Shelf Life Of Fresh-cut Fruits Research Articles

Zein film loaded with Fructus Ligustri Lucidi essential oil: Preparation, characterization and application in fresh-cut apple preservation

Fresh-cut fruits and vegetables are a type of convenient, ready-to-use food that offers consumers a healthy choice. However, the peeling and slicing operations make them susceptible to microbial contaminations and oxidation. In this study, zein was used as the film-forming substrate, and Fructus Ligustri Lucidi essential oil (FEO), a natural bacteriostatic agent, was incorporated into zein film to prepare a film with antibacterial and antioxidant properties to prolong the shelf life of fresh-cut fruits and vegetables. Polyethylene glycol 400 (PEG400) and glucose were used as plasticizers, and the optimal formulation of the film (FZF) was obtained by orthogonal experiment: 10% PEG400, 5% glucose and 10% FEO. The films were characterized by scanning electron microscope (SEM), Fourier transform infrared spectrum (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), and the influence of FEO on the physical, chemical, and biological characteristics of the films was explored. The results demonstrated that FEO was successfully loaded into zein film and distributed evenly. The FZF film exhibited excellent antioxidant activity, when the concentration of FEO was 200 μg/mL, the scavenging rate of DPPH and ABTS was 81.63 ± 0.69% and 91.44 ± 0.55% respectively. Furthermore, the FZF film showed antibacterial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and low cytotoxicity in vitro. Moreover, the FZF film demonstrated anti-browning capabilities, effectively prolonging the shelf life of fresh-cut apple slices. Thus, the FZF film possesses considerable potential for utilization in food packaging.

Pullulan nanofibrous films incorporated with W/O emulsions via microfluidic solution blow spinning technology

In this work, pullulan (PUL) nanofibrous films incorporated with water-in-oil emulsions (PE) were prepared by microfluidic blowing spinning (MBS). The microstructures of nanofibers were characterized by scanning electron microscopy (SEM), fourier transform infrared (FT-IR), and X-ray diffraction (XRD). With the addition of W/O emulsions, the thermal stability, mechanical, and water barrier properties of PUL nanofibers were improved. Increases in emulsion content significantly affected the antioxidant and antimicrobial properties of nanofibrous films. ABTS and DPPH free radical scavenging rates increased from 10.26 % and 8.57 % to 60.66 % and 57.54 %, respectively. The inhibition zone of PE nanofibers against E. coli and S. aureus increased from 11.00 to 20.00 and from 15.67 to 21.17 mm, respectively. In addition, we investigated the freshness effectiveness of PE nanofibrous films on fresh-cut apples. PE nanofibrous films significantly maintained the firmness, and reduced the weight loss and browning index of the fresh-cut apple, throughout the 4 days of storage. Thus, the PE nanofibrous films exhibited good potential to prolong the shelf life of fresh-cut fruit and promote the development of active food packaging.

Quality and shelf life of fresh-cut pineapple (Ananas comosus) coated with aloe vera and honey in the refrigerated condition

This research work aimed to investigate the effects of different concentrations of Aloe vera gel (50%, 75%, and 100%) and honey (25%, 50%, and 100%) on the physicochemical changes in fresh-cut pineapple stored at 4 °C. The pineapple pieces were prepared by washing and cutting them into 2 cm sections, followed by coating them with the Aloe vera and honey solutions for 2 min. Subsequently, the samples were stored at 4 °C for duration of 12 days. During the storage period, various parameters such as juice leakage, firmness, pH, total soluble solids, vitamin C content, colour, and microbial load were monitored. Additionally, sensory testing was conducted to evaluate the acceptability of the treated samples. The findings revealed significant differences in weight loss, vitamin C content, colour, flavor, and textural properties between the treated samples and the control group throughout the entire 12-day storage period. Among the different treatments, the application of 100% Aloe vera gel exhibited the highest effectiveness in preventing physicochemical changes and extending the shelf life of fresh-cut pineapple where as honey shows the opposite. Notably, the sample coated with 100% Aloe vera showed the highest vitamin C content (27.35 mg/100 g) at the end of the storage period where as 100% honey shows the second position. Based on the results, this study concludes that Aloe vera gel can be utilized as an efficient coating material to mitigate physicochemical and microbial changes in fresh-cut pineapple during refrigerated storage. The findings highlight the potential of Aloe vera gel is more effective then honey in every ways in preserving the quality and extending the shelf life of fresh-cut fruits, providing opportunities for practical applications in the food industry.

Characterization of polysaccharide-based antibacterial films properties of loaded with Nisin and preservation of fresh-cut watermelon

The study aimed to improve polysaccharide-based packaging to extend the shelf life of fresh produce; a composite film with antimicrobial function was developed and tested. The packaging film is a blend of agar, a film-forming substrate; carrageenan, as a reinforcing agent; glycerol, as a plasticizer; and Nisin, an antimicrobial agent. The film was evaluated for its antibacterial, mechanical, and barrier properties at different humidity levels, using fresh-cut watermelon as the test food material. The film effectively inhibited the growth of Staphylococcus aureus and Listeria monocytogenes. Under relative humidity of 20%, 50%, and 90%, the tensile strength of the antibacterial film containing 0.28% Nisin was 23.08 ± 0.65, 16.09 ± 1.73, and 6.52 ± 0.56 MPa, respectively, and the film also had excellent barrier and heat-sealing properties. The packaging test using fresh-cut watermelon sealed in the antibacterial film containing 0.28% Nisin, under controlled atmosphere storage at either 4 °C or 20 °C, effectively inhibited microbial colonization in the melon and slowed the deterioration of the fruit, as indicated by measures of hardness, weight loss, and soluble solids. This method can extend the shelf life of fresh-cut fruit and provide a reference for further research on polysaccharide-based protective film for fresh produce.

Cactus polysaccharides enhance preservative effects of ultrasound treatment on fresh-cut potatoes

The shelf life of fresh-cut fruits and vegetables is affected by microbial growth, enzymatic browning, and loss of flavor. Although ultrasound (US) treatment is often used in the preservation of fresh-cut fruits and vegetables, it has limited antibacterial and preservative effects. Here, we used cactus polysaccharides (CP) to enhance the preservative effect of ultrasound treatment and extended the shelf life of fresh-cut potatoes. The results showed that combined treatment (CP + US) exerted better antimicrobial and anti-browning effects than individual treatments (either US or CP alone). In addition, CP + US has no adverse effect on texture and quality properties, as well as reduced the mobility of internal water. Combination treatment not only significantly decreased the activities of polyphenol oxidase and peroxidase (P < 0.05), but also maintained a high level of phenylalanine ammonia lyase activity and total phenol content during storage. It also maintained the integrity of cell membrane and reduced its permeability by inhibiting the peroxidation of membrane lipids. In addition, CP + US treatment significantly inhibited the activity of antioxidant enzymes and maintained a high DPPH scavenging ability. GC-IMS technology was used to evaluate the flavor of fresh-cut potatoes. The results showed that CP + US treatment reduced the production of a peculiar smell during storage and maintained a good flavor by inhibiting the production of aldehydes. Taken together, these results indicate that the effective preservation method of CP + US treatment can be utilized to increase the shelf life of fresh-cut potatoes.

An in‐depth review of novel cold plasma technology for fresh‐cut produce

Fresh-cut fruits and vegetables refer to edible commodities that are free from large-scale and typical traditional processing operations. However, maintaining their nutritional value and microbiological integrity is challenging. The processing operations such as peeling, cutting, and trimming done in the fresh-cut industry can trigger deteriorative reactions such as tissue softening and enzymatic browning. As a countermeasure, cold plasma technology has emerged as an innovation for minimal processing of several edible foods including fresh-cut produce. Cold plasma may be generated using a variety of technologies, including microwave frequencies, infrared frequencies, radio-wave frequencies, dielectric barrier discharge, and plasma jet devices. This review enlightens the effects of cold plasma on fresh-cut produce from physicochemical and organoleptic aspects. Although cold plasma technology has proven to be beneficial for fresh-cut fruits and vegetables, several aspects, including its impact on nutrition and flavor, need to be investigated further. Novelty impact statement Cold plasma, being one of the most advanced and safest of techniques, has been extensively discussed with reference to different types, techniques, and operational parameters used in various studies. This review highlights non-thermal novelties in the processing and preservation of fresh-cut produce. The effects of cold plasma technology on the physicochemical attributes, organoleptic characteristics, and shelf life of fresh-cut fruits and vegetables have been reviewed.

Review: Effects of edible coating on fresh-cut fruits

Fresh-cut fruits have a shorter shelf life due to its perishable nature. Edible coating being biodegradable and environmental friendly, provides protective covering to fresh-cut fruits. This review covered the effects of edible coating on fresh cut fruits, i.e., apple, apricot, banana, kiwi, mango, papaya, pineapple, strawberries, watermelon and melon. It was observed that edible coating positively affected weight loss, titratable acidity, ph, firmness, shelf life, color, respiration rate and microbial load in fresh cut fruits. Shelf life of all fresh-cut fruits was significantly enhanced by edible coating. Being pre-processed products, it also reduced the time required for cutting fruits. Sensory scores were also acceptable for edible-coated fruits. Literature available on the extension of shelf life of fresh-cut fruits are not sufficient especially of kiwi, strawberry, banana and mango.

Bioactive edible film based on Konjac glucomannan and probiotic Lactobacillus plantarum strains: Physicochemical properties and shelf life of fresh-cut kiwis.

This study investigates the efficacy of Lactobacillus plantarum strains (L. plantarum LP3, L. plantarum AF1, and L. plantarum LU5) incorporated into a Konjac-based edible coating in order to prevent fungi growth and retain physicochemical characteristics of fresh-cut kiwis kept at 4°C for 5 days. For this purpose, probiotic survivability, fungi counts, decay percentage, color changes, titratable acidity (TA), total soluble solids (TSS), ascorbic acid content, chlorophyll amount, total phenolics, and DPPH radical scavenging of fresh-cut kiwis were evaluated. Results indicated that the population of L. plantarum strains in all treated groups retained at sufficient amounts of probiotic consumption (above 6 and 7 log CFU/g) at the end of the storage period and L. plantarum LP3 had the highest viability in comparison to other strains. The incorporation of L. plantarum in Konjac coatings markedly reduced the amount of decay and color changes and maintained the chlorophyll and ascorbic acid contents of fresh-cut kiwis compared to control samples. After 5 days of storage, total phenol content and the DPPH antiradical activities of coated kiwi slices treated with probiotics were observed about 1.2 and 10.23g/kg compared to the pure Konjac-coated (0.84 and 7.6g/kg) and Konjac-uncoated samples (0.44 and 4.1g/kg), respectively. No significant difference in TSS and TA of various treatments was detected. Coated kiwi slices loaded with probiotics had higher overall acceptability compared to Konjac-coated and control samples. In addition, probiotic treatment significantly reduced mold and yeast counts compared to the control group. PRACTICAL APPLICATIONS: Recently, edible films have received more consideration as a promising method to enhance the shelf life of fresh-cut fruit. The presence of probiotics in edible films reduces the growth of spoilage microorganisms and improves consumer health. Our findings encourage the application of edible coating incorporated with L. plantarum to design multifunctional foods and preserve the qualities of fresh-cut kiwifruit.

Sensory quality and flavour of alginate coated and repetitive pulsed light treated fresh-cut cantaloupes (Cucumis melo L. Var. Reticulatus Cv. Glamour) during storage

Fresh-cut fruits are popular due to the convenience provided. However, fresh-cut processes damage fruit tissues and reduce the shelf life of products. Pulsed light (PL) treatment is a decontamination method of foods. PL treatment given repetitively at a certain interval during storage could further extend the shelf life of fresh-cut fruits. Edible coating preserves fresh-cut fruits by providing mechanical strength and reducing respiration and water loss. This study was to evaluate the effects of alginate coating combined with repetitive pulsed light (RPL) on sensory quality and flavour of fresh-cut cantaloupes during storage. Cantaloupes were treated with alginate (1.86%, w/v) and RPL (0.9J/cm2 at every 48h up to 26days) alone or in combination. Flavour analysis of fresh-cut cantaloupes was carried out every 12days during storage at 4 ± 1°C while sensory analysis was performed on day 32. Alginate coating and/or RPL retained sugar contents (17.92-20.01g/kg FW for fructose, 18.77-19.98g/kg FW for glucose and 23.02-29.41g/kg FW for sucrose) in fresh-cut cantaloupes during storage. Combination of alginate with RPL reduced accumulation of lactic acid although alginate coating was more effective to minimise changes of other organic acids in fresh-cut cantaloupes. The combined treatment was also more effective than individual treatment in retaining total aroma compound concentration of fresh-cut cantaloupes during storage with the highest relative concentration, i.e. 3.174 on day 36. Overall, the combined alginate coating and RPL was effective to maintain the fresh-like sensory quality of fresh-cut cantaloupes with insignificant overall acceptability compared to the control.

A REVIEW ON POSTHARVEST MANAGEMENT AND ADVANCES IN THE MINIMAL PROCESSING OF FRESH-CUT FRUITS AND VEGETABLES

The review mainly focused on ready-to-eat (RTE) fresh-cut fruits and vegetable (F&amp;V) which are consumed raw or processed. In recent years, there has been growing evidence of consumption of minimally processed fruits and vegetable for the prevention of many chronic diseases. Some chemicals like chlorine, calcium chloride, etc., are used for sanitisation purpose in fruit and vegetable industry, but these chemicals form carcinogenic chlorinated compounds which have adverse human health impacts. Therefore, advanced alternative sanitisation techniques, processing methods and improved packaging materials may be implemented for ensuring safety and extending the shelf life of fresh-cut fruit and vegetable. Edible coating materials like methylcellulose, carrageenan and alginate are used for reduction of microbial load and preservation of fruit from the fruit and vegetable surface after harvesting. Some emerging alternative methods such as irradiation, high-pressure processing, power ultrasound, cold plasma and limitations of chemical methods have also been reported in this review for maintaining the quality and prevention of spoilage to a greater extent. The review also covers some post-harvest processing steps such as washing, sanitation, cutting and dipping treatments used for processing of fruits and vegetable. The information presented in this manuscript would be highly beneficial and effective for preservation, sensorial and nutritional quality of fresh-cut fruit and vegetable.

Innovative Coating Technologies to Extend the Shelf Life of Fresh-Cut Fruits by Edible Film Materials

In this work, the application of a novel strategy to extend the shelf life of fresh cut fruits isproposed. In particular, edible film coatings from natural resources were used with the aim ofextending the shelf life of fresh cut apples. Chitosan and carboxymethylcellulose were consideredand a promising formulation was developed. The evaluation of the shelf life extension of fruits wasperformed in a multiparametric way over a period of 10 days. The percentage weight losses werecalculated for treated and untreated fruits in order to evaluate the performances of the coatingmaterialto avoid contact with environment. In the meanwhile, gas chromatography coupled to massspectrometry (GC-MS) was considered to determine the volatile compounds producing acharacteristic flavor of apples. Results demonstrated a significant improvement in the physiologicalloss in weight of treated fruits with respect to controls, while the study of the volatile componentindicated the ability of treated fruits to retain its freshness during storage.

Combination of alginate coating and repetitive pulsed light for shelf life extension of fresh-cut cantaloupe (Cucumis melo L. reticulatus cv. Glamour)

This study was to optimise the alginate coating formulations for shelf life extension of fresh-cut cantaloupe treated with repetitive pulsed light (RPL). The optimised coating formulation was 1.86% alginate and 1.47% glycerol. The fresh-cut cantaloupe was coated with the optimised coating followed by RPL using 0.9 J cm−2 at every 48 hr for the first 26 days during 40 days of storage at 4 ± 1 °C. The combined treatment prolonged the shelf life of fresh-cut cantaloupe in term of microbiological quality with extended 28 and 24 days compared to the untreated and alginate-coated samples, respectively. The coating reduced fluid loss of cantaloupe while maintaining its physicochemical quality, that is, headspace gas composition, firmness, colour, pH, titratable acidity and nutritional quality such as total phenolic, ascorbic acid and total carotenoid contents. Overall, the combined treatment was more effective to preserve fresh-cut cantaloupes compared to RPL or coating alone. Practical applications Fresh-cut cantaloupes are receiving great interest due to the benefits of convenience and fresh-like quality provided. However, fresh-cut cantaloupes are susceptible to microbial contamination and deterioration as a result of tissue injury caused by fresh-cut processes. Pulsed light treatment is a nonthermal technique that can preserve fresh-cut fruits by inactivating microorganisms. However, PL treatment alone is insufficient to preserve quality of fresh-cut fruits. Hurdle technology by combining repetitive PL treatment and edible coating is an efficient approach for extending shelf life of fresh-cut fruits in terms of microbiological and physicochemical properties. The results from this study contribute to the knowledge regarding the feasibility of combining RPL treatment and edible coating to further extend shelf life of fresh-cut cantaloupes compared to the individual treatment. The knowledge can be utilised by food producers for commercialising fresh-cut products.

Recent advances in modified atmosphere packaging and edible coatings to maintain quality of fresh-cut fruits and vegetables

ABSTRACTProcessing of fruits and vegetables generates physiological stresses in the still living cut tissue, leading to quality deterioration and shorter shelf life as compared with fresh intact produces. Several strategies can be implemented with the aim to reduce the rate of deterioration of fresh-cut commodities. Such strategies include low temperature maintenance from harvest to retail and the application of physical and chemical treatments such as modified atmosphere packaging (MAP) with low O2 and high CO2 levels and antioxidant dips. Other technologies such as edible coatings with natural additives, new generation of coatings using nanotechnological solutions such as nanoparticles, nanoencapsulation, and multilayered systems, and nonconventional atmospheres such as the use of pressurized inert/noble gases and high levels of O2 have gained a lot of interest as a possibility to extend the shelf life of minimally processed fruits and vegetables. However, the high perishability of these products challenges in many cases their marketability by not achieving sufficient shelf life to survive the distribution system, requiring the combination of treatments to assure safety and quality. This review reports the recent advances in the use of MAP, edible coatings, and the combined effect of both technologies to extend the shelf life of fresh-cut fruits and vegetables.

Utilização de revestimento comestível à base de quitosana para aumentar a vida útil de melão minimamente processado

Edible coatings may contribute to extend the shelf life of fresh-cut fruits by reducing moisture and solute migration, gas exchange, respiration, and oxidative reaction rates, as well as by reducing physiological disorders. The objective of this study was to evaluate the effects of chitosan application associated with montmorillonite clay and essential oil of cloves in relation to chemical, physical, microbiological ( Escherichia coli , Salmonella and Yeast and Mold) and sensory attributes characteristics of melon ( Cucumis melo L. ) minimally processed when stored at 4±1°C. The melons were washed, peeled, seeds removed, diced, was applied coatings and then the cubes were stored in a PET (polyethylene terephthalate) packaging for a period of 7 days at 4±1°C. Analyses of pH, total soluble solids, titratable acidity, microbiological ( Escherichia coli , Salmonella , Molds and Yeasts) and sensory analysis (texture, color, aroma and overall assessment) were carried out. The analyses were performed in triplicate on the processing day (day 0) of the samples and after 1, 3, 5 and 7 days of storage. It can be concluded that the that coatings containing chitosan together with Montmorillonite clay and essential oil of clove (T3 and T4) were more efficient in conserving the physical and chemical characteristics of minimally processed melon when compared to the control sample and treatment contained only chitosan. The use of chitosan alone and together with montmorillonite and Clove essential oil were effective in maintaining the sensory and microbiological characteristics for a longer time.

Extension of Chinese Water Chestnut

Prolonging shelf life of fresh-cut Chinese water chestnut (CWC) by citric acid, D-ascorbic acid and L-cysteine (L-Cys) was investigated. Browning degree and eating quality were evaluated as sensory indices of shelf life of fresh-cut CWC. The optimal method of prolonging shelf life of fresh-cut CWC by antioxidant was as follows: fresh-cut CWC was surface sterilized by immersing in 0.1% (w/v) NaClO solution for 10 min, and air-dried for 30 min. Then 12 pieces of fresh-cut CWC were immersed in 200 mL 0.4% L-Cys aqueous solution for 20 min and air-dried for 30 min, and stored at 4C in a temperature-controlled room. The method can prolong shelf life of fresh-cut CWC 5 by days than that of storage at 4C only. Practical Applications The paper can provide a new effective method to prolong shelf life of fresh-cut fruit and vegetable.

Repetitive pulsed light treatment at certain interval on fresh-cut cantaloupe (Cucumis melo L. reticulatus cv. Glamour)

Abstract This study was done in order to investigate the effect of repetitive pulsed light (RPL) treatment at certain interval on microbiological stability, quality and physicochemical changes of fresh-cut cantaloupes during storage. Fresh-cut cantaloupes packed in polypropylene bag were exposed to RPL treatment with fluences of 0.3, 0.6, 0.9 and 1.2 J/cm2 every 48 h up to 28 days of storage at 4 ± 1 °C. The microbiological quality, headspace gas composition, physical quality (firmness, fluid loss and colour), chemical quality (pH, titratable acidity, total soluble solids, total phenolic content and ascorbic acid content) and microscopic observations of fresh-cut cantaloupes were determined during storage. No significant (p > 0.05) effect was observed for firmness, colour and total soluble solids of fresh-cut cantaloupes treated with RPL throughout the storage study. Repetitive PL treatment using 0.9 J/cm2 was the most effective fluence for extending the shelf life of fresh-cut cantaloupes with extension by 20 days compared to control in term of microbiological quality while maintaining all quality parameters. Negative effect of single PL treatment (SPL) (11.7 J/cm2) on tissue structure of fresh-cut cantaloupes during storage was minimised by applying RPL treatment (0.9 J/cm2 for every 48 h interval). Industrial relevance Fresh-cut cantaloupes are becoming more popular due to the benefits of convenience and fresh-like quality provided. However, fresh-cut cantaloupes are susceptible to microbial contamination and deterioration as the fruit tissue is injured due to cutting of the product into pieces. Repetitive PL (RPL) treatment is an alternative application to single PL (SPL) treatment for extending shelf life of fresh-cut fruits by minimising the negative effect of SPL treatment on the tissue structure. This study demonstrates the usefulness of RPL treatment to further extend the shelf life of fresh-cut cantaloupes compared to SPL treatment. This is crucial for vending cut fruits through refrigerators equipped with RPL system. The RPL application contributes to reduced postharvest loss and increased convenience and availability of fresh-cut fruits to the public which benefit both producers and consumers.

Combined Effect of Ozone Treatment and Modified Atmosphere Packaging on Antioxidant Defense System of Fresh-Cut Green Peppers

The changes in respiration rates, malondialdehyde (MDA) content and antioxidant enzyme activities of fresh-cut green peppers treated with ozone (6.42 mg/cm3, 15 min), modified atmosphere packaging (MAP; 3% O2, 4% CO2 and 93% N2) and ozone + MAP during storage at 5C for 21 days were investigated in a laboratory environment. The three treatments all reduced respiration rates and MDA content compared to the control group. The enzyme activities in fresh-cut green peppers including peroxidase (POD), superoxidase dismutase (SOD) and L-phenylalanin ammonia-lyase (PAL) were induced by ozone and MAP treatments while polyphenol oxidase (PPO) activities were inhibited. And a much better effect was observed when the ozone and MAP treatment were combined which indicated ozone and MAP had a synergistic effect on inhibiting the respiration rates and the predication of MAD by enhancing the effectiveness of the antioxidant defense system through enhancing the activity of POD, SOD, PAL and inhibiting the activity of PPO. Practical Applications Because of the nutritional qualities and convenience, fresh-cut fruits and vegetables have gained popularity in recent years. However, fresh-cut fruits and vegetables shelf ife are limited due to the natural inherent barriers of fruits and vegetables are damaged during processing. The antioxidant defense system which consists of a series of antioxidase such as superoxidase dismutase, peroxidase, catalase, is an important enzyme system which can inhibit oxidation reactions in tissues. It is beneficial for extending shelf life of fresh-cut fruits and vegetables. This study has given an experimental evidence that ozone and modified atmosphere packaging (MAP) both can enhance the effectiveness of the antioxidant defense system. And the combination of ozone and MAP treatment can enhance the induction. Thus, ozone and MAP treatment have the advantages of prolonging shelf life of fresh-cut fruits and vegetables.

UV-A light treatment for controlling enzymatic browning of fresh-cut fruits

Abstract Enzymatic browning is critical in the preservation of the quality and the shelf-life of fresh-cut fruits. Non-thermal technologies such as UV radiation are emerging for controlling polyphenol oxidase (PPO) activity, the main agent responsible for browning. After determining the best operational conditions of a UV LED illuminator (2.43 · 10 − 3 Wm − 2 irradiance), the anti-browning effect of UV-A light (390 nm) treatment at 25 °C over increasing time periods up to 60 min was assessed on fresh-cut apples and pears. Color variation (ΔE) and its percent reduction (%RΔE) were measured using a colorimeter and the greatest effect was observed in apples which showed higher %RΔE values than pears (58% vs 25% after 60 min exposure, respectively). Anti-browning was found to be related to irradiance, exposure time and the fruit cultivar. Overall this study confirmed UV-A LED technology as an eco-friendly alternative to traditional approaches for reducing browning of minimally processed products. Industrial relevance Treatment of fresh-cut products with UV-A LED is not only easy and inexpensive to produce but also presents few hazards for humans. Moreover, the use of LED light sources brings many advantages such as energy savings, device durability, low environmental impact, high luminous efficiency and little thermal effect. UV-A LED technology has great potential to meet the demands of the food industry in the processing of fresh-cut fruits and vegetables. In addition it could also be considered a pre-treatment of fruits and vegetables being processed for the production of snacks.

Effect of ripeness stage during processing on Listeria monocytogenes growth on fresh-cut ‘Conference’ pears

There are several factors that affect the shelf life of fresh-cut fruit, including the cultivar, the ripeness stage of the fruit during processing and the fruit's storage atmosphere and temperature. The effect of fruit ripeness during processing on the survival and growth of Listeria monocytogenes on fresh-cut ‘Conference’ pear slices at different temperatures (5, 10 and 20 °C) was studied. The four ripeness stages studied in this work (assessed by a fruit's firmness) were mature-green (54–60 N), partially ripe (43–53 N), ripe (31–42 N) and overripe (<31 N). In our studies, pH, acidity and soluble solids content did not significantly change during conditioning at 20 °C. L. monocytogenes grew under all experimental conditions, showing an increase of approximately 2 log CFU g−1 after 8 days of storage at 5 °C. There were significant differences in the L. monocytogenes population between different ripeness stages at the end of the experiments at 10 and 20 °C. Regardless of the ripeness stage of a fresh-cut pear, the growth potential of L. monocytogenes increased with increasing temperature. A pear's ripeness stage during processing is an important consideration to ensure the quality of a fresh-cut pear, but it is not as important for preventing L. monocytogenes growth at common storage temperatures.

Quality characteristics of fresh-cut ‘Fuji’ apple slices from 1-methylcyclopropene-, calcium chloride-, and rare earth-treated intact fruits

The residual influence of preservers on the subsequent fresh-cut fruit products has not been well studied. In order to investigate the quality maintenance of fresh-cut products, quality characteristics of fresh-cut ‘Fuji’ apple slices from 1-methylcyclopropene (1-MCP)-, calcium chloride-, or rare earth-treated intact fruits were studied by measuring ethylene production, respiration rate, weight loss, surface color, firmness, titratable acidity (TA), and sensory evaluation during storage. Rare earth pretreatment significantly reduced respiration rate, weight loss percentage, and softness of post-cutting pieces, as compared to control, and the reduced levels were similar to those of calcium treatment. 1-MCP was the most effective treatment in reducing respiration rate and ethylene production of apple slices during the whole storage period. However, rare earth pretreatment was found to be more effective in maintaining cut surface color and TA of post-cutting pieces when compared to calcium and 1-MCP. Rare earth and 1-MCP pretreated samples gave the higher scores of human sensory preference than calcium treated samples. The results suggest that rare earth, along with calcium and 1-MCP, can be used for intact fruits as a potentially promising preserver for better maintenance of firmness, surface color, and prolonged shelf life of fresh-cut fruits.