yield and quality trait data were collected on processing type backcross progeny (BC1–5 and BC2S3) derived from an initial ‘Chipper’ (tolerant) × line M 29 (susceptible) mating, and rate of progression to the recurrent parent was determined by simple sequence repeat marker and morphological trait analyses. Substantial degrees of the recurrent parent phenotype and nuclear genome were recovered by the BC2 generation (P = 0.001), with nearly complete recovery of recurrent parental traits and its nuclear genome occurring by the BC3. General combining ability (GCA) of derived BC2S3 lines was significant for yield, yield/plant, length (L), diameter (D), and L:D ratios. The BC2S3 line GCA and rate of progression towards the recurrent parent for economically important traits suggests that elite chilling tolerant cucumber germplasm can be developed rapidly through IB and marker genotyping.

PTR-ToF-MS, A Novel, Rapid, High Sensitivity and Non-Invasive Tool to Monitor Volatile Compound Release During Fruit Post-Harvest Storage: The Case Study of Apple Ripening

In the present study, the potential of PTR-ToF-MS for addressing fundamental and technical post-harvest issues was tested on the non-destructive and rapid monitoring of volatile compound evolution in three apple cultivars (‘Golden Delicious’, ‘Braeburn’ and ‘Gold Rush’) during 25 days of post-harvest shelf life ripening. There were more than 800 peaks in the PTR-ToF-MS spectra of apple headspace and many of them were associated with relevant compounds. Besides the ion produced upon proton transfer, we used the ion at mass 28.031 (C2H 4 + ) produced by charge transfer from residual O 2 + as a monitor for ethylene concentration. ‘Golden Delicious’ apples were characterised by higher ethylene emission rates than ‘Gold Rush’ and ‘Braeburn’, and quantitative comparison has been supported by two segment piecewise linear model fitting. Ester evolution during post-harvest ripening is strongly dependent on endogenous ethylene concentration levels. For ‘Golden Delicious’ and ‘Braeburn’, sesquiterpenes (alpha-farnesene) exhibited a fast response to ethylene emission followed by a rapid decline after the endogenous ethylene maximum peak. Carbonyl compounds displayed a different time evolution as compared to esters and terpenes and did not show any evident relationship with ethylene. Methanol and ethanol concentrations during the entire storage period did not change significantly. We show how multivariate analysis can efficiently handle the large datasets produced by PTR-ToF-MS and that the outcomes obtained are in agreement with the literature. The different volatile compounds could be simultaneously monitored with high time resolution, providing advantages over the more established techniques for the investigation of VOC dynamics in fruit post-harvest storage trials.