Search

Microorganisms play an important role in plant growth, health and ecological function. It is necessary to explore the microbial community because of the significant ecological and economic value of apples (Malus x domestica). However, the related bacterial communities in different ecological habitats are not clear in the unique scion/rootstock combinations of apples. In this study, the Illumina Miseq platform was used to analyze the bacterial communities in different niches (bulk soil, rhizosphere soil and roots) of two scion/rootstock combinations [Fuji/Malus xiaojinensis Cheng et Jiang (Mx) and Fuji/Malus baccata (L.) Borkh. (Mb)]. The relationship between the microbial community, soil properties, and plant characters was explored. The results showed that the diversity of the bacterial community decreased from bulk soil to rhizosphere soil and then to roots. In addition, at the phylum level, Proteobacteria, Actinobacteria and Acitinobacteria were dominant and had notable divergence in different ecological niches. Distinct niches had remarkable effects on the diversity and composition of the bacterial community according to PCoA. The rootstock genotype had an effect on the bacterial composition but no effect on the diversity. pH, soil organic matter (SOM), alkaline hydrolyzable nitrogen (AN) were the main factor affecting the structure of bacterial community in rhizosphere soil, as shown by Pearson analysis. Bacteria taxa in the roots were affected by starch, fructose, sucrose and sorbitol. This study showed the microbial community structure in different ecological niches of different scion/rootstock combinations and provided some evidence for understanding the microbial-plant interaction of apple rootstocks. [ABSTRACT FROM AUTHOR]

We investigated the relationship between apple skin color and internal quality characteristics, such as the concentration of functional compounds, physicochemical and textural properties. The skin color of 'Fuji' apples (N = 420) was determined and the apples were categorized into three classes (class A, N = 231; class B, N = 130; class C, N = 59). The apple skin color values correlated significantly with flesh color intensity. For sensory attributes, the yellow color intensity of apple flesh had a positive correlation with redness (a*, r = 0.781) and ΔE(r = 0.787) of apple flesh color (r = 0.787). There was strong correlation between a*, and the chemical properties of apple flesh. Apple skin color (a*) was positively correlated with total juice content (r = 0.784), soluble solid contents (r = 0.626), soluble solid contents/total acidity (r = 0.697), fructose (r = 0.444), sorbitol (r = 0.476), and sucrose concentrations (r = 0.823), respectively. However, malic acid (r = − 0.525), shikimic acid (r = − 0.443), and total organic acid concentrations (r = − 0.519) correlated negatively with a*. The a* value also showed positive correlations with phenol and anthocyanidine concentrations, but a negative correlation with DPPH, FRAP, and ABTS concentrations. A principal component analysis was performed to analyze functional compounds, sensory attributes, and physicochemical properties of apple skin and flesh; the total variance was 91.31% (F1; 58.92%, F2: 32.39%), 84.55% (F1;50.86%, F2;33.69%), 90.37% (F1;75.74%, F2; 14.63%) and 57.20% (F1;41.92%, F2;15.28%), respectively. Our results confirmed a strong correlation between the ΔE and a*, which are indicative of the skin color and the internal quality measures of the Fuji apple. Thus, the skin color of Fuji apples seems to be a reliable index of internal fruit quality. [ABSTRACT FROM AUTHOR]

Highlights • Aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP) are pre-harvest PGRs. • Effectiveness of PGRs is affected by cultivar and timing of application. • PGRs inconsistently lower IEC. • PGRs do not consistently affect the rate of fruit softening or starch hydrolysis. Abstract Aminoethoxyvinylglycine (AVG; ReTain®) and 1-methylcyclopropene (1-MCP; Harvista™) are used to delay apple fruit maturation and ripening, and thereby reduce fruit drop and manage harvest logistics. In this study, 'McIntosh' and 'Empire' fruit were treated with AVG at four weeks or two weeks, or with 1-MCP one week, prior to the anticipated first harvest date, to assess effects of these chemicals on maturation and ripening in relation to starch degradation. In a second season, 'Empire' fruit were treated with either AVG or 1-MCP four weeks and one week prior to the anticipated first harvest. Fruit from this experiment were also harvested to investigate the effects of treatment on ripening in air storage. Cultivar and timing of application influenced the efficacy of both AVG and 1-MCP in delaying the increase of internal ethylene concentration (IEC) and the starch pattern index (SPI), and the decrease of starch concentration, in the fruit. Little effect of treatment was found for the high ethylene producing 'McIntosh', with only the SPI being affected on the date of first harvest. 'Empire' fruit from trees treated with 1-MCP or AVG had lower IEC and were greener (higher absorbance difference index (I AD) values), and had lower SPIs and higher starch concentrations, but the effects were inconsistent and limited to only some harvest dates. In storage, only 1-MCP applied 10 d before harvest markedly slowed the increase in IEC and the rate of softening. AVG treatment effects on IEC were intermediate, between the one week 1-MCP treatment and the untreated controls and 4 week 1-MCP treatment, while it did not affect softening. Treatments did not affect the rate of starch concentration loss during storage. [ABSTRACT FROM AUTHOR]

Ultrasound-assisted aqueous extraction (UAE) of soluble matter (°Brix), catechin and total phenolic contents (TPC) from flesh and peel of apple tissues were studied. The commercial green (Granny Smith) and red (Red delicious) apples were used in the investigation. All extractions were done at fixed temperature, T  = 50 °C, and protocols with different specific energy inputs, S 1 ( W  = 0 kJ/kg), S 2 ( W  ≈ 6.5 kJ/kg), S 3 ( W  ≈ 10.6 kJ/kg), S 4 ( W  ≈ 21.3 kJ/kg), and S 5 ( W  ≈ 26.8 kJ/kg) during the initial period of extraction (first 300–350 s). The total aqueous extraction time was up to 3 h. The kinetics of extractions, and correlations o Brix and concentration of catechin, C , were compared for flesh and peel tissues. The increase of energy resulted in increase of o Brix and C values. For both green and red apples, the values of °Brix and C were noticeably higher for peel as compared to flesh. The distinct correlations between saturation levels of C m and TPC m at the long extraction time (≈3 h) were observed. However, the relative content of catechin in TPC (i.e., ratio C m /TPC m ) evidenced the presence of selectivity in extraction of catechin. This selectivity depends from the type of tissue (flesh or skin), apple variety (green or red) and applied treatment protocols. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the ameliorating effect of 5-aminolevulinic acid (ALA) on physiological and biochemical changes of induced NaCl-salinity stress on in vitro shoot and callus cultured of red-fleshed apple. Shoot and callus segments of the red-flesh apple of Local Iranian genotype were cultured on MS medium containing different levels of NaCl (0, 30, 60 and 90 mM) and ALA (0, 2.5, 5, 10 and 20 µM). Physiological and biochemical variations of treated explants with or without NaCl and ALA treatments were recorded. In both explants, salinity reduced chlorophyll and carotenoids contents, but the activities of antioxidant enzymes and accumulation of total phenol and anthocyanin increased with increasing salinity level (90mM). Exogenous ALA in 5 and particularly in 10 µM was effective in enhancing chlorophyll and carotenoids contents, increasing the activities of superoxide dismutase, ascorbate peroxidase and accumulating of total phenol and anthocyanin. These results indicate that ALA has a powerful salinity-ameliorating potential on in vitro cultured shoot and callus of Iranian red-fleshed apple. [ABSTRACT FROM AUTHOR]

This work explored the potential of supercritical fluid extraction (SFE) to recover phenolic compounds and antioxidants from apple pomace. SFE was carried out at 20 and 30 MPa and temperature of 45 and 55 °C in absence and presence of ethanol (5%) as co-solvent. The results were then compared to those obtained by Soxhlet extraction with ethanol and boiling water maceration. All the extraction techniques were performed on fresh, oven and freeze dried samples. The extracts were characterized for their antioxidants capacity with different assays, such as the Folin-Ciocalteu, the 2,2-diphenyl-1-picryhydrazyl radical (DPPH) and a flow injection coulometry technique. The results showed that the extracts obtained from SFE, carried out on freeze dried apple pomace at 30 MPa and 45 °C for 2 h with ethanol (5%) as co-solvent, led to a higher antioxidant activity (5.63 ± 0.10 mg TEA/g of extract) than conventional extraction technologies such as Soxhlet with ethanol (2.05 ± 0.21 mg TEA/g of extract) and boiling water maceration (1.14 ± 0.01 mg TEA/g of extract). The HPLC-DAD-MS analysis also confirmed the abundance of some phenolic compounds in SFE extract. Overall, the study presented here is one of the first investigations to assess the impact of supercritical carbon dioxide for the extraction of antioxidants from apple pomace. [ABSTRACT FROM AUTHOR]

Mid-summer leaf analyses are commonly used as the standard method worldwide to assess the nutritional status of fruit trees. However, the analyses performed at this period yield information only about current nutritional status of the trees. Several physiological processes influencing yield and quality take place early in spring. It was reported in previous studies that dormant-season shoot analyses for some nutrients may reliably be used to assess early-season nutritional status of peach trees.The present study was conducted with the shoot samples taken in dormant-season of 150 apple orchards from Isparta region during the years 2010 and 2011. Shoot samples were taken 15 days before full bloom stage and samples were subjected to nutrient analyses. Reference values for each nutrient were indicated as 25 and 75% of the resultant values. The shoot reference values for N, P, K, Ca, Mg, Fe, Mn, Zn and B were respectively observed as 0.66-0.82%, 0.12-0.15%, 0.37-0.45%, 0.84-1.24%, 0.11-0.16%, 24.55-32.24 ppm, 11.12-17.55 ppm, 12.96-21.90 ppm and 13.33-16.00 ppm. To check the reliability of shoot analyses, leaf samples were taken from the same orchards in 7 different periods until mid-vegetation season and correlations between nutrient contents of shoots and nutrient contents of leaves taken in all periods were investigated. Significant correlations were observed between N, P, K, Mg, Mn and B contents of shoots and leaves. Therefore, it was concluded that early-season shoot N, P, K, Mg, Mn and B analyses could reliably be used to assess nutritional status of apple trees. [ABSTRACT FROM AUTHOR]

In the present study, we analysed the distribution of AGPs in cells forming the epidermal, parenchymal, and sclerenchyma tissue and proposed possible roles of AGPs during apple fruit senescence. The use of immunofluorescence reactions with JIM13, JIM15, and MAC207 antibodies (CLSM) allowed for the determination of the presence and changes in the localization of AGP epitopes at different periods of apple fruit storage. The immunogold labelling technique (TEM) revealed the changeable location of AGPs in cell walls. The storage-dependent subcellular localization of AGPs spread from the periphery of the fresh fruit cell walls to the whole surface after 3 months of storage. The variable AGP arrangement in the fruit tissues was strictly related to fruit senescence; this allowed us to form a conclusion about their specific function in the loss of firm texture which is associated with fruit quality and storage limitations. [ABSTRACT FROM AUTHOR]

In apple fruit, phenolic compounds are the major sources of antioxidants, which are particularly concentrated in the skin. In the present experiment apples (cv. Red Delicious) were analyzed for their phenolic composition after the exposure to UV-B for 36 h (219 kJ m −2 ) and during storage (7, 14 and 21 d after the end of the treatment) in order to assess if UV-B treatment could improve marketability of the products as well as shelf-life. Since UV-B irradiation is also known to induce the generation of reactive oxygen species (ROS), the spin-trapping technique was applied to monitor the generation of free radicals under UV-B. The UV-B for 36 h treatment induced the generation of carbon-centered radicals in the skin, the tissue more exposed to radiation, but fruit quality parameters were not affected. Even if firmness progressively decreased and an increasing weight loss occurred during storage, differences between treated and control fruit were not observed. The different phenolic classes of apple skin reacted differently to the UV-B for 36 h irradiation, hydroxycinnamic acids increasing and flavonols decreasing. However, during storage, hydroxycinnamic acids and anthocyanins increased in UV-B-treated samples, as well as flavonols at the end of the storage period. As a consequence, the fruit skin showed a higher antioxidant activity in all the treated samples during storage, increasing the healthy properties of the fruit. This suggests that UV-B technique results in a valid strategy to induce antioxidant production in apple, increasing their nutraceutical value, thus allowing the attainment of phenolic-enriched fruit. [ABSTRACT FROM AUTHOR]

A simple and efficient ultrasound extraction method for phenolic compounds in the pulp and peel of Malus sylvestris (wild apples) was developed using multivariate methodology. Optimal extraction conditions were obtained using this methodology for peel and pulp samples (2.0 g), including solvent volume 100 mL and 79 mL, methanol concentration 100% (v/v) and 20% (v/v), extraction time 33 min and 40 min, extraction temperature 65 °C and 80 °C, respectively. The peel and pulp extracts were analysed by HPLC-PDA using a C 18 Phenomenex Kinetex column. Among the phenolic compounds present in our samples, we quantified (mg/g fresh weight) chlorogenic acid, 0.791; epicatechin, 1.18; and phloridzin, 0.106 in the pulp extract, whereas the peel extract contained chlorogenic acid, 0.568; epicatechin, 1.36; phloridzin, 0.207; catechin, 0.187; hyperoside, 0.261; and quercitrin, 0.256 mg/g. The antioxidant activity of the extracts was measured by spectrophotometric methods Peel extract proved to be a better antioxidant than pulp extract. Additionally, the stability of the analysed phenolic compounds was tested by in vitro digestion procedures. Simulated in vitro digestion showed that the concentrations of all analysed phenolic compounds (except chlorogenic acid) decreased during the intestinal phase of digestion. [ABSTRACT FROM AUTHOR]

The basic chemical composition, polyphenols and antioxidant capacity in 22 old apple cultivars grown in Poland were determined. Fruits were analyzed for contents of individual polyphenolics with the ultra-performance liquid chromatography photodiode detector-quadrupole/time-of-flight mass spectrometry (UPLC-PDA-Q/TOF-MS) method, sugar with the high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) method, and antioxidant capacity with the ABTS and FRAP radical method. A total of 29 bioactive compounds, including 26 polyphenolic compounds (7 flavan-3-ols, 2 dihydrochalcones, 4 anthocyanins, 5 phenolic acids, 8 flavonols) and 3 triterpenoids (ursolic, betulinic and oleanolic acids), were identified in fruits. All the apple cultivars were found to be rich in polyphenols [average 2139.21 mg/100 g dry matter (dm)], especially phenolic acid (average 694.12 mg/kg dm), flavan-3-ols (average 1259.80 mg/kg dm), flavonols (average 106.78 mg/kg dm) and triterpenoids (average 2552.20 µg/g dm), particularly ursolic acid (average 2234.50 µg/g dm), with high ABTS and FRAP capacity (average 72.14 and 46.77 µmol Trolox/100 g dm). The apple cultivars were also found to be a good source of pectins (average 1.19%), acids (average 0.67%) and sugars (average 9.11 g/100 g). [ABSTRACT FROM AUTHOR]

Copyright of Lucrari Stiintifice, Universitatea de Stiinte Agricole Si Medicina Veterinara Ion Ionescu de la Brad Iasi, Seria Horticultura is the property of University of Agricultural Sciences and Veterinary Medicine (Editura Ion Ionescu de la Brad) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate ethylene effects on fruit cuticular wax during cold storage, apple fruit ( Malus domestica Borkh. c.v. Starkrimson) were treated with 500 mg L −1 ethephon and 1 μL L −1 1-methylcyclopropene (1-MCP), and the composition and contents of the cuticular wax were analyzed at 20 d intervals during cold storage. The results showed that the prevailing cuticular wax components were acids, 1-alcohols and n-alkanes. Ethephon accelerated fruit senescence, positively regulated total wax quantity and its alcohol, olefin, alkane, and acid constituents during cold storage, especially 1-pentacosanol, 1-octacosanol, α-farnesane, n-octacosanoic acid, stearyl acid butyl ester, stearic acid hexyl ester and n-tetradecanal, while 1-MCP inhibited these processes. It can be concluded that ethylene altered the fruit cuticular wax contents and constituents, which may alter the subsequent postharvest qualities of the fruit and the susceptibility of the fruit to disorders during cold storage. [ABSTRACT FROM AUTHOR]

Apple orchards are being increasingly installed with high tree density, using different training systems. Although, some information about how training systems affect fruit parameters, few are known regarding the physiological performance under different tree architecture. Consequently, in this study, leaf gas exchange parameters, but also leaf biochemistry and antioxidant activity were assessed. The study was carried out in an orchard located in Carrazeda de Ansiães, northeast of Portugal, during the year of 2015, in two years old apple trees of “Royal Gala” cultivar (first harvest), grafted onto M9 rootstock, grown using the central leader and the bi-axis training systems. While minor influence was found on leaf biochemical and antioxidant parameters, namely only an increase of the starch content in the bi-axis training system, leaf gas exchange parameters showed to be strongly influenced by the training system. Higher A, E, g s and C i rates, were recorded for the bi-axis training system, however A/g s was higher in the central leader training system. These results clearly illustrate the effect of the training system on apple trees that can ultimately influence fruit production and quality. [ABSTRACT FROM AUTHOR]

The objective of the present work was to evaluate the appropriate respiratory quotient (RQ) value to achieve a safe lowest oxygen limit (LOL), during storage of ‘Fuji Suprema’ apples, in dynamic controlled atmosphere (DCA), treated with or without 1-methylcyclopropene (1-MCP). The apples were stored in DCA-RQ, a new technology for storing fruits, and were compared with the HarvestWatch™, a system based on chlorophyll fluorescence DCA (DCA-CF), and static controlled atmosphere. DCA-RQ1.5 is the most suited for the storage of ‘Fuji Suprema’ apples. In this condition fermentative products were induced, which reduced ethylene production and respiration rate; however, it did not increase physiological disorders, and the concentration of ethyl acetate was below the odour threshold. 1-MCP application maintained higher flesh firmness and reduced the anaerobic metabolism, although it decreased fruit quality due to the occurrence of cavities, therefore its application is not recommended for ‘Fuji Suprema’ apple stored in DCA conditions. [ABSTRACT FROM AUTHOR]

This study aimed to detect possible changes in the volatile organic compounds (VOCs) of Fuji apples induced by gelatin-based edible coating (EC), during 21 days of storage at room temperature. VOCs were analyzed by solid-phase micro extraction-gas chromatography-mass spectrometry. Data were analyzed by one-way ANOVA and principal component analysis. Control apples showed a greater presence of total aldehydes and acids at 7 and 14 days, respectively, while coated apples were characterized by higher proportions of alcohols (from 1.3- to 2-fold) at 7 day till the end of the storage. The higher ethanol proportions detected in coated apples (154-fold higher after 7 days) indicate a likely partial anaerobiosis, confirmed by the lower CO 2 emission (reaching -68% after 21 days). Esters responsible of the varietal aroma of Fuji were identified also in coated fruits, suggesting that gelatin did not modify the typical aroma extensively. Acetate esters, normally increasing with maturity, were less concentrated in coated apples (-78% 2-methylbutyl acetate and -73% hexyl acetate, after 1 and 7 days respectively), suggesting a likely slowdown of the ripening due to the EC. Further investigation is needed to improve this storage technology considering that aroma is an important determinant of food quality. [ABSTRACT FROM AUTHOR]

Uninformative biological variability elimination methods were studied in the near-infrared calibration model for predicting the soluble solids content of apples. Four different preprocessing methods, namely, Savitzky-Golay smoothing, multiplicative scatter correction, standard normal variate, and mean normalization, as well as their combinations were conducted on raw Fourier transform near-infrared spectra to eliminate the uninformative biological variability. Subsequently, robust calibration models were established by using partial least squares regression analysis and wavelength selection algorithms. Results indicated that the partial least squares calibration models with characteristic variables selected by CARS method coupled with preprocessing of Savitzky-Golay smoothing and multiplicative scatter correction had a considerable potential for predicting apple soluble solids content regardless of the biological variability. [ABSTRACT FROM AUTHOR]

Fringe projection technique was used to evaluate the changes in topography of apple samples which were evaluated over time. Since for the food industry the color and texture of fruit are also important, thus, measurements of applés variations in color and shape were made to evaluate the degradation of the fruit over time. Measurements of an apple topography, color, moisture and firmness were done and compared every three days during a period of two months in which the samples were stored under refrigerated conditions. Experimental results of color changes (RGB and L*a*b*) and size changes and their relation to the apple quality are presented. [ABSTRACT FROM AUTHOR]

The effects of pulsed electric fields (PEF, 0.008–1.3 kJ kg −1 ) on the total phenolic, flavonoid and flavan-3-ol contents, as well as on the antioxidant capacity of apples stored at different temperatures (4 and 22 °C) along 48 h were studied. Contents of phenolic compounds observed in PEF-treated apples were higher than those of untreated. The mildest PEF treatment (0.008 kJ kg −1 ) produced the maximum increases of total phenolics (13%) and flavan-3-ol (92%) contents in apples stored during 24 h at 22 °C, while it was observed at 4 °C for flavonoids (58%). On the other hand, the antioxidant capacity of apples was enhanced by 43% respect to that of untreated with the mildest PEF treatment after 12 h at 4 °C and by 15% after 24 h at 22 °C. Therefore, PEF technology could be used to increase the antioxidant potential of apples by controlling treatment and storage conditions. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate the efficacy of ascorbic acid and nisin on quality of fresh-cut Fuji apples. Apple pieces were coated with sodium alginate (1% w/v), ascorbic acid (0-2% w/v) and nisin (0-75 ppm). Then, microbial growth, color, firmness, weight loss, and sensory qualities were measured during storage at 4°C. Coated samples had significantly lower aerobic microbial counts and fewer changes in color, texture and weight loss when compared to those of control samples. In sensory evaluation, the coated samples obtained the significantly higher acceptability scores than control samples at the same days of storage. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the influence of 1-methylcyclopropene (1-MCP) treatment and ultra-low oxygen (ULO)-controlled atmosphere conditions: 2.0% CO2 and 1.0% O2 (ULO1), and 2.5% CO2 and 1.5% O2 (ULO2) on the changes in chemical composition in the apples of one of the commercially available and the most consumerpreferred cultivar 'Auksis' during long-term storage. This study was conducted from 2012 to 2014 at the Institute of Horticulture, Latvia University of Agriculture in Dobele. The results of the current research evidence that in many cases the chemical composition of 'Auksis' apples depends on the weather conditions (growing season) and storage technology. In terms of storage technology, a better preservation of soluble solids was achieved when ULO conditions and 1-MCP treatment were applied. Moreover, findings reveal that polyphenols present in 'Auksis' apples remained unchanged after six months' storage under ULO conditions. While due to further ripening process in control and 1-MCP treated apples the content of polyphenols increased. The harvest time is the key factor influencing the total pectin content, while, during six months' storage the main factors affecting the content of pectin were the growing season and storage technology. Analysis of variance showed that the content of vitamin C in 'Auksis' apples depended mainly on the weather conditions, whereas post-harvest vitamin C losses are affected by harvesting time and storage technology. [ABSTRACT FROM AUTHOR]

Residues of dinotefuran and its metabolites, 1-methyl-3-(tetrahydro-3-furylmethyl)urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl)guanidine (DN), in apple were investigated using a 'QuEChERS' (quick, easy, cheap, effective, rugged, safe) pretreatment and liquid chromatography-tandem mass spectrometry. Limits of detection (LODs) and quantification (LOQs) of dinotefuran, UF, and DN in apples were 0.011-0.960 and 0.037-3.200 μg/kg, respectively. The average recoveries of dinotefuran, UF, and DN in apple ranged from 70.0 to 83.6% with relative standard deviations less than 13%. A formulation of 20% water-dispersible dinotefuran granules was sprayed at 1-1.5-fold the recommended dose 3-4 times on apple trees. Total terminal residues of dinotefuran in apple were less than 2 mg/kg, which is the maximum residue limit (MRL) set by Japan. When following the recommended application guidelines, dinotefuran is unlikely to present significant health concerns to the Chinese population because the risk quotient (RQ) is less than 100%. This work could provide guidance for the safe use of dinotefuran and serve as a reference for the establishment of a maximum residue limit of dinotefuran in apple in China. [ABSTRACT FROM AUTHOR]

Cytokinin signaling is a key regulatory pathway of many aspects in plant development and environmental stresses. Herein, we initiated the identification and functional characterization of the five CHASE-containing histidine kinases (CHK) in the economically important Malus domestica species. These cytokinin receptors named MdCHK2, MdCHK3a/MdCHK3b, and MdCHK4a/MdCHK4b by homology with Arabidopsis AHK clearly displayed three distinct profiles. The three groups exhibited architectural variations, especially in the N-terminal part including the cytokinin sensing domain. Using a yeast complementation assay, we showed that MdCHK2 perceives a broad spectrum of cytokinins with a substantial sensitivity whereas both MdCHK4 homologs exhibit a narrow spectrum. Both MdCHK3 homologs perceived some cytokinins but surprisingly they exhibited a basal constitutive activity. Interaction studies revealed that MdCHK2, MdCHK4a, and MdCHK4b homodimerized whereas MdCHK3a and MdCHK3b did not. Finally, qPCR analysis and bioinformatics approach pointed out contrasted expression patterns among the three MdCHK groups as well as distinct sets of co-expressed genes. Our study characterized for the first time the five cytokinin receptors in apple tree and provided a framework for their further functional studies. [ABSTRACT FROM AUTHOR]

The method for separating and purifying chlorogenic acid (CA), epicatechin (EC), hyperoside (HY) and phlorizin (PH) simutaneously from young Qinguan apples by successive use of X-5 and polyamide resins has been developed in this study. The order of adsorption capacities of X-5 for the four phenolics was PH > HY > EC > CA, and the adsorption equilibriums of the four phenolics onto X-5 resin conformed to Langmuir isotherms preferentially. The adsorption kinetics of EC and CA onto X-5 conformed to the pseudo-first-order model, while that of HY and PH accorded with the pseudo-second-order model. Interestingly, the values of equilibrium adsorption capacities ( Q e ) calculated in the preferential kinetics models were closer to that of theoretical maximum adsorption capacities ( Q 0 ) calculated by Langmuir isotherms. Through dynamic adsorption and desorption using X-5 and polyamide resins with ethanol solution as strippant, CA, EC, HY and PH were obtained with purities of 96.21%, 95.34%, 95.36% and 97.36%, respectively. [ABSTRACT FROM AUTHOR]

Apple pomace is a promising source of carbohydrates, proteins, amino acids, fatty acids, phenolic compounds, vitamins, and other compounds with a vast range of food applications. This review focuses on the valorization of apple pomace towards the recovery of the main compounds, namely pectin and polyphenols. Applications, advantages, and drawbacks of conventional extraction (acidic medium under high temperatures) compared with novel extraction technologies are presented. The comparison is based on an extensive literature review of research on extraction of valuable compounds from plant matrixes, particularly apple pomace. Novel extraction techniques involving enzymes, electric field, ultrasound, microwave heating, pressurized liquid, and super/subcritical fluid are also discussed. These techniques offer several advantages, including shorter extraction time, increased yield, reduction-or suppression-of solvents, and minimization of the environmental impact. This paper may help researchers and food industry professionals on the scaling-up and optimization of eco-friendly extractions of pectin and phenolic compounds. [ABSTRACT FROM AUTHOR]

The present study aimed at characterising the flavour composition of apple cultivars grown in the Northeast Italy through different cultivation methods, by combining Head Space-Solid Phase Micro Extraction/Gas Chromatography Mass Spectrometry (HS-SPME/GC-MS) analysis of volatile fraction with chemometric tools for class modeling. In order to represent the overall production in the target area, the investigation included 42 apples varieties consisting of ancient, non-native and new hybrid cultivars grown in Friuli Venezia Giulia and Alto Adige-South Tyrol, respectively. Moreover, apple samples from both conventional and organic agricultural practices were considered. Overall 118 volatile compounds were identified in the samples and Partial Least Squares-Discriminant Analysis (PLS-DA) was used to classify apples based on their different geographical origin or growing conditions. Models highlighted good classification results both in calibration (over 91%) and cross-validation (over 87%), enabling to obtain a good separation between apple categories with high prediction accuracy (over 90%). In addition, the Variable Importance in Projection (VIP) scores of the PLS-DA models were calculated, allowing to identify a reduced number of volatiles (e.g., ethanol, ethyl acetate, isobutyl acetate, propyl propanoate, 1-hexanol, d -limonene, (Z)-2-hexen-1-ol acetate and others) which are relevant for the discrimination of different apple groups. The proposed approach may represent a powerful tool for fruit traceability. [ABSTRACT FROM AUTHOR]

Currently, a wide range of differently processed apple juices is available on the market. In this study the quality of commercial apple juices from four product categories was evaluated on the basis of their chemical profiles (total soluble solids, pH, titratable acidity, ratio of soluble solids to acidity, sugars, total phenolics content, and antioxidant activity) using multivariate methods. Principal component analysis has revealed, that the chemical parameters, such as titratable acidity, ratio of soluble solids to acidity, and pH (PC1) and sugars and total soluble solids (PC2) appears to be the parameters most differentiating the samples. Five classes of juices with similar chemical composition were detected using hierarchical cluster analysis. The exploratory analysis of the overall chemical profiles revealed that the juices clear from concentrate, cloudy not from concentrate and freshly squeezed, were easily distinguishable due to their unique properties. In contrast, cloudy juices from concentrate showed properties similar to juices of other classes. The classification based onk-nearest neighbors method had high sensitivity and low classification error for clear juices from concentrate and cloudy not from concentrate. The classification failed for the cloudy juices from concentrate. [ABSTRACT FROM AUTHOR]

The polyphenol profile of apple ( Malus × domestica) is dominated by the dihydrochalcone glycoside phloridzin, but its physiological role is yet to be elucidated. Biosynthesis of phloridzin occurs as a side branch of the main phenylpropanoid pathway, with the final step mediated by the phloretin-specific glycosyltransferase UGT88F1. Unexpectedly, given that UGTs are sometimes viewed as 'decorating enzymes', UGT88F1 knockdown lines were severely dwarfed, with greatly reduced internode lengths, narrow lanceolate leaves, and changes in leaf and fruit cellular morphology. These changes suggested that auxin transport had been altered in the knockdown lines, which was confirmed in assays showing that auxin flux from the shoot apex was increased in the transgenic lines. Metabolite analysis revealed no accumulation of the phloretin aglycone, as well as decreases in many non-target phenylpropanoid compounds. This decreased accumulation of metabolites appeared to be mediated by the repression of the phenylpropanoid pathway via a reduction in key transcript levels (e.g. phenylalanine ammonia lyase, PAL) and enzyme activities ( PAL and chalcone synthase). Application of exogenous phloridzin to the UGT88F1 knockdown lines in tissue culture enhanced axial leaf growth and partially restored some aspects of 'normal' apple leaf growth. Together, our results strongly implicate dihydrochalcones as critical compounds in modulating phenylpropanoid pathway flux and establishing auxin patterning early in apple development. [ABSTRACT FROM AUTHOR]

The present study aimed to throw light on the dissipation and residual levels of diazinon in apple fruits under open field conditions. The pesticide residues found in cultivated fruits from Dakahlia Governorate, Egypt during 2016, using the QuEChERS method prior to analysis by HPLC-DAD. The method validation for extraction and quantitative analysis of diazinon residues in apple fruits using HPLC-DAD, at fortification levels of 0.01, 0.1 and 1.0 mg/kg in apple fruits was used . The obtained results indicated that mean recoveries were ranged from 84.29% to 94.88% with relative standard deviations (RSDs) < 2.30% for HPLC-DAD. In this respect, good linearity was achieved with a determination coefficient (R2) of 0.999 for the 0.01-5 mg/ L concentration range for HPLC-DAD. The limit of quantification (LOQ) of the method was 0.01 mg/ kg. The results suggest that the diazinon dissipation curves followed the first order kinetics and its half-life was 2.03 days in apple. The residues in apple were below the European Union residue limit (MRL) (0.01 mg/kg) after 10 days of the application. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of young apple polyphenols (YAP) on the quality of grass cap surimi (GCS) during storage at 4 °C. The addition of YAP into GCS was found to be effective in delaying lipid oxidation, soluble myofibrillar protein (SMP) degradation and changes of L ∗ , a ∗ and b ∗ values of GCS. Chlorogenic acid was screened to be the primary component showing preservative effects. YAP was shown to protect the functional properties of SMP during cold storage, retarding both the decrease in emulsifying activity and stability, and the increase in surface hydrophobicity of SMP. Additionally, the loss of gel strength and texture of GCS with YAP were significantly ( P < 0.05) lower than that of GCS without YAP during cold storage. Therefore, YAP may be developed as a natural antioxidant to maintain the quality and to extend the shelf life of freshwater fish surimi. [ABSTRACT FROM AUTHOR]

Apples are rich source of phenolic compounds exhibiting a strong antioxidant activity. Although type 2 red-fleshed apples highly accumulate health-promoting anthocyanins, accumulation profiles of other phenolic compounds had not been investigated. The objective of this study was to characterize the accumulation profiles of eight phenolic compounds in five type 2 red-fleshed apple varieties with different color intensities in their cortex. Quantification of the phenolic compounds revealed that not only cyanidin-3-galactoside but also chlorogenic acid and epicatechin are the dominant phenolic compounds in type 2 red-fleshed cultivars except for a red flesh lineage showing a white cortex. Bioinformatic analysis further revealed that cultivars with a deep red flesh accumulated caffeic acid and procyanidin B2, but cultivars with a pale-red flesh accumulated catechin and epicatechin. In pale-red flesh cultivars, the correlation between the expression of MdMYB110a gene responsible for the type 2 red flesh phenotype and the two phenylpropanoid pathway genes MdC3H and MdLAR were also observed during the fruit development. Taken together, these results indicate that there is a significant variation in the contents of phenolic compounds between type 2 red-fleshed cultivars and suggest the possibility that biosynthesis of some phenolic compounds other than anthocyanins is also regulated through MdMYB110a. In addition, for selecting type 2 red-fleshed cultivars efficiently, we also reported the development of a dCAPS marker which can detect functional MdMYB110a allele accurately. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the interaction between four storage conditions and three maturity stages of ‘Galaxy’ apple at harvest (unripe, ripe and overripe, based on starch pattern index) on its metabolism and volatile concentrations after harvest and 9 months of storage plus 7 days of shelf life at 20 °C. Storage conditions were: [1] Controlled atmosphere (CA) (1.2 kPa O 2 + 2.0 kPa CO 2 ); [2] CA + 1-methylcyclopropene (1-MCP) (0.625 μL L −1 ); [3] Dynamic controlled atmosphere based on respiratory quotient 1.3 (DCA-RQ 1.3) + 1.2 kPa CO 2 and [4] DCA-RQ 1.5 + 1.2 kPa CO 2 . Fruit stored under DCA-RQ 1.5 had higher concentrations of total esters and characteristic aroma volatile compounds in extracted juice. Highest ester concentrations occurred in overripe fruit stored at DCA-RQ 1.3 and DCA-RQ 1.5. 1-MCP application suppressed volatile compound production, not allowing its increment with advanced of the maturity stage and reduced the main esters after storage. DCA-RQ suppressed internal ethylene concentration, ethylene production, and respiration rate, but the low metabolism in fruit stored under DCA-RQ 1.5 did not result in lower volatile compound production. [ABSTRACT FROM AUTHOR]

Several wild apple accessions ( Malus sieversii ) from Kazakhstan and two ( Malus × soulardii , Malus sylvestris ) from other parts of the world are highly resistant to blue mold decay caused by Penicillium expansum . Previous studies on the wound responses of these apples to infection by this fungus suggest multiple mechanisms of resistance including innate immunity. In this study, the phenolic composition of extracts from mature wild apples resistant (GMAL 4317.f, PI 589391, and PI 369855) and susceptible (GMAL 3623.i) to blue mold, as well as the susceptible cultivar ‘Golden Delicious’ ( Malus × domestica ) were investigated using ultra-high-performance liquid chromatography coupled to diode array detection and high resolution multiple stage mass spectrometry (UHPLC/DAD/HRMS). The metabolomic and quantitative results of this study support the hypothesis of the possible relationship between the phenolic content of wild apples and their resistance to P. expansum . Apple accessions resistant to P. expansum had higher concentrations of procyanidins, dihydrochalocone, flavonols, and hydroxycinnamic acids. Findings from this study may lead to development of the physiological markers of resistance that could be used by breeders in evaluating crosses for resistance to blue mold and may be helpful to further define apple defense mechanism(s) against P. expansum . [ABSTRACT FROM AUTHOR]

The influence of the addition of calcium lactate (CaLac) and ascorbic acid (AA) to sucrose (Sue) osmotic solutions on osmotic dehydration kinetics and endogenous metabolic heat production of apple tissue was evaluated. Our research goal was to characterize mass transfer and endogenous metabolic phenomena of the tissue to obtain minimally processed apples. The presence of CaLac and AA in solution affected the mass transfer of water and solutes, which was attributed to the changes in the cellular structure and thus to spaces available for solute transport. The metabolic heat production in samples treated in sucrose solutions was slightly lower than in untreated samples, and it was further reduced with CaLac addition. However, samples impregnated with AA exhibited a higher heat production due to a metabolic response of the tissue to AA treatment. When combined with CaLac, the heat production decreased to a level lower than untreated samples, except for those that were treated for 120 and 240min (higher impregnation), achieving the highest heat production values. These results confirm previous findings, suggesting that AA solution can promote a stress response on specific fresh-cut vegetable tissues, as well as an increase of their endogenous metabolic activity, as confirmed by the higher O2 consumption observed with the head space gas determination. [ABSTRACT FROM AUTHOR]

Flavonoids are major polyphenol compounds in plant secondary metabolism. Wild red-fleshed apples ( Malus sieversii f . niedzwetzkyana) are an excellent resource because of their much high flavonoid content than cultivated apples. In this work, R6R6, R6R1 and R1R1 genotypes were identified in an F1 segregating population of M. sieversii f . niedzwetzkyana. Significant differences in flavonoid composition and content were detected among the three genotypes by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry analysis. Furthermore, two putative flavonoid-related genes encoding R2R3- MYB transcription factors, designated MYB12 and MYB22, were cloned and characterized. The expression patterns of MYB12 and MYB22 directly correlated with those of leucoanthocyanidin reductase and flavonol synthase, respectively. Their roles in flavonoid biosynthesis were identified by overexpression in apple callus and ectopic expression in Arabidopsis. MYB12 expression in the Arabidopsis TT2 mutant complemented its proanthocyanidin-deficient phenotype. Likewise, MYB22 expression in an Arabidopsis triple mutant complemented its flavonol-deficient phenotype. MYB12 could interact with bHLH3 and bHLH33 and played an essential role in proanthocyanidin synthesis. MYB22 was found to activate flavonol pathways by combining directly with the flavonol synthase promoter. Our findings provide a valuable perspective on flavonoid synthesis and provide a basis for breeding elite functional apples with a high flavonoid content. [ABSTRACT FROM AUTHOR]

Dry and fresh apples have been studied monitoring their polyphenolic profiles through 1 H NMR, antioxidant capacity and total polyphenol content. Six ancient and underutilized apple varieties (Mantovana, Mora, Nesta, Cipolla, Ruggina, Sassola) and a commercial one (Golden Delicious) were dried with an air-drying system at 45 °C for 19 h. Although some of their polyphenol constituents were lost during drying, the antioxidant capacity of some apple varieties remained higher compared to Golden Delicious. This result is very important for ancient and underutilized varieties that are not consumed on large scale as fresh product since they have low attractiveness, due to their ugly appearance. Combining quantitative NMR spectroscopy with principal component analysis we have identified and quantified several polyphenols (such as catechin, epicathechin, and chlorogenic acid) that are important to establish the nutraceutical value of the different investigated apple varieties. [ABSTRACT FROM AUTHOR]

The effect of pulsed light (0, 8.8 and 17.5 J cm-2) on selected properties of cut apple (thermal power, oxygen consumption, volatile compounds, colour and firmness) was investigated during storage at 30 °C for up to 6 days. Samples exposed to pulsed light showed lower heat production due to a decrease in tissue respiration. Pulsed light treated samples also showed different evolution of volatile compounds (ethanol, acetaldehyde and ethyl acetate), browning and tissue softening. Modification of tissue metabolisms by pulsed light could be exploited in the processing of fresh-cut fruit and vegetables leading to advantages well beyond its germicidal activity. [ABSTRACT FROM AUTHOR]

In this study, magnetite-molecularly imprinted polymer has been used for the first time as selective adsorbent before the fluorimetric determination of carbendazim. Adsorption capacity of the magnetite-molecularly imprinted polymer was found to be 2.31 ± 0.63 mg g − 1 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) of the method were found to be 2.3 and 7.8 μg L − 1 , respectively. Calibration graph was linear in the range of 10–1000 μg L − 1 . Rapidity is an important advantage of the method where re-binding and recovery processes of carbendazim can be completed within an hour. The same imprinted polymer can be used for the determination of carbendazim without any capacity loss repeatedly for at least ten times. Proposed method has been successfully applied to determine carbendazim residues in apple and orange, where the recoveries of the spiked samples were found to be in the range of 95.7–103%. Characterization of the adsorbent and the effects of some potential interferences were also evaluated. With the reasonably high capacity and reusability of the adsorbent, dynamic calibration range, rapidity, simplicity, cost-effectiveness and with suitable LOD and LOQ, the proposed method is an ideal method for the determination of carbendazim. [ABSTRACT FROM AUTHOR]

The samples of spatial soils and different organs of Prunus persica L. Batech and Malus domestica were analyzed by methods such as inductively coupled plasma optical emission spectroscopy (ICP-OES), Hierarchical Cluster Analysis (HCA), One-way ANOVA, and calculation of biological accumulation factors (BAFs) with the aim of investigating whether these methods may help in the evaluation of trace metals in plants, as well as in the estimation of plant bioaccumulation potentials. ICP-OES provided accurate data on present concentrations of Cu, Zn, Pb, As, Cd, and Ni which showed that most concentrations were in normal ranges, except in some cases for Cu, Zn, and As. HCA illustrated nicely various specifics in the distribution of metals in both investigated systems plant-soil. One-way ANOVA pointed successfully on the existing statistical differences between metal concentrations. Calculated BAFs showed that both plants had very low accumulation rates for all elements; they acted as metal excluders. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effect of grinding at different vacuum levels (2.67, 6.67, 13.33, 19.99, and 101.33 kPa) on key quality factors of apple. In the control apple, ground at atmospheric pressure of 101.33 kPa, the antioxidant activities rapidly decreased within the first 30 min, then plateaued thereafter, while enzymatic browning increased. When apples were ground and held under vacuum, changes in color and antioxidant activity were much less, and the least change was measured in samples prepared at the lowest pressure. Model fitting of the data showed that antioxidant activity decreased as a function of the logarithm of the absolute pressure. The results from analysis for key phenolic compounds including chlorogenic acid, procyanidin B2, and epicatechin indicated that these compounds were least changed at vacuum grinding at 2.67 kPa, compared to atmospheric grinding. [ABSTRACT FROM AUTHOR]

Apple ( Malus domestica Borkh.) leaves are good source of polyphenols. Considering the increasing demand of such phytochemicals, particularly in healthcare sector, the objective of this study was to evaluate the bioactivity of apple leaves phenolics. Different solvent mediated extracts obtained from the apple leaves were assessed for presence of phenolic compounds. Among different extracts, the highest phenolic content of 30.38 ± 0.50 mg/g were recorded in 70% aqueous ethanol (ALE-7) with subsequent high antioxidant value (IC 50 49.16 μg/mL) by ABTS assay. RP-HPLC-DAD phenolic profiling of leaves extract, irrespective of solvent used for extraction, revealed presence of five major compounds with maximum yield of phloridzin (24.43 ± 0.05 mg/g), followed by quercitrin (2.06 ± 0.05 mg/g), quercetin-3- O -glucoside (1.55 ± 0.001 mg/g), epicatechin (0.37 ± 0.07 mg/g) and phloretin (0.15 ± 0.05 mg/g). ALE-7 extract was further fractionated with hexane (ALH) and ethyl acetate (ALEA), which were evaluated for their in vitro biological activities. ALEA extract exhibited higher nitric oxide (NO) scavenging activity (63.3%) at 200 μg/mL. This fraction also showed maximum lymphocyte proliferation (34%) at 25 μg/mL after 48 h. The antimicrobial testing of isolated fractions revealed that ALH fraction (MIC value ranging from 1.18–2.37 μg/mL) could be a good candidate, especially for controlling food borne pathogen. Furthermore, the in vitro cytotoxicity assessment of different apple leaves fractions was also performed against human cancer cell lines (KB, SiHa and A-549), but none of the fraction was found cytotoxic against selected cell line. In conclusion, the presence of biologically active phenolics in apple leaves makes it a feasible renewable bioresource for extraction of such phytochemicals for the development of nutraceuticals particularly against inflammation and microbial infections. [ABSTRACT FROM AUTHOR]

Kanzi is a recently developed apple cultivar that has an extremely low ethylene production, and maintains its crispiness during ripening. To identify key determinants of the slow softening behaviour of Kanzi apples, a comparative analysis of pectin biochemistry and tissue fracture pattern during different ripening stages of Kanzi apples was performed against Golden Delicious, a rapid softening cultivar. While substantial pectin depolymerisation and solubilisation was observed during softening in Golden Delicious apples, no depolymerisation or increased solubilisation was observed in Kanzi apples. Moreover, tissue failure during ripening was mainly by cell breakage in Kanzi apples and, in contrast, by cell separation in Golden Delicious apples. Kanzi apples had lower activity of beta-galactosidase, with no decline in the extent of branching of the pectin chain. A sudden decrease in firmness observed during senescence in Kanzi apples was not due to middle lamella dissolution, as tissue failure still occurred by cell breakage. [ABSTRACT FROM AUTHOR]

The principal aim of this study was to investigate the effects of superficial scald control methods having different effect mechanisms on scald formation and α-farnesene content in Granny Smith apples. It was also aimed to evaluate possible alternatives to diphenylamine (DPA) that has been banned in many countries. By this aim, lovastatin and DPA with combined treatments such as heat + oil and ethanol vapour + heat were used. The experiment was conducted with ‘Granny Smith’ cultivar, very sensitive to superficial scald, grown in Isparta (Turkey). After treatments, apples were stored in normal atmosphere (air) at 0 °C and 90 ± 5% RH for 6 months. In the apples taken from storage in monthly intervals, α-farnesene content and scald intensity were determined. It was found that all treatments decreased both α-farnesene content and superficial scald formation compared to control group. However, poor correlation between α-farnesene content and scald formation during the storage was found. α-Farnesene contents of lovastatin treated apples were lower than those of DPA during the storage. The methods having different mechanism for control of apple superficial scald should be investigated elaborately. [ABSTRACT FROM AUTHOR]

The paper presents the results of the research on the impact of enzymatic liquefaction, freezing and thawing on the efficiency of juice pressure extraction from apple pulp and quality of the obtained juices. The research was conducted using three types of pretreatment prior the pressing: crushing and enzymatic liquefaction in temperature of 25 °C, crushing and enzymatic liquefaction in temperature of 45 °C and crushing followed by freezing and thawing of the pulp. The study included three varieties of apples. The juice was obtained using a laboratory basket press. It was determined that the pretreatment of the pulp as well as the varietal characteristics of the fruits have a significant impact on the efficiency of the pressure extraction process. The enzymatic treatment of the pulp, irrespective of the temperature at which it was conducted, significantly increased the efficiency of the process. No effect of the temperature (25 or 45 °C) of enzymatic treatment on the efficiency of the pressure extraction process was found. Pretreatment of the pulp based on freezing and thawing contributes to the increase of efficiency of pressing in the case of two apple cultivars, that is, Idared and Red Delicious. It was showed that total phenolic content, antioxidant activity, the soluble solids content and juice acidity (pH) depend on the pretreatment of the pulp and the varietal characteristics of apples. Following the application of pretreatment of the pulp, an increase was observed in the content of polyphenols and in the antioxidant activity of the juices obtained. [ABSTRACT FROM AUTHOR]

The effect of instant controlled pressure drop-assisted hot air drying ( AD- DIC) on browning-related components in apple slices was studied. Results showed the AD temperature had no significant effect on colour index of final apple slices. The aspartic acid, glutamic acid, lysine, histidine, arginine, sucrose and dehydroascorbic acid ( DHAA) in apple slices increased firstly during the AD process and then decreased during DIC process. The fructose, glucose, reduced ascorbic acid and major phenolic compounds reduced with the abrupt increase of 5-hydroxymethylfurfural (5- HMF) during AD- DIC. There were significant correlations ( P < 0.05) among moisture content ( w.b.), water activity ( a w), water state, reduced ascorbic acid, DHAA, chlorogenic acid, procyanidin B1, (+)-catechin, (−)-epicatechin and phlorizin during AD- DIC. The colour difference showed that the major browning reaction of apple slices during the predrying process was enzymatic browning, while nonenzymatic browning played a crucial role on green-red value ( CIE a* value) during DIC. [ABSTRACT FROM AUTHOR]

An intermittent microwave convective drying method combined with a real-time computer vision technique was employed to detect the effect of drying parameters on color properties of apple slices. The experiments were performed at air temperature of 40 to 80℃, air velocities of 1–2 m/s, microwave powers of 200–600 W, and pulse ratios (PRs) of 2–6. Drying rate and drying time varied from 0.014 to 0.000001 min−1 and 27 to 244 min, respectively. The normalized lightness values had ascending and descending parabolic trends with decrease in product moisture content. With descending dimensionless moisture content, redness, yellowness, color change, hue angle, and chroma were enlarged. The normalized redness values changed from −4 to 3. Models relating drying parameters with drying time, drying rate, and lightness were obtained and found to be significant (P < 0.01). Results indicated that microwave power and PRs had more influence on lightness and color change than other parameters. [ABSTRACT FROM AUTHOR]

An experimental impregnation system based on the inductive methodology was established and used to investigate the effect of electric fields on the calcium content of fresh-cut apples. An induced electric field was generated when the Ca 2+ solution acted as the secondary coil of the transformer system under the action of an alternating magnetic flux. The calcium content in fresh-cut apples was found to increase with the enhancement of the excitation voltage. Additionally, samples immersed in a CaCl 2 solution exhibited a calcium content higher than those suspended in the calcium lactate solution. The latter presented a higher load power factor, the impedance in the CaCl 2 solution being lower. Frequency at 20–60 kHz had a negative impact on the calcium content of fresh-cut apples due to the weakening of the electropermeabilization effect. This method utilized the conversion of electric energy into magnetic energy, and the electric field induced needing no insertion of powered electrodes into the solution under treatment. This might provide a reference for rapid impregnation of agricultural materials. [ABSTRACT FROM AUTHOR]

Organic acids play a critical role in flavor and overall organoleptic quality of fruit. Malate has been considered to be the major organic acid determining apple fruit acidity. Here, we found that 1-methylcyclopropene (1-MCP) delayed the loss of malate and citrate during storage. 1-MCP-treated fruit showed higher level of phosphoenol pyruvate carboxylase (PEPC) and cytosolic NAD-dependent malate dehydrogenase (cyNAD-MDH) activities, but lower or similar phosphoenolpyruvate carboxylase kinase (PEPCK) and cytosolic NAD-dependent malate dehydrogenase (cyNADP-ME) activities compared to the control. Moreover, the expression of acid transport genes, including MdVHA-A , MdVHP and Ma1 , was up-regulated in 1-MCP-treated fruit, resulting in retention of malate in the vacuole, and eventual higher malate content. Hence, 1-MCP maintained fruit acidity by regulating the balance between malate biosynthesis and degradation. These findings provide molecular evidence for understanding the mode of action of 1-MCP regulating organic acid metabolism in apple fruit during storage. [ABSTRACT FROM AUTHOR]

The influence of cylindrical sizes of samples and velocity of impact on its course and strength parameters for the “Braeburn” variety apples was studied. Three sample lengths of 17, 19, and 21 mm, three diameters of 10, 15, and 20 mm and four impact velocities of 0.25, 0.5, 0.75, and 1 ms–1were applied. Failure stress and strain, impact energy, absorbed energy as well as tissue stiffness and toughness were determined as dependent variables. The influence of the sample diameter on maximum force response, impact energy, absorbed energy, and tissue stiffness was studied. The other independent variables: Sample length and impact velocity did not show significant influence on the strength parameters of the apple tissue. The shock wave speed in the apple tissue was independent of both sample sizes and impact velocity. Its mean value amounted to 292 ms–1. Under the experimental conditions the mean value of the absorbed energy contribution to the impact energy amounted to 9.9%. The experiment confirmed importance of a critical stress criterion as regards cylindrical samples of apples under impact conditions. [ABSTRACT FROM PUBLISHER]

A novel syringe needle-based sampling approach coupled with liquid-phase extraction (NBS−LPE) was developed and applied to the extraction of l -ascorbic acid (AsA) in apple. In NBS−LPE, only a small amount of apple flesh (ca. 10 mg) was sampled directly using a syringe needle and placed in a glass insert for liquid extraction of AsA by 80 μL oxalic acid–acetic acid. The extract was then directly analyzed by liquid chromatography. This new procedure is simple, convenient, almost organic solvent free, and causes far less damage to the fruit. To demonstrate the applicability of NBS−LPE, AsA levels at different sampling points in a single apple were determined to reveal the spatial distribution of the analyte in a three-dimensional model. The results also showed that this method had good sensitivity (limit of detection of 0.0097 mg/100 g; limit of quantification of 0.0323 mg/100 g), acceptable reproducibility (relative standard deviation of 5.01% ( n = 6)), a wide linear range of between 0.05 and 50 mg/100 g, and good linearity ( r 2 = 0.9921). This interesting extraction technique and modeling approach can be used to measure and monitor a wide range of compounds in various parts of different soft-matrix fruits and vegetables, including single specimens. [ABSTRACT FROM AUTHOR]