Physiological disorders in cold-stored 'Autumn Sense' hardy kiwifruit depend- on the storage temperature and the modulation of targeted metabolites.

This study aimed to elucidate the effects of storage temperature on various fruit quality attributes, physiological disorders, and associated metabolites in the 0.5, 3, or 10 °C stored hardy kiwifruit. Peel pitting, which was highest in the 0.5 °C stored fruit, was identified as a chilling injury symptom of hardy kiwifruit. Proline and branched-chain amino acid contents showed higher values at 0.5 °C stored fruit as chilling responses. On the other hand, fruit shriveling and decay were highest in the 10 °C after 5 weeks of storage. The 10 °C storage induced fruit ripening during 3 weeks, but fruit shriveling and decay were severe after 5 weeks of storage. Therefore, storing the 'Autumn Sense' hardy kiwifruit at proper temperatures would be more beneficial, as it alters targeted metabolites and helps reduce the incidence of physiological disorders during cold storage.

Is calcium deficiency the real cause of bitter pit? A review.

Bitter pit is a disorder affecting the appearance of apples. Susceptibility is genetically controlled by both the cultivar and rootstock, with both environmental and horticultural factors affecting its severity and proportional incidence. Symptoms appear more frequently at the calyx end of the fruit and consist of circular necrotic spots, which take on a "corky" appearance visible through the peel. Bitter pit may develop before harvest, or after harvest, reducing the proportions of marketable fruit. In this review, current knowledge of the factors associated with the occurrence of bitter pit in apples is summarized and discussed along with their interactions with Ca uptake and distribution to fruit. This disorder has been previously linked with localized Ca deficiencies in fruit during its development. However, these relationships are not always clear. Even with over a century of research, the precise mechanisms involved in its development are still not fully understood. Additional factors also contribute to bitter pit development, like imbalances of mineral nutrients, low concentration of auxins, high concentration of gibberellins, changes in xylem functionality, or physiological responses to abiotic stress. Bitter pit remains a complex disorder with multiple factors contributing to its development including changes at whole plant and cellular scales. Apple growers must carefully navigate these complex interactions between genetics, environment, and management decisions to minimize bitter pit in susceptible cultivars. Accordingly, management of plant nutrition, fruit crop load, and tree vigor still stands as the most important contribution to reducing bitter pit development. Even so, there will be situations where the occurrence of bitter pit will be inevitable due to cultivar and/or abiotic stress conditions.

Postharvest Storage Differentially Modulates the Enzymatic and Non-Enzymatic Antioxidant System of the Exocarp and Mesocarp of Hass Avocado: Implications for Disorders.

The present study evaluated the performance of some enzymatic and non-enzymatic antioxidant systems against oxidative stress for 10 to 30 d of refrigeration (R) and 15 to 50 d in controlled atmosphere (CA) conditions in both exocarp and mesocarp of Hass avocados from early and late harvests and at shelf life (SL) or consumption maturity. The possible relationship of the antioxidant systems with the occurrence of physiological disorders is also evaluated. The results indicate that the enzymatic system-superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), phenylalanine ammonium lyase (PAL) and polyphenoloxidase (PPO)-as well as the non-enzymatic system-such as phenolic compounds (PC)-showed different responses to the stress generated during storage and shelf life. In general, SOD, CAT, PAL and PPO did not significantly vary in storage (R or CA). At consumption maturity, SOD, POD and PAL activities decreased in the mesocarp (RSL and CASL), while CAT increased in the exocarp for CASL15-50d. PC instead decreased in the exocarp as the harvest period progressed while it increased in the mesocarp. Physiological disorders (dark spots) showed only in refrigeration on the exocarp at R30d and in mesocarp at RSL30d coincident with low SOD and low SOD and POD activity values, as well as low PC contents (p-coumaric and its derivatives and caffeic acid derivatives), respectively. The results support the use of CA as a postharvest technology to prevent the development of physiological disorders through the joint action of antioxidative defenses during avocado transport to distant markets until consumption maturity is reached.

Nondestructive characterization of diseased Chinese chive leaves using X-ray intensity ratios with microbeam synchrotron radiation X-ray fluorescence spectrometry.

The Chinese chive (Allium tuberosum) is a core crop grown in Kochi Prefecture, Japan. However, withering symptoms occur during greenhouse growing, which have a negative impact on crop management Chinese chive leaves with physiological disorders (PD) or necrotic streak disease (ND) present with withering as typical blight symptoms. Excess or deficiency of elements may cause such withering in Chinese chive leaves with PD. Therefore, visualizing the elemental distribution in plant bodies may help clarify the cause of this withering. In this study, using synchrotron radiation X-ray fluorescence (SR-XRF) imaging, we examined the elemental distribution conditions in healthy Chinese chive leaves without withering, those that withered due to PD, and those that withered due to ND. Segmentation analysis of inductively coupled plasma-optical emission spectroscopy (ICP-OES) was performed on the SR-XRF imaged Chinese chive leaves and the data from the two analytical methods were compared. SR-XRF imaging provided more detailed data on elemental distribution compared with segmentation analysis using ICP-OES. Based on the SR-XRF imaging results, the X-ray intensity ratios for Ca/K, Fe/Mn, and Zn/Cu were calculated. These findings support that the Ca/K, Fe/Mn, and Zn/Cu X-ray intensity ratios can be used in the early detection of withered leaves and to predict the factors causing withering.

Application of quantitative proteomics to investigate fruit ripening and eating quality.

The consumption of fruit and vegetables play an important role in human nutrition, dietary diversity and health. Fruit and vegetable industries impart significant impact on our society, economy, and environment, contributing towards sustainable development in both developing and developed countries. The eating quality of fruit is determined by its appearance, color, firmness, flavor, nutritional components, and the absence of defects from physiological disorders. However, all of these components are affected by many pre- and postharvest factors that influence fruit ripening and senescence. Significant efforts have been made to maintain and improve fruit eating quality by expanding our knowledge of fruit ripening and senescence, as well as by controlling and reducing losses. Innovative approaches are required to gain better understanding of the management of eating quality. With completion of the genome sequence for many horticultural products in recent years and development of the proteomic research technique, quantitative proteomic research on fruit is changing rapidly and represents a complementary research platform to address how genetics and environment influence the quality attributes of various produce. Quantiative proteomic research on fruit is advancing from protein abundance and protein quantitation to gene-protein interactions and post-translational modifications of proteins that occur during fruit development, ripening and in response to environmental influences. All of these techniques help to provide a comprehensive understanding of eating quality. This review focuses on current developments in the field as well as limitations and challenges, both in broad term and with specific examples. These examples include our own research experience in applying quantitative proteomic techniques to identify and quantify the protein changes in association with fruit ripening, quality and development of disorders, as well as possible control mechanisms.

Physical activity behavior in people with asthma and COPD overlap residing in Spain: a cross-sectional analysis.

OBJECTIVES: To identify levels of physical activity (PA) among the Spanish population with asthma and chronic obstructive pulmonary disease overlap (ACO). A further aim was to analyze differences in PA levels by sex, age, education, marital status, cohabiting, smoking habits, alcohol consumption and body mass index (BMI). METHODS: In this cross sectional study, data from the Spanish National Health Survey 2017 were analyzed. A total of 198 people with ACO aged 15-69 years were included in the analyses. The short version of the international physical activity questionnaire (IPAQ) was used to measure total PA (MET·min/week). PA was further classified as low, moderate and high, and analyzed according to sample characteristics. Data were analyzed using the Mann-Whitney U test, Kruskal-Wallis H test and chi squared test. Statistical significance was set at p < 0.05. RESULTS: People with ACO engaged in a mean volume of 2038.1 MET·min/week. Those aged 30-60 years and those with normal weight were significantly more active than those aged ≥60 and those with obesity. When classifying PA level in low, moderate and high, results showed no significant differences between sample characteristics. Overall, moderate and high levels of PA were the most and least frequent levels (48.0% and 16.2%, respectively). CONCLUSIONS: More than three out of ten Spanish adults with ACO do not achieve PA recommendations. Therefore, it is recommended to implement programs that promote the importance and benefits of PA among the Spanish population with ACO, and such programs should focus on older adults and those who are obese.

Computer-Based Tools Unmask Critical Mineral Nutrient Interactions in Hoagland Solution for Healthy Kiwiberry Plant Acclimatization.

The aim of this study was to better understand the response of ex vitro acclimatized plants grown to a set of mineral nutrient combinations based on Hoagland solution. To reach that, two computer-based tools were used: the design of experiments (DOE) and a hybrid artificial intelligence technology that combines artificial neural networks with fuzzy logic. DOE was employed to create a five-dimensional IV-design space by categorizing all macroelements and one microelement (copper) of Hoagland mineral solution, reducing the experimental design space from 243 (35) to 19 treatments. Typical growth parameters included hardening efficiency (Hard), newly formed shoot length (SL), total leaf number (TLN), leaf chlorophyll content (LCC), and leaf area (LA). Moreover, three physiological disorders, namely, leaf necrosis (LN), leaf spot (LS), and curled leaf (CL), were evaluated for each treatment (mineral formulation). All the growth parameters plus LN were successfully modeled using neuro-fuzzy logic with a high train set R 2 between experimental and predicted values (72.67 < R 2 < 98.79). The model deciphered new insights using different sets of "IF-THEN" rules, pinpointing the positive role of Mg2+ and Ca2+ to improve Hard, SL, TLN, and LA and alleviate LN but with opposite influences on LCC. On the contrary, TLN and LCC were negatively affected by the addition of NO3 - into the media, while NH4 + in complex interaction with Cu2+ or Mg2+ positively enhanced SL, TLN, LCC, and LA. In our opinion, the approach and results achieved in this work are extremely fruitful to understand the effect of Hoagland mineral nutrients on the healthy growth of ex vitro acclimatized plants, through identifying key factors, which favor growth and limit physiological abnormalities.

Strategies to Preserve Postharvest Quality of Horticultural Crops and Superficial Scald Control: From Diphenylamine Antioxidant Usage to More Recent Approaches.

Horticultural crops are vulnerable to several disorders, which affect their physiological and organoleptic quality. For about forty years, the control of physiological disorders (such as superficial scald) in horticultural crops, particularly in fruit, was achieved through the application of the antioxidant diphenylamine (DPA), usually combined with controlled atmosphere (CA) conditions. However, identification of DPA residues and metabolites in treated fruits, associated with their toxicity, banned the use of this antioxidant in Europe. This triggered the urgent need for novel and, ideally, natural and sustainable alternatives, combined with adequate storage conditions to protect cultivars from harmful agents. This review systematizes the state-of-the-art DPA application on several fresh cultivars, such as apples, pears, and vegetables (potatoes, spinach, etc.), as well as the possible mechanisms of the action and effects of DPA, emphasizing its antioxidant properties. Alternative methods to DPA are also discussed, as well as respective effects and limitations. Recent research on scald development molecular pathways are highlighted to open new non-chemical strategies opportunities. This appraisal shows that most of the current solutions have not lead to satisfactory commercial results; thus, further research aimed to understand the mechanisms underlying postharvest disorders and to design sustainable and safe solutions to improve horticultural products storage is needed.

Phytohormone profiles are strongly altered during induction and symptom development of the physiological ripening disorder berry shrivel in grapevine.

The process of grape berry ripening follows three phases with distinct metabolic processes and complex regulations via phytohormones. The physiological ripening disorder berry shrivel (BS) is characterized by reduced sugar accumulation, low anthocyanin contents, and high acidity in affected berries. The processes leading to BS induction are unknown, but recent transcriptional data on reduced expression of switch genes hint towards a disturbed ripening onset. Herein we investigated the phytohormone composition throughout grape berry ripening in healthy and BS berries in Vitis vinifera L. cultivar Blauer Zweigelt. Thereby we hypothesize that phytohormones are key players for BS induction and suppress the expression of switch genes at veraison. The presented metabolomics and RNAseq data describe two distinct phytohormone profiles in BS berries, differing between pre- and post-veraison with a clear ethylene precursor (aminocyclopropane-1-carboxylic acid, ACC) peak before veraison. Exogenous application of ACC led to BS symptoms, while ethephone application led to berry abscission. During post-veraison, we observed high ABA-glucose ester (ABA-GE) and low indole-3-acetate aspartate (IAA-Asp) and isopentenyladenine (iP) contents in BS berries and the transcriptional induction of several phytohormone pathways. The presented descriptive data provide valuable knowledge to further decipher the role of phytohormones in BS induction and BS symptom development.

Modeling and Optimizing Culture Medium Mineral Composition for in vitro Propagation of Actinidia arguta.

The design of plant tissue culture media remains a complicated task due to the interactions of many factors. The use of computer-based tools is still very scarce, although they have demonstrated great advantages when used in large dataset analysis. In this study, design of experiments (DOE) and three machine learning (ML) algorithms, artificial neural networks (ANNs), fuzzy logic, and genetic algorithms (GA), were combined to decipher the key minerals and predict the optimal combination of salts for hardy kiwi (Actinidia arguta) in vitro micropropagation. A five-factor experimental design of 33 salt treatments was defined using DOE. Later, the effect of the ionic variations generated by these five factors on three morpho-physiological growth responses - shoot number (SN), shoot length (SL), and leaves area (LA) - and on three quality responses - shoots quality (SQ), basal callus (BC), and hyperhydricity (H) - were modeled and analyzed simultaneously. Neurofuzzy logic models demonstrated that just 11 ions (five macronutrients (N, K, P, Mg, and S) and six micronutrients (Cl, Fe, B, Mo, Na, and I)) out of the 18 tested explained the results obtained. The rules "IF - THEN" allow for easy deduction of the concentration range of each ion that causes a positive effect on growth responses and guarantees healthy shoots. Secondly, using a combination of ANNs-GA, a new optimized medium was designed and the desired values for each response parameter were accurately predicted. Finally, the experimental validation of the model showed that the optimized medium significantly promotes SQ and reduces BC and H compared to standard media generally used in plant tissue culture. This study demonstrated the suitability of computer-based tools for improving plant in vitro micropropagation: (i) DOE to design more efficient experiments, saving time and cost; (ii) ANNs combined with fuzzy logic to understand the cause-effect of several factors on the response parameters; and (iii) ANNs-GA to predict new mineral media formulation, which improve growth response, avoiding morpho-physiological abnormalities. The lack of predictability on some response parameters can be due to other key media components, such as vitamins, PGRs, or organic compounds, particularly glycine, which could modulate the effect of the ions and needs further research for confirmation.

Severe asthma and bronchiectasis.

Objective: The aim of our study was to determine the tomographic findings and prevalence of bronchiectasis in our population of patients with severe asthma, and to identify factors associated with the presence of bronchiectasis in these patients. Materials and methods: We retrospectively collected data from the medical histories of patients referred to the asthma unit of our hospital, with a diagnosis of severe asthma between 2015 and 2017. Patients with ABPA, cystic fibrosis, immunodeficiency or systemic disease were excluded. High-resolution thorax-computed tomodensitography (HRCT) was performed in all patients. A standardized protocol was applied in data collection. Results: A total of 108 patients comprising 50 men (46%) and 58 women (54%) were included in the study. Of the 108 patients, 59 (55%) had at least one abnormality detected by HRCT, the most commonly reported abnormalities being bronchiectasis (35%), bronchial wall thickening (33%), emphysema (7%), atelectasis area (6%), mosaic attenuation due to air trapping (4%), and "tree in bud" image (2%). Subjects with bronchiectasis were older (p = 0.001), had a longer asthma history (p = 0.048), had poorer pulmonary function tests with lower FVC (p = 0.031), had more severe bronchial obstruction with lower FEV1 (p = 0.008) and had lower FEV1/FVC (p = 0.003). They also experienced more frequent hospitalizations in the previous year (p = 0.019) and received treatment with omalizumab more frequently (p = 0.049). Plasma eosinophil count and IgE levels were comparable in both groups. In the multivariate analysis, the presence of bronchiectasis was associated with ages older than 40 (OR: 8.3; 95% CI: 1.7-41.2) and chronic airflow obstruction (OR: 5.4; 95% CI: 1.9-15.3). Conclusions: We found that in patients with severe asthma, the prevalence of bronchiectasis is high and that bronchiectasis is associated with a longer asthma history, greater severity and, more importantly, chronic airflow obstruction. These findings are still insufficient evidence to considere features of asthma-bronchiectasis overlap syndrome, a distinct phenotype of severe asthma, but bronchiectasis is a frequent phenomenon leading to a more severe disease with frequent exacerbations. The performance of thorax HRCT on patients with severe asthma can help to evaluate management strategies for the disease in order to improve treatment and prognosis.

Dynamic controlled atmosphere: Impact of elevated storage temperature on anaerobic metabolism and quality of 'Nicoter' apples.

The aim of the study was to evaluate an elevated (3.0 °C) and low (1.0 °C) storage temperature combined with dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) and chlorophyll fluorescence (DCA-CF) on anaerobic metabolism, physiological storage disorders and overall quality of 'Nicoter' ('Kanzi®') apples after 5.5 and 8.0 months of storage plus 7d shelf-life. Fruit stored under DCA-RQ 2.0 accumulated the highest amounts of anaerobic metabolites (acetaldehyde, ethanol and ethyl acetate), regardless of storage temperature and timing of storage outturn evaluation, but it did not result in higher electrolyte leakage. Flesh breakdown, core breakdown and cavity formation were reduced at 3 °C. Storage at 3 °C combined with DCA maintained higher flesh firmness after 8.0 months storage plus 7d shelf-life. 'Nicoter' apples can be stored at 3 °C using a DCA system, based either on CF or on RQ, to save electrical energy.

Respiratory waveform variation can prevent pulsus paradoxus measurement by sphygmomanometry.

BACKGROUND: Pulsus paradoxus (PP) represents increased fluctuation of systolic pressure during the respiratory cycle. PP increases in pathologic conditions, including asthma and other obstructive airways diseases. Respiratory waveform variation (RWV) represents arterial-waveform baseline variability resulting from intra-pleural pressure changes during the respiratory cycle in the presence of airway obstruction. It is not known whether RWV influences manual PP measurement using a sphygmomanometer and stethoscope. METHODS: We performed an observational study in six healthy adults. Participants performed tidal-breathing through a breathing apparatus with pre-determined inspiratory (0-45.6 cm H2O) and expiratory (0-24.4 cm H2O) resistance levels for a total of 23 data sets per participant. PP was measured from continuous radial artery pressure recordings as the absolute difference between maximum and minimum systolic pressure levels during a complete respiratory cycle. RESULTS: In this study, PP values measured without applied airway resistance exceeded 10 mmHg, the traditional definition of PP, in five of the six participants. Manual measurement of PP would not be possible at greater RWV because the maximum diastolic pressure exceeded minimum systolic pressure during RWV. CONCLUSIONS: PP in normal adults may exceed 10 mmHg, and RWV may be of sufficient magnitude to preclude manual PP measurement.

The association between bronchial asthma and periodontitis: A case-control study in Jordan.

OBJECTIVE: Our aim is to study the association between bronchial asthma (BA) and periodontitis in Jordan. METHODS: A case control study of 260 subjects; 130 with BA and 130 without BA (controls) were recruited at a university hospital in Jordan. BA cases were physician-diagnosed and on anti-asthma medications for 12 months. Periodontitis was defined as the presence of ≥ 4 teeth with ≥ 1 site with probing pocket depth (PPD) ≥ 4 mm and clinical attachment level (CAL) ≥ 3 mm. RESULTS: Mean age of participants was 45.3 years (range, 18-65) and 58.1% were females. Patients with BA had lower education and tended to live in rural areas. Periodontitis was present in 52 (40.0%) patients with BA and 26 (20.0%) in the control group, p < 0.005. Binary logistic regression indicated that patients with BA were more likely to have periodontitis than controls [adjusted odd ratio (OR) = 2.91, 95% CI (1.39-6.11), p = 0.005]. Patients with BA had higher percentage of sites with: PPD ≥ 3 mm, CAL ≥ 3 mm, and CAL ≥ 4 mm than controls, p < 0.05. The risk of periodontitis [OR = 5.27, 95% CI (1.59-17.51)] and CAL ≥ 3 mm were higher in patients on oral corticosteroids compared to inhaled corticosteroids, p < 0.05. CONCLUSIONS: Adult Jordanians with bronchial asthma are at higher risk of periodontitis, particularly those on oral corticosteroids. Large and longitudinal studies are needed to better understand this significant association.

Combining DOE With Neurofuzzy Logic for Healthy Mineral Nutrition of Pistachio Rootstocks in vitro Culture.

The aim of this study was to determine the effects of Murashige and Skoog (MS) salts on optimal growth of two pistachio rootstocks, P. vera cv. "Ghazvini" and "UCB1" using design of experiments (DOE) and artificial intelligence (AI) tools. MS medium with 14 macro-and micro-elements was used as base point and its concentration varied from 0 to 5 × MS concentrations. Design of experiments (DOE) software was used to generate a five-dimensional design space by categorizing MS salts into five independent factors (NH4NO3, KNO3, mesos, micros and iron), reducing the experimental design space from 3,125 to just 29 treatments. Typical plant growth parameters such as shoot quality (SQ), proliferation rate (PR), shoot length (SL), and some physiological disorders including shoot-tip necrosis (STN) and callus formation at the base of explants (BC) were evaluated for each treatment. The results were successfully modeled using neurofuzzy logic software. The model delivered new insights, by different sets of "IF-THEN" rules, pinpointing the key role of some ion interactions ( SO 4 2 - × Cl-, K+ × SO 4 2 - × EDTA-, and Fe2+ × Cu2+ × NO 3 - ) for SQ, PR, and SL, whilst physiological disorders (STN and BC) were governed mainly by independent ions as Fe2+ and EDTA-, respectively. In our opinion, the methodology and results obtained in this study is extremely useful to understand the effect of mineral nutrients on pistachio in vitro culture, through discovering new complex interactions among macro-and micro-elements which can be implemented to design new media of plant tissue culture and improve healthy plant micropropagation for any plant species.

Use of Biostimulants for Organic Apple Production: Effects on Tree Growth, Yield, and Fruit Quality at Harvest and During Storage.

The experiment was conducted during two consecutive seasons (years 2016 and 2017) in an organic apple orchard of the cultivar Jonathan. Several biostimulants were tested (10 in total), including humic acids, macro and micro seaweed extracts, alfalfa protein hydrolysate, amino acids alone or in combination with zinc, B-group vitamins, chitosan and a commercial product containing silicon. Treatments were performed at weekly intervals, starting from the end of May until mid-August. The macroseaweed extract was effective in stimulate tree growth potential in both years, as shown by a significantly larger leaf area (+20% as compared to control) and by an higher chlorophyll content and leaf photosynthetic rate in year 2016. As for the yield performances and apples quality traits at harvest (average fruit weight, soluble solids content, titratable acidity, and flesh firmness), they were generally affected by the different climatic conditions that characterized the two growing seasons (year 2017 being characterized by higher maximal and average temperatures and by limited rainfalls at the beginning of the season). Treatments with macroseaweed extract, B-group vitamins and alfalfa protein hydrolysate were able to significantly improve the intensity and extension of the red coloration of apples at harvest. Correspondingly, the anthocyanin content in the skin of apples treated with the same biostimulants resulted significantly higher than control, highlighting the potential influence of these substances on the synthesis of secondary metabolites in apple. The incidence of physiological disorders was also monitored during apple storage period. Amino acids plus zinc application was effective in reducing (more than 50%) the incidence of the "Jonathan spot," the main post-harvest disorder for this cultivar.

Thidiazuron-induced abnormalities in plant tissue cultures.

Thidiazuron (TDZ) is a proven effective and potent synthetic plant growth regulator for organogenic, regeneration, and developmental pathways, including axillary and adventitious shoot proliferation, somatic embryogenesis, and in vitro flowering. TDZ has facilitated the establishment of in vitro cultures for several plant species, especially woody and recalcitrant plants, which has enabled their genetic transformation and improvement. Despite the effectiveness and advantages of using TDZ, several drawbacks are associated with its application in plant tissue culture. This review addresses the morphological, physiological, and cytogenetic abnormalities associated with the use of TDZ in vitro, and provides a summary of these abnormalities in several plant species.

Metabolomic and physico-chemical approach unravel dynamic regulation of calcium in sweet cherry fruit physiology.

Calcium (Ca2) nutrition has a significant role in fruit physiology; however, the underlying mechanism is still unclear. In this study, fruit quality in response to CaCl2, applied via foliar sprays (Ca2) or/and hydro-cooling water (CaHC), was characterized in 'Lapins' cherries at harvest, just after cold storage (20 days at 0 °C) as well as after cold storage followed by 2 days at 20 °C, herein defined as shelf-life period. Data indicated that pre- and post-harvest Ca2+ applications increased total Ca2+ and cell wall bound Ca2+, respectively. Treatment with Ca reduced cracking whereas Ca + CaHC condition depressed stem browning. Both skin penetration and stem removal were affected by Ca2+ feeding. Also, several color- and antioxidant-related parameters were induced by Ca2+ treatments. Metabolomic analysis revealed significant alterations in primary metabolites among the Ca2+ treatments, including sugars (eg., glucose, fructose), soluble alcohols (eg., arabitol, sorbitol), organic acids (eg.,malate, quinate) and amino acids (eg., glycine, beta-alanine). This work helps to improve our knowledge on the fruit's response to Ca2+ nutrition.

Effect of dynamic controlled atmosphere monitored by respiratory quotient and 1-methylcyclopropene on the metabolism and quality of 'Galaxy' apple harvested at three maturity stages.

The objective of this study was to evaluate the interaction between controlled atmosphere (CA), CA+1-methylcyclopropene (1-MCP) and dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) with three fruit maturity stages at harvest (early harvest date, optimal harvest date and late harvest date) on 'Galaxy' apple metabolism and quality after harvest and 9months storage plus 7days of shelf life at 20°C. Fruit stored under dynamic controlled atmosphere monitored by respiratory quotient 1.3 (DCA-RQ 1.3) showed lower ethylene production, respiration rate, mealiness and higher flesh firmness in comparison to CA stored fruit, but did not differ from those treated with 1-MCP. The dynamic controlled atmosphere monitored by respiratory quotient 1.5 (DCA-RQ 1.5) increased the acetaldehyde, ethanol and ethyl acetate concentration, regardless of the fruit maturity at harvest. The storage of 'Galaxy' apple under DCA-RQ 1.3 is efficient in keeping quality regardless of the maturity stage at harvest.

Effects of dynamic controlled atmosphere by respiratory quotient on some quality parameters and volatile profile of 'Royal Gala' apple after long-term storage.

The effects of dynamic controlled atmosphere (DCA) storage based on chlorophyll fluorescence (DCA-CF) and respiratory quotient (DCA-RQ) on the quality and volatile profile of 'Royal Gala' apple were evaluated. DCA storage reduces ACC (1-aminocyclopropane-1-carboxylate) oxidase activity, ethylene production and respiration rate of apples stored for 9months at 1.0°C plus 7days at 20°C, resulting in higher flesh firmness, titratable acidity and lesser physiological disorders, and provided a higher proportion of healthy fruit. Storage in a regular controlled atmosphere gave higher levels of key volatiles (butyl acetate, 2-methylbutyl acetate and hexyl acetate), as compared to fruit stored under DCA-CF, but fruit stored under DCA-RQ 1.5 and RQ 2.0 also showed higher amounts of key volatile compounds, with increment in ethanol and ethyl acetate, but far below the odour threshold. Storage in DCA-CF reduces fruit ester production, especially 2-methylbutyl acetate, which is the most important component of 'Royal Gala' apple flavour.