Quality Of Nectarines Research Articles

Biodegradable soy protein isolate carvacrol coating controls soft rot on nectarines by enhancing defense response

Nectarine fruits are rich in nutrients, which are susceptible to fungal infection during postharvest, resulting in quality deterioration and decay. This study aimed to assess the effect of different concentrations of carvacrol and soy protein isolate coatings on the fungal infection and quality characteristics of nectarines during postharvest storage. The results showed that soy protein isolate carvacrol (SPI-C) coating inhibited the growth of Rhizopus stolonifer in vitro. The SPI-C coating significantly reduced the incidence of postharvest soft rot, maintained the postharvest quality of nectarines during storage. SPI-C coating induces the defense response to soft rot by enhancing the accumulation of phenolic, flavonoids and lignin, and up-regulating the expression of defense-related genes in nectarines. The SPI-C coating activated the transcription of antioxidant enzymes (CAT, SOD and POD) and eliminated ROS damage. The disease resistance response promotes the production of defense-related substances by upregulating the gene expression of PpPPO and PpPAL. In summary, SPI-C coating significantly reduces the incidence of postharvest soft rot, maintains the postharvest quality and induces defense response to soft rot by enhancing the expression of genes involved in phenylpropanoid metabolism in nectarines during storage.

Caffeic acid enhances the postharvest quality by maintaining the nutritional features and improving the aroma volatiles for nectarine fruit

Maintaining the quality of postharvest nectarine fruit is considerably challenging owing to their vigorous metabolism processes. This study explored the effectiveness of the natural preservative caffeic acid in extending the shelf-life and improving the flavor quality of nectarine. The decay rate of caffeic acid-treated fruit was only 40.00 % but 73.33 % in control group at the end of storage. Other results showed that caffeic acid inhibited fruit quality deterioration, reflected in weight loss, peel color, pulp softening, respiration rate, malondialdehyde accumulation and ethylene biosynthesis. Findings might be attributed to increased levels of antioxidant compounds, such as ascorbic acid, simple phenols and flavonoids, which maintained high antioxidant capacity and metal reducing power of fruit cells. Notably, the content of phenolics was maintained at 241.11 mg kg−1 in caffeic acid-treated fruit by 8 d, which was only 138.21 mg kg−1 in control. Importantly, nectarine treated with caffeic acid possessed a suitable sugar-to-acid ratio, imparting the fruit with an excellent taste. Additionally, caffeic acid facilitated the effective release of esters and lactones, especially γ- and δ-decalactone with fruity aroma, and prevented green aroma and alcoholic off-flavor. The level of lactones in caffeic acid-treated fruit reached 126.76 μg kg−1 during mid-storage, giving the fruit an attractive flavor quality, while was only 50.61 μg kg−1 in control. Overall, caffeic acid exhibited the potential to preserve the quality of nectarine, ensuring both nutritional and edible value for fruit.

1-MCP delays ripening and maintains postharvest quality of nectarines by regulating transcriptional and metabolic responses

Fast ripening and senescence is one of the major problems for postharvest nectarines, leading to a rapid decline in postharvest quality. As an ethylene-action inhibitor, 1-methylcyclopropene (1-MCP) was applied to treat nectarines with a concentration of 1 μL L−1 for 18 h and stored at 0 °C for 25 d. The postharvest physiological quality attributes including the flesh color, total soluble solids (TSS), titratable acid (TA), and aroma quality of fruit flesh from different positions (top, equatorial, and bottom of nectarine fruit) were evaluated to elucidate that 1-MCP differentially influence the flesh ripening and biological metabolism. The findings indicated that 1-MCP treatment effectively delayed ripening and senescence processes. Moreover, the cellular microstructure and intracellular organelles were observed which suggested that 1-MCP delayed the deformation of the cellular microstructure and maintained its integrity. Furthermore, transcriptomic and metabolomic analyses explored the differential metabolites and their biological features. The differential metabolites after 1-MCP treatment were related to signal transduction, membrane transport, genetic translation, and metabolism pathways. The KEGG enrichment results showed that the most impacted pathways by 1-MCP include glycolysis and gluconeogenesis.

Effect of nano-calcium on carotenoid and anthocyanin contents of nectarine fruit

Increasing the carotenoid content of nectarine (Prunus persica var. nucipersica) is of great significance for improving its quality and economic value. A two years study was carried out on ‘Shuguang’ nectarine to evaluate the effect of calcium chloride (Cl–Ca) and L-aspartic acid nano calcium [Ca (L-asp) - NPs] (nano-Ca) on carotenoid accumulation. The results show that both Cl–Ca and nano-Ca could increase the carotenoid content of nectarine fruit flesh, but the effect of nano-Ca was more significant. Nano-Ca is more easily absorbed by nectarine leaves and fruits, which improves the calmodulin activity of leaves, peel and flesh, and up-regulates the expression of carotenoid synthesis-related genes PpPSY, PpPDS, PpZDS, PpLCY-B, PpCHY-B and PpZEP. Nano-Ca also significantly up-regulated the expression of sucrose synthesis related genes PpSUS1 and PpSUS3 in leaves and sucrose transport related genes PpSUT2 and PpSUT4 in stem phloem, promoting the transport of more photosynthetic products to fruits, providing raw materials for carotenoid synthesis, and increasing the content of total sugars and ascorbic acid (Vc). In addition, nano-Ca can also up-regulate the expression levels of PpMYB10.1 and PpUFGT and promote total anthocyanins accumulation in peel. The results of our study will be useful for clarifying how nano-fertilizer improve the fruit quality of nectarine.

Differential Response of the Leaf Fruit Ratio and Girdling on the Leaf Nutrient Concentrations, Yield, and Quality of Nectarine

Differential Response of the Leaf Fruit Ratio and Girdling on the Leaf Nutrient Concentrations, Yield, and Quality of Nectarine

Combination of Sodium Bicarbonate (SBC) with Bacterial Antagonists for the Control of Brown Rot Disease of Fruit.

Simultaneous treatment with antagonistic bacteria Bacillus amylolquefaciens (SF14), Alcaligenes faecalis (ACBC1), and the food additive sodium bicarbonate (SBC) to control post-harvest brown rot disease caused by Monilinia fructigena, and their effect on the post-harvest quality of nectarines were evaluated. Four concentrations of SBC (0.5, 2, 3.5, and 5%) were tested. Results showed that bacterial antagonists displayed remarkable compatibility with different concentrations of SBC and that their viability was not affected. The results obtained in vitro and in vivo bioassays showed a strong inhibitory effect of all treatments. The combination of each bacterial antagonist with SBC revealed a significant improvement in their biocontrol efficacies. The inhibition rates of mycelial growth ranged from 60.97 to 100%. These results also indicated that bacterial antagonists (SF14 or ACBC1) used at 1 × 108 CFU/ mL in combination with 2, 3.5, or 5% SBC significantly improved the control of M. fructigina by inhibiting the germination of spores. Interestingly, disease incidence and lesion diameter in fruits treated with SF14, ACBC1 alone, or in combination with SBC were significantly lower than those in the untreated fruits. In vivo results showed a significant reduction in disease severity ranging from 9.27 to 64.83% compared to the untreated control, while maintaining the appearance, firmness, total soluble solids (TSS), and titratable acidity (TA) of fruits. These results suggested that the improved disease control by the two antagonistic bacteria was more likely due to the additional inhibitory effects of SBC on the mycelial growth and spore germination of the pathogenic fungus. Overall, the combination of both bacteria with SBC provided better control of brown rot disease. Therefore, a mixture of different management strategies can effectively control brown rot decay on fruits.

Polarization imaging based bruise detection of nectarine by using ResNet-18 and ghost bottleneck

Bruise reduces the edible quality of nectarines and brings potential risks of cross-infection of fruit, but it is challenging to accurately detect bruised nectarines because of the color similarity between a sound and bruised area in nectarine fruit. Therefore, this research aims to develop an effective and efficient method, based on polarization imaging (PI) technology, for the detection of bruised nectarines. A total of 406 nectarines from three varieties, including 206 sound nectarines and 280 bruised nectarines made by the impact method, were used in the experiment. Polarization images of nectarines at four polarization angles (0°, 45°, 90°, and 135°) in five periods (6, 12, 24, 48, and 96 h after bruise formation), were acquired using a visible PI system. A lightweight network (ResNet-G18) that integrates ResNet-18 and ghost bottleneck was used to develop a classification model for sound and bruised nectarines based on the polarization image data. The results indicated that polarization images can effectively suppress the glare resulting from the smooth surface of nectarines, and overcome the interference of dark colors in detecting bruises. Meanwhile, the ResNet-G18 detection model achieves the best performance in both detection accuracy and efficiency, with a total classification precision of 96.21% and a true positive rate of 97.69% for bruised nectarines, and an average detection time of 17.32 ms for each fruit. Furthermore, the ResNet-G18 can recall all nectarines bruised for 12 h and above with 98.62% precision, showing excellent detection performance for early bruises. This study has demonstrated that the proposed PI technology coupled with an appropriate lightweight classification network can be effective and efficient for the detection of bruised nectarines.

Non-destructive determination of ‘Big Bang’ nectarine quality and harvest maturity

Non-destructive determination of ‘Big Bang’ nectarine quality and harvest maturity

Field non-destructive determination of nectarine quality under deficit irrigation

Field non-destructive determination of nectarine quality under deficit irrigation

Influence of plant extract and edible coatings on quality of nectarine (Prunus persica) fruits

A study was carried out on the influence of plant extract and edible coating on nectarine fruits during 2019-20 at ICAR-IARI, New Delhi. We attempted the use of different hydrocolloid-based coatings like carboxy methylcellulose (CMC) and chitosan (CH) alone and in combination with mixed plant extract (MPE) of moringa, eucalyptus and marigold on Snow Queen nectarine fruits. Fruits were coated with these coatings and stored at supermarket conditions (18 ± 2ºC and 85-90% RH) for 16 days. During storage, observations on weight loss, fruit firmness, quality attributes and sensory evaluation were recorded at 4 days interval. The results revealed that the weight loss (WL) and fruit firmness decreased with the increase in storage period, and fruits coated with layer-by-layer coatings of CMC-CHMPE exhibited the highest lowest WL and highest fruit firmness at the end of storage. The total soluble solids (TSS) and ascorbic acid content increased up to some period, and then these attributes showed declining trend. In all, layerby- layer coating of CMC-CH-MPE was the best treatment for reducing WL, maintaining fruit firmness and quality of Snow Queen up to 16 days of storage at supermarket conditions.

A process-based model of nectarine quality development during pre- and post-harvest

A new mathematical modeling framework able to simulate the combined effect of fruit growth and post-harvest storage conditions (temperature and relative humidity) on nectarine quality is here proposed. The seasonal course of fruit surface conductance to water vapor, fruit mass loss during storage, and sugar concentration dynamics in fruit pulp were modeled. The three sub-models were integrated into a model capable of calculating a fruit sweetness index and relative water loss during storage, which were selected as nectarine quality criteria. Sub-models parameters were calibrated through results from experiments carried on during 2018 and 2019, where horticultural practices (irrigation and fruit load) and storage conditions were jointly varied.Irrigation level influenced fruit surface conductance to water vapor at harvest, but experimental results point out that this variable may have little influence on fruit mass loss during storage, which was mainly driven by relative humidity in the storage chamber. Irrigation intensity was also influential on sugar dynamics, along with storage temperature, with fruit stored at the higher temperature (25 °C) being sweeter than those stored at lower ones (2 and 15 °C). These experimental results were well replicated by the sub-model outputs.Model simulations during storage revealed a trade-off between the two selected quality criteria, which increased with increasing storage temperature and decreasing relative humidity. The best scenario in terms of acceptable fruit mass loss and sweetness index was for fruit from water-stressed and low crop-loaded trees, 15 °C and 70% relative humidity. Moreover, storage duration was shown to increase fruit mass loss and, to a lesser extent, the sweetness index, while fruit from late harvest dates had higher sweetness at the end of storage. The model can potentially be used to manage and optimize pre-harvest and storage practices that will maximize sweetness and minimize mass loss to meet fruit quality standards along supply chains.

Quality inspection of nectarine based on hyperspectral imaging technology

ABSTRACT In this paper, the quality detection of nectarines based on hyperspectral imaging technology is proposed. The external quality indexes consist of the intact, cracked, rust, dysmorphic and dark damaged, while the internal quality index is composed of the soluble solid content (SSC). Firstly, 480 nectarine samples (160 intact and 320 defective nectarines) with the similar shape and size are selected. Secondly, 5 spectral principal components and 6 texture values are acquired in the spectral range of 420–1000 nm based on the indexes of external and internal quality. Finally, the methods of Partial Least Squares (PLS), Least Squares Support Vector Machine(LS-SVM) and Extreme Learning Machine (ELM) are used to establish the external quality discrimination models and internal quality prediction models, respectively. As a result, accuracies of 89.73%, 94.45% and 88.62% are obtained in the identification of the external quality. SSC is predicted with determination coefficients of 0.8540, 0.8747, 0.8146, and the root mean squared errors of 0.9849, 0.9101, 1.0732. The results obtained indicate the great potential of the LS-SVM model to predict and discriminate the inner and outer quality of nectarines.

Influence of hydrocolloid-based edible coatings on fruit firmness and quality of nectarine (Prunus persica var. nucipersica) cv. Snow Queen at low temperature storage

Nectarine (Prunus persica var. nucipersica) is known for its characteristic flavor and fuzzless nature in contrast to its progenitor peaches. It is an important stone fruit with immense nutrients and antioxidant capacity. The smooth texture and glossy cosmetic appeal makes the nectarine popular among the consumers as well as growers. But the postharvest life of this functional fruit is only 3-4 days under ambient conditions due to its high perishability and its unfamiliarity among the growers as its newly introduced crop causes a significant postharvest loss to the growers. Hence, this experiment was conducted to enhance the marketability of commercially important nectarine cultivar Snow Queen fruit by coating them with various plants (hydrocolloids) based edible coating. Fruits were treated with various plant based edible coating such as carboxymethyl cellulose (1%, 1.5%) and GA (gum Arabica) (8%, 10%, 12%). The fruits were dipped in various coating material and dried under ambient condition and stored at cold storage conditions (1±1 oC and 85-90% relative humidity). The observations on various physical, physiological and biochemical attributes were recorded at weekly interval. The results revealed that among the various edible coatings applied, 1% CMC and 10% GA were found to be effective in reducing the respiration rate and maintaining better fruit firmness than other concentrations of edible coating. These treatments were also better in maintaining other biochemical parameters and extended the shelf life of Snow Queen fruit to about 28 days under storage with better organoleptic properties.

Effect of melatonin treatments on biochemical quality and postharvest life of nectarines

The study investigated the effects of melatonin on the postharvest quality of nectarine fruit (cv. Fantasia). Fruits were dipped in melatonin concentrations (control, 250, 500 and 1000 µmol l− 1) and stored for 40 days at 0–1 °C and 85–90% relative humidity. Changes in weight loss, respiration rate, fruit firmness, total soluble solids, titratable acidity, chilling injury, ascorbic acid, total flavonoids, total phenolics and total antioxidants were evaluated during 0, 10, 20, 30 and 40 day. According to the results, melatonin treatments effectively slowed process of senescence, as indicated by reduced fruit softening, chilling injury and respiration rate. Moreover, this effect is concentration-dependent, with 1000 µmol l− 1 melatonin treatment more effective than other doses during the 40 days of storage. Melatonin treated nectarines exhibited higher total antioxidant activity than controls, which was correlated primarily to the high levels of total phenolics and to lesser loss to ascorbic acid and flavonoids contents. These results demonstrated that melatonin treatment could be a good practice for extending postharvest life of nectarine fruits, maintaining the appearance and nutrient value, and reducing the loss of health-promoting compounds.

Changes in the volatile profile of ‘Fantasia’ nectarines [Prunus persica (L.) Batsch, var. nectarina] treated with an enhanced freshness formulation (EFF) containing hexanal

Postharvest technologies play a key role in enhancing shelf life and maintaining quality characteristics of tender fruits, such as nectarines (Prunus persica [L.] Batsch var. nectarina). This research investigated the effects of an enhanced freshness formulation (EFF), containing hexanal as the key ingredient, in enhancing the shelf life of field grown nectarines and its effects on the composition of volatile organic compounds (VOCs). ‘Fantasia’ nectarine fruits at two commercial orchards in the Niagara region were subject to preharvest sprays of 2% EFF (15 and 7 days preharvest) and stored at ambient conditions (25 °C) with volatile analyses conducted at 0, 3, 5, 7, and 11 days postharvest. The volatile analysis study indicated for the first time that hexanal is naturally present in nectarine fruit. This was confirmed by GC–MS analysis and validated with standards. GC–EIMS analyses of targeted VOCs validated with standards indicated reduced levels of VOCs associated with fruit ripening and fruity odor, such as lactones, in hexanal-treated fruit, and an increased level of C6 compounds associated with unripe fruit. Principal component analysis biplot with scores and loadings of the fruit VOCs and quality parameters indicated a tight association between TSS and lactones, which was inversely associated with firmness, ground color, acetates, and ester compounds. Pearson correlation coefficients also indicated a very high positive correlation between hexanal and levels of VOCs, such as 1-hexanol, E-2-hexanal, 3-hexanal, hexen-1-ol, and other C6 acetates. These findings may indicate a delay in the ripening process caused by hexanal formulation, which may be associated with modulated expression of key ripening-related volatile pathways, therefore enhancing the shelf life and quality of nectarines.

Influence of in-package use of ethylene absorbents on shelf life and quality of nectarine during supermarket conditions

Influence of in-package use of ethylene absorbents on shelf life and quality of nectarine during supermarket conditions

Efficacy evaluation of ultrasound treatment on the postharvest storability of white nectarine by both physicochemical and image processing analyses

Ultrasound is a non-thermal method to preserve the postharvest quality of fresh fruit during storage that is also non-toxic and environmentally friendly. In this study, the effects of ultrasound treated at 0, 100, 200, 300, and 500 W on the quality of white nectarine stored at 4 ℃ for 50 d were investigated. Additionally, image processing techniques were used as a means of qualitative analysis. Weight loss, pH, total soluble solids (TSS), in-package gas concentration, decay rate, instrumental color, texture, and Fourier transform near-infrared (FT-NIR) were measurements were done in this study. Color and morphological characteristics of white nectarines were also identified by image processing techniques. Based on the results of physicochemical analyses, ultrasound treatment at 300 W power best-maintained nectarine quality. The decay rate was found to be 20% in the control fruit (CNT) and 3,3% in the 300 W treatment at the end of the storage. These results were supported by color and morphological characteristics obtained by image processing techniques. Overall, the results indicated that the non-thermal ultrasound technique could be used to increase storage quality of white nectarines, and image processing techniques could be implemented as objective, rapid and non-destructive analysis methods by the food industry.

Use of hyperspectral transmittance imaging to evaluate the internal quality of nectarines

The internal quality of nectarines (Prunus persica L. Batsch var. nucipersica) cv. ‘Big Top’ (yellow flesh) and ‘Magique’ (white flesh) has been inspected using hyperspectral transmittance imaging. Hyperspectral images of intact fruits were acquired in the spectral range of 630–900 nm using transmittance mode during their ripening under controlled conditions. The detection of split pit disorder and classification according to an established firmness threshold were performed using PLS-DA. The prediction of the Internal Quality Index (IQI) related to ripeness was performed using PLS-R. The most important variables were selected using interval-PLS. As a result, an accuracy of 94.7% was obtained in the detection of fruits with split pit of the ‘Big Top’ cultivar. Accuracies of 95.7% and 94.6% were achieved in the classification of the ‘Big Top’ and ‘Magique’ cultivars, respectively, according to the firmness threshold. The internal quality was predicted through the IQI with R2 values of 0.88 and 0.86 for the two cultivars. The results obtained indicate the great potential of hyperspectral transmittance imaging for the assessment of the internal quality of intact nectarines.

Impact of nitric oxide on shelf life and quality of nectarine (Prunus persica var. nucipersica)

Nectarine is an emerging fruit crop in India which has immense nutritional quality and fairly good amount of antioxidants. In India, peach orchards are being replaced by nectarine primarily because of fuzzless peel. However, shelf life of nectarine is lean due to its climacteric behaviour. Hence, we attempted to observe the effect of nitric oxide (NO), using its donor compound, namely sodium nitroprusside (SNP) on postharvest life and quality of ‘Silver Queen’ nectarine fruit. In this study, fruit of ‘Silver Queen’ nectarine were treated with various concentrations of SNP (0.25 mM, 0.5 mM, 1.0 mM, 1.5 mM) after harvesting at climacteric stage of maturity. Fruit were stored at ambient condition for further analysis on daily basis, after air drying at room temperature. Our results revealed that among the various concentrations of SNP, 0.5 mM was found to be best in reducing physiological loss in weight (PLW), maintaining firmness and retaining higher phenolics, antioxidant activity, exhibiting slower increase in lipoxygenase (LOX) and pectin methylesterase (PME) activity and better quality fruit up to 8 days than 4 days of untreated fruit. Hence, postharvest dip of ‘Silver Queen’ nectarine fruit in 0.5 mM solution of SNP could be recommended for enhancing the shelf life by 4 days.

Impact of Ethylene Absorbents on Fruit Firmness and Quality of Nectarine (Prunus persica var. nectarina) Fruits during storage at Super Market Conditions

Impact of Ethylene Absorbents on Fruit Firmness and Quality of Nectarine (Prunus persica var. nectarina) Fruits during storage at Super Market Conditions