The paper presents kinetics of osmotic dehydration of plums in relation to the treatment time and concentration of sucrose solution. The main aim of the study was polyoptimisation of the preservation ...process, namely selection of optimal parameters of osmotic dehydration processes including changes in selected quality indicators. Defining of optimal conditions of the entire course of preservation may influence limitation of consumption of preserving substances (osmotic substances) and reduction of the energy demand. Based on the research which was carried out, it was found that parameters of osmotic dehydration had a significant impact on mass transfer coefficients and physico-chemical indicators of fruit - along with the increase of concentration of osmotic solution and extension of the time of the process, the increase of the investigated sizes was observed. In the second part of the paper, optimization of the fruit preservation process was performed. The idea of the objective function consisted in minimization of the difference between the expected values of criteria and the values obtained from the experimental results. For the defined scalar optimization criterion an explicit relation between quality and cost of the product was showed.
The objective of this work was to study the effect of an osmotic solution (containing water, glycerol and inulin) on water loss (WL), weight reduction (WR), inulin gain (INU), glycerol gain (GLY), ...water activity, colour parameters and mechanical properties of dehydrated plum. Only the second-degree polynomial model obtained using response surface methodology for WL, WR, INU and GLY proved appropriate for predicting experimental data. The optimum proportions were 522 g water, 219 g glycerol and 100 g inulin, which produced WL, WR, INU and GLY values of approximately 30% and 29%, and 119 mg/g and 373 mg/g, respectively.
•Extension the shelf-life of plums.•Osmotic dehydration as pre-treatment before conventional drying to improve quality.•Application of the prebiotic inulin as a component of the osmotic solution.•Obtention of new functional foods through an osmotic dehydration process.•Study of mass transfer and quality parameters during osmotic dehydration process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Rootstocks affect strongly fruit quality based on fruit phytochemical composition.•Plum based hybrids increase sugars and antioxidants content in nectarine fruits.•‘Pollizo’ plums could increase the ...sweetness of the low-acid ‘Big Top’ nectarine.•‘Big Top’ fruit quality can be enhanced choosing the best graft-combination.
Thirteen Prunus rootstocks with different genetic background five peach-almond hybrids: Adafuel, Adarcias, GF 677, PADAC 9902-01 and Rootpac 70; one P. persica x P. davidiana hybrid: Cadaman; three hexaploid P. insititia plums: Adesoto 101, PM 105 AD, and PM 150 AD; three plum x peach-almond hybrids (PADAC 04-01, PADAC 04-03 and PADAC 99-05), and a plum-almond hybrid (Rootpac R) were budded with the ‘Big Top’ nectarine and evaluated in typical Mediterranean growing conditions. Biochemical fruit compounds, such as sugars and organic acids profile, and antioxidant compounds were assessed to enhance fruit quality and beneficial effects of ‘Big Top’. For three consecutive years (2014–2016), sugars and organic acids were analysed by high-performance liquid chromatography and phenolic compounds by spectrophotometry. Statistical analyses showed that rootstocks affected strongly fruit phytochemical composition, although it was also influenced by year. Compared with peach-based rootstocks, the hexaploid ‘Pollizo’ plums Adesoto 101 and PM 150 AD can increase the sweetness of the low-acid ‘Big Top’ nectarine, inducing higher contents of sugars and organic acids. Similarly, beneficial antioxidant effects can be enhanced on diploid plum based hybrids PADAC 04-01, PADAC 99-05 and Rootpac R, inducing higher contents on sugars and bioactive compounds (total phenols, flavonoids and vitamin C) and antioxidant capacities. High significant correlations were found between all studied compounds. New plum based rootstocks seem to induce higher fruit quality based on sugars and organic acids profile, and antioxidants compounds.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We investigated the effects of nitric oxide (NO) fumigation on fruit ripening, chilling injury, and quality of Japanese plums cv. ‘Amber Jewel’. Commercially mature fruit were fumigated with 0, 5, ...10, and 20
μL
L
−1 NO gas at 20
°C for 2
h. Post-fumigation, fruit were either allowed to ripen at 21
±
1
°C or were stored at 0
°C for 5, 6, and 7 weeks followed by ripening for 5 d at 21
±
1
°C. NO-fumigation, irrespective of concentration applied, significantly (
P
≤
0.5) suppressed respiration and ethylene production rates during ripening at 21
±
1
°C. At 21
±
1
°C, the delay in ripening caused by NO-fumigation was evident from the restricted skin colour changes and retarded softening in fumigated fruit. NO treatments (10 and 20
μL
L
−1) delayed the decrease in titratable acidity (TA) without a significant (
P
≤
0.5) effect on soluble solids concentration (SSC) during ripening. During 5, 6, and 7 weeks of storage at 0
°C, NO-fumigation was effective towards restricting changes in the ripening related parameters, skin colour, firmness, and TA. The individual sugar (fructose, glucose, sucrose, and sorbitol) profiles of NO-fumigated fruit were significantly different from those of non-fumigated fruit after cold storage and ripening at 21
±
1
°C. CI symptoms, manifest in the form of flesh browning and translucency, were significantly lower in NO-fumigated fruit than in non-fumigated fruit after 5, 6, and 7 weeks storage followed by ripening for 5 d at 21
±
1
°C. NO-fumigation was effective in reducing decay incidence in plums during ripening without storage and after cold storage at 0
°C for 5, 6, and 7 weeks. In conclusion, the postharvest exposure of ‘Amber Jewel’ plums to NO gas (10
μL
L
−1) delayed ripening by 3–4 d at 21
±
1
°C, and also alleviated chilling injury symptoms during cold storage at 0
°C for 6 weeks.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Drying of plums to prunes is an important postharvest processing step, as it results in a product with higher nutrient density, increased shelf life, and significantly greater antioxidant and fiber ...content. However, due to the waxy layer present on the plums surface having low permeability toward moisture, plum dries very slowly which is an energy-demanding process. Therefore, to breakdown waxy layer on the surface and enhancement of skin moisture diffusivity, two genotypes (V91074 and V95141) of Yellow European Plums (YEPs) were dipped in 1% (w/v) of Ascorbic Acid (AA), Citric Acid (CA), and Potassium Meta-bisulfite (KMS) solution for 1 min at 40°C. The pretreated YEPs were dried at three different temperatures (50°C, 60°C, and 70°C) until a final moisture content of approximately 30% (wet basis) was reached. It was observed that treated samples (AA and KMS) dried faster as compared to untreated samples, except for CA treatment where no significant difference in drying time was observed. One model cannot be selected for describing the thin layer drying characteristics of YEPs. Five out of 11 models used were found to be a perfect fit for genotype V91074 and genotype V95141, respectively. Pretreatment had a significant effect on effective moisture diffusivity (D
eff
). D
eff
for untreated and treated plum samples ranged between 4.6 × 10
−11
to 8.6 × 10
−11
(m
2
/s) and 4.9 × 10
−11
to 9.1 × 10
−11
(m
2
/s). The drying temperature had a significant effect on phenolic content and antioxidant activity, whereas no significant effect of pretreatment was observed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Highlight textA mutation in the plum auxin-receptor encoded by PslAFB5, which acts as a negative regulator of auxin responses, results in inactive Pslafb5 protein causing accelerated fruit-ontogeny ...events associated with auxin hypersensitivity.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
A technology of obtaining active carbon from plum stones by chemical activation with KOH is described. The effect of carbonisation temperature as well as activation procedure on the textural ...parameters, acid-base character of the surface and sorption properties of active carbons has been checked. The sorption properties of the activated carbons obtained were characterised by determination of nitrogen dioxide adsorption in dry and wet conditions. The final products were microporous activated carbons of well-developed surface area varying from 2174 to 3228 m(2)/g and pore volume from 1.09 to 1.61 cm(3)/g, showing different acid-base character of the surface. The results obtained in our study have proved that a suitable choice of the carbonisation and activation procedure for plum stones can produce activated carbons with high capacity of nitrogen dioxide, reaching to 67 and 42 mg NO(2)/g in dry and wet conditions, respectively. The results of our study have also shown that the adsorption ability of carbonaceous sorbents depends both on the method of preparation as well as on the textural parameters and acid-base properties of their surface.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
► We measure condensation processes in plastic film packaging of plums. ► Condensation dynamics on different surface areas are analysed. ► Retention time and intensity of condensation are identified ...as substantial components. ► Water condensation at the film as well as at the fruit surfaces is of particular interest.
Water condensation on the surface of fruit and vegetables causes defects of the external appearance, promotes both the forming of spores and the growth of micro-organisms, and thus accelerates deterioration. Even at low temperature fluctuations of ambient air, condensation on relevant surfaces can be observed due to comparatively high air humidity inside the film packaging. The objective of the present study was to determine condensation dynamics and intensity within plastic film packaging for fruit under changing environmental conditions. Using packages of plums as a test case, it could be shown that water condensation processes occur time-delayed and superimposed with varying intensities on the surface of the fruit, on the inner film surface, and on the inner tray walls. Retention time and intensity of condensation were identified as the substantial components of condensation. In addition to the external temperature cycle the external mass transfer and the air volume within the packaging were taken into consideration. The condensation on the inner film surface was especially influenced by the flow conditions, the external temperature amplitude and the inner air volume. In contrast, condensation processes on fruit surfaces were caused primarily by temperature amplitude and cycle time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•On-branch fruits can be recognized by color images and a deep learning algorithm.•The method is independent of the natural environment of orchards.•Significant improvement on robustness of the ...algorithm by Global Average Pooling.•Low running time for ensuring real-time applications in precision horticulture.
Real-time and accurate on-branch fruit recognition in an uncontrolled/unstructured environment of orchards could facilitate Precision Horticulture (PH) practices. These practices which are based on the site-specific or variety-specific treatment of an orchard include applications like remote recognition of tree species, variety-specific orchard agrochemical applications, orchard yield mapping, robotic fruit picking, fruit tree disease treatment, etc. For this purpose, in the current work a Convolutional Neural Network (CNN) was developed and optimized for fruit recognition based on RGB images. The images from six classes of on-branch fruits i.e. green apples, nectarine, apricot, peach, sour cherry, and amber-colored plums were captured from local orchards at Semnan province, Iran. To avoid over-fitting, the dataset was then augmented to create more training data from existing samples. The model consisted of multiple convolutional, max-pooling, Global Average Pooling (GAP), and fully connected layers. Using GAP instead of the Flatten layer improved the performance of the model by increasing the accuracy as well as significantly reducing the trainable parameters (about 65 times reduction). The optimization phase of the model development was performed by testing four optimizers (RMSprop, SGD, Adam, and Nadam) with three batch sizes (16, 32, and 64) each with 50 epochs. Accordingly, Nadam optimizer with batch size = 32 demonstrated the best results. The best configuration achieved the accuracy of 99.8% and the cross-entropy loss of 0.019 for the test dataset. This result shows that the model is well developed and has good generalization. This reflects the potential of the method for the remote recognition and classification of different varieties of fruits in an orchard regardless of the environmental effects like complex background, variable light, overlaps, and occlusions with other plant parts, etc. The proposed network was also compared with popular structures like VGG11, ResNet50, ResNet152, and YOLOv3. The processing time of this model was about 8 ms per image while it was 351 ms for ResNet152, proving that the proposed network is much better for real-time applications. Consequently, this study presents a robust method for fulfilling the requirements of a PH practice in a high-tech horticulture system.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The fruits of the European plum Prunus domestica exhibit a great diversity in appearance including skin colors. This study attempts to elucidate the phenylpropanoid and flavonoid profiles of 28 plum ...varieties belonging to P. domestica and related species as well as hybrids. A total of 49 phenolic compounds extracted from the fruit skin were quantitatively evaluated in an HPLC-DAD-based metabolomic study. The total phenolic contents of the cultivars varied among 0.4–29.9 mg/g fresh weight. The predominant anthocyanins were glycosides of cyanidin and peonidin, and rutin was the principal flavonol, whereas neochlorogenic acid and n-chlorogenic acid were the main hydroxycinnamic acids. Aside from these major phenolic classes, a group of tentatively identified flavones and several acylated flavonoids were also found. Principal component analysis revealed that anthocyanins and hydroxycinnamic acids contributed most to variety separation. The heterogeneity between the different varieties was also assessed using hierarchical cluster analysis of sample phenolics profile. A simple separation of species could not be found confirming the close relationship among them.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
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