Real-time and visual loop-mediated isothermal amplification: Efficient GMO screening targeting pat and pmi marker genes

Rapid and efficient screening assays based on loop-mediated isothermal amplification (LAMP) were developed, targeting two marker genes, namely, phosphinothricin-N-acetyltransferase (pat) and phosphomannose isomerase (pmi). These marker genes are being employed in more than 35% of GM events approved globally. Specificity of developed visual and real-time LAMP assays was confirmed using seven GM events of two crops, viz., maize (3272, 59122, Bt11, Bt176, MIR604, TC1507), and cotton (Widestrike™). In visual LAMP, positive amplification can be directly analyzed by the colorimetric change from orange to green, whereas real-time LAMP is based on the monitoring of fluorescence signals as amplification and annealing curves. Visual LAMP was found sensitive enough to detect up to 0.05% GM content for pat and 0.1% for pmi within 40 min. Real-time LAMP efficiently detected up to 0.01% GM content within 30 min. Practical applicability of developed assays was confirmed using proficiency test samples of maize. LAMP assays for pmi gene have been reported for the first time. Due to portability of systems, the developed LAMP assays when combined with a fast DNA extraction method could facilitate on-site GMO screening.     

GMO matrix: A cost-effective approach for screening unauthorized genetically modified events in India

Use of a pragmatic, affordable and reliable approach for screening and detection of a large number of genetically modified (GM) crops/events is the need of hour. A cost-effective matrix approach to check the GM status of food/feed products and for screening the presence of authorized and unauthorized GM events in India is being reported in the present study. A genetically modified organism (GMO) screening matrix, with the information on 106 genetic element targets for detection of 141 GM events of 21 crops, is being presented. These include commercially cultivated Bt cotton events and other GM events, under field trials during the past six years (2006–2012) in the country. The information on GM events, which were either indigenously developed or imported for research purposes, is also presented in brief. Ten most frequently present targets, viz., [P-35S] [T-nos] [Os-Msca1] [cry1Ab] [cry1Ac] [cry1C] [cry2Ab] [GA20 oxidase1] [nptII] [bar], were identified to screen these events using a GMOseek algorithm. This user-friendly screening tool is flexible for further updates with the new GM events and targets/elements. The data reported here related to the GM crops/events in India and the related GMO matrix are valuable tools to assist in the detection of accidental presence of unauthorized GM events in the food and supply chain globally, as well as in the context of the new labelling requirements for food commodities, as per the amendment to enforce GM food labelling from January 2013 in India. The reported GMO matrix approach would facilitate efficient, rapid and cost-effective preliminary screening by eliminating the need for development of specific testing methodologies for each GM event.     

Motives towards traceable food choice: A comparison between French and Italian consumers

Food traceability standards aim to reduce the risk of food-borne disease by facilitating the withdrawal of food and feed products and to provide consumers with targeted information. This paper analyses consumers' attitude and behaviour towards traceable food in two different European countries: Italy and France. A survey has been conducted on two samples of Italian (n = 503) and French (n = 501) consumers, aiming to explain the intention toward purchasing traceable food using the theory of planned behaviour (TPB). The predictive power of the TPB model significantly increases in both countries when new variables are added: habits, trust, past behaviour and socio-demographics. The results show that attitudes drive the intention to purchase traceable chicken and honey in France. Trust affects the intention to purchase traceable chicken and honey in Italy. These findings may serve to target public interventions and private strategies towards food traceability.     

Loop-mediated isothermal amplification targeting insect resistant and herbicide tolerant transgenes: Monitoring for GM contamination in supply chain

Efficient detection strategies for genetically modified (GM) crops are required to effectively address some of the biosafety and post-release monitoring issues, as global adoption of GM crops has been unprecedently increased. Herbicide tolerance and insecticide resistance are the major traits in commercialized GM food crops. Visual as well as real-time detection system based on loop-mediated isothermal amplification (LAMP) targeting lepidopteron insect resistant cry1Ac, cry2Ab2 and glyphosate tolerant cp4-epsps genes has been reported. Specificity of LAMP assays were confirmed using fourteen GM events of four crops, namely, corn (MON810, NK603, Bt11, Bt176, MON89034), cotton (MON531, MON15985, GFM-cry1A, Event1, MLS9124, MON1445, MON15985 × MON88913), eggplant (EE1) and soybean (GTS40-3-2). Real-time LAMP was found sensitive enough to detect as low as 2 copies for cry1Ac and 4 copies for cry2Ab2 and cp4-epsps within 35 min using a calibration curve. The limit of detection (LOD) of visual LAMP assays was down to 0.01% (4 copies of GM content) which is lower than conventional PCR (detecting 40–400 copies depending on target). LAMP assays are faster and more user-friendly than conventional PCR and could be efficiently utilized for monitoring of GM contamination in food and feed supply chain, with high specificity and sensitivity. The developed assays, when combined with a fast DNA extraction method, will facilitate on-site detection to check the GM status of a sample or product at ports of entry and in farmers' fields.     

Comparison of the resistance of mono- and multilayer packaging films to stored-product insects in a laboratory test

Stored-product insects frequently infest packaged food, causing significant monetary losses to both the food industry and consumers worldwide. This work compared the resistance of 9 new monolayer and multilayer food-packaging films to infestation by 4 key insect food pests (Sitophilus granarius, Rhyzopertha dominica, Oryzaephilus surinamensis and Plodia interpunctella). A series of laboratory tests were conducted over 3 months to determine the package penetration by the stored-product insects. The tested pest species differed in their chewing capacity and in the size of their entrance hole (P. interpunctella larvae, 15 ± 17 mm² penetrated area/hole; S. granarius, 6 ± 5 mm²; R. dominica, 6 ± 2 mm²; and O. surinamensis, unable to penetrate). The insects also caused mechanical weakening of the film surface by creating multiple small superficial holes covering a 10–20× larger area of the film surface than the penetrated area. For insect invaders (S. granarius, R. dominica, and P. interpunctella), porous paper and an unprinted polyethylene monolayer (40 μm thick) provided the least mechanical resistance, while the highest level of mechanical resistance was recorded for 50-μm-thick polypropylene/metalized-polypropylene. The most innovative findings of this study were that the unprinted parts of the polypropylene monofilm were less protective against R. dominica penetration than the printed parts and that duplex and triplex films were more resistant to insect feeding and penetration than single-layer films, irrespective of their thickness. Some multilayer films showed (in our experimental settings and for the packaging machines used) low resistance to O. surinamensis invasion through crevices caused by sealing imperfections. The results of this study are discussed in the context of film application to protect packaged foods against insect contamination.     

Viability of Listeria monocytogenes in an experimental model of nigiri sushi of halibut (Hippoglossus hippoglossus) and salmon (Salmo salar)

Sushi is a traditional Japanese food, mostly consisting of raw seafood in combination with rice. However, eating sushi has become popular among consumers in many countries outside Japan. Sushi is not free from health risks and foodborne illness linked to this product has been caused by Listeria monocytogenes. The aim of our work was to study viability of L. monocytogenes in emulated nigiri sushi comprised of halibut and salmon. Raw samples of halibut and salmon were inoculated with the pathogen and subsequently put on top of vinegar marinated sushi rice followed by storage for 7 days at 4 and 8 °C. As controls, inoculated seafood without rice was used. The experiments demonstrated that the level of L. monocytogenes in nigiri sushi was significant lower during storage over 7 days at 4 and 8 °C compared to controls, in case of inoculated seafood only. The pH drop in the fish muscle, caused by the sushi rice, is believed to be the reason for the decrease in viability of L. monocytogenes in nigiri sushi.     

Antifungal activity of Michelia alba oil in the vapor phase and the synergistic effect of major essential oil components against Aspergillus flavus on brown rice

The objectives of this study were to investigate the effect of essential oil (Michelia alba) vapor on the spore germination and mycelium growth of Aspergillus flavus on brown rice and to perceive the shelf life of the brown rice could be extended to a longer storage time. Different volumes (150, 300, 450 μl) of M. alba and a 300 μl linalool/caryophyllene combination at ratios of 10:1, 1:1, and 1:10 were first absorbed into plant absorbent material (Φ∼20 mm) before being put into a closed glass box (1L) containing A. flavus spore and the mycelium (Φ∼5 mm) in a Malt Extract Agar (uncovered plate). Mold testing was also carried out on brown rice with A. flavus spore suspension before being incubated at 25° C and 100% RH for 16 weeks. Quality tests e.g. texture, a sensorial evaluation (hedonic scale) of brown rice were also conducted. Results indicated that the vapor phase of M. alba at ≥ 300 μl L⁻¹ air could inhibit both spore germination and A. flavus mycelium. Antifungal activity of M. alba in air was strongly correlated with the linalool/caryophyllene combination at the ratio of 10:1 in 300 μl L⁻¹ air. In addition, M. alba vapor at 300 μl L⁻¹ air was found to extend the shelf-life of the brown rice by four times (16 weeks) in comparison with the control treated without essential oil (4 weeks). After being cooked, the hardness of brown rice with volatile essential oil was found to be reduced by one third (compared to the control brown rice). The hedonic value (overall liking) of cooked brown rice packed with M. alba vapor at 300 μl for 1 week and then stored for 16 weeks was a 7, rated as “like moderately”. Therefore, this study has demonstrated the good potential of M. alba vapor to control mold growth on the surface of brown rice.     

Fiber optic and light scattering sensors: Complimentary approaches to rapid detection of Salmonella enterica in food samples

Salmonella-related foodborne infections present a major public health problem worldwide despite more stringent regulations. Salmonella enterica serovars Enteritidis and Typhimurium are the two most frequent causes of poultry related outbreaks; therefore, their rapid and accurate detection would improve Salmonella control at the farm, processing plant, and at retail. In this study, we investigated if a fiber optic immunosensor and light scattering sensor, BARDOT (bacterial rapid detection using optical scattering technology) could facilitate the detection of these two serovars in naturally contaminated poultry (n = 50). The fiber optic sensor with a detection limit of 10³ CFU/ml identified S. enterica in selective enrichment broth in less than 12 h. The colonies (1.0 ± 0.2 mm) produced by plating the enriched samples on selective XLT4 agar for 13–15 h were scanned using BARDOT and S. enterica was identified after matching individual colony scatter patterns to the scatter image library with a sample-to-answer time of about 24 h. Both sensors identified 4 positive samples (8%), which corresponded to the results of the USDA-FSIS protocol, PCR, and lateral flow immunoassays. The colony scatter patterns identified all natural isolates as S. Enteritidis, which was further verified by serovar-specific PCR. The sensors used individually or in combination demonstrate potential for accurate and rapid detection of S. enterica in poultry.     

Event-specific analytical methods for six genetically modified maize events using visual and real-time loop-mediated isothermal amplification

Currently 138 genetically modified (GM) maize events have been authorized for commercial cultivation, comprising more than 65 per cent stacked events. With the increase in number of GM maize events globally, cost- and time-efficient diagnostics with on-site applicability are required to check for authorized GM events. Six GM maize events, namely, Bt11, GA21, MON810, MON89034, NK603 and TC1507, also present in 89 stacked events, are being widely commercialized in more than 17 countries. Visual and real-time loop-mediated isothermal amplification (LAMP) assays targeting these six GM maize events are being reported in the present study. Specificity of the developed LAMP assays was confirmed using fourteen commercialized GM maize events. Limit of detection of visual and real-time LAMP assays targeting Bt11, GA21, MON810, MON89034 and TC1507, was up to 0.01%, detecting 8 target copies, and for NK603 event-specific assays, was up to 0.1% detecting 73 target copies. Practical applicability of developed LAMP assays was verified using a set of five stacked GM maize events, namely, Bt11 × GA21, MON89034 × NK603, MON89034 × NK603 × TC1507, TC1507 × NK603 and TC1507 × MON810; and six powdered maize samples of proficiency testing. The reported LAMP assays can be efficiently employed for screening for presence of selected GM maize events in single or stacked form.     

Correlation of viscoelastic behavior with water state and ultrastructure in hot air-dried carrots

This study evaluated and correlated the viscoelastic behavior, water state and ultrastructure of hot air-dried carrots. The results revealed that with increasing time, hot air-drying increased loss tangent (Tan δ) and reduced storage (G′) and loss (G″) moduli, cell wall components including total pectin (Tp), hemicellulose (He), and cellulose (Ce), free water (reflected by relaxation time T₂₃ and relative area M₂₃) in vacuoles, and immobilized water (T₂₂ and M₂₂) in cytoplasm and extracellular space in carrots. Pearson's correlation analysis showed that G′ and G″ were positively correlated (p < 0.01) with T₂₂, T₂₃, M₂₃, Tp, He, and Ce in dried carrots, whereas Tan δ was negatively with these indicators (p < 0.01). Principal component regression analysis revealed that the contribution rate of principal factor 1 and 2 (F1 and F2) was 72.7 and 21.9%, respectively. The Tp, He, Ce, T₂₃, and M₂₃ (42.3, 42.7, 42.5, 43.8 and 44.2% of the explained variance, respectively) were well explained by F1. The G′, G″, and Tan δ could be predicted by the following regression equation, G′ = 0.696 × F1, G″ = 0.680 × F1, and Tan δ = 0.341 − 0.652 × F1. These relationships were consistent with the more pronounced changes (plasmolysis of cytoplasm, disruption of plasmalemma and tonoplast, and degradation of cell walls and middle lamella) in the ultrastructure of dried carrots.     

Combined effect of carvacrol and citral on the growth of Listeria monocytogenes and Listeria innocua and on the occurrence of damaged cells

The aim of this study was to evaluate the growth kinetics of Listeria innocua Serovar 6a (CECT 910) and Listeria monocytogenes Serovar 4b (CECT 4032) exposed to combinations of carvacrol and citral (0.0 μL/mL (control), 0.050 μL/mL of carvacrol and 0.075 μL/mL of citral, 0.050 μL/mL of carvacrol and 0.125 μL/mL of citral, 0.085 μL/mL of carvacrol and 0.075 μL/mL of citral, and 0.085 μL/mL of carvacrol and 0.125 μL/mL of citral), with two initial inoculum concentrations, and also the occurrence of sublethal damage in these cell populations. The terpene combinations exhibited antibacterial activity against L. innocua and L. monocytogenes and the effects were dependent on the concentration of terpenes present in the culture medium (p ≤ 0.05). When terpene-treated L. innocua and L. monocytogenes were incubated in TSB, significant differences in lag phase and growth rate were observed between low and high inoculum concentrations (p ≤ 0.05), indicating that the inoculum level should be taken into account in modeling studies. When bacterial cells were exposed to terpenes the proportion of sublethally injured cells increased with the increase in the terpene dose (p ≤ 0.05). In conclusion, all of these results show that carvacrol and citral can be used in combination at 25% of the MIC in order to control Listeria growth.     

A rapid loop-mediated isothermal amplification method for detection of the modified GM cry1A gene in transgenic insect-resistant cotton and rice

Among the commercial genetically modified (GM) crops, the insect-resistant GM crops are the major cultivars that cry gene is introduced into. A cry1Ab/1Ac GM fusion gene (GFM cry1A) and a GM truncated cry1Ac gene (cry1Ac-Mon) is the key foreign gene employed for construction of GM crops by China researchers and Monsanto Technology LLC respectively. Here these two genes are entitled “GM cry1A” gene and a rapid visual loop-mediated isothermal amplification (LAMP) assay method for detection of GM cry1A in transgenic insect-resistant crops was established. The LAMP assay was performed at an optimal temperature of 65 °C for 60 min in the presence of a set of four specific primers recognized six distinct sequences of the GM cry1A gene. The rough detection limit to the GM cry1A in samples is as low as 0.01% (a weight ratio of transgenic insect-resistant rice/cotton to non-transgenic rice/cotton). Comparatively, the sensitivity of this LAMP method is 10 times over that of the conventional PCR method. Fifteen cultivars/events and five Bt strains with or without cry1A gene were analyzed using the LAMP method as well as PCR method. The results demonstrate that this LAMP method shows a distinct specificity to the GM cry1A gene comparing with PCR analysis. Therefore, this LAMP method will be a potential effective tool for screening the GM cry1A gene in GM crops which are widely plant in China and other developing countries.     

Risk assessment for listeriosis in consumers of Parma and San Daniele hams

Following the detection of Listeria monocytogenes in samples of dry cured ham imported in the USA from Italy, the Italian Ministry of Health planned a risk assessment for listeriosis in ham consumers. The risk assessment was performed according to international guidelines set by FAO and WHO. Expected incidence of illness was 4.7 × 10⁻¹⁰ cases per serving in the case of normal adult population, 6.1 × 10⁻⁷ in the case of organ transplanted patients, the most susceptible risk sub-population. Due to the low value of water activity even in the deeper parts of the ham, bacterial growth had a very slight effect on the probability of illness.     

The efficacy of disinfectant misting in the lairage of a pig abattoir to reduce Salmonella and Enterobacteriaceae on pigs prior to slaughter

Water misting/showers are used in abattoir lairages to improve meat quality, and to cool and calm pigs after transport and during hot weather. One novel approach, which has not been investigated to date, is to add a disinfectant to the misting water as a means of topically reducing Salmonella on pigs prior to slaughter, thereby potentially controlling this organism in the abattoir. The objective of this study was therefore to evaluate misting with water or with Virkon^® S (an approved disinfectant for use in the presence of animals), for their ability to topically reduce Salmonella on high seroprevalence pig herds before stunning and to reduce Enterobacteriaceae.Three experimental groups were investigated: control group (i.e., no misting); water group (misting with cold, 15–17 °C, water, herein referred to as water); and a disinfectant group (misting with 0.5% Virkon^® S). As pigs entered the abattoir, each animal was swabbed along its back before being allocated to its experimental group. Each group was randomly assigned to one of 3 lairage pens that were separated by non-trial pens. After 30 min of misting with water or disinfectant, pigs were moved to the stunning area, where each pig was again swabbed, as above. Swabs were analyzed for the presence of Salmonella and enumeration of Enterobacteriaceae.Before misting, Salmonella prevalence on the pigs was 79.0%, 72.1% and 83.6% for the control, water and disinfectant groups, respectively. After misting, Salmonella prevalence increased to 94.3% in the water group; whereas for the disinfectant group, the prevalence increased marginally to 85.9%. No change in Salmonella prevalence was detected for the control group. In line with the Salmonella results, no significant differences were observed in Enterobacteriaceae counts in the control group at either time point (4.37 and 5.01 log₁₀ CFU/cm², respectively) or in the disinfectant group before and after misting (4.02 and 4.26 log₁₀ CFU/cm², respectively). However, a 2.3 log₁₀ CFU/cm² increase in Enterobacteriaceae was recorded for the water group after misting as compared to before misting (p < 0.05).Since misting with water alone increased topical Salmonella contamination on pigs before slaughter, a risk assessment based on known Salmonella data, meat quality and welfare is recommended to determine whether its use is justifiable. On the other hand, the findings from this study suggest that misting with Virkon^® S at 0.5% could have a role in topical antisepsis of pigs contaminated with Salmonella prior to slaughter and as such this warrants further investigation.     

Adventitious presence of transgenic events in the maize supply chain in Peru: A case study

Cultivation and trade of transgenic or genetically modified organisms (GMO) and commodities has become widespread worldwide. In particular, production of transgenic crops has seen an accelerated growth along with a complex regulatory process. Current Peruvian legislation prohibits import of transgenic seeds and cultivation of transgenic crops in National territory but allows import of GMO-derived products and commodities. In addition, there is legislation that mandates the labeling of food products containing transgenic ingredients but the labeling threshold is still under discussion and the enforcement of this law is on hold. In this context, we evaluated adventitious presence of transgenic events in locally traded yellow maize using PCR- and immuno-based detection methods. Our results indicated that contamination during the distribution system of lots derived from non-transgenic maize was unavoidable and generally below 1.0% (w/w). Transgenic event MON810 was found in truck-loads of nationally grown maize. In general, frequencies of GMO-derived targets in whole-grain lots were 2.2% (GMO content ≥ 1%), 16.4% (GMO content ≤ 1%) and 81.3% (GMO content below our detection levels). When samples of de-germinated maize where evaluated, frequencies were 25.6% (GMO content > 0.9%), 65.1% (GMO content ≤ 0.9%) and 9.3% (GMO content below our detection levels). We believe this information will aid policy makers in establishing a suitable threshold for trade and product labeling as well as to conduct further investigation on other crops and scenarios.     

Curcuma longa L. essential oil composition,antioxidant effect,and effect on Fusarium verticillioides and fumonisin production

Essential oils may be an alternative to the use of synthetic fungicides for the control of fungi involved in agricultural product deterioration. The aim of the present study was to evaluate the composition and antioxidant effect of turmeric essential oil and its antifungal and antimycotoxigenic action on Fusarium verticillioides (Sacc.) Nirenberg. The essential oil major components were α-turmerone (42.6%), β-turmerone (16.0%) and ar-turmerone (12.9%). The half-maximal inhibitory concentration (IC₅₀) for the radical scavenging capacities of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were 0.54 and 10.03 mg/ml, respectively, indicating good antioxidant activity. The application of 17.9 and 294.9 μg/ml of turmeric essential oil decreased the development of F. verticillioides by 56.0 and 79.3%, respectively, when compared with the fungal control. The scanning electron microscopy demonstrated that the oil decreased the thickness and the length of the microconidia. Ergosterol production significantly decreased (p < 0.05) in groups treated with the essential oil relative to the control, indicating an effect of the oil on fungal biomass. The production of B₁ and B₂ fumonisins was significantly inhibited (p < 0.05) in groups treated with the essential oil. The results suggest that turmeric essential oil has antioxidant, antifungal and antimycotoxigenic activities.     

The monitoring of semolina contamination by insect fragments using the light filth method in an Italian mill

Although insect contamination decreases the quality and safety of cereal products there has been no quantitative or qualitative risk evaluation of semolina contamination by insect fragments in European mills. Monitoring of semolina contamination in Italian mills over one year (June 2008 to June 2009) enabled us to evaluate (i) the frequency, (ii) quantity, (iii) seasonal dynamics, and (iv) pest origin (e.g. pest species that are responsible for contamination) of contamination. Insect fragments and undamaged whole insect bodies were extracted from semolina samples. The frequency of fragments in samples decreased as follows: mandibles, legs, adult cuticle fragments. The amount of contamination ranged from 0 to 15 (median = 2) insect fragments per 50 g of semolina. The level of contamination was below the Italian regulatory limit (e.g. ≤ 75 fragments/50 g of semolina). Internally feeding grain pests (Sitophilus spp., Rhyzopertha sp.) were mainly responsible for the contamination. Contamination by externally feeding pests (Tribolium spp., Cryptolestes spp., Oryzaephilus spp., Nemapogon sp., and psocids) and pests infesting wheat in the field (thrips and aphids) was less frequent. There was a seasonal increase in the number of fragments from April to June. The number of fragments decreased after mill fumigation for one month (September 2008). Although internally feeding grain pests arrive at the mills as a hidden infestation from the grain stores, these are the main cause of semolina contamination. The presence of whole insect bodies in semolina and a decrease in fragment numbers after fumigation indicated that mill infestation is partly responsible for insect fragment contamination in semolina.     

Salmonella prevalence associated with chicken parts with and without skin from retail establishments in Atlanta metropolitan area,Georgia

The objective of this study was to determine Salmonella prevalence in chicken parts with and without skin collected from retail establishments in Atlanta metropolitan area (Georgia, USA). Retail packs (n = 525) of cut-up chicken parts (i.e., breasts and thighs with skin-on and skin-off, and drumsticks with skin-on) were collected from supermarket stores in five counties in Atlanta metropolitan area. The skin-on and skin-off retail chicken packs by part type were paired by production company, plant numbers, and sell-by date. The skin from skin-on parts was removed and analyzed for presence of Salmonella; whereas the top layer of meat from skin-off parts was removed and analyzed for this pathogen. Additionally, Salmonella isolates were genotypically characterized. Salmonella prevalence in the skin of chicken breasts (44.7%) was significantly (P < 0.05) higher than in the meat (12.3%) of skin-off breast samples. Similarly, the prevalence was significantly (P < 0.05) higher in the skin of chicken thighs (40.9%) than that in the meat of skin-off thighs (22.8%). Salmonella prevalence in skin of drumsticks was 41%. Among the 117 isolates characterized, eight Salmonella serotypes were identified including Heidelberg (46.1%), Kentucky (26.4%), Typhimurium (11.1%), Infantis (5.1%), Seftenberg (2.5%), and Thompson (0.8%). High clonality of Salmonella isolates within and between chicken part type was observed. Skin-on chicken part may act as a greater source of Salmonella transmission to consumers compared to skin-off chicken parts.     

Consumers' evaluation of volition,control, anticipated regret,and perceived food health risk. Evidence from a field experiment in a traditional vegetable market in Kenya

Food markets in developing countries encompass a wide spectrum of food health risk exposures for consumers, but little is known about how consumers make judgments and decisions in relation to these risks. This study examined the relationship between perceived food health risk, anticipated regret from adverse health outcomes, command over exposure (volition), and command over outcome (control). A field experiment was conducted with consumers of kale (Brassica oleracea) at a traditional peri-urban market in Nairobi, Kenya. The intervention introduced a sales point developed to meet high food safety standards with produce being specifically sourced and controlled for safe production, transport, and handling practices. The treatment group (n = 152) received information about actions taken through the intervention to minimize risks and participants used their own money to bid to upgrade from kale sold from non-intervention sales stands. Participants in the control group (n = 100) were observed after buying kale from non-intervention sales points within the same market. The results showed that consequentialist and emotion-based risk measures were related, as were volition and control for both groups, but the levels were different. Moreover, in the treatment group perceived risk was related to volition and anticipated regret, but control was only related to perceived risk. These findings have implications for food risk communication and actions to improve local conditions under which food is sold.     

Short communication: Fate of major foodborne pathogens and Bacillus cereus spores in sterilized and non-sterilized Korean turbid rice wine (Makgeolli)

The objective of this study was to examine the fate of foodborne pathogens (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Staphylococcus aureus) and B. cereus spores in Korean turbid rice wine (Makgeolli). Samples of sterilized and non-sterilized turbid rice wine were inoculated with each of the vegetative bacteria or B. cereus spores at 3–4 log CFU/ml. The samples were stored at 5 °C or 22 °C, and bacterial survival was monitored over 28 days. Despite the harsh environment (alcohol content: 6–7% and pH: 3.43–3.98), long-term survival of pathogens was observed. Survival time was different depending on the type of beverage (pathogens survived longer in sterilized wine than in non-sterilized wine), cellular state (spores survived longer than vegetative cells), species (B. cereus survived longer than other species), and storage temperature (pathogens survived longer at 5 °C then at 22 °C). The number of B. cereus spores remained constant at both temperatures. The vegetative B. cereus population declined rapidly within 1 day, but then remained steady for up to 28 days (1.20–1.55 log CFU/ml in sterile wine). These results indicate that B. cereus formed spores that survived for a long time; therefore, it is possible that B. cereus may exist as spores in turbid rice wine. E. coli O157:H7, L. monocytogenes, S. Typhimurium, and S. aureus survived for up to 28, 14, 14, and 14 days, respectively, in sterilized wine at 5 °C. Thus, the health implications of the long-term survival of pathogens in alcoholic beverages should be carefully considered. The results provide new information that may be useful in predicting the potential microbiological hazards associated with turbid rice wine.