Search

The global demand for minimally processed vegetables (MPVs) has grown, driven by changes in the population’s lifestyle. MPVs are fresh vegetables that undergo several processing steps, resulting in ready-to-eat products, providing convenience for consumers and food companies. Among the processing steps, washing–disinfection plays an important role in reducing the microbial load and eliminating pathogens that may be present. However, poor hygiene practices can jeopardize the microbiological quality and safety of these products, thereby posing potential risks to consumer health. This study provides an overview of minimally processed vegetables (MPVs), with a specific focus on the Brazilian market. It includes information on the pricing of fresh vegetables and MPVs, as well as an examination of the various processing steps involved, and the microbiological aspects associated with MPVs. Data on the occurrence of hygiene indicators and pathogenic microorganisms in these products are presented. The focus of most studies has been on the detection of Escherichia coli, Salmonella spp., and Listeria monocytogenes, with prevalence rates ranging from 0.7% to 100%, 0.6% to 26.7%, and 0.2% to 33.3%, respectively. Foodborne outbreaks associated with the consumption of fresh vegetables in Brazil between 2000 and 2021 were also addressed. Although there is no information about whether these vegetables were consumed as fresh vegetables or MPVs, these data highlight the need for control measures to guarantee products with quality and safety to consumers.

Laboratory-based nucleic acid amplification tests (NAATs) are highly sensitive and specific, but they require the transportation of samples to centralized testing facilities and have long turnaround times. During the Coronavirus Disease 2019 (COVID-19) pandemic, substantial advancement has been achieved with the development of paper-based point-of-care (POC) NAATs, offering features such as low cost, being easy to use, and providing rapid sample-to-answer times. Although most of the POC NAATs innovations are towards clinical settings, we have developed a portable, paper-based loop-mediated isothermal amplification (LAMP) testing platform for on-farm applications, capable of detecting Bacteroidales as a fecal contamination biomarker. Our integrated platform includes a drop generator, a heating and imaging unit, and paper-based biosensors, providing sensitive results (limit of detection 3 copies of Bacteroidales per cm2) within an hour of sample collection. We evaluated this integrated platform on a commercial lettuce farm with a concordance of 100% when compared to lab-based tests. Our integrated paper-based LAMP testing platform holds great promise as a reliable and convenient tool for on-site NAATs. We expect that this innovation will encourage the fresh produce industry to adopt NAATs as a complementary tool for decision-making in growing and harvesting. We also hope that our work can stimulate further research in the development of on-farm diagnostic tools for other agricultural applications, leading to improved food safety and technology innovation. [Display omitted] [ABSTRACT FROM AUTHOR]

Contaminated fresh produce has been identified as a vehicle for human foodborne illness. The present study investigated the counts, antimicrobial resistance profile, and genome-based characterization of Escherichia coli in 11 different types of fresh salad vegetable products (n = 400) sampled from retailers in Abu Dhabi and Dubai in the United Arab Emirates. E. coli was detected in 30% of the tested fresh salad vegetable items, with 26.5% of the samples having an unsatisfactory level (≥100 CFU/g) of E. coli, notably arugula and spinach. The study also assessed the effect of the variability in sample conditions on E. coli counts and found, based on negative binominal regression analysis, that samples from local produce had a significantly higher (p-value < 0.001) E. coli count than imported samples. The analysis also indicated that fresh salad vegetables from the soil-less farming system (e.g., hydroponic and aeroponic) had significantly (p-value < 0.001) fewer E. coli than those from traditional produce farming. The study also examined the antimicrobial resistance in E. coli (n = 145) recovered from fresh salad vegetables and found that isolates exhibited the highest phenotypic resistance toward ampicillin (20.68%), tetracycline (20%), and trimethoprim-sulfamethoxazole (10.35%). A total of 20 (13.79%) of the 145 E. coli isolates exhibited a multidrug-resistant phenotype, all from locally sourced leafy salad vegetables. The study further characterized 18 of the 20 multidrug-resistant E. coli isolates using whole-genome sequencing and found that the isolates had varying numbers of virulence-related genes, ranging from 8 to 25 per isolate. The frequently observed genes likely involved in extra-intestinal infection were CsgA, FimH, iss, and afaA. The β-lactamases gene blaCTX-M-15 was prevalent in 50% (9/18) of the E. coli isolates identified from leafy salad vegetable samples. The study highlights the potential risk of foodborne illness and the likely spread of antimicrobial resistance and resistance genes associated with consuming leafy salad vegetables and emphasizes the importance of proper food safety practices, including proper storage and handling of fresh produce.

The consumption of fresh produce and fruits has increased over the last few years as a result of increasing consumer awareness of healthy lifestyles. Several studies have shown that fresh produces and fruits could be potential sources of human pathogens and antibiotic-resistant bacteria. In this study, 248 strains were isolated from lettuce and surrounding soil samples, and 202 single isolates selected by the random amplified polymorphic DNA (RAPD) fingerprinting method were further characterized. From 202 strains, 184 (91.2%) could be identified based on 16S rRNA gene sequencing, while 18 isolates (8.9%) could not be unequivocally identified. A total of 133 (69.3%) and 105 (54.7%) strains showed a resistance phenotype to ampicillin and cefoxitin, respectively, while resistance to gentamicin, tobramycin, ciprofloxacin, and tetracycline occurred only at low incidences. A closer investigation of selected strains by whole genome sequencing showed that seven of the fifteen sequenced strains did not possess any genes related to acquired antibiotic resistance. In addition, only one strain possessed potentially transferable antibiotic resistance genes together with plasmid-related sequences. Therefore, this study indicates that there is a low possibility of transferring antibiotic resistance by potential pathogenic enterobacteria via fresh produce in Korea. However, with regards to public health and consumer safety, fresh produce should nevertheless be continuously monitored to detect the occurrence of foodborne pathogens and to hinder the transfer of antibiotic resistance genes potentially present in these bacteria.

Despite the wide variety of native and exotic fruits in Brazil, there is limited understanding of their ability to support pathogens during storage. This study aimed to evaluate the behavior of Salmonella enterica and Listeria monocytogenes inoculated into the pulp of eight fruits native and exotic to Brazil: Jenipapo (Genipa americana L.), Umbu (Spondias tuberosa Arruda), Maná (Solanum sessiliflorum), Cajá-manga (Spondias dulcis), Physalis (Physalis angulata L.), Feijoa (Acca sellowiana), Cupuaçu (Theobroma grandiflorum) (average pH < 3.3) and in a low acidy fruit: Abiu (Pouteria caimito) (pH 6.11). The pathogens were inoculated into the different fruits and stored at 10, 20, 30 and 37 °C for up to 12 h and 6 days, respectively. Among the fruits evaluated, Abiu was the only one that allowed Salmonella growth, showing higher δ-values at 20 and 30 °C (5.6 log CFU/g for both temperatures). For Physalis and Feijoa , there was a small reduction in the pathogen concentration (<1 log-cycle), mainly at 10 and 20 °C, indicating its ability to remain in the matrices. For the other fruits, notable negative δ-values were obtained, indicating a tendency towards microbial inactivation. The survival potential was significantly affected by temperature in Abiu , Maná , Cupuaçu , and Cajá-manga (p < 0.05). The same phenomena regarding δ-value were observed for L. monocytogenes population, with the greatest survival potential observed at 20 °C in Abiu (3.3 log CFU/g). Regarding the exponential growth rates in Abiu , the highest values were observed at 30 and 37 °C, both for Salmonella (4.6 and 4.9 log (CFU/g)/day, respectively) and for L. monocytogenes (2.8 and 2.7 log (CFU/g)/day, respectively), with no significant difference between both temperatures. Regarding microbial inactivation, L. monocytogenes showed greater resistance than Salmonella in practically all matrices. Jenipapo and Umbu were the pulps that, in general, had the greatest effect on reducing the population of pathogens. Furthermore, the increase in storage temperature seems to favor the increase on inactivation rates. In conclusion, Salmonella and L. monocytogenes can grow only in Abiu pulp, although they can survive in some acidic tropical fruits kept at refrigeration and abusive temperatures. • S. enterica (Se) and L. monocytogenes (Lm) growth not supported in acidic fruits. • In Abiu , a low-acid fruit, the growth rate of Se exceeds that of Lm. • Se population in Physalis and Feijoa remained stable in all conditions evaluated. • Umbu and Jenipapo were the pulps most unfavorable for survival of the pathogens. • The temperature impact on the survival potential of Se and Lm varied with the fruit. [ABSTRACT FROM AUTHOR]

Microbial contamination of fresh produce poses significant challenges to food safety and public health. Postharvest washing is a common practice in the fresh produce industry to reduce microbial load. This study aimed to elucidate the mechanisms involved in bacterial removal from produce surfaces during washing, using model colloids as bacterial surrogates and polydimethylsiloxane (PDMS) replicas of tomato, lettuce, and spinach as model produce surfaces. Colloids were deposited onto the PDMS surfaces and subsequently washed using different solutions (DI water, NaCl, and surfactants Tween 80 and sodium dodecyl sulfate) at varying concentrations. The PDMS surfaces were then withdrawn from the solutions at two distinct velocities. Colloid removal efficacy and the associated physicochemical interactions between colloids and substrate surfaces under various washing conditions were quantified. The results revealed that colloid removal was controlled by the residual amount of washing solution retained and contact line action. These factors, in turn, were influenced by the sample-withdrawal velocity and physicochemical properties of substrate surfaces, colloids, and washing solutions. Specifically, SDS at 2 mol/m3 combined with a slow withdrawal velocity significantly optimized colloid removal, achieving up to 79.0% efficiency. Conversely, using Tween 80 at 0.08 mol/m3 concentration significantly impeded removal efficiency. Understanding these dynamics to minimize residual solution retention and optimize colloid/bacteria movement with the contact line upon washing can significantly enhance the cleaning efficacy of fresh produce. The findings of this study provide an improved understanding on the key factors governing the retention and removal of colloidal particles (including microorganisms) that can guide the development of effective decontamination strategies. • Model colloids and PDMS replicas were used to study bacteria-produce interactions. • Mechanisms of colloid removal from produce replicas during wash were studied. • Colloid removal was affected by washing solution retention and contact line action. • Optimal wash conditions to maximize colloid removal from replicas were identified. • Elucidated mechanisms advance fresh produce decontamination methods. [ABSTRACT FROM AUTHOR]

Non-typhoid Salmonella enterica causes salmonellosis illness, and this bacterium can contaminate food throughout the production chain, including those that are consumed as raw products. Salmonella enterica can adhere to and internalize into fresh produce such as cherry tomatoes. It has been reported that lytic bacteriophages (phages) can be used as a biocontrol agent in the agricultural field, being an alternative for the control of Salmonella in red meat, fish, lettuce, and cabbage. The aim of this study was to characterize the two phages present in the PHA46 cocktail to determine their morphology, genome, host range, and resistance to different temperatures and pHs values; and later evaluate their lytic activity to reduce the adherence to and internalization of Salmonella enterica serovars Newport and Typhimurium into cherry tomatoes. In addition, in this work, we also explored the effect of the PHA46 cocktail on the virulence of S. Newport-45 and S. Typhimurium SL1344, recovered from the interior of cherry tomatoes, on the lifespan of the animal model Caenorhabditis elegans. The nematode C. elegans, recently has been used to test the virulence of Salmonella and it is easy to maintain and work with in the laboratory. The results revealed that the morphology obtained by Transmission Electron Microscopy of two phages from the PHA46 cocktail correspond to a myovirus, the analyses of their genomes sequences did not report virulence or antimicrobial resistance genes. The PHA46 sample is specific for 33 different serovars from different Salmonella strains and shows stability at 7 °C and pH 6. Also, the PHA46 cocktail was effective in reducing the adherence of S. Newport-45 and S. Typhimurium SL1344 to cherry tomatoes, at an average of 0.9 log 10 , respectively. Regarding internalized bacteria, the reduction was at an average of 1.2 log 10 , of the serovars mentioned above. The lifespan experiments in C. elegans showed by itself, that the PHA46 cocktail was harmless to the nematode, and the virulence from both Salmonella strains grown in vitro is diminished in the presence of the PHA46 cocktail. In conclusion, these results showed that the PHA46 cocktail could be a good candidate to be used as a biocontrol agent against Salmonella enterica. • One jumbo phage is contained in the phage cocktail PHA46. • Phage cocktail PHA46 has a wider host range than other phage cocktail reported. • Phage cocktail PHA46 reduced the internalization of S. enterica into cherry tomatoes. • Phage cocktail PHA46 is innocuous to C. elegans. • Phage cocktail PHA46 reduces virulence of S. enterica in the C. elegans model. [ABSTRACT FROM AUTHOR]

The impact of cold plasma (CP) treatment on anthocyanin accumulation in postharvest blueberries is well-documented. However, the underlying regulatory mechanisms are still not fully understood. To gain further insights, we conducted biochemistry, transcriptomic, and metabolomic analyses. The comparison between control and CP-treated samples revealed 948 differentially expressed genes (DEGs) and 20 differentially accumulated metabolites (DAMs) (Malvidin-3-O-galactoside, Cyanidin-3-O-galactoside, proanthocyanidin B1, peonidin-3-O-galactoside, etc.). A total of 63 DEGs may be involved in anthocyanins biosynthesis, including PAL, C4H, 4CL, CHS, CHI, F3H, F3'H, F3'5'H, FLS, DFR, LDOX, F3GT, UGT, and GST. The co-expression network analysis revealed that UGT plays an important role in the biosynthesis of anthocyanins in CP-treated blueberry at postharvest. These findings indicate that CP treatment promotes the accumulation of anthocyanins by affecting the phenylpropanoid pathways and flavonoid biosynthesis. This research provides fundamental insights into the molecular mechanisms underlying anthocyanin accumulation in blueberries following CP treatment. [Display omitted] • CP treatment led to an approximate 25 % increase in blueberry anthocyanin contents. • Multiomics analysis of the accumulation mechanism of CP-treated blueberry anthocyanin. • Anthocyanin accumulation in CP-treated blueberry is associated with UGT. • Co-expression network was used to analyze the synthesis of blueberry anthocyanin. [ABSTRACT FROM AUTHOR]

Foodborne illness and spoilage losses caused by microbial contamination or colonization are still major postharvest issues of horticultural produce. Simple treatments (such as washing and precooling) can only reduce microorganisms on the surface of produce and slow their growth. Chlorine dioxide (ClO 2) that has been widely used in postharvest handling of fresh produce is a superior antimicrobial and preservative due to its broad-spectrum, efficient, green, and safe. However, the specific antimicrobial mechanisms and impacts on fresh produce need to be further elucidated. This paper reviews action mechanism of ClO 2 based on its selective oxidation capacity, action sites, and intracellular interactions, particularly the antimicrobial effect and mechanism on different bacteria and fungi. Its antimicrobial effect is closely related to its action form (gaseous and aqueous), microbial species, treatment concentration and time. ClO 2 first contacts the cell membrane wall, and then subsequently enters the cell to affect the internal components of the cell. Different biomolecules have different sensitivities to ClO 2 , both in vitro and in cells. We present some of the additional advantages that ClO 2 shows in its postharvest application. For instance, ClO 2 is able to stimulate plant innate immunity, preserve the quality characteristics of the commodity, remove hazardous factors, and as a potential controlled release agent in antimicrobial packaging. Overall, this study could provide useful information and new insights into the rational application of ClO 2 for microbial safety. [Display omitted] • Antimicrobial mechanism of chlorine dioxide (ClO 2) is determined by oxidation ability and action site. • ClO 2 stimulates plant innate immunity. • ClO 2 maintains horticultural produce quality in postharvest management applications. • ClO 2 is a potential controlled release agent in antimicrobial packaging. [ABSTRACT FROM AUTHOR]

The exchange of strategic information between firms is essential to maintain a whole-of-chain competitive advantage. Fourteen fresh produce experts were interviewed to identify barriers to and mechanism which improve strategic information sharing. Experts identified strategic information was exchanged in market orientated chains where there was trust, relationships and transparent information exchanges between firms. Barriers to information sharing were a lack of accurate and reliable information, a production focus and adversarial relationships. Face to face meetings with all firms in the chain to understand what information is important to who is recommended as a way to improve strategic information sharing. [ABSTRACT FROM AUTHOR]

In this study, thymol-loaded hydrophobically modified phytoglycogen/zein nanocomplexes with a particle size around 100 nm were developed for improving microbial safety of fresh produce. The antimicrobial activities, including the determination of minimum inhibitory and bactericidal concentration, growth kinetic curves, and inhibition zone of the nanocomplexes against foodborne pathogens (Listeria monocytogenes , Salmonella enteritidis , and Escherichia coli) were evaluated. The results showed that the antimicrobial activities of the nanocomplexes were significantly stronger than that of free thymol control (without encapsulation), and the antimicrobial efficacy remained unchanged after storage at 4 °C for 60 days. The morphological results from atomic force microscope revealed that small micellar blebs were formed at the surface of bacteria after treatment with nanocomplexes and the gradual disappearance of the cell boundary indicated the occurrence of cytolysis. The potential applications of this nanocomplex as disinfectant agent in wash water were evaluated on different types of fresh produce (lettuce, cantaloupe, and strawberries). Notably, the nanocomplexes also demonstrated efficacy in biofilm removal. Findings from this study clearly demonstrated that the thymol-loaded nanocomplexes hold promising potential for the disinfection of fresh produce to improve their microbial safety and quality. [Display omitted] • Thymol was successfully encapsulated by PG-zein nanocomplexes (NCs). • Thymol-NCs showed significantly lower MBC than the free control for all bacteria. • NCs triggered the cytolysis and leakage of intracellular compounds of bacterial cells. • Thymol-loaded NCs can inhibit the formation of biofilm on fresh produce. [ABSTRACT FROM AUTHOR]

Incidence of postharvest losses in the fresh produce value chain is a worldwide concern facing food security and sustainability. Postharvest losses can occur along the supply chain stages such as harvesting, storing, handling, packaging, transporting, and marketing. Mechanical damage caused by vibration is one of the most common quality challenges to fresh produce during transit. Mechanical damage of fresh produce can cause considerable economic losses by reducing quality and can result in severe food safety concerns. Understanding the factors affecting fresh produce damage during transportation is significant in developing strategies for reducing postharvest losses. We review transport as an essential component in the postharvest supply chain and critically discuss the adverse effect on fresh produce, mainly due to vibration. The experimental approaches applied to measure the vibration levels during transport of fresh produce are presented. Factors influencing the vibration level discussed herein include surface condition, vehicle speed, vibration duration, vibration direction, packaging unit, etc. A comprehensive discussion on the effects of packing unit type and surface of packaging material, location of the package on the vehicle, and height of the package in a stack on the vibration level is presented. Vibration during transportation is difficult to avoid; however, applying good management practices like improving the refrigeration system, utilization of appropriate packaging, and incorporating suitable cushioning materials can reduce produce damage during transit. Overall, careful selection of better solutions to this critical issue can help to reduce fresh produce susceptibility to vibration damage during road transport and thereby reduce incidence of postharvest losses of fresh commodities. • Vibration during transit can affect the fresh produce quality. • Factors affecting for vibration level during transit are reviewed. • Role of packaging on vibration level is discussed. • Use of simulation studies are reviewed. • Strategies to fresh produce damage reduction during transit are discussed. [ABSTRACT FROM AUTHOR]

Background and Aim: Fresh produce farms represents a major source of concern since they are becoming increasingly antibiotic resistant. This study aimed to investigate t he occurrence of carbapenemase and extended-spectrum-betalactamases (ESBL) - producing genes in Klebsiella pneumoniae isolated from fresh produce farms in Egypt, irrigation water, and people working in these fields. Materials and Methods: One hundred tomatoes from typical farms were collected in plastic bags. The study also included 20 surface-water samples from different irrigation watersheds in fresh produce farms, as well as 50 feces samples from farmworkers. Suspected K. pneumoniae was grown on Eosin Methylene Blue agar for 24 h before being biochemically identified using the RapID ONE test. PCR was used to detect carbapenemase (blaKPC, blaOXA-48, and blaNDM) and ESBL (blaSHV, blaTEM, and blaCTX) expressing genes on isolates. Results: K. pneumoniae was identified in 30% of water and 10% of worker samples, while only one isolate was found in tomato samples. One of the six irrigation water isolates tested positive for carbapenem-resistant NDM. In contrast, two isolates tested positive for ESBL determinants, one of which was blaSHV and the other having both blaSHV and blaTEM genes. Two of the five K. pneumoniae isolates from farmworkers were positive for blaNDM, with one isolate also testing positive for blaSHV and blaTEM. The blaOXA-48 gene was also discovered in the carbapenem-resistant K. pneumoniae tomato isolate used in this study. Conclusion: Carbapenemase- and ESBL-producing K. pneumoniae were found in fresh produce farms, implying that these resistance genes were being passed down to Egyptian consumers. [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate a new organic mixed peroxyacid solution produce wash composed of a combination of organic acids (lactic acid and one or more fruit acids) and hydrogen peroxide for activity against foodborne pathogens. The mixed peroxyacid was challenged against Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes in suspension or on the surface of dip-inoculated cherry tomatoes. Cherry tomatoes were also treated with 8 ppm of free chlorine in the form of sodium hypochlorite. When tested against planktonic cells of Salmonella and E. coli O157:H7 in pure culture for 120 s, these pathogens were reduced by 7.5 and 7.1 log CFU/mL, respectively, by the 0.40% peroxyacid solution, and L. monocytogenes was decreased by 5.0 log CFU/mL by the 0.80% solution. When cherry tomatoes were dip inoculated and treated with 8 ppm of free chlorine, Salmonella and E. coli O157:H7 populations decreased by 2.5 and 2.6 log CFU/g, respectively; these reductions were not significantly different from those obtained after sterile water rinses. However, the 1.0% peroxyacid solution reduced the same microorganisms by 3.8 and 3.4 log CFU/g, respectively, which was significantly greater (P < 0.05) than the reductions achieved by the 2-min sterile water rinse. For tomatoes dip inoculated with L. monocytogenes, populations were reduced by 3.5 log CFU/g by the 1.0% peroxyacid solution, which was significantly greater (P , 0.05) than reductions achieved by 8 ppm of free chlorine (2.6 log CFU/g) or sterile water (1.7 log CFU/g). These results indicate that this peroxyacid combination is an effective organic antimicrobial agent for preventing cross-contamination during the washing of cherry tomatoes and can inactivate S. enterica, E. coli O157:H7, and L. monocytogenes by up to 3.8, 3.4, and 3.5 log CFU/g, respectively. [ABSTRACT FROM AUTHOR]

To evaluate the influence of the Growing Together Illinois fresh produce donation program and understand factors that affect produce distribution at participating food pantries. In this intervention at 17 Illinois food pantries, Master Gardeners supported food donation gardens, and Supplemental Nutrition Assistance Program Education provided educational and environmental interventions to increase selection and use of fresh produce. This mixed-methods pre-post study assessed pantry characteristics and program impact via Nutrition Environment Food Pantry Assessment Tool evaluations, interview feedback from pantry staff, and structured pantry observations. Pantries experienced significant increases from preintervention to postintervention in providing various types of produce, marketing and nudging healthful products, providing additional resources, and total Nutrition Environment Food Pantry Assessment Tool scores. Participants had positive feedback about the program and educational interventions and reported the weekly timing of donations mitigated potential storage and spoilage issues. Future research could focus on approaches to increase fresh produce in food pantries while supporting clients via nutrition and cooking education. [ABSTRACT FROM AUTHOR]

The cold chain—the system of refrigerated storage and transport that provides fresh produce or other essentials to be maintained at desired temperatures and environmental conditions—is responsible for substantial energy consumption and greenhouse gas (GHG) emissions, and failures in the cold chain lead to food and energy waste. Here, we introduce the mini container concept as an alternative to conventional reefers, particularly for small growers. Mini containers are relatively small, insulated boxes, with environmental conditions controlled by an electric-powered central driving unit, which can be aggregated as needed and transported by non-refrigerated trucks and trailers. We analyze the energy consumption and GHG emissions for the transport of tomatoes in two cities representing contrasting climates, Phoenix, Arizona, and Chicago, Illinois, for conventional reefers and the proposed mini containers. These two cities provide the opportunity to compare the energy consumption and GHG emissions for the proposed mini containers versus conventional refrigerated transport under extremely different climate conditions. The results show that, as expected in both cases, as the ambient air temperature increases, the energy consumption and GHG emissions also increase. For partial reefer loads less than 72% and 85% for Phoenix and Chicago, respectively, the use of the mini containers reduces energy consumption and GHG emissions because of the reduced volume requiring refrigeration. In general, since the mini containers are fully electrified, their corresponding GHG emissions can be dramatically reduced, and since the fresh produce can be pre-cooled with renewable energy, GHG emissions can even be eliminated. [ABSTRACT FROM AUTHOR]

This paper examines a newsvendor problem for fresh produce with bidirectional option contracts, in which the stochastic demand is price-dependent. The bidirectional option, which may be exercised as either a call or put option, provides the newsvendor the flexibility to increase or decrease the initial order after real demand is realized, respectively. The condition of the fresh produce may deteriorate during circulation. The optimal order and pricing decisions for the newsvendor are analytically derived with the bidirectional option and circulation loss. Comparative statics analysis show that the optimal total order quantity and optimal retail price of the newsvendor decrease with the option price but increase with the exercise price. In addition, numerical examples show that the optimal total order quantity and optimal retail price of the newsvendor increase with the circulation loss. The optimal option order quantity first decreases then increases with the exercise price. The optimal firm order quantity first increases then decreases with the circulation loss. The maximum profit of the newsvendor decreases with the option price and circulation loss but increases with the exercise price. Furthermore, the values of bidirectional option contracts are more significant when the demand uncertainty and the circulation loss become more volatile. [ABSTRACT FROM AUTHOR]

Surface water used as an irrigation source can be a significant source of viral contamination of fresh produce. Enteric viruses such as hepatitis A virus (HAV) and human norovirus genogroup I (HNoV GI) and genogroup II (HNoV GII) can be transmitted to human via fresh produce when irrigated with contaminated water or when prepared by infected food handlers. In the current study, we investigated the presence of HAV, HNoV GI and GII in fresh produce and surface water used in cultivation of this produce using real-time PCR. Samples were collected from six different points in the Mansoura and Giza regions, Egypt. Our analysis showed that at least one virus was found in 41.6% (30/72) of surface water samples and 27% (13/48) of fresh produce samples. HAV (23/72) with a mean viral concentration = 4 × 106 genome copies/litre (GC/L) was the most frequently identified virus in surface water samples, followed by human norovirus genogroup II (HNoV GII) (15/72, with a mean concentration = 1.2 × 106 GC/L, and human noroviruses genogroup I (HNoV GI) (12/72, with a mean concentration = 1.4 × 104 GC/L). Additionally, HAV (10/48) with a mean concentration = 5.2 × 105 genome copies/gram (GC/g) was also the most frequently detected virus in the fresh produce samples, followed by HNoV GII (8/48, with a mean concentration = 1.7 × 104 GC/g); meanwhile, HNoV GI (6/48) was less detected virus with a mean concentration = 3 × 103 GC/g. This work suggests a wide prevalence of human enteric viruses in surface waters and fresh produce, which is of concern when the fresh produce is eaten raw. Thus, additional monitoring for viral pathogens in irrigation water and food is needed to increase the awareness of this issue to rise the control measures to reduce illness from contaminated food. [ABSTRACT FROM AUTHOR]

This study investigates a supply chain of fresh produce with consideration of option contracts and where stochastic market demand depends on freshness-keeping effort. Firstly, we investigate a benchmark scenario of an integrated supply chain with freshness effort and consideration of decreases in both the quality and quantity of produce while in the supply chain. Secondly, we introduce call, put, and bidirectional option contracts to mitigate risks of the retailer. A call option contract can reduce the underage risk, while a put option contract can reduce the overage risk, and a bidirectional option contract can reduce bilateral risks. We derive the optimal ordering decisions and freshness-keeping effort for a retailer in a supply chain of fresh produce with option contracts, and the conditions for achieving coordination of the supply chain. We find that the bidirectional option results in the highest option price and lowest option order quantity, while the call option results in the lowest initial order quantity and the put option results in the highest initial order quantity. Finally, numerical examples are given to demonstrate the impacts of various parameters on optimal decision-making. This paper provides managerial insights for reducing risk in fresh produce supply chains. [ABSTRACT FROM AUTHOR]

In this study, oligomers of carboxymethyl cellulose (O-CMC) were used as a new postharvest treatment for fresh produce. The oligomers were prepared by green and cost-effective enzymatic hydrolysis and applied to prevent spoilage and improve storability of fresh-cut strawberries. The produce quality was improved by all formulations containing O-CMC in comparison to the control, as indicated by the decrease in decay incidence, weight loss (min ~2–5 times less), higher firmness, microbial load decrease, better appearance, and sensorial quality of the fruits. Natural resources: ascorbic acid, gallic acid, and vanillin were further added to enhance the beneficial effect. O-CMC with vanillin was most efficient in all of the tested parameters, exhibiting the full prevention of fruit decay during all 7 days of refrigerated storage. In addition, fruits coated with O-CMC vanillin have the smallest weight loss (%), minimum browning, and highest antimicrobial effect preventing bacterial (~3 log, 2 log) and yeast/mold contaminations. Based on the obtained positive results, O-CMC may provide a new, safe, and effective tool for the postharvest treatment of fresh produce that can be used alone or in combination with other active agents. [ABSTRACT FROM AUTHOR]

Traditional ultrasound (US)-assisted disinfection is only effective during washing. Coating is an effective method to control microbial growth after washing; however, cross-contamination can occur during immersion in the coating aqueous solution. Tap water (TW) rinsing is generally used to remove sanitizer residues after US-assisted washing; however, the Food and Drug Administration stated that rinsing is unnecessary when the peracetic acid (PAA) concentration does not exceed 80 ppm. In this study, we proposed a novel US-assisted hurdle technology of 80 ppm PAA combined with low-frequency US (25 kHz) during washing, followed by US-assisted aerosolization processing (nonimmersion coating). Ascorbic acid (AA), a safe and low-cost agent, was selected as the aerosolization solution. Cherry tomatoes were selected as the model, and the proposed method was compared with traditional US-assisted disinfection methods (US-10 ppm free chlorine washing + TW rinsing and US-5 ppm chlorine dioxide washing + TW rinsing) to analyze the disinfection efficacy and quality changes. During storage, US-PAA + 1%AA facilitated additional 0.7–0.9, 0.6–0.8, 0.7–1.0, and 0.5–1.0 log CFU/g reductions in the counts of Escherichia coli O157:H7, Salmonella Typhimurium, aerobic mesophilic counts, and molds and yeasts, respectively, as compared with traditional US-assisted methods. Sensory properties, color index, total soluble solids, titratable acidity, and weight loss were not negatively affected by any of the treatments. Firmness was slightly reduced after all treatments; however, the firmness of the samples was maintained during storage, in contrast with the decreased firmness observed in the control. Phenolic content and antioxidant activity significantly increased after all treatments. Further analysis of two key enzymes (phenylalanine ammonia-lyase and 4-coumarate-CoA ligase) involved in phenolic synthesis showed that their levels significantly increased following all treatments, leading to an increase in phenolic content and antioxidant activity. This result also indicated that US-assisted washing could act as an abiotic elicitor to increase nutritional content. Overall, US-PAA + 1%AA treatment served as an effective method for disinfecting produce during washing and for controlling microbial growth after washing without prolonging the processing time, which is an advantage over traditional US-assisted washing.