Quality Of Fresh-cut Apples Research Articles

Strigolactone Preserves Fresh-Cut Apple Quality during Shelf Life

Strigolactone Preserves Fresh-Cut Apple Quality during Shelf Life

Metagenomic and transcriptome insights into the disease resistance mechanisms in fresh-cut apple under pyridoxine treatment

Microbial spoilage poses a significant challenge to fresh-cut apples during storage, impacting quality and consumer health. This study explores pyridoxine’s (vitamin B6; VB6) potential mode of action to mitigate microbial spoilage in fresh-cut apples through physiological, transcriptomic, and metagenomic analysis. VB6 notably reduces microbial spoilage at room temperature by suppressing bacterial genera (Pseudomonas, Curtobacterium, Frigoribacterium) and fungal genera (Alternaria, Penicillium, Aureobasidium, Pseudogymnoascus) proliferation. Spoilage-causing identified biomarkers include species related to Pseudomonas, Curtobacterium, Frigoribacterium, and Penicillium. KEGG analysis suggests correlations of induced disease resistance with tropane alkaloids biosynthesis, plant-pathogen interaction, and phenylpropanoid biosynthesis pathways in fresh-cut apples. Moreover, VB6 treatment enhanced the antioxidant system via maintaining higher total phenolic contents, total flavonoid contents, and ascorbic acid under elevated catalase, superoxide dismutase, and ascorbate peroxidase enzymes activities, induced disease resistance under higher enzymes activities including phenylalanine ammonialyase, chitinase, cinnamate 4-hydroxylase, β-1,3-glucanase, and 4-coumarate: co-enzyme A ligase enzymes activities, maintained elevated VB6 contents, and reduced H2O2 accumulation. Notably, 6 elevated transcription factors involving WRKY, NAC and MYB might regulate disease resistance pathways in fresh-cut apples under VB6 treatment. This research establishes a theoretical and practical foundation for preserving post-processing quality of fresh-cut apples by restraining microbial proliferation through the proposed VB6-induced disease resistance regulatory mechanism.

Enhancing Fresh-Cut Apple Preservation: Impact of Slightly Acidic Electrolyzed Water and Chitosan-Apple Essence Microencapsulation Coating on Browning and Flavor.

Fresh-cut apple preservation is a critical concern in the food industry due to the rapid deterioration of texture, color, and flavor. While our previous study introduced apple essence microencapsulation (AEM) to enhance flavor during storage, its impact on overall storage quality was minimal. Thus, this study explores the application of two preservation techniques, namely, slightly acidic electrolyzed water (SAEW) and chitosan-apple essence microencapsulation (CH-AEM) coating, to enhance the quality of fresh-cut apples. Our findings reveal that SAEW treatment significantly reduces the browning index (from 65.38 to 57.36) and respiratory rate (from 5.10% to 4.30% of CO2), and maintains a desirable aroma profile compared to uncoated treatment during 10 days of storage. Additionally, the CH-AEM coating acts as a protective barrier, further preserving the sensory characteristics of fresh-cut apples. Notably, the SAEW-CH-AEM group exhibits superior performance in firmness (8.14 N), respiratory rate (3.37% of CO2), ion leakage (34.86%), and juice yield (47.52%) after 10 days. Our research highlights the synergistic effect of combining these preservation strategies, providing a promising approach for extending the shelf life of fresh-cut apples while maintaining their visual appeal and aromatic quality. These results offer valuable insights for the fresh-cut produce industry, contributing to improved apple product preservation and consumer satisfaction.

Selenium application during fruit development can effectively inhibit browning of fresh-cut apples by enhancing antioxidant capacity and suppressing polyphenol oxidase activity

Browning is a crucial factor affecting the quality of fresh-cut apples. A safe, simple, and effective method to inhibit browning is urgently needed in fresh-cut apple production. We carried out this study to explore the effect mechanism of exogenous selenium (Se) fertilizer on fresh-cut apple browning. During the development of apples, 0.75 kg/plant Se fertilizer was exerted on the ‘Fuji’ apple tree at the critical stage of the young fruit stage (late May), early fruit expansion stage (late June), and fruit expansion stage (late July), an equal amount of Se-free organic fertilizer was used as control. Polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia-lyase (PAL) activities, phenolic and malondialdehyde (MDA) content, antioxidant enzymes activity, and DPPH free radical scavenging rate of the apple at different development stages were investigated. The highest Se accumulation efficiency was observed in apple fruit one month after applying Se fertilizer, which was 41.1%. Se-rich apples exhibited a more remarkable ability to resist browning than control after fresh-cut. The anti-browning effect of the fertilization group (M7) was the best, the PPO activity decreased to 0.5 × 103 U kg−1, and the browning index was 28.6. The total Se content (TSC) of 331.4 μg kg−1 DW and organic Se content (OSC) of 292.0 μg kg−1 DW were the highest in the apple samples, reached the classification standard of Se content in Se-rich food. The correlation analysis found that fresh-cut apple browning was closely related to antioxidant capacity and PPO activity. The stronger the antioxidant capacity of fresh-cut apples treated with Se fertilizer, the lower their browning degree. Therefore, exogenous Se can alleviate fresh-cut apples browning by improving antioxidant capacity and reducing PPO activity. Se-rich apples could increase the Se content of the human essential trace element and inhibit the browning of fresh-cut apples, which would become a new, safe and effective way to solve the fresh-cut apples browning.

Effects of cellulose nanofibrils treatment on antioxidant properties and aroma of fresh-cut apples.

Horticultural products tend to deteriorate during postharvest storage and processing. In this study, cellulose nanofibers (CNFs) were prepared from wood to investigate the effects of CNF treatment on the storage quality, aroma composition, and antioxidant system of fresh-cut apple (Malus domestica) wedges. Compared with control treatment, CNF coating treatment significantly improved the appearance of apple wedges; reduced the decay rate of apple wedges; and delayed the decline in weight loss, firmness, and titratable acid during storage. Gas chromatography-mass spectrometry showed that CNF treatment could maintain the aroma components of apple wedges (stored for 4days). Further investigations showed that CNF treatment increased the antioxidant system level and decreased reactive oxygen species content and membrane lipid peroxidation level of apple wedges. Overall, this study showed that CNF coating could effectively maintain the quality of fresh-cut apples during cold storage.

Effect of Olive Pomace Extract Application and Packaging Material on the Preservation of Fresh-Cut Royal Gala Apples.

The efficiency of natural olive pomace extracts for enhancing the quality of fresh-cut apples was compared with commercial ascorbic acid and two different packaging films (biodegradable polylactic acid (PLA) and oriented polypropylene (OPP)) were tested. The composition of atmosphere inside the packages, the physicochemical parameters (firmness, weight loss and color), the microbial load, total phenolic content and antioxidant activity of fresh-cut apples were evaluated throughout 12 days of storage at 4 °C. After 12 days of refrigerated storage, a significant decrease in O2 was promoted in PLA films, and the weight loss of the whole packaging was higher in PLA films (5.4%) than in OPP films (0.2%). Natural olive pomace extracts reduced the load of mesophilic bacteria (3.4 ± 0.1 log CFU/g and 2.4 ± 0.1 log CFU/g for OPP and PLA films, respectively) and filamentous fungi (3.3 ± 0.1 log CFU/g and 2.44 ± 0.05 log CFU/g for OPP and PLA films, respectively) growth in fresh-cut apples after five days of storage at 4 °C, and no detection of coliforms was verified throughout the 12 days of storage. In general, the olive pomace extract preserved or improved the total phenolic index and antioxidant potential of the fruit, without significant changes in their firmness. Moreover, this extract seemed to be more effective when combined with the biodegradable PLA film packaging. This work can contribute to the availability of effective natural food additives, the sustainability of the olive oil industries and the reduction of environmental impact. It can also be useful in meeting the food industries requirements to develop new functional food products.

Effects of Variety and Pulsed Electric Field on the Quality of Fresh-Cut Apples

The suitability of five apple varieties (Ralls, Qinguan, Fuji, Delicious, and Cattle) for fresh-cut processing was compared based on the evaluation of weight loss, firmness, color, titratable acid (TA), polyphenoloxidase (PPO) activity and peroxidase (POD) activity, and the impact of pulsed electronic field (PEF) on fresh-cut apples’ quality was explored. The results showed that the changes to Delicious apples in terms of the color parameter, firmness, and weight loss were comparable to or lower than the other samples, while the TA content was higher than the other samples during storage. Therefore, Delicious was selected for the study of the effects of PEF on fresh-cut apples. By measuring the physicochemical properties and microbiological characteristics within 10 days of storage, it was found that the PPO and POD activity of apples treated with PEF at 3 kV/cm on the 10th day decreased the most, with 44.61% and 36.48% decreases, respectively. In addition, apples treated with 5 kV/cm showed the greatest decrease in malondialdehyde (MDA) content and the number of microorganisms, 63.98%, and 9.17%, respectively. In general, the PEF-treated apples retained a high level of quality. These results suggested that PEF treatment is a promising technology for extending the storage period of fresh-cut apples.

Effects of Slightly Acidic Electrolyzed Water on the Quality of Fresh-Cut Apple.

To investigate the effects of a slightly acidic electrolyzed water (SAEW) treatment on the quality of fresh-cut apples during storage, this research used a Box-Behnken design to determine the optimal SAEW treatment conditions. Then, the fresh-cut apple was treated under the optimal condition and subjected to a 13-d storage experiment at 4 °C. For fresh-cut apple treated under the optimal SAEW treatment conditions, the total number of surface colonies was reduced by 2.82 logarithms compared to the control group and the sensory score was 8.73. For the treated fresh-cut apple during storage, the quality of the treated group was significantly greater than the non-treatment group. Thus, the SAEW treatment not only effectively controlled the number of microbes on fresh-cut apple, but also slowed quality deterioration during storage.

Phytochemicals-based edible coating for photodynamic preservation of fresh-cut apples

Nature-derived chemicals have recently gained increased attention to settle down the challenges in the food industry. Quercetin has long been used as a natural medicine but its photoactivity has been neglected. In this work, by combining photodynamic bacteria inactivation (PDI) with an edible coating (Pectin/Quercetin) derived from FDA-approved chemicals, extend shelf-life and protected commercial quality of fresh-cut apples were achieved. Firstly, the potential photoactivated antibacterial performance of Quercetin (a natural plant flavonoid) was clarified with the treatment of a simulated sunlight lamp, realizing antibacterial efficacy of 100 % towards S. aureus (50 min) and L. monocytogenes (80 min) with light treatment. To develop safe and effective preservation of fresh-cut apples, Pectin/Quercetin edible coatings with 100 μmol/L quercetin were adopted. The results showed that the prepared edible coatings form a protective barrier over the surface of apples, effectively resisting bacterial infection and extending shelf life to 10 days while maintaining good commercial quality (including preferable color, keeping 100 % hardness, 80 % sugar content and 17.3 % weightlessness rate). Therefore, the prepared light-driven Pectin/Quercetin in this work has the potential to develop as fresh-cut fruit preservation technology.

Influence of plasma activated water treatment on enzyme activity and quality of fresh-cut apples

Plasma activated water (PAW) is a new approach to disinfecting surfaces including fresh-cut foods while maintaining their quality attributes. The aim of this study was to evaluate the effect of PAW on enzyme activity, microbial and physicochemical quality of fresh-cut apples. PAW was produced at different production activation times of 10 min, 20 min, 30 min, 45 min and 60 min and the fresh-cut apple slices were washed with PAW for 5 min and stored at 4 °C for 12 days. Results showed that PAW treatments reduced the polyphenol oxidase activity immediately after treatment and the lowest activity was recorded in PAW-20 min (5.10 ± 0.16 U/g FW) after 12 days. Conversely, peroxidase activity of the samples increased immediately after PAW treatment and the samples treated with PAW activated for 30 min had the lowest peroxidase activity at the end of 12 days of storage. No significant changes in the total phenolic content and FRAP antioxidant activity of the fresh-cut apple samples after PAW treatments. The results from firmness, membrane permeability, respiration rate and microstructural imaging showed that at higher PAW activation times (45 min and 60 min) had adverse effects on the quality of fresh-cut apples. Significant reductions in the total aerobic bacteria and total yeast and molds were observed in all PAW treatments except PAW activated for 10 min. The results suggests that plasma activated water could maintain the quality of the fresh-cut apples during storage for plasma activation times of 20 min and 30 min for up to 12 days of storage.

Phytic Acid Treatment Inhibits Browning and Lignification to Promote the Quality of Fresh-Cut Apples during Storage.

Browning and lignification often occur in fresh-cut apple processing, leading to quality deterioration and limiting the shelf life of products. In this study, 0.8% (v/v) phytic acid was used to improve the quality and shelf life of fresh-cut apples. From the results, the browning was inhibited by the phytic acid treatment and the browning index (BI) of the control fruit was 1.62 times that of phytic acid treatment at 2 d of storage. The lignin content in phytic acid-treated fruit significantly decreased at 2, 4, and 6 d of storage compared to the control. Phytic acid treatment also reduced H2O2 and malonaldehyde (MDA) contents, which may indicate lighter membrane damage to apples. Compared with the control, the polyphenol oxidase (PPO) and peroxidase (POD) activities decreased while superoxide dismutase (SOD) and catalase (CAT) activities increased in phytic acid-treated fruit. Consistent with the lignin content, the activities of phenylpropane metabolism-related enzymes phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate: CoA ligase (4CL) were inhibited by phytic acid treatment. In conclusion, phytic acid alleviated the browning and lignification of fresh-cut apples by reducing PPO and POD activities, maintaining cell membrane integrity, and inhibiting phenylpropane metabolism.

Preparation of an Antimicrobial and Antioxidant Bio-Polymer Film and Its Application as Glazing Shell for Postharvest Quality of Fresh-Cut Apple.

The aim of this work is to glazing a modified bio-polymer shell as substitute of peel to keep the postharvest quality of fresh-cut fruits. In this study, chitosan as backbone of the shell was modified by addition of the functional extracts obtained from Zanthoxylum, in which 12 kinds of main identified bio-active components consisted of over 55% of the total extracts. The introduction of the extracts improved physic and mechanical properties of the shell, and endowed it with significant antimicrobial and antioxidant activity. Accordingly, the modified chitosan was used as the substitute of peel to preserve fresh-cut apples. Results exhibited that such treatments obviously delayed the decline process of overall postharvest quality of the preserved apple samples throughout all the storage period, represented by the variations in physical, chemical, and microbial properties of the apple samples were significantly inhibited. The overall observations revealed promising potential of the bio-polymer shell in food application.

Apple peel extracts as preservation solution to maintain the quality of fresh-cut apples

Apple peel extracts as preservation solution to maintain the quality of fresh-cut apples

Quality of fresh-cut apples as affected by dip wash treatments with organic acids and acidic electrolyzed water

The objective of this study was to investigate the effects of dipping in solutions of citric (2%), benzoic (0.2%), sorbic (0.2%) and ascorbic (0.5%) acids and in acidic electrolyzed water on the quality attributes and surface microbiota of fresh-cut apples, cvs ‘Florina’ and ‘Ionathan’, packaged in disposable plastic containers under normal atmospheric conditions during 14 days storage at 8 °C. The colour, firmness, total phenolic content, antioxidant activity and surface microbial load were determined weekly throughout storage. The colour results indicated that acidic electrolyzed water reduced browning while the ascorbic and citric acids were less effective in controlling the enzymatic browning of fresh-cut apples. After 14 days of refrigerated storage, the samples treated with 2% citric acid and acidic electrolyzed water maintained significantly higher firmness, total phenolic content and antioxidant activity than the other treated and control samples. The microbiological analysis revealed that organic acids successfully suppressed bacterial growth throughout the storage period as compared to the control samples. The sorbic and benzoic acids at 0.2% were also effective on yeasts but these dip treatments determined a higher darkening, yellowing and loss of firmness and of antioxidant activity during storage.

The Effect of Lactiplantibacillus plantarum BX62 Alone or in Combination with Chitosan on the Qualitative Characteristics of Fresh-Cut Apples during Cold Storage

In order to explore whether beneficial lactic acid bacteria (LAB) could prolong the shelf life and improve the quality of fresh-cut apples, Lactiplantibacillus plantarum BX62, which was isolated from traditional fermented yak yogurt, and chitosan (CT), were applied to fresh-cut apples, subsequently stored at 4 °C. On days 0, 2, 4, 6, and 8, apple slices were taken for physicochemical, microbiological analysis, and sensory evaluation. The results showed that apple slices coated with L. plantarum BX62 (8 log CFU/mL) presented lower weight loss and browning rate, higher DPPH scavenging capacity, and achieved more effective inhibition of polyphenol oxidase (PPO) and peroxidase (POD) activities compared to the control samples. The application of CT alone or in combination with L. plantarum BX62 resulted in a significant reduction in aerobic mesophilic bacteria (AMB), aerobic psychrophilic bacterial (APB), yeast and molds (YAMs) counts (2.31 log CFU/g for AMB, 2.55 for APB, and 1.58 for YAMs). In addition, L. plantarum BX62 coated apples showed acceptable sensory properties in terms of color, flavor, taste, texture, and overall visual quality during 8 d of storage. On this basis, L. plantarum BX62 could be used as an excellent bio-preservative to extend the shelf life and improve the quality of fresh-cut apples.

Influence of Modified Atmospheres on Shelf Life and Quality of Fresh-Cut Apples

Influence of Modified Atmospheres on Shelf Life and Quality of Fresh-Cut Apples

Composite Films of Thermoplastic Starch and CaCl2 Extracted from Eggshells for Extending Food Shelf-Life

Calcium chloride (CaCl2) has been widely used to maintain the quality of fresh-cut fruits and vegetables because it stabilizes and strengthens the membrane system against fungal attacks. It is mainly applied via spray coating and dip coating techniques. This study explored a method of incorporating calcium chloride extracted from eggshells in a packaging material, thermoplastic starch (TPS), via a hot-melt extrusion process. The composites were characterized by FTIR, DSC, SEM-EDX and tensile testing. FTIR confirmed the chemical reactions between CaCl2 and TPS. DSC results showed a significant decrease in the heat of fusion by adding 20 wt% of CaCl2 content in TPS, indicating a drop in the degree of crystallinity. The Young’s modulus of TPS was not significantly affected by the incorporation of 10 wt% CaCl2 (P = 0.968), but reduced notably with the addition of 20 wt% CaCl2 (P = 0.05), indicating the plasticizer effect of the CaCl2. Physiochemical analysis of fresh-cut apple slices was assessed. Samples placed on the surface of the TPS/CaCl2 composites displayed less pH reduction, reduced antioxidant activity, more weight loss and increased reducing sugar compared to the samples placed on the surface of virgin TPS films. CaCl2 released from the TPS/CaCl2 films was measured and their antimicrobial activity was confirmed by bacterial inhibitory growth assessment. Fungal growth was observed on apple slices placed on virgin TPS film by day 21 while apple slices placed on TPS/CaCl2 20 wt% composites did not support any fungal growth for 28 days. In summary, TPS and eggshell-extracted CaCl2 showed the ability to maintain the quality of fresh-cut apples, and TPS/CaCl2 10 wt% composite could be a good option as a packaging material for fresh-cut fruits due to active antimicrobial activity and maintained Young’s modulus.

Development of active packaging film from sodium alginate/carboxymethyl cellulose containing shallot waste extracts for anti-browning of fresh-cut produce

Owing to growing concerns about making pollution-free sustainable environment by reducing the dumping of agricultural waste and convert it into valuable product is a key to carry out the present study. The ultimate goal of this study is to convert shallot onion wastes (SOWs) into active packaging and evaluating the anti-browning effect due to the SOWs holding rich polyphenols and antioxidants. The active packaging film was fabricated by using sodium alginate (SA) and carboxymethyl cellulose (CMC) along with shallot onion waste extract (SOWEs) such as peel and stalk at 0.2% and 0.5% concentration. The film made with SA/CMC/SOWEs had good physical, mechanical, optical and barrier property, higher phenolic and antioxidant activity compared to control. In addition, the effect of SA/CMC/SOWEs film packaging on anti-browning and quality of fresh-cut apple and potato stored at 4 °C was studied. The results show the SA/CMC/SOWEs film had better effect on controlling browning index in fresh-cut apple and potato over the storage of 12 days and 5 days. This study concludes that the SA/CMC film developed with shallot stalk extract can be used for wrapping of fresh-cut fruits and vegetables. It also prevents browning and maintains the overall quality than control and shallot peel incorporated film.

Aqueous ozone treatment inhibited degradation of cellwall polysaccharides in fresh-cut apple during cold storage

The effects of aqueous ozone (AO) treatment on the firmness, cellwall polysaccharide content, enzymatic activity, and gene expression of cell wall-degrading enzymes were investigated in fresh-cut apple during cold storage. AO treatment (1.4 mg L−1 for 5 min) delayed degradation of cellwall polysaccharides to reduce softening of fresh-cut apple. Water-soluble pectin content increased more slowly, while protopectin content, 4% KOH-soluble fraction, and cellulose content decreased at a lower rate in AO-treated fresh-cut apple compared with the control. However, no significant influence was shown on the 24% KOH-soluble fraction. AO treatment promoted increased pectin methylesterase activity, and distinctly inhibited β-galactosidase and α-arabinofuranosidase activities during storage. Polygalacturonase activity was not affected by AO treatment. Meanwhile, AO maintained the intactness of cell walls through repression of Mdβ-Gal and Mdα-Af transcript levels, thereby preserving the textural quality of fresh-cut apple during cold storage.

Calcium ascorbate treatments to control the fresh-cut apple quality reduction when stored at high temperature

Calcium ascorbate treatments to control the fresh-cut apple quality reduction when stored at high temperature