Fresh-cut Carrots Research Articles

Shelf Life Extension of Fresh Cut Carrot by the Application of Cinnamon Extract Infused Edible Coating

The consumer demand for fresh cut fruits and vegetables is increasing rapidly owing to fast paced life style changes. The main problem with fresh cut fruits and vegetables is deterioration in term of color, taste, firmness etc. To solve these issues, researcher and processors have been using edible coatings to maintain quality of fresh cut commodities. Objective: To assess the potential effects of cinnamon extract infused edible coating formulated for shelf life extension of fresh cut carrots. Methods: Cinnamon extract was added as an antioxidant, aimed to aid in shelf life extension of fresh cut carrots. Cinnamon extract was obtained in an aqueous medium. The treatments were stored at 5oC for 21 days for shelf life study. The treatments were assessed for weight loss%, %acidity, TSS, firmness, color and ascorbic acid content at 7 days. Results: Coated treatments had better quality after storage period in term of wt. loss %, firmness and color, as compared to non-coated control treatments. Conclusions: Result suggests that edible coating enhanced with antioxidants have the potential to extend shelf life of fresh cut fruits and vegetables.

Combined Ascorbic Acid and Mild Heat Treatment to Improve the Quality of Fresh-Cut Carrots.

Mild heat (MH) treatment and ascorbic acid (AsA) addition can improve the quality of fresh-cut produce when used individually; however, their combined effect remains unclear. Herein, fresh-cut carrots were used as models to explore the effects of MH (50 °C)-AsA (0.5%) on quality properties including reactive oxygen species (ROS) metabolism, antioxidants, lignin metabolism, naturally present microbes, and inoculated pathogens (Escherichia coli O157: H7 and Salmonella Typhimurium) during storage (0-5 d, 4 °C). The results indicate that the antioxidant properties in the MH-AsA group were consistent with those of single treatments, resulting in a consistent ROS-scavenging effect. From day 3-5, lignin synthesis was significantly inhibited by MH-AsA as compared with single treatments, probably because the two enzymes (phenylalanine ammonia-lyase and peroxidase) responsible for lignin synthesis exhibited lower expressions. Microbial analysis revealed that MH-AsA treatment led to the lowest counts of both pathogens and aerobic mesophilic bacteria at 0-5 d. Conversely, the inhibitory effect of MH-AsA treatment on mold and yeast was consistent with the single treatments. These results suggest that MH-AsA is a low-cost and safe approach to improve the physiological characteristics of fresh-cut produce while reducing microbial risk.

Effects of Different Cutting Styles on Physiological Properties in Fresh-Cut Carrots.

With the internationalization of Chinese culture, ready-to-cook Chinese food has become popular. Vegetables in Chinese preparations are usually cut into slices, cubes, and shreds. Carrots, as a typical Chinese side dish, were selected as the model in this work. The polyphenol content, antioxidant capacity, O2-, hydrogen peroxide, malondialdehyde, lignin, antioxidant enzymes, and other enzymes activities were analyzed. The results indicated that these parameters were insignificantly different between three cutting styles. Therefore, metabolomics is further employed. Pathway enrichment indicated that glyceollin II and 6″-malonylgenistin were metabolites particularly expressed in the isoflavonoid biosynthesis pathway; (+)-gallocatechin, trans-chlorogenic acid, and (-)-epiafzelechin were specifically identified in the flavonoid biosynthesis pathway after slicing; and shredding caused the expression of coniferyl aldehyde and eugenol, which were specifically expressed in the phenylpropanoid biosynthesis pathway. These results indicate that different cutting styles do not change the physiological indicators of carrots but induce the expression of specific metabolites.

Effects of dielectric barrier discharge cold plasma treatment on quality maintenance, energy and γ-aminobutyric acid accumulation of fresh-cut carrots

The effects of a novel method non-thermal cold plasma (CP) treatment on microbial control, quality maintenance, and γ-aminobutyric acid (GABA) accumulation of shred carrots were investigated. Results revealed CP treatment suppressed microbial growth and inhibited the increase in L* value and whiteness index, while stimulated the generation of reactive oxygen species. Meanwhile, it also enhanced activities and transcriptions of glutamate decarboxylase and GABA transaminase in GABA shunt, and strengthened the polyamine degradation pathway via enhancing activities of diamine oxidase (DAO), polyamine oxidase (PAO), aminoaldehyde dehydrogenase (AMADH), and the expression of DcPAO, thus in turn promoting GABA accumulation through facilitating the conversion from glutamate and polyamines into GABA. Moreover, CP treatment improved the energy status and reducing power by upregulating energy metabolism and pentose phosphate pathway. Therefore, these findings indicated that CP treatment was effective for microbial reduction, quality preservation, and GABA accumulation in fresh-cut carrots, thereby providing potential strategies for the preservation and processing of fresh-cut produce.

Potential use of UVC light for increasing nutraceutical quality in fresh-cut carrots of different root colors

Potential use of UVC light for increasing nutraceutical quality in fresh-cut carrots of different root colors

Glutamate application maintains quality and antioxidant capacity of fresh-cut carrots by modulating GABA shunt, phenylpropanoid and ROS metabolism

The effects of exogenous glutamate treatment on the quality attributes, γ-aminobutyric acid (GABA) shunt, phenylpropanoid pathway, and antioxidant capacity of fresh-cut carrots were investigated. Results showed that glutamate treatment suppressed the increases in lightness and whiteness values, inhibited the degradation of total carotenoids and maintained better flavor and taste in fresh-cut carrots. Moreover, glutamate treatment rapidly promoted the activities of glutamate decarboxylase and GABA transaminase, thus improving the GABA content. It also significantly enhanced the activities of phenylalanine ammonia-lyase, cinnamate-4-hydroxylase, and 4-coumarate coenzyme A ligase and promoted the accumulation of total phenolics as well as the main individual phenolic compounds, including chlorogenic and caffeic acid. In addition, glutamate application activated the reactive oxygen system-related enzyme including peroxidase, superoxide dismutase, ascorbate peroxidase, and catalase activities to maintain higher antioxidant capacity in fresh-cut carrots. These results demonstrated that exogenous glutamate treatment maintained better nutritional quality and alleviated color deterioration by accelerating the accumulation of GABA and phenolics and enhancing the antioxidant capacity in fresh-cut carrots.

Enzyme activity and nutritional profile of different-sized carrot cubes treated with supercritical carbon dioxide

This study evaluated changes in the enzyme activity, color, carotenoids, sugar profile, individual phenolic compounds, and antioxidant capacity of supercritical carbon dioxide (SCCD)-treated carrot cubes of different sizes (1 cm and 2 cm). Results demonstrated that SCCD reduced the activities of polyphenol oxidase (PPO) and peroxidase (POD) more in 1 cm carrot cubes than in 2 cm carrot cubes. Nevertheless, the a* , b* , and ∆E values of 1 cm SCCD-treated were enhanced compared to 2 cm SCCD-treated samples. The carotenoids, phenolic compounds, and antioxidant capacity of 1 cm SCCD-treated samples were increased under moderate processing conditions. In contrast, the nutritional composition in 1 cm SCCD-treated samples was lower than in 2 cm SCCD-treated samples at harsh processing conditions. The principal component and correction analysis displayed a visual variation between the enzyme activities and nutritional composition of 1 cm and 2 cm carrot cubes after SCCD processing. According to the results above, 1 cm carrot cubes processed with SCCD at 10 MPa, 35 ℃, and 45 min are the most effective at preserving fresh-cut carrots with relatively high enzyme inactivation and the highest retention of bioactive compounds. This work provides a more comprehensive theoretical basis for optimizing SCCD processing for fresh-cut carrots and recommendations for industrial production.

Calcium chloride treatment maintains quality and enhances antioxidant capacity of fresh-cut carrots through modulating DcCMLs-DcCAMTA3-mediated phenylpropanoid pathway

Whitening and microbial infection are two major reasons to induce quality deterioration in fresh-cut carrots. Calcium chloride (CaCl2) could enhance the quality attributes in fresh-cut carrots, but the molecular mechanism is still not illuminated. In this study, CaCl2 treatment suppressed the increases of whiteness index and total bacterial count as well as enhanced the antioxidant capacity of fresh-cut carrots. In addition, CaCl2 treatment promoted phenolics accumulation by upregulating the transcripts and enzyme activity of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate coenzyme A ligase (4CL) in phenylpropanoid pathway. However, this treatment inhibited the increase of enzyme activity and gene expression of cinnamyl alcohol dehydrogenase (CAD), thus suppressing lignin synthesis and whitening process in fresh-cut carrots. Moreover, a calmodulin-binding transcription activator (CAMTA) transcription factor DcCAMTA3, was induced in response to CaCl2 treatment. DcCAMTA3 activated the transcription of DcPAL1, DcC4H and Dc4CL1 genes and repressed the expression of DcCAD1 gene by directly targeting the CG-box. DcCML3/11, a calmodulin-like protein, interacted with DcCAMTA3, and this interaction enhanced DcCAMTA3-mediated transcriptional activation of DcPAL1, DcC4H and Dc4CL1 and repression of DcCAD1. Therefore, CaCl2 treatment is effective in maintaining quality and enhancing antioxidant capacity of fresh-cut carrots by the cooperative action of DcCMLs and DcCAMTA3 in positively regulating phenylpropanoid pathway.

The interaction between DcCaM7 and DcCAMTA6 promotes γ-aminobutyric acid (GABA) accumulation via regulating GABA shunt in fresh-cut carrots

The potential regulatory mechanisms of 1 % calcium chloride (CaCl2) treatment on the γ-aminobutyric acid (GABA) accumulation of fresh-cut carrots were investigated. The results indicated that CaCl2 application enhanced the contents of GABA shunt-related substances and activated the GABA shunt via enhancing the activities and genes expression of glutamate decarboxylase (GAD) and GABA transaminase (GABA-T). Moreover, CaCl2 treatment enhanced the levels of [Ca2+]cyt, as well as up-regulated the expression of DcCaM7 and DcCAMTA6. However, the EGTA, a Ca2+ chelating agent treatment had the opposite effect on both GABA shunt and calcium signal-related components. Importantly, DcCaM7 interacted with DcCAMTA6 through an IQ motif, forming a heterodimer that facilitated the enhanced transcriptional regulation of DcCAMTA6 in the expression of DcGAD and DcGABA-T genes. Therefore, our results indicated that DcCaM7-DcCAMTA6 complex positively regulate GABA accumulation by activating GABA shunt in fresh-cut carrots.

Differential and Cultivar-Dependent Antioxidant Response of Whole and Fresh-Cut Carrots of Different Root Colors to Postharvest UV-C Radiation

Fresh-cut produce have become widely popular, increasing vegetable consumption in many parts of the word. However, they are more perishable than unprocessed fresh vegetables, requiring cold storage to preserve their quality and palatability. In addition to cold storage, UV radiation has been used experimentally to try to increase nutritional quality and postharvest shelf life, revealing increased antioxidant levels in some fruits and vegetables, including orange carrots. Carrot is one of the main whole and fresh-cut vegetables worldwide. In addition to orange carrots, other root color phenotypes (e.g., purple, yellow, red) are becoming increasingly popular in some markets. The effect of the UV radiation and cold storage has not been explored in these root phenotypes. This study investigated the effect of postharvest UV-C radiation in whole and fresh-cut (sliced and shredded) roots of two purple, one yellow, and one orange-rooted cultivar, with regard to changes in concentration of total phenolics (TP) and hydroxycinnamic acids (HA), chlorogenic acid (CGA), total and individual anthocyanins, antioxidant capacity (by DPPH and ABTS), and superficial color appearance, monitoring such changes during cold storage. Results revealed that the UV-C radiation, the fresh-cut processing, and the cold storage influenced the content of antioxidant compounds and activities to varying extents, depending on the carrot cultivar, the degree of processing, and the phytochemical compound analyzed. UV-C radiation increased antioxidant capacity up to 2.1, 3.8, 2.5-folds; TP up to 2.0, 2.2, and 2.1-folds; and CGA up to 3.2, 6.6, and 2.5-folds, relative to UV-C untreated controls, for orange, yellow, and purple carrots, respectively. Anthocyanin levels were not significantly modified by the UV-C in both purple carrots evaluated. A moderate increase in tissue browning was found in some fresh-cut processed UV-C treated samples of yellow and purple but not orange roots. These data suggest variable potential for increasing functional value by UV-C radiation in different carrot root colors.

Listeria monocytogenes loss of cultivability on carrot is associated with the formation of mesosome-like structures

Raw carrot is known to have antimicrobial activity against Listeria monocytogenes, but the mechanism of action has not been fully elucidated. In this study, we examined carrot antilisterial activity against several strains of Listeria species (including L. grayi, L. innocua, L. seeligeri, and L. welshimeri) and L. monocytogenes. A representative strain of L. monocytogenes was subsequently used for further characterizing carrot antilisterial activity. Exposure to fresh-cut carrot for 15 min resulted in a similar loss of cultivability, ranging from 2.5 to 4.7 log units, across all Listeria strains evaluated. L. monocytogenes recovered from the fresh-cut surface of different raw carrots was 1.6 to 4.1 log lower than levels obtained from paired boiled carrot samples with abolished antilisterial activity. L. monocytogenes levels recovered from fresh-cut carrot were 2.8 to 3.1 log lower when enumerated by culture-dependent methods than by the culture-independent method of PMAxx-qPCR, a qPCR assay that is performed using DNA pre-treated to selectively sequester DNA from cells with injured membranes. These results suggested that L. monocytogenes loss of cultivability on fresh-cut carrot was not associated with a loss of L. monocytogenes cell membrane integrity and putative cell viability. Transmission electron microscopy imaging revealed that L. monocytogenes rapidly formed mesosome-like structures upon exposure to carrot fresh-cut surface but not upon exposure to boiled carrot surface, suggesting there may be an association between the formation of these mesosome-like structures and a loss of cultivability in L. monocytogenes. However, further research is necessary to conclude the causality of this association.

Bionanocomposite films with plasticized WPI-jujube polysaccharide/starch nanocrystal blends for packaging fresh-cut carrots

New nanocomposite films with whey protein isolate (WPI, 5–10%), purified jujube polysaccharide (JPS, 5–15%) with a molecular weight of 1.35 × 105 Da, and ∼67.5 nm spherical-like starch nanocrystal (SNC, 0.32–3.68%) were optimally developed. The use of 10.0% WPI, 12.72% JPS, and 1.31% SNC resulted in the best physical (i.e., thickness: 0.15 mm, density: 0.86 g/cm3, contact angle: 66.9°, moisture content: 21.06%, water solubility: 41.68%, and moisture absorption: 77.56%), and mechanical (i.e., tensile strength: 14.0 MPa, elongation at break: 14.87%, and elastic modulus: 47.80 MPa) properties. Scanning electron (SEM) and atomic force (AFM) microscopies images proved that the SNC ensures the development of a more continuous and homogeneous surface with lower roughness. The optimal bionanocomposites with favorable water-vapor (0.63 ×10-10 g/m s Pa) and oxygen (9.62 cm3/m2 d atm) permeability better maintained the physicochemical, sensory, and microbiological properties of fresh-cut carrots than polyvinyl chloride (PVC) film during the cold storage.

Effects of Different Treatments on White-blush of Fresh-cut Carrots During Storage

In order to screen out the preservatives that had better effects on inhibiting the white-blush of freshcut carrots, prolong its shelf life. Using fresh carrots as the test material, the effects of different treatments on the white-blush of fresh-cut carrots during storage were compared, and the changes in whiteness value of fresh-cut carrots in each group were analyzed. Other relevant physical and chemical indicators were measured. The results showed that compared with other treatment groups, the onion treatment group had the lowest whiteness index, the strongest antioxidant capacity, and the best quality of fresh-cut carrots. This indicated that onions were suitable for processing fresh-cut carrots, which cold better inhibit the activities of POD, PAL, and other enzymes, inhibit the white-blush of fresh-cut carrots, and delay their aging.

Increasing the Safety and Storage of Pre-Packed Fresh-Cut Fruits and Vegetables by Supercritical CO2 Process.

This work presents a feasibility lab-scale study for a new preservation method to inactivate microorganisms and increase the shelf life of pre-packed fresh-cut products. Experiments were conducted on coriander leaves and fresh-cut carrots and coconut. The technology used the combination of hydrostatic pressure (<15 MPa), low temperature (≤45 °C), and CO2 modified atmosphere packaging (MAP). The inactivation was achieved for the naturally present microorganisms (total mesophilic bacteria, yeasts and molds, total coliforms) and inoculated E. coli. Yeasts and molds and coliform were under the detection limit in all the treated samples, while mesophiles were strongly reduced, but below the detection limit only in carrots. Inoculated E. coli strains were completely inactivated (>6.0 log CFU/g) on coconut, while a reduction >4.0 log CFU/g was achieved for carrots and coriander. For all the treated products, the texture was similar to the fresh ones, while a small alteration of color was detected. Microbiological stability was achieved for up to 14 days for both fresh-cut carrots and coconut. Overall, the results are promising for the development of a new mild and innovative food preservation technique for fresh food.

Characterization of Abscisic Acid and Ethylene in Regulating the White Blush in Fresh-Cut Carrots.

The surface of fresh-cut carrots is apt to white blush, however the physiological and molecular mechanism for this process is not yet fully understood. In this study, exogenous abscisic acid (ABA) and ethylene separately promoted and inhibited the white-blush formation after three days after treatment, respectively. Metabolome analysis found that white-blush components mainly consist of p-hydroxyphenyl lignin and guaiacyl lignin. Transcriptome analysis found an increase in the whiteness values was consistent with the higher expression of genes encoding O-methyltransferase, trans-anol O-methyltransferase, bergaptol O-methyltransferase, caffeic acid 3-O-methyltransferase, phenylalanine ammonia-lyase, and ferulate-5-hydroxylase, together with the lower expression of genes encoding cinnamic acid 4-hydroxylase caffeoyl-CoA O-methyltransferase and 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase. In conclusion, ABA plays an important role in lignin biosynthesis essential to the formation of white blush in fresh-cut carrots. This is the first report that uncovers the physiological and molecular causes of white blush in fresh-cut carrots, providing a basis for white-blush control in fresh-cut carrots.

Multi-Target Alternative Approaches to Promoting Fresh-Cut Carrots' Bioactive and Fresh-like Quality.

Fresh-cut fruits and vegetables, as near-fresh foods, are a quick and easy solution to a healthy and balanced diet. The rapid degradation of nutritional and sensory quality during the processing and storage of a product is critical and plant-type-dependent. The introduction of disruptive technological solutions in fresh-cut processing, which could maintain fresh-like quality with less environmental impact, is an emerging research concept. The application of abiotic stress treatments (heat shock and UV-C) induces metabolic responses and microbial effects in plant tissues, potentially slowing down several quality senescence pathways. The previously selected combined and single effects of heat shock (100 °C/45 s; in the whole root) and UV-C (2.5 kJ/m2) treatments and two packaging conditions (oriented polypropylene (OPP) vs. micro-perforated OPP films) on controlling critical degradation pathways of fresh-cut carrots and on promoting bioactive and sensory quality during storage (5 °C, 14 days) were studied. Among the tested combinations, synergistic effects on the quality retention of fresh-cut carrots were only attained for applying heat shock associated with micro-perforated OPP film packaging. Its effects on reducing (3.3 Log10 CFU/g) the initial contamination and controlling microbiological spoilage (counts below the threshold limit of 7.5 Log10 CFU/g), increasing the bioactive content (38% and 72% in total phenolic content and chlorogenic acid, respectively), and preserving fresh quality attributes prove to be a viable alternative technology for shredded carrot processing.

Optimization of Disinfection Treatment for Shelf Life Extension of Fresh Cut Salad Vegetables

In the present study, disinfectant pre-treatment conditions were optimized for Fresh cut salad vegetables after evaluating bactericidal efficacy of the five different disinfectants viz. Sodium hypochlorite, potassium metabisulfite, citric acid, acetic acid and benzoic acid. Sodium hypochlorite @ 100ppm was selected for disinfectant pretreatment of fresh cut vegetables viz. cucumber, carrot and tomato through physicochemical and microbial analysis. Optimization of pre-treatment conditions viz. temperature, pH and contact time was statistically designed and analyzed using response surface methodology. Numerical optimization of results revealed a temperature of 6.5, 10.0 and 6.5°C; pH 6.0, 7.0 and 7.0; contact time 23.0, 8.0 and 30.0 minutes was found to be optimized for fresh cut cucumber, carrot and tomato disinfectant pretreatment with a desirability level of 94, 94 and 92%, respectively. Shelf life analysis of pre-treated (under optimized conditions) and untreated fresh cut vegetables stored under refrigeration conditions (5-7°C) revealed enhancement in shelf life of treated fresh cut vegetables from 6, 9 and 6 days to 9, 12 and 9 days of fresh cut cucumber, carrot and tomato, respectively. During shelf life period, all physicochemical parameters of pre-treated fresh cut vegetables differed non-significantly along with microbial load under acceptable limits and a good sensory score.

Efficacy of Pectin-Based Coating Added with a Lemon Byproduct Extract on Quality Preservation of Fresh-Cut Carrots.

The effect of an edible pectin-based coating supplemented with a lemon byproduct extract on the quality attributes of fresh-cut carrots was studied. Color, hardness, microbial growth, respiratory activity, and antioxidant properties of fresh-cut carrots were studied during 14 days of storage at 4 °C. The application of a pectin-based coating containing a lemon byproduct extract preserved carrots’ physiological parameters, reduced their physiological activity and, thus, delayed senescence. This aspect was also confirmed by the reduced O2 consumption of the coated carrots due to the slowing down of the product’s metabolic reactions. Moreover, coated carrots were characterized by limited changes in colour (ΔE < 3) and white-blush development on both cortical tissue and vascular cylinder, and the presence of calcium chloride in the coating formulation helped to maintain carrots’ hardness throughout storage. In addition, treatment with pectin-based coating and lemon byproduct extract improved microbiological stability of fresh-cut carrots, showing the lowest value of total bacterial count immediately after treatment (2.58 log CFU g−1). This kind of treatment also resulted in a significant preservation of valuable compounds (17.22 mg GAE 100 g−1) and antioxidant activity level (289.49 µM Trolox 100 g−1), reducing the wounding stress induced by processing operations for at least ten days.

Inactivation of Shigella flexneri by 405-nm Light-Emitting Diode Treatment and Possible Mechanism of Action.

Shigella flexneri, a common Gram-negative foodborne pathogen, is widely distributed in fresh-cut fruits and vegetables, unpasteurized milk, and food processing environments. The aims of this study were to evaluate the antibacterial effects of 405-nm light-emitting diode (LED) treatment on S. flexneri and to investigate the possible mechanism. The results showed that LED irradiation (360 min) reduced the number of S. flexneri in phosphate-buffered saline by 3.29 log colony-forming unit (CFU)/mL (initial bacterial count: 6.81 log CFU/mL). The cells in reconstituted infant formula, cells on fresh-cut carrot slices, and biofilm-associated cells on stainless steel surfaces were reduced by 1.83 log CFU/mL, 7.00 log CFU/cm2, and 4.35 log CFU/cm2 following LED treatment for 360, 120, and 120 min, respectively. LED treatment damaged both DNA and cell wall of S. flexneri and changed cell morphology and cell membrane permeability. In addition, LED treatment decreased total cell protein concentration of S. flexneri. These results indicated that 405-nm LED treatment effectively controlled S. flexneri contamination of foods and food contact surfaces and that the bacterial inactivation may be the result of damage to multiple cellular components. These findings highlight the potential of LED technology in controlling S. flexneri during food processing, storage, and preparation.

Effects of temperature abuse on the growth and survival of Listeria monocytogenes on a wide variety of whole and fresh-cut fruits and vegetables during storage

Twenty types of fruits and vegetables representing a broad range of fresh produce categories were assessed for the growth potential and growth kinetics of Listeria monocytogenes under conditions reflecting commercial practices for storage and distribution and conditions reflecting sustained temperature abuse. Whole and fresh-cut produce was obtained from various commercial sources and inoculated with L. monocytogenes strains to evaluate the survival and growth for up to 25 days, depending on the projected commercial storage or retail shelf life for each commodity. The L.monocytogenes populations showed a sustained decline on all tested whole fruits, including avocado, blueberry, grape, mango, peach, green pepper, and tomato. Under “normal” storage conditions (defined as those reflective of common commercial practices), significant L. monocytogenes growth was only observed on fresh-cut cantaloupe (∼0.8 log) and fresh-cut mango (∼0.6 log). Exposure to temperature abuse conditions did not change the overall trends of L. monocytogenes survival on the whole fruits but did result in significant growth on several fresh-cut products, including celery, cauliflower, mango, onion, romaine lettuce, and cantaloupe. After inoculation on certain products (e.g., fresh-cut carrot and whole peach), L. monocytogenes seemed to lose cultivability rapidly but did retain viability as determined by the maintenance of cell membrane integrity.