Fresh-cut Bell Pepper Research Articles

Characterization and Antioxidant and Antibacterial Activities of Carboxymethylated Tamarind Seed Polysaccharide Composite Films Incorporated with ε-Polylysine and Their Application in Fresh-Cut Green Bell Pepper Preservation.

Traditional petroleum-based food-packaging materials have poor permeability, limited active packaging properties, and difficulty in biodegradation, limiting their application. We developed a carboxymethylated tamarind seed polysaccharide composite film incorporated with ε-polylysine (CTPε) for better application in fresh-cut agricultural products. The CTPε films exhibit excellent water vapor barrier properties, but the mechanical properties are slightly reduced. Fourier transform infrared spectroscopy and X-ray diffraction spectra indicate the formation of hydrogen bonds between ε-PL and CTP, leading to their internal reorganization and dense network structure. With the increase of ε-PL concentration, composite films showed notable inhibition of postharvest pathogenic fungi and bacteria, a significant enhancement of 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging activity, and gradual improvement of wettability performance. Cytotoxicity experiments confirmed the favorable biocompatibility when ε-PL was added at 0.3% (CTPε2). In fresh-cut bell pepper preservation experiments, the CTPε2 coating effectively delayed weight loss and malondialdehyde increase preserved the hardness, color, and nutrients of fresh-cut peppers and prolonged the shelf life of the fresh-cut peppers, as compared with the control group. Therefore, CTPε composite films are expected to be a valuable packaging material for extending the shelf life of freshly cut agricultural products.

Development of xanthan gum/hydroxypropyl methyl cellulose composite films incorporating tea polyphenol and its application on fresh-cut green bell peppers preservation

The aim of this work was to develop an edible packaging material with good performance that can be used for fresh-cut vegetables preservation. The xanthan (XG)-hydroxypropyl methylcellulose (HPMC)-tea polyphenols (TP) composite film (XHT) was prepared by adding TP to the composite film-forming solution of XG and HPMC. At optimum TP dosage of 6% (XHT6), the tensile strength and elongation at break were at the maximum. The antioxidant activity and antibacterial properties were also enhanced, demonstrated good inhibitory ability to Staphylococcus aureus. After 8 days, the amount of Vitamin C that was retained by XHT6 was 127.81% and 7.83% higher than unpackaged and XHT0, respectively. Additionally, the MDA content in green peppers were 39.16% and 78.87% higher than that of unpackaged and XHT0, respectively. Practical applications of XHT films in preserving fresh-cut bell peppers had also shown positive results, making it possible as potential food packaging.

A new way to reduce postharvest loss of vegetables: Antibacterial products of vegetable fermentation and its controlling soft rot caused by Pectobacterium carotovorum

Bacterial soft rot caused by Pectobacterium carotovorum has brought huge economic losses to post-harvest vegetables. In this study, vegetables were used as raw materials to produce food-grade antibacterial products, fermented by lactic acid bacteria, to control P. carotovorum. A total of 32 kinds of vegetables were fermented by Lactobacillus paracasei WX322, results showed that 31 vegetable fermentation products had antibacterial activities at different levels. The green pepper fermentation antibacterial product (GPFA) had the highest activity and was selected for further analysis. On the 7th day of fermentation, the antibacterial activity of GPFA reached the maximum, with 640 AU/mL. Two bacteriocins, GP-19 and EP-20, were identified by LC-MS/MS. Growth curve and time-kill curve showed that the GPFA could effectively inhibit and kill P. carotovorum at a dose-dependent manner. SYTO9TM/PI staining observation further confirmed its bactericidal ability. Meanwhile, GPFA treatment led to irregular deformation of cells with rough surface observed using scanning electron microscopy (SEM). Moreover, in vivo assay showed that GPFA treatment significantly reduced the disease incidence and decay degree of pepper soft rot. In addition, GPFA treatment could prolong the shelf life of fresh-cut bell pepper. This study indicates that antibacterial products based on vegetable fermentation can provide a new method for the control of vegetable soft rot.

Slightly acidic electrolyzed water combination with antioxidants and fumaric acid treatment to maintain the quality of fresh-cut bell peppers

This work evaluated the effect of slightly acidic electrolyzed water (SAEW), fumaric acid (FA) and antioxidant solution treatments on the quality of red and yellow fresh-cut bell pepper (FCBP) challenged with foodborne pathogens (Listeria monocytogenes and Salmonella sp.). The quality of the FCBP was determined in terms of the microbial contamination, and sensory properties. The sanitizer treatment such as (T1-T6) significantly inhibited the microbial colonization comparing to the untreated control (T0) group of R-FCBP and Y-FCBP. Total bacterial count (TBC) was reduced by 4.1 and 76.8 fold for Y-FCBP and R-FCBP respectively when treated with T6 during the 15 day of storage. The treatment of T6 significantly reduced the total fungal (TF) counts by 7.9 fold for Y-FCBP and 7.7 fold for R-FCBP comparing to T0 at 15 day of interval. Also, this treatment inhibited the total Salmonella sp., (TSC) by 4.93 fold for Y-FCBP and 4.23 fold for R-FCBP when comparing to T0 at 15 day of interval. These results proved the efficiency of T6 (FA, SAEW, and antioxidant solution) treatment compared to untreated control (T0) expands the quality of FCBP up to 9 days when preserved at 4 °C through inhibiting the microbial colonization.

The Impact of N2-Assisted High-Pressure Processing on the Microorganisms and Quality Indices of Fresh-Cut Bell Peppers.

This work aimed to evaluate the effects of N2-assisted high-pressure processing (HPP, 400 MPa/7.5 min and 500 MPa/7.5 min) on the microorganisms and physicochemical, nutritional, and sensory characteristics of fresh-cut bell peppers (FCBP) during 25 days of storage at 4 °C. Yeasts and molds were not detected, and the counts of total aerobic bacteria were less than 4 log10 CFU/g during storage at 4 °C. The total soluble solids and L* values were maintained in HPP-treated FCBP during storage. After the HPP treatment, an 18.7–21.9% weight loss ratio and 54–60% loss of hardness were found, and the polyphenol oxidase (PPO) activity was significantly inactivated (33.87–55.91% of its original activity). During storage, the weight loss ratio and PPO activity of the samples increased significantly, but the hardness of 500 MPa/7.5 min for treated FCBP showed no significant change (9.79–11.54 N). HPP also effectively improved the total phenol content and antioxidant capacity of FCBP to 106.69–108.79 mg GAE/100 g and 5.76–6.55 mmol Trolox/L; however, a non-negligible reduction in total phenols, ascorbic acid, and antioxidant capacity was found during storage. Overall, HPP treatments did not negatively impact the acceptability of all sensory attributes during storage, especially after the 500 MPa/7.5 min treatment. Therefore, N2-assisted HPP processing is a good choice for the preservation of FCBP.

Chitosan-tea tree oil nanoemulsion and calcium chloride tailored edible coating increase the shelf life of fresh cut red bell pepper

High nutritional values and unique taste of whole or fresh-cut bell pepper is increase the consumption rate and that lead its commercial demand globally. The major challenges in fresh-cut bell pepper consumption is foodborne pathogenic contaminations and quality loss. Hence, this study aimed to evaluate the impact of calcium chloride (CaCl2), and low molecular weight chitosan (LMWCS)/ tea tree oil (TTO) nanoemulsion coating on the fresh-cut red bell pepper (FCRBP) shelf life and quality for 21 days stored at 4 °C. The combined CaCl2-LMWCS/TTO emulsion treatment maintained the texture, sensory behavior, and overall quality of FCRBP for eighteen days through controlling the contamination of foodborne pathogenic fungi and bacteria including Salmonella enterica, and Listeria monocytogens.,. Furthermore, combined treatment diminishes the microbial colonization on FCRBP was confirmed using UHR-scanning electron microscope. Additionally, total phenolic (89.89 mg/g of GAE), flavonoid content (5.12 mg/g of QE) and antioxidant activity (> 80 %) were retained in FCRBP coated with CaCl2and nanoemulsion than uncoated control. Therefore, this work demonstrated the potantial of nanoemulsion (LMWCS/TTO) and CaCl2to serve as coating agent to maintain the self-life and quality of FCRBP up to 18 days at 4 °C and it received the industrial importance.

Edible treatments of Capsicum extracts inactivate the microbial contaminations to improve the quality of fresh‐cut bell pepper ( Capsicum annuum L. var. grossum (L.) Sendt)

The present study aimed to examine the efficiency of ethanolic extract of Capsicum annuum L (CAE) in improving the shelf life and quality of fresh-cut C. annuum (FCCa). The uniformly sliced FCCa were prewashed with sodium hypochlorite solution (NaOCl) and then treated with 10% of CAE. The foodborne pathogens of Listeria monocytogenes and Salmonella enterica were patched on the surface of FCCa and stored at 15°C and 4°C for 12 days. The shelf life of FCCa was examined in terms of physical appearance, weight loss, total flavonoid, and phenolic content, antioxidant, and antimicrobial activity in a regular interval. The results revealed that the combinational treatment diminished the pathogen load, and the outcomes of the study suggested that the conventional method of NaOCl washing with CAE significantly improved the shelf life of FCCa by retaining its antioxidant, and phytochemical compositions at 4°C for 12 days. Practical applications Washing is an efficient strategy to extend the life span of fruits and vegetables, from this prospective NaOCl with ethanolic extract of Capsicum annuum extending the shelf life of fresh-cut bell pepper were detailed documented. The combinational treatment was markedly diminished the foodborne pathogen load with a notable antioxidant activity through maintaining its total phenolic and flavonoid content throughout the storage period. Taken together the possible practical outcome of this study suggested that conventional methods of chlorine solution with C. annuum extracts enhance the shelf life of the fresh-cut form of fruits and vegetables and prevent economic loss during the storing period.

Chitosan nanoparticles as edible surface coating agent to preserve the fresh-cut bell pepper (Capsicum annuum L. var. grossum (L.) Sendt)

This work synthesized chitosan nanoparticles (CSNPs) by ionic gelation method using sodium tripolyphosphate pentabasic (STPP) and applied as nano-coating agent to extend the shelf life of fresh cut bell pepper (FCP) by preventing the microbial contaminations. The CSNPs were spherical shaped and 22.55 ± 1.69 d.nm sized with ζ-potential of 45.10 ± 1.42 mV confirmed by UHR-SEM, FE-TEM, and ζ-potential size analyses. The crystallinity and functional group changes were determined by XRD and FT-IR analyses respectivelly. The antioxidant activity of CSNPs was determined in terms of DPPH and ABTS scavenging activities. The 1% and 3% of CSNPs were found to be minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) respectively against all tested bacteria. The MBC of CSNPs was exhibited the promising anti-biofilm activity. Therefore, the 3% of CSNPs was used to prepare the chitosan nano-coating (CSNC), and applied on surface of FCP to prevent the microbial contaminations such as fungi, bacteria including Listeria monocytogenes and Salmonella enterica. The experimental results showed that the application of CSNC was maintained the FCP for 12 days at 5 °C without loss of weight, and sensory quality.

Lactobacillus rhamnosus GG and Biochemical Agents Enrich the Shelf Life of Fresh-Cut Bell Pepper (Capsicum annuum L. var. grossum (L.) Sendt).

This work analyzed the individual and combined effects of biochemical additives and probiotic strain Lactobacillus rhamnosus GG on red and yellow fresh-cut bell pepper (R- and Y-FCBP, respectively) stored at two different temperatures (4 °C and 15 °C) for 15 days. The results revealed that the combined application of biochemical additives and L. rhamnosus GG inhibited the colonization of total bacterial counts (25.10%), total Salmonella counts (38.32%), total Listeria counts (23.75%), and total fungal counts (61.90%) in FCBP. Total bacterial colonization was found to be higher in R-FCBP (1188.09 ± 9.25 CFU g−1) than Y-FCBP (863.96 ± 7.21 CFU g−1). The storage at 4 °C was prevented 35.38% of microbial colonization in FCBP. Importantly, the L. rhamnosus GG count remained for up to 12 days. Moreover, the combined inoculation of the biochemical additives and L. rhamnosus GG treatments (T3) maintained the quality of R- and Y-FCBP for up to 12 days at 4 °C without any loss of antioxidant properties. This work reports the successful utilization of L. rhamnosus GG as a preservative agent for maintaining the quality of FCBP by preventing microbial colonization.

The Bactericidal Effect of Intense Pulsed Light (IPL) on Fresh-cut Bell Pepper and Ginger

This study evaluated the microbiological quality of fresh-cut bell pepper and ginger, as well as the inactivation effects of intense pulsed light (IPL) on E. coli ATCC 25922 inoculated in the fresh-cut samples by varying the treatment voltages (1,200-2,400 V) and time (1–7 min). The contamination levels of mesophilic bacteria, psychrophilic bacteria, yeast and mold for bell pepper and ginger were 6.64±0.81 and 6.35±1.96 log CFU/g, 6.75±1.13 and 5.63±1.89 log CFU/g, and 4.68±0.43 and 4.57±1.25 log CFU/g respectively. Through the IPL treatment at 2,400 V for 7 min, 2.04 and 2.11 log of E. coli ATCC 25922 inoculated in bell pepper and ginger were reduced, respectively, with a negligible temperature rise (< 2.2oC). Although the reduction rate varied, the bactericidal effect of E. coli ATCC 25922 showed an increase as treatment time and voltage increased. Under the same treatment conditions, temperature increased by 1.71oC and 2.13oC for bell pepper and ginger, respectively. These results demonstrate that IPL is a suitable device for inactivating E. coli ATCC 25922 on fresh-cut bell pepper and ginger.

Fresh-Cut Bell Peppers in Modified Atmosphere Packaging: Improving Shelf Life to Answer Food Security Concerns.

The influence of modified atmosphere packaging (MAP, 10% O2 and 45% CO2) on the quality characteristics of fresh-cut green, red and yellow bell peppers (Capsicum annuum L. var annuum) was investigated. Packaging film bags (Krehalon MLF40-PA/PE) with fresh-cut bell peppers were stored for up to 17 days at 5 °C. The in-package O2 level ranged between 10 and 15%, respecting the current recommendations for fresh-cut vegetable products. Initial CO2 levels were higher than commonly used (from 5 to 10%), decreasing progressively over time due to the permeability of the selected polyethylene film. At the end of the storage period, they stabilized between 2 and 5%. A small variation in texture, moisture, titratable acidity, pH and microbial growth was observed during the storage period, as well as a good color retention and sensory properties maintenance. Negligible losses in the antioxidant activity and bioactive compounds (total phenol, flavonoid, anthocyanin and carotenoid content) were noted at the end of the study. Sensory analysis showed that panelists could not detect significant differences among sampling periods. A PCA with predictive biplots confirmed the existence of significant correlations. The products retain their initial characteristics without severe loss of quality until at least the 17th storage day. Given the current commercial shelf life of fresh-cut bell peppers, ranging from 9 to 14 days, the described treatment enabled an increase of at least 3 days (20%) of the products shelf life, reducing food waste and contributing to food security.

Biogenic silver nanoparticles-polyvinylpyrrolidone based glycerosomes coating to expand the shelf life of fresh-cut bell pepper (Capsicum annuum L. var. grossum (L.) Sendt)

The present work reported the comparative analysis on the preparation and characterization of chemically and green synthesized silver nanoparticles polyvinylpyrrolidone (PVP) based glycerosomes (C/G-PVP-AgNPs) and their function as antimicrobial nanocoating agent to augment the shelf life of the fresh cut pepper (FCP). The UV Spectrophotometer results revealed peak at 400–420 nm indicating the formation of G-AgNPs and C-PVP-AgNPs. The Fourier-transform infrared spectroscopy (FTIR) results indicated the involvement of phytomolecules from the pedicel extracts on the synthesis of G-AgNPs and this analysis displayed the peaks corresponding to copolymers PVP and glycerol in G/C-PVP-AgNPs. The X-ray diffractometer (XRD) results confirmed G-AgNPs followed the occurrence of the Ag in G/C-PVP-AgNPs. The particle size analyzer (PSA) and field emission transmission electron microscopy- Energy Dispersive X-ray Spectroscopy (FETEM-EDS) revealed the mean size of 37.01 nm for G-AgNPs, 123 nm for G-PVP-AgNPs and 45.26 nm for C-PVP-AgNPs. The G-PVP-AgNPs showed more antibacterial activities than the C-PVP-AgNPs as evident by low minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The application of the nano coating of G-PVP-AgNPs extended the shelf life of the red or yellow FCP (Fresh Cut bell Pepper) for 12 d at 4 °C without causing any harm to cellular or physicochemical properties of FCP. The G/C-PVP-AgNPs coated FCP juices did not cause any toxicity to the survival of roundworms while the uncoated FCP juice caused the cellular damage in the roundworm. These results suggested the potential application of G-PVP-AgNPs as a preservative agent to augment the shelf life of FCP in food industry for the future.

Hyperspectral fluorescence imaging for shelf life evaluation of fresh-cut Bell and Jalapeno Pepper

Unlike many of the fresh-cut popular leafy vegetables whose deterioration becomes apparent in wilting and browning, fresh-cut pepper (Capsicum spp.) undergoes subtler visible changes. The current study investigated hyperspectral fluorescence imaging as an alternative to monitor the physical changes to sliced pepper rings in cold storage (4 °C, 0–21 d). Five accessions of bell-type pepper and an equal number of jalapeno-type pepper accessions were prepared by routine fresh-cut operation and placed in cold storage. At weekly intervals, pepper samples were scanned by UV-excited (365 nm) hyperspectral fluorescence imaging (464–799 nm response range), whereupon quantitative and qualitative modeling was performed in trials to respectively a) model electrolyte leakage percentage by partial least squares regression, and b) compare storage days by linear discriminant analysis (LDA). LDA classification models were moderately successful at distinguishing post-cut storage times 0, 7, 14, and 21 d. As with previous studies on the physiological effects of slicing peppers, the fluorescence response was variable across accessions within pepper type and between the two pepper types studied, which is attributed to the complicating effects of fluorescence reabsorption and cell injury response and genotypic differences that influence suitability for fresh-cut applications among the accessions evaluated.

Effect of Decontamination Treatment on Vitamin C and Potassium Attributes of Fresh-Cut Bell Pepper at Post-Washing Stage

To investigate the effect of decontamination treatment on the nutritional attributes of fresh-cut produce, fresh-cut slices of immature bell peppers were soaked in sodium hypochlorite solutions or slightly acidic electrolyzed water with varying concentrations of effective free chlorine. Changes in the residual ratios of the water-soluble nutrients, vitamin C (L-ascorbic acid, L-AsA) and potassium, were measured, as well as aerobic plate counts (APCs), after decontamination. The L-AsA ratios of the samples that were decontaminated with the sodium hypochlorite solutions exhibited a gradual decrease when higher concentrations of detergent and longer soaking times were employed. In contrast, the potassium ratio remained mostly constant around 50% after 1 min of soaking. A decrease in the L-AsA ratio to 80% was observed within 5 min of a soak in deionized water (a 0 ppm solution). Soakings in the slightly acidic electrolyzed water also resulted in a decrease in L-AsA ratios, yet the trend was not similar to that associated with the sodium hypochlorite solutions. These results indicate that water-soluble nutrient contents of fresh-cut produce decrease during a decontamination process that uses chlorine-based solutions according to the free chlorine concentration and the soaking time. Moreover, the reduction in nutrient content varied depending on the disinfectant used, even if the free chlorine concentration was the same for the different disinfectants.

Synergistic Effect of Slightly Acidic Electrolyzed Water and Ultrasound at Mild Heat Temperature in Microbial Reduction and Shelf-Life Extension of Fresh-Cut Bell Pepper.

The objectives of this study were to evaluate the effect of combined treatments (slightly acidic electrolyzed water (SAEW), ultrasound (US), or mild heat (60°C)) on the growth of Listeria monocytogenes and Salmonella enterica serovar Typhimurium in fresh-cut bell pepper, and the shelf-life and sensory quality (color and texture) were followed during storage at 4°C and 25°C. An additional 0.65, 1.72, and 2.70 log CFU/g reduction was achieved by heat treatments at 60°C for 1 min for DW, SAEW, and SAEW+US, respectively. Regardless of the type of pathogen, the combined treatment (SAEW+US+60°C) achieved a significantly (p < 0.05) longer lag time in all treatment groups. This combined treatment also prolonged the shelf-life of bell pepper up to 8 days and 30 h for the storage at 4°C and 25°C, respectively. There was also no significant difference in the color and hardness of treated (SAEW+US+60°C) bell pepper from that of control during the storage. This new hurdle approach is thus expected to improve the microbial safety of bell peppers during storage and distribution.

Inactivation kinetics of Listeria monocytogenes and Salmonella enterica serovar Typhimurium on fresh-cut bell pepper treated with slightly acidic electrolyzed water combined with ultrasound and mild heat

The goal of this study was to enhance the antimicrobial effect of slightly acidic electrolyzed water (SAEW) through addition of synergistic treatment with ultrasound (US) and mild heat treatment in order to improve the microbial safety of fresh-cut bell pepper. To evaluate the synergistic effects, the Weibull model was used to mathematically measure the effectiveness of the individual and combined treatments against Listeria monocytogenes and Salmonella Typhimurium on the pepper. The combined treatment (SAEW+US+60 °C) resulted in the TR values of 0.04 and 0.09 min for L. monocytogenes and S. Typhimurium, respectively, as consequence of the minimum value. Subsequently, texture analysis was carried out to test the potential effect on quality of the samples due to the involved mild heat and ultrasound treatment. When compared to the control, there was no significant change (p ≥ 0.05) in the texture (color and hardness) of the samples that were treated by 1 min of the combined treatment (SAEW+US+60 °C) during storage at 4 °C for 7 days. This combined treatment achieved approximately 3.0 log CFU/g reduction in the two pathogens. The results demonstrate that the involved hurdle factors which are ultrasound and mild heat achieved the synergistic effect of SAEW against the two pathogens. According to the results of texture analysis, 1 min of SAEW+US+60 °C is the optimal condition due to without negative influence on the quality of the samples during the storage. The optimal condition shows the enhanced antimicrobial effect of SAEW and enables to improve microbial safety of fresh bell pepper in food industry as a consequence of hurdle approach.

Reduction of Escherichia coli O157, Listeria monocytogenes and Salmonella enterica sv. Typhimurium populations on fresh-cut bell pepper using gaseous ozone

Bacterial contamination is the main cause of food poisoning which can lead to diarrhoea, abdominal cramp, vomiting as well as death. Bacterial contamination can potentially be controlled by application of gaseous ozone due to its antibacterial activity. Therefore, the objective of this study was to investigate the efficacy of gaseous ozone for reducing food-borne pathogens such as Escherichia coli O157, Listeria monocytogenes and Salmonella enterica sv. Typhimurium on fresh-cut bell pepper. Efficacy of gaseous ozone to reduce bacterial populations was investigated in vitro and in vivo. Results showed that optimum effect of ozone on reducing bacterial populations was achieved with short term exposures of less than 6 h. Ozone reduced the bacterial population by disrupting bacterial cell structure, which lead to cellular death. Results also showed that bacterial cells have different resistance to ozone where ozone was more effective against L. monocytogenes, followed by E. coli O157 and Salmonella Typhimurium. Optimal reduction of the bacterial population on fresh-cut bell pepper was achieved with exposure to 9 ppm ozone for 6 h. This treatment reduced 2.89, 2.56 and 3.06 log of E. coli O157, Salmonella Typhimurium and L. monocytogenes populations, respectively. In conclusion, exposure to 9 ppm ozone for 6 h helps in reducing food-borne pathogen on fresh-cut bell pepper and has high potential to be an alternative sanitization treatment to reduce pathogen population on fruit.

Effect of Low O_2 and High CO_2 Atmosphere on Residual Ascorbic Acid Rate, Brix Percentage and Firmness of Immature and Mature Fresh-Cut Bell Peppers during Cold Storage

Effect of Low O_2 and High CO_2 Atmosphere on Residual Ascorbic Acid Rate, Brix Percentage and Firmness of Immature and Mature Fresh-Cut Bell Peppers during Cold Storage

Active Modified Atmosphere Packaging of Fresh-cut Bell Peppers: Effect on Quality Indices

&lt;p&gt;Fresh-cut green bell peppers (&lt;em&gt;Capsicum annuum L.&lt;/em&gt;) were stored in modified atmosphere packaging (MAP) made of impermeable high-density polyethylene film. Two in-packaging atmospheres and storage temperatures (0 &lt;sup&gt;o&lt;/sup&gt;C and 5 &lt;sup&gt;o&lt;/sup&gt;C) were tested. The respiration rate of the unpackaged produce and the in-package gas concentration, mass loss, firmness, skin colour, ascorbic acid and visual quality of the packaged produce were estimated. Cutting, increased respiration rate of the unpackaged produce by 24% compared to the intact produce for the same storage temperature. After 5 days of storage at 5 °C, significant O&lt;sub&gt;2&lt;/sub&gt; depletion of the active modified atmosphere was found. Limited mass loss (0.4-0.5% of the initial mass) and firmness degradation were estimated in both storage temperatures due to the beneficial effect of packaging. The hue angle (h*) reduction was limited in all cases and the initial green colour was preserved. Initial ascorbic acid content was preserved at 0 °C, but significantly increased at 5 °C. The visual quality of the packaged produce was assessed by six trained panelists and found that was not significantly changed at 0 °C storage. In conclusion, the tested active MAP maintained the initial quality indices of fresh-cut peppers (&lt;em&gt;cv.&lt;/em&gt; &lt;em&gt;Twingo F1&lt;/em&gt;) for up to 10 days at 0 °C but not at 5 °C.&lt;/p&gt;

Respiration rates of fresh-cut bell peppers under supertamospheric and low oxygen with or without high carbon dioxide

The respiration rates of fresh-cut bell peppers under diverse high and low O 2 levels, with or without 20 kPa CO 2, at 2, 7 and 14 °C, were studied. Weight loss and off-odor development were also monitored. A constant respiration rate of pepper dices throughout 3 days under different conditions was found. Fresh-cut peppers exposed to 0, 0.5, 1, 3 and 9 kPa O 2 (all CO 2-free), and to 0 kPa O 2 + 20 kPa CO 2, had a lower respiration rate than peppers in the range 20–100 kPa O 2 with or without CO 2. Under high O 2, 20 kPa CO 2 increased the respiration rate by about 20–40% compared to that in free-CO 2 atmospheres, this effect being lower at low temperature. High O 2 had little (at 14 °C) or no effect (at 2 and 7 °C) in stimulating both CO 2 production and O 2 consumption compared to normal air. High CO 2 in the range 20–100 kPa O 2 increased the respiratory activity of pepper dices, probably because physiological injury occurred at 14 °C. However, 20 kPa CO 2 combined with superatmospheric O 2 neither induced a poor visual appearance nor off-odors. Consequently 50–80 kPa O 2 combined with 20 kPa CO 2 could be used in innovative modified atmosphere packaging of pepper dices to avoid fermentation and inhibit growth of spoilage microorganisms.