Safety Of Vegetables Research Articles

Persistencia, internalización y translocación de Escherichia coli O157:H7, O157:H16 y O105ab en plantas y frutos de tomate (Solanum lycopersicum L.)

The presence of pathogenic bacteria, such as Escherichia coli affects the quality and safety of vegetables that are consumed fresh and is associated with serious health problems. The objective of this study was to determine if three different strains of E. coli can penetrate and remain in plants and tomato fruits. A completely randomized experimental design was followed for which a tomato crop (“Cid” variety) was established under greenhouse conditions and three treatments were evaluated, T1 (E. coli O157:H7), T2 (E. coli from tomato cultivation [EcT] O157:H16), T3 (E. coli from spinach cultivation [EcH] O105ab) and a T4 control, with 100 plants each and four forms of inoculation: in the substrate, steam, petiole and the peduncle. Samples were carried out in vegetative stage, flowering, fruiting and physiological maturity to quantify in petri dish CFU/g and know if the bacteria managed to move around and recover in root, stem, flower and fruit. The phylogenetic groups that corresponded to the bacteria recovered were confirmed by biochemical tests, serotyping and PCR. At 120 days the recovery of bacteria in the plant was 23% (E. coli O157:H7), 28% (EcT O157:H16) and 55% (EcH O105ab) whit inoculation to the substrate while the inoculation by puncture the recovery was (in the same order) of 5%, 3%, and 4% at 30 days; 37%, 35% and 30% at 90 days; and 42%, 39% and 13% at 65 days. The strains submit the ability to enter the tomato plant and to stay in it and transported to the fruit, without producing that indicate their presence.

Data Mining in Evaluating the Impact of Perceived Trust in the Consumption of Safe Foods in Vietnamese Households: The Case of Vegetables in Hanoi

Food safety is as much of a concern to Vietnamese citizens as it is to the public authorities. As safe vegetables are classified as credence goods, the markets of which exhibit a high level of information asymmetry between the buyers and the suppliers. As such, making the market for safe vegetables become more transparent and grow sustainably is a must, but not an easy task. In this paper, we use a Kernel regression method to discover the main determinants of consumers’ decisions for the consumption of “safe” vegetables with more focus on perceived levels of trust. The result shows that apart from other traditional factors, perceived trust is an important determinant of consumers’ decisions. However, the data shows that consumers put more trust in un-verified factors such as “store’s reputation” or “label” and much less on formal factors such as “government certificates”. This result raises some alarm as other studies show that without trusted involvement from the Government, signals from suppliers, such as labeling are not reliable.

Determinants of urban consumers’ participation in informal vegetable markets: Evidence from Mahikeng, North West province, South Africa, and implications for policy

Background: This article seeks to examine the perceptions of urban dwellers towards participating in informal vegetable markets and determine the underlying factors shaping their decisions to participate in such markets. Aim and setting: The objectives were achieved by using cross-sectional data obtained from a random sample of 230 households from Mahikeng in the North West province of South Africa. Households’ perceptions were measured using numeric responses to several questions, which covered various issues related to vegetable marketing and consumption. Principal component analysis (PCA) was employed to draw dominant perceptions from the set of responses. Method: The probit model was used to determine factors influencing households’ decisions of whether or not to participate in informal vegetable markets. Explanatory variables included demographic and socio-economic factors as well as perception-related factors, which were proxied by the dominant principal components (PCs) obtained from the PCA results. Results: Two PCs were found dominant, representing safety and quality perceptions as well as the convenience and bargaining opportunities provided by informal traders. The probit regression results indicated that households’ preference for the informal vegetable market were positively influenced by age of household head, low level of education of adult household members, and convenience provided by informal markets. However, households’ wealth status and the perceptions on safety and quality of vegetables were found to have a significant negative influence on participation in the informal market. Conclusion: Given that informal vegetable trade forms an integral part of the urban economy by offering easy access to food in public spaces and connecting with the formal economy where informal traders source their supplies, the study concludes by highlighting policy interventions aimed at improving the quality of food traded in the informal sector.

FEATURES OF VEGETABLES MARKET DEVELOPMENT IN CHINA

Against the backdrop of the slow recovery of the world economy from the consequences of the global financial and economic crisis, the world community is to find a new model of interaction and create new mechanisms for economic development. In the course of integrating the Chinese economy into the world economy, China is ready to assume more international responsibilities and obligations in accordance with its capabilities, including in the field of providing the population with food. The history of reforming the food market in general and the vegetable market in particular began in the PRC in 1978 from the countryside and in 2017 reached the world scale in the framework of creating international economic relations under the project One belt – one way. The article deals with the development of the vegetable market in China, ensuring safety and high quality standards of vegetables in the country, as well as the direction of international development of China's economic relations in the course of solving the problem of providing the population with food. As a result of the research, the development of the vegetable market in China was revealed.

Induction of Bacteriocins from Lactic Acid Bacteria; a Strategy to Improve the Safety of Fresh Fruits and Vegetables

Induction of Bacteriocins from Lactic Acid Bacteria; a Strategy to Improve the Safety of Fresh Fruits and Vegetables

Innovative approaches to improve quality and safety of fresh minimally-processed fruit and vegetables

Innovative approaches to improve quality and safety of fresh minimally-processed fruit and vegetables

Postharvest treatments to improve quality and safety of locally-grown vegetables stored at non-optimum temperatures

Postharvest treatments to improve quality and safety of locally-grown vegetables stored at non-optimum temperatures

Essential oil components inhibit biofilm formation in Erwinia carotovora and Pseudomonas fluorescens via anti-quorum sensing activity

The effect of 10 essential oil (EO) components on biofilm formation for vegetable spoilage Erwinia carotovora and Pseudomonas fluorescens at sub-MICs were investigated. Chromobacterium violaceum CV026 (CV026) was selected as quorum sensing (QS) biosensor bacterium. The swimming, swarming, twitching motility, exopolysaccharide (EPS) production and biofilm formation were determined. All tested EO components showed QS inhibition of CV026, E. carotovora and P. fluorescens. Biofilms were inhibited by all EO components by inhibiting their motilities and EPS production. Salicylic acid and thymol showed the best inhibitory effect on biofilm formation of P. fluorescens (37.61%) and E. carotovora (47.24%) respectively. Hexanal as QS inhibitor for biofilm formation was first reported, with inhibition ratio of 25.86% and 20.18%, which was confirmed by scanning electron and fluorescence microscopy. Inhibition of biofilm formation by anti-QS EO components could be novel intervention strategy to enhance safety and quality of vegetables in the food industry.

Behaviors in the market for safe vegetables under information asymmetry: modeling approach

The paper proposes a theoretical model that depicts a shop owner’s behavior in the market for safe vegetables under informational asymmetry between sellers and buyers. In the model, the shop owner claims his shop provides safe vegetables and is maximizing profit by mixing ordinary vegetables with safe vegetables. The buyers make their decision about buying or not buying vegetables from the shop based on their own belief in the information supplied by the sellers. The results from numerical studies show that low credibility leads to limited efficiency of inspection activities. Raising credibility can make the whole society better off, including the sellers as well as the buyers. In addition, the ratio of safe vegetables as well as the total sale of genuinely safe vegetables will also increase. Hence, the paper calls for a trustworthy inspection system so that consumers can have higher trust in the credibility of the information they receive.

Microbiological Quality and Safety of Fresh Fruits and Vegetables at Retail Levels in Korea.

The aim of this study was to evaluate the microbiological quality and safety of fresh produce at retail level in Korea in order to periodically update information and establish available risks associated with consumption of fresh fruits and vegetables. The samples from different markets located in 3 provinces of South Korea were collected. The protocol in the Korean Food Standards Codex was applied and generic Escherichia coli, coliforms, aerobic mesophilic bacteria (AMB), and yeast and mold (YM) in 360 packaged and unpackaged fresh fruits and vegetables were analyzed. Presence of pathogens was examined using real-time polymerase chain reaction (q-PCR) after enrichment of samples. For all, the microbial counts ranged from 1.7 to 10.6 log cfu/g for AMB, 2.2 to 7.9 log cfu/g for coliforms, and 5.5 to 7.9 log cfu/g for YM. Three lettuce samples were contaminated by E. coli with a bacterial load ranging from 2 to 4 log cfu/g. Salmonella spp. were not detected in any fresh produce. Listeria monocytogenes, E. coli O157:H7, and Staphylococcus aureus were found in 1 (0.6%), 3 (0.8%), and 5 (1.4%) fresh produce samples, respectively. Bacillus cereus (50.3%) and Clostridium perfringens (13.3%) had the highest prevalence. These results indicate the need for employing strict control measures and developing preventive strategies to improve the quality and safety of fresh produce in Korea.

Value Chain Analysis of Vegetables on Urban Vietnam - Case of Danang City

Safe food has been “a constant worry of the people and a controversial problem that need to be solved at the earliest in Vietnam”. Over the past recent years, the government has had a various policies in order to support developing both producing and distributing safe vegetables. However, up to now, the supply chain of safe vegetables (SV) still has some drawbacks. While everybody has the need to consume SV and the government has made so many efforts to support, why the supply chain of SV still has not developed strongly and taken the place of the normal supply chain? This research focuses on analyzing the vegetables value chain, comparing between the supply chain of SV and the supply chain of normal vegetables, including qualitative and quantitative analysis. The finding will partly point out some problems in dividing the cost and the value of the supply chain of SV in order to suggest some solutions for the development of the supply chain.

Bacteriological quality and safety of green pepper and tomato irrigated with Abay River water in Bahir Dar town

The objective of this study was to determine the bacteriological quality and safety of green pepper (Capsicum annuum) and tomato (Lycopersicon esculentum) grown along Abay river of Bahir Dar town, Ethiopia. The mean aerobic mesophilic counts from tomato and green pepper were 4.72 and 5.01 respectively. The mean total coliform counts from tomato was 234.9 MPN/g and green pepper 303.2 MPN/g. Similarly, the mean fecal coliform counts of tomato was 45.08 MPN/g and 58.1MPN/g from green pepper. The mean bacterial counts of green pepper were higher than tomato vegetables. Moreover, 5 (8.3%) Salmonella, 3 (5%) Shigella spp. and 6 (10% ) E. coli spp. were isolated from tomato; and 6 (10%) Salmonella, 5 (8.3%) Shigella and 9 (15%) E. coli spp. were detected from green pepper samples. The mean total coliform counts from Bezawit were 1040 MPN/100ml and 711.67MPN/100ml Gudguad site. Similarly, the mean fecal coliform counts of Bezawit was 689.67MPN/100ml and 390.00MPN/100ml from Gudguad. In both sites, lack of awareness and poor irrigation practice promote the probability of vegetable contamination. Therefore, keeping the irrigation practice of irrigated vegetable and providing regular training for farmers are some of the practices to improve bacteriological quality, safety and shelflife of vegetables and their products.

Cloud-based system for rational use of pesticide to guarantee the source safety of traceable vegetables

Recent legal requirements and market demands have motivated more food companies to implement traceability systems. Ensuring safe farming practices is the first step in food supply chain traceability, and reasonable pesticide use is a main feature of food safety and sustainable production. This study describes the design and development of a cloud-based platform for rational pesticide use to guarantee the source safety of traceable vegetables. The system includes a pesticide use control cloud platform (PUCC) and a pesticide user application (PUA), which interactively guide users through the steps of pesticide purchasing, pesticide application, harvest time, and pesticide evaluation. Models for evaluating and recommending potential pesticides were developed based on an open library of pesticide use rules. The PUCC, which includes the main functions of farmer registration, authentication of platform administrator, and information management for plant protection service agencies, was developed using Microsoft Visual Studio 2010 and deployed on the Internet. The PUA provides interfaces for pesticide purchasing guideline, pesticide application, optimal harvest time, and feedback. As a case study, the system was used for about a year in 24 vegetable bases in Tianjin. The effectiveness of the system was evaluated by investigating 8 management center staff members and 41 farmers. Management agencies noted the positive effects of promoting reasonable pesticide use, facilitating information accessibility, and enhancing management. Advantages to farmers included reducing the risk of unreasonable pesticide usage, decreasing the risk of counterfeit pesticides, and improving vegetable quality and safety; disadvantages included increased costs and reduced efficiency. In addition, the system improved external and internal traceability to ensure crop quality and safety.

In-situ examination of graphene and graphene oxide impact on the depuration of phenanthrene and fluoranthene adsorbed onto spinach (Spinacia oleracea L.) leaf surfaces

To further assess the human being's exposure to polycyclic aromatic hydrocarbons (PAHs) through the dietary pathway, understanding the partitioning of these chemicals co-existed with nanomaterials in edible vegetable systems deserves specific consideration. In this study, the fiber-optic fluorimetry was applied to in situ examine the effects of graphene (GNS) and graphene oxide (GO) nanosheets on the quantification and depuration of three-ringed phenanthrene (Phe) and four-ringed fluoranthene (Fla) adsorbed individually onto the living spinach (Spinacia oleracea L.) surfaces. When the GNS and GO dosages separately increased to the maximum values: a respective red-shift of 4–5 nm and blue-shift of 2–3 nm occurred for the optimal detection emission wavelengths (λem) of the two PAHs, indicating that individual GNS and GO resulted in different changes to the epicuticular wax (ECW) polarity; GNS-inducing fluorescence quenching for the PAHs was about two times greater than GO, owing to the stronger π-π interactions between PAH molecules and GNS relative to GO; the volatilization coefficients (kC1) were reduced by 31.1% versus 26.7% for Phe, and 51.6% versus 34.4% for Fla, mainly via providing an additional adsorbent and promoting the accessibility of the leaf cuticle; respective photolysis coefficients (kP2) of Phe and Fla decreased by 42.9% and 50.0% with GNS, primarily owing to the enhancement of the ECW light-adsorption capacity, but increased by 33.3% and 40.0% with GO due to its photocatalytic activities; overall, total depuration coefficients (kT1, kT2) of the two PAHs decreased by 11.1–55.6%. These findings demonstrate that GNS and GO significantly alter the depuration behavior of PAHs in vegetable systems, potentially posing a threat to the safety of edible vegetables.

Cadmium accumulation in edible flowering cabbages in the Pearl River Delta, China: Critical soil factors and enrichment models.

Although many previous studies have reported the soil pH and organic matter to be the most critical factors that affect the transfer of Cd in soil-crop systems in temperate zones, the behavior of Cd transfer is different in the Pearl River Delta (PRD), which is located in a subtropical zone with different climate and soil conditions. Therefore, we must determine the critical environmental factors that influence the transfer of Cd in the soil-vegetable system in the PRD region. Such knowledge can improve the safety of vegetables. In this study, the soil geochemical properties are investigated to explore the key soil factors that control the uptake of Cd by flowering cabbage, a popular leaf vegetable in China, from soils in the PRD region. The Cd contents in vegetables were most positively correlated to soil oxalate-Cd (p<0.01), which indicates that amorphous Cd is the most available form for uptake into the cabbages. With the characteristics of rich in Fe oxide and Al oxide in the PRD soils, soil Fe and Al oxides were found to be the most relevant to the transfer factors of Cd from the soils to the cabbages. Soil secondary minerals are the key factor that affects the transfer of Cd, thereby influencing the migration and fate of Cd in soil-cabbage systems, with DCB-Fe significantly decreasing the Cd accumulation in cabbages. Additionally, models were developed to predict the enrichment of Cd in flowering cabbages, in which oxalate-Cd, DCB-Fe, and NaOAc-Al in soils were determined to be the most important factors that affect the Cd enrichment in flowering cabbages. In this study, we determine the important role of soil secondary minerals in affecting the transfer of Cd in soil-cabbage systems in the PRD. These observations are important to evaluate the accumulation of Cd in vegetables in subtropical zones.

Effect of electro-activated solutions of sodium acetate and sodium propionate on geosmin producing Streptomyces avermitilis strain

Electro-activated solutions of salts of weak organic acids are defined as novel potent disinfecting agents that can be used in the agri-food industry. The aim of the present work is to study and understand the destruction mechanism of electro-activated solutions of sodium acetate (EAA) and sodium propionate (EAP) against Streptomyces avermitilis spores. The results of antibacterial activity showed high bacteriostatic effect for all the tested solutions, including sodium hypochlorite used as positive control. Under specific conditions, test on minimal inhibitory concentration demonstrated that the used electro-activated solutions have inhibition activity comparable or higher than the control solution, with the following inhibiting concentrations of 0.004, 0.002 and 0.073 mol/L, for EAA, EAP and NaOCl, respectively. The most active solutions resulted in destruction effect of more than 7 log CFU/mL. The physiological state of the S. avermitilis spores was assessed by transmission electron microscopy after treatments with the electro-activated organic solutions and NaOCl. The results displayed coreless and/or deformed cellular forms with ruptured membranes and released components of spores.The main practical importance of this study is that the targeted final objective is to develop safe and effective alternative to sodium hypochlorite to ensure microbial safety of fresh vegetables under storage conditions. In this context, we studied the potential of electro-activated solutions of sodium acetate and sodium propionate against spores of Streptomyces avermitilis and compared this activity with sodium hypochlorite, the mostly used disinfecting agent in the agri-food industry.

Impact of gamma irradiation and osmotic dehydration on quality characteristics of guava (Psidium guajava ) slices

A multi-target (combination preservation) technique has been extensively applied to develop minimally processed and completely stabilized shelf stable food produces. A combination of irradiation and osmotic dehydration decrease the need for thermal treatments for enhancing the shelf life and microbial safety of cut fruits and vegetables. The present study aims at identifying combined effect of ã-irradiation pre-treatment and osmotic dehydration treatment on guava. The guavas packed in LDPE pouches were irradiated at 0.25 kGy, and 1.0 kGy dosages at the dose rate of 2.75 kGy/hr. The guava slices with and without irradiation were infused for osmotic dehydration process. Optimization of the process time (3,6 and 9 hr) was also investigated. Further, stored guava slices were analyzed for their physico – chemical, antioxidant and microbial analysis. Mass transfer kinetics of guava slices osmotically dehydrated in sucrose solutions were significantly affected by irradiation dosage and sucrose concentration and treatment duration. The evaluation of hurdle approach on guava slices showed that, combination treated slices were significantly less susceptible to nutrient and colour changes during storage. The synergy between the irradiation and dehydration also resulted in adequate microbiological stability of the slices.

Factors affecting the competitiveness of Ho Chi Minh City’s safe vegetables

This paper aims to discuss the competitiveness of safe vegetables of Ho Chi Minh City (HCMC). We employed Exploratory Factors Analysis and Regression Analysis methods on data collected from a survey of 150 respondents in Binh Chanh and Cu Chi districts. The results indicate that factors affecting the competitiveness of HCMC’s safe vegetables are price, packing, quality, diversity, flexibility and distribution system. The paper also offers three policy suggestions, namely 1) expanding scale and reducing costs to decrease the price HCMC’s safe vegetables; 2) improving the quality of HCMC’s safe vegetables; 3) diversifying types of HCMC’s safe vegetables.

A study on the possibility to use pheromone traps to control the diamondback moth [Plutella xylostella (L.)] – a cabbage pest in Hanoi, Vietnam

Background. The diamondback moth [Plutella xylostella (L.)] is a major insect pest of cruciferous vegetables due to its infestation and resistance to pesticides. Pheromones have highly specialised advantages for each species and they leave no chemical residues. This study was an attempt to improve the understanding of the pheromone trap technique, a necessary step to produce safe vegetables in Vietnam. Material and methods. The investigations were conducted on cabbage (Brassica oleracea L. var. capitata) in Hanoi. Pheromone traps were used to catch adult diamondback moths every day and to count larvae on cabbage every 7 days. The data were analysed with Microsoft Excel 2007 and Irristat 4.0. Results. The highest number of diamondback moths in the first season was 21.2 larvae per 1 m2 in the trapping variant and 22.1 larvae per 1 m2 in the non-trapping variant; in the second season it was 17.5 and 19.5, respectively. The F parameter significance between the number of adult insects in the trap and the larval density was linearly proportional, i.e. F = 0.000202 (< 0.05) in the first season and F = 0.000146 (< 0.05) in the second season. The use of pesticides required higher investment, but yielded lower profit than the pheromone trap (552 €/ha vs 572 €/ha). Conclusions. The larval density in the formula with pheromone traps was always lower than in the one without traps. Pheromone traps affected the density of larvae in the field. Not only do they bring more economic benefits than the use of pesticides only, but they also protect the environment and ensure the sustainability of ecosystems.

Consumers’ familiarity with and attitudes towards food quality certifications for rice and vegetables in Vietnam

This study investigates consumers’ attitudes towards, and familiarity with, food quality certification in selected urban areas in the South of Vietnam. Cross-sectional data were collected by means of a consumer survey (n = 500). Consumers’ awareness of food quality-related terms was relatively low. Less than half the participants claimed to understand the meaning of good agricultural practices (GAP), organic food and sustainability. Consumers’ familiarity with food quality certification (Vietnamese Good Agricultural Practices (VietGAP), Global Good Agricultural Practices (GLOBALG.A.P.), organic, and Hazard Analysis and Critical Control Points (HACCP)) was also low. Familiarity with food quality certification was positively associated with general attitude and food choice motives, namely food safety concern, perceived importance of healthy eating, and perceived importance of environmental consequences relating to food purchase. Food safety concern and perceived importance of environmental consequences were positively associated with consumers’ attitudes towards safe vegetables, as well as high quality rice. Perceived importance of healthy eating was positively related to attitude towards high quality rice. Findings suggest that food safety aspects of safe vegetables and high quality rice should be emphasized during policy and marketing activities for food quality certification. Additionally, an increase in the perceived importance of environmental consequences relating to quality food purchase should be encouraged to enhance positive consumer attitudes towards quality food. Efforts to improve public awareness and knowledge of food quality certification and sustainable agricultural practices in developing countries such as Vietnam are highly recommended.