Tap Water Washing Research Articles

Dissipation kinetics, dietary risk assessment and decontamination studies of tolfenpyrad in okra

QuEChERS method with liquid chromatography-mass spectrometry (LC-MS/MS) technique was employed for the estimation of tolfenpyrad residues in okra crop. The method was validated in terms of linearity, matrix effect, limit of quantification (LOQ), limit of detection, recovery, repeatability and reproducibility as per SANTE (2021) guidelines. After two applications of tolfenpyrad @150 (X), 187.5 (1.25X), 300 g a.i. ha−1 (2X), the mean initial residues were found to be 0.57, 0.78, and 1.21 mg kg −1. The residues reached below limit of quantification of 0.01 mg kg−1 after 10th, 15th, and 20th day at all the three doses, respectively. Dissipation kinetics of tolfenpyrad in okra was calculated to follow first order kinetics with half-life (T1/2) values of 2.10, 2.16, and 2.24 days at X, 1.25X and 2X dosages, respectively. Risk assessment in terms of hazard quotient (HQ) revealed that the application of tolfenpyrad was safe for safe consumption. Decontamination processes involved tap water wash, soaking in 2% salt solution, soaking in 2% salt solution along with boiling, soaking in 0.1% sodium bicarbonate solution, soaking in 0.01% potassium permanganate solution, boiling and frying. Frying followed by soaking in 2 per cent salt solution along with boiling proved to be highly effective in reducing tolfenpyrad residues by 80–85 and 76–79 per cent, respectively at all the three treatments.

Tandem mass spectrometric analysis of residual persistence, decontamination and dehydration on cyantraniliprole residues in Chilli

The dissipation behavior and persistence of cyantraniliprole residues in chilli and soil were assessed using high performance liquid chromatography and tandem mass spectrometry. Analytical methodology was suitably validated for recovery, precision, accuracy and sensitivity Limit of quantification (LOQ) and limit of detection (LOD) were found to be 0.01 and 0.003 mg kg-1. After two applications of cyantraniliprole @ 60, 75, 120 g a.i ha-1, the average initial deposits were found to be 0.69–0.72, 0.88–0.92, 1.40–1.42 mg kg-1, respectively, years 2021 & 2022. Half-life values (T1/2) for cyantraniliprole in chilli were 3.24, 3.53 and 3.89 days in 2021 and 3.78, 3.62 and 3.79 days in 2022, respectively for 60, 75, 120 g a.i ha-1 dose. Household processing methods were evaluated for decontamination of residues such as tap water wash, luke warm water wash, baking soda, common salt, acetic acid, potassium permanganate and boiling water. Among these methods, washing with boiling water was found to be most effective in reducing cyantraniliprole residues (up to 86%) followed by soaking in potassium permanganate (up to 72.27%) and soaking in baking soda (up to 69.37%). After dehydration of red chilli fruits, highest processing factor was 2.40 and 2.45 after application of cyantraniliprole @ 75 and 120 g a.i ha-1 in the test years.

Analysis of cyantraniliprole residues in beetroot and beet top using LC-MS/MS, dietary exposure assessment, and evaluation of decontamination techniques.

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was standardized for the analysis of cyantraniliprole residues in beetroot and beet top (Beta vulgaris ssp. vulgaris L.) using liquid chromatography-mass spectrometry/mass spectrometry. Samples were extracted with acetonitrile and cleaned up by dispersive solid phase extraction. Acceptable recovery of 84.74%-104.24% for beetroot and 80.19%-118.55% for beet top matrix was achieved at fortification levels ranging from 0.02 to 0.025μg g-1 , with relative standard deviation<20% that signified the application of the method for detecting cyantraniliprole residues. A field experiment was conducted to determine the half-life and preharvest interval for cyantraniliprole residues in beetroot and beet top. The half-life obtained was 1.86-2.7 days for beetroot and 3.65-5.33 days for beet top. The preharvest interval calculated was 9.12-12.90 and 22.12-37.98 days for beetroot and top, respectively. The dietary exposure assessment at studied doses found cyantraniliprole residues below acceptable daily contact limits. Among different decontamination techniques evaluated, peeling + tap water washing resulted in a higher reduction of residues while cooking and juicing resulted in moderate removal of residues.

Efficiency of Magnetically Treated Water on Decontamination of Chlorpyrifos® Residual: A Practically Water Insoluble Organophosphate in Brassica chinensis Linn.

Chlorpyrifos® (Thaion Agro Chemical CO., Ltd. Yannawa, Bangkok 10120, Thailand) (an almost water insoluble organophosphate insecticide) has been extensively used, resulting in the presence as a surface contaminant in foodstuffs, surface streams and soils. It is thus critically essential to develop methods to degrade or remove and eliminate this pollutant from environments. Chlorpyrifos® has very limited solubility and so it is primarily a contaminant of the surfaces of foodstuffs. We present the effect of magnetically treated water (MTW) to remove Chlorpyrifos® contaminating in Brassica chinensis Linn., a commonly eaten vegetable in Thailand and globally. Samples were washed with magnetically treated water (MTW) prior to detection of Chlorpyrifos® with GC-MS (Gas Chromatograph-Mass Spectroscopy). Chlorpyrifos® was removed by a factor of 413 times (−99.7%) by MTW compared to the un-washed sample, whereas the removal factor for tap water washing was only 9.6 (−89%). The MTW washed material easily passed safety criteria (Maximum Residue Load—MRL), but the tap water washed vegetables did not do so reliably. Although Chlorpyrifos® may be banned in many countries, the binding properties of replacement organophosphates are likely to be similar, and so our results should generalize to pesticides in the organophosphate chemical class that are not readily water soluble.

Simultaneous Monitoring and Decontamination of Pesticide Residues in Phytomedicine-Enriched Betel Leaf Utilizing QuEChERS-GC-MS/MS Technology to Safeguard Public Health.

The presence of undesirable substances, including pesticides (xenobiotics) in betel leaf (Piper betel), is a great concern for consumers because it is chewed and consumed directly. To protect the consumer's health, a modified QuEChERS method for monitoring purposes and subsequent decontamination process has been developed. The goal of this work was to establish a multi-residue analytical method for monitoring nonpermitted organophosphorus pesticide residues in betel leaf, as well as cost-effective cleaning strategies. The homogenized 15 g samples (20 betel leaf samples collected in West Bengal, India) were extracted with a modified QuEChERS method using acetonitrile, reconstituted to acetone, and finally analyzed by GC-MS/MS. Possible decontamination techniques (such as tap water washing, 2% saltwater washing, and lukewarm water washing) were evaluated. The limit of detection ranged from 0.003 to 0.005 mg/kg, and limit of quantification was 0.01 mg/kg. Recoveries ranged from 80 to 120% with RSDr 9%. One sample was found to contain three pesticides 4 to 7 times higher than MRLs. Suggested decontamination methods allowed reducing toxic traces below European limits. The suggested approach is useful for determining pesticide residues in betel leaves quickly. Traditional techniques of processing betel leaves may reduce pesticide residues below regulatory limits. A multi-residue method and decontamination of pesticides in betel leaf using QuEChERS-GC-MS/MS technology with satisfactory method performance was achieved. Domestic decontamination techniques have a high efficacy in reducing pesticide residues from betel leaves, making them safe for human consumption.

Distribution pattern, removal effect, transfer behavior of ten pesticides and one metabolite during the processing of grapes

Grapes' growth and processing conditions have various effects on pesticides with different physicochemical properties. Therefore, it is important for the healthy human diet to investigate pesticide residue behavior. To explore the relationship between pesticide residue behavior and physicochemical properties, the distribution of ten pesticides and one metabolite on grape peel and pulp was examined and the results showed that pesticides with low octanol–water partition coefficient (Kow) were more likely to be transferred to the pulp as the harvest interval increases. The removal methods were ranked according to pesticide removal effectiveness as follows: peeling > ozone water washing > tap water washing. Furthermore, the logKow played a key role in pesticide transfer rates during the juicing and winemaking. Notably, drying was the process of increasing pesticide residues. Additionally, the prediction models for the PFs of the pesticides in the juicing and winemaking processes were constructed as PFj = 0.952–0.116logKow (r = 0.886) and PFw = 0.736–0.143logKow (r = 0.959) by stepwise regression analysis. The prediction models recommended that Kow could be used to predict pesticide residues in grape juice and wine, which can predict the effect of pesticide physicochemical properties on PFs.

Contrast analysis recommends flame sterilization for surface depuration in coconut (Cocos nucifera) meristem culture

Five different surface sterilization treatments were carried out along with the control treatment for obtaining sterile explants in coconut (Cocos nucifera L.) at ICAR-CPCRI, Kasaragod, Kerala, during 2019–20. The treatments included different combinations of mercuric chloride, sodium hypochoride, tween-20 and flame sterilization. While 100% of the meristem got contaminated in the control treatment which was surface sterilization with 0.1% mercuric chloride (HgCl2) treatment for 3 minutes, followed by 20% sodium hypochlorite (NaOCl) treatment for 10 minutes, only 26.67% contamination was found in the treatment five which included 20% sodium hypochlorite with 250 |L tween 20 treatment for 10 minutes followed by tap water wash for 30 minutes, 0.1% mercuric chloride treatment for 3 minutes, 20% sodium hypochlorite treatment for 5 minutes and finally flame sterilization before chopping and inoculating the meristem. Contrast analysis was carried out for flame sterilization and difference between the means of two groups was statistically significant in both bacteria and fungi contamination revealing that flame sterilization has resulted in reduction of contamination.

Comparative study of UV-C and Titanium dioxide/UV-C Photo catalytic washing disinfection in fresh cut cabbage

Growing incidents of foodborne disease outbreaks linked to fruits and vegetables have drawn concern on efficient cleaning of leafy vegetables. A photocatalytic reaction under UV radiation with titanium dioxide (TiO2) gives a good disinfection efficiency. Our aims were to set up a photocatalytic system for fresh cabbage. In addition, we evaluated the cleaning disinfection efficacy of Titanium-dioxide (TiO2) illuminated with UV-C for 20 mins on fresh-cut white cabbage against surface microbes. The photocatalytic experiments were compared with tap water washing for 2 mins which is a common practice for home. The effects UV-C lights (20 mins) and TiO2 photocatalyst (5 min) alone were also studied. The overall quality parameters were compared before and after treatments. Photocatalyst TiO2 illuminated under UV-C showed significant reduction in total aerobic bacteria (2.67 log cfu/g) and yeast mold count (2.93 log cfu/g) followed by UV-C (TAC-2.25 log cfu/g; TYC-2.23 log cfu/g). The effects of TiO2 alone and tap water exhibited same effect as control. The pH of fresh cut cabbage remained same when treated with UV-C with or without photocatalysts. However, Vitamin-C and phenolic content of fresh cut cabbage were reduced when treated with UV-C without photocatalysts by 18.42 mg/100g. TiO2 with UV-C retained the health components like ascorbic acid (28.63±0.77 mg/100g) and TPC(128.54±0.63 mg GAE/100g) showed better disinfection efficacy against natural surface pathogens on cabbage than UV-C alone, can be established as better washing alternative at home and in industry.

Effects of an Eco-Friendly Sanitizing Wash on Spinach Leaf Bacterial Community Structure and Diversity

Ready-to-eat (RTE) spinach is considered a high-risk food, susceptible to colonization by foodborne pathogens; however, other microbial populations present on the vegetable surface may interact with foodborne pathogens by inhibiting/inactivating their growth. In addition, sanitizers applied to minimally processed salad leaves should not disrupt this autochthonous barrier and should be maintained throughout the shelf life of the product. This investigation aimed at comparing the effects of a pH neutral electrochemically activated solution (ECAS), a peroxyacetic acid (PAA)-based commercial sanitizer (Ecolab Tsunami® 100), and tap water wash on the minimally processed spinach leaf microbiome profile for 10 days after washing. The bacterial microbiota composition on spinach samples was assessed by 16S rRNA pyrosequencing and downstream analyses. Predominant phyla observed in decreasing order of abundance were Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes corresponding with the dominant families Micrococcaceae, Clostridiales Family XII, Flavobacteriaceae, Pseudomonadaceae, and Burkholderiaceae. Bacterial species richness and evenness (alpha diversity) and bacterial community composition among all wash types were not significantly different. However, a significant difference was apparent between sampling days, corresponding to a loss of overall heterogeneity over time. Analysis of composition of microbiome (ANCOM) did not identify any amplicon sequence variants (ASVs) or families having significantly different abundance in wash types; however, differences (17 ASVs and five families) were found depending on sampling day. This was the first bacterial microbiome composition study focused on ECAS and PAA-based wash solutions. These wash alternatives do not significantly alter microbial community composition of RTE spinach leaves; however, storage at refrigerated temperature reduces bacterial species heterogeneity.

Selected food processing techniques as a factor for pesticide residue removal in apple fruit.

In this study, various food processing techniques, including high-temperature processes (pasteurization/sterilization and boiling), low-temperature processes (freezing), mechanical processing (peeling and juicing), and water-based processes (washing with tap water and ultrasonic washing) were used to identify the most effective way to remove contamination of 5 fungicides (cyprodinil, difenoconazole, fluopyram, tebuconazole, and fludioxonil). The most effective processes were juicing and freezing in the range between 63 and 100% and from 52 to almost 100%, respectively. Ultrasonic washing and boiling also significantly removed pesticide residues ranging from 79 to 84% and from 72 to 78%, respectively. The same trend was observed by peeling process where maximum reduction of 80% was achieved almost for all fungicides. Washing with tap water decreased the concentration levels in the range of 35-38%. This study demonstrated that the least effective and unpredictable method of decontamination of pesticides was sterilization and pasteurization, due to the large variation in pesticide levels during the process.

Evaluating a Combined Method of UV and Washing for Sanitizing Blueberries, Tomatoes, Strawberries, Baby Spinach, and Lettuce

We assessed a fresh produce decontamination system using a combined method of UV and washing (water-assisted UV [WUV]) in different scales. The system used tap water to wash fresh produce while exposing it to UV light. First, the reduction of Salmonella in tap water under UV treatment (1 to 1,740 mJ/cm2) was determined. Increasing the UV dose significantly (P < 0.05) increased the Salmonella reduction in wash water, and UV intensity of more than 2 mW/cm2 could reduce Salmonella in tap water to below 1 CFU/mL given enough processing time (more than 1 min; UV dose of 120 mJ/cm2). Then, the decontamination effectiveness of a small WUV system was tested on blueberries (50 g). Blueberries were spot or dip inoculated with a Salmonella cocktail and treated by the small WUV system (200 mL of water). In general, WUV treatments achieved significantly better Salmonella inactivation than tap water wash; tap water wash (10 min) and 2 mW/cm2 WUV treatment (with a UV dose of 1,200 mJ/cm2) reduced populations of spot-inoculated Salmonella on blueberries by 2.44 and 5.45 log, respectively. Compared with spot-inoculated Salmonella on blueberries, dip-inoculated Salmonella was more difficult to be inactivated by WUV treatments. Then, the decontamination effectiveness of WUV treatments was tested on blueberries (170 g), tomatoes (290 g), strawberries (170 g), baby spinach (60 g), and lettuce (60 g) using a larger WUV system. In general, 10 min of 29 mW/cm2 WUV treatment (a high UV dose of 17,400 mJ/cm2) resulted in significantly better Salmonella inactivation than tap water wash (for 10 min) regardless the inoculation method, agreeing with the results of the small-scale study. For both spot- and dip-inoculated lettuce, no significant difference (P > 0.05) in Salmonella inactivation by WUV treatments was observed when the quantity of lettuce increased from 50 to 100 g.

Assessing washing methods for reduction of pesticide residues in Capia pepper with LC-MS/MS

The effects of washing treatments on removal rates of some pesticides residues (acetamiprid, chlorpyrifos and formetanate hydrochloride) on pepper were investigated. Method verification was conducted through spiking pepper samples at 0.1, 1.0 and 10.0 × MRL. QuEChERS method produced average recovery of 104.91% with relative standard deviation (RSD) of 13.41%. LOQ values of acetamiprid, chlorpyrifos and formetanate hydrochloride were estimated as 2, 10 and 5 µg/kg, respectively. Capia peppers grown in open fields were sprayed three times with pesticides. Peppers were harvested after 1st, 2nd and 3rd day of the treatments. Then the peppers were subjected to tap water, acetic acid and citric acid washing and ultrasonic cleaning treatments (for 2 and 5 min). Based on three different harvest times and two different washing durations, processing factors (PFs) and reduction rates were calculated for each washing treatment. The residues gradually decreased during washing treatments with increasing process duration. Similarly, a gradual reduction was noted with the progress of harvest times. This in turn corresponded to an increase in PF. Ultrasonic cleaning and citric acid (9%) washing were more effective than the others. Non-systemic pesticides (chlorpyrifos) were more readily removed than the systemic ones (acetamiprid). Similarly, highly soluble pesticides exhibited higher reduction.

The Use of One Normal Hydrochloric Acid as a Background Cleaner for Periodic Acid–Schiff Staining Technique

Abstract Objectives Sulfurous rinsing was considered nonessential as contained in the published periodic acid–Schiff technique because it did not clear the background better than tap water washing. The objective of this work is to elucidate the use of 1N HCl as a better background cleaner in the periodic acid–Schiff staining technique. Methods This is an experimental research. Normal samples of antrium, kidney, spleen, muscle, liver, and appendix, as well as histopathologically diagnosed samples of glycogen storage disease of the liver, alpha-1-antitrypsin deficient liver, aspergillosis nasal cavity sample, and glomerulosclerosis samples were obtained from the pathological archive. These samples were stained with a newly purchased commercially prepared Schiff reagent and overstained commercially prepared Schiff’s solution causing nonspecific background staining and laboratory-prepared Schiff reagent. Oxidation was done with 1% periodic acid for 5 minutes, washed for 5 minutes with distilled water, and stained for 10 minutes in Schiff’s reagent, but 20-minute staining was observed for the overstained Schiff reagent, oxidized in running tap water for 15 minutes. It was then rinsed in 1N HCl for 20 seconds, washed in tap water for 2 minutes, and counterstained with hematoxylin for 2 minutes. The same procedure was done for another set of slides as standards without 1N HCl rinsing done. The slides were examined under the microscope and compared for specificity. Results Slides rinsed in 1N HCl showed a clear differentiation of strong, weak, and non-PAS-positive substances. The overall effect of these staining characteristics was more pronounced in the use of laboratory-prepared Schiff. Conclusion The use of 1N HCl as a differentiator made the PAS technique more specific in its staining characteristics, especially with the use of laboratory-prepared Schiff’s reagent, which is commonly used in developing countries owing to a high cost of commercially prepared Schiff’s solution.

Effect of surface treatments on the cross-section area and on the tensile properties of sisal fibers

ABSTRACTThis work deals with the effect that surface treatments can cause on the cross-section and on the tensile properties of sisal fibers. The simplest treatment of washing in tap water, at room temperature and at 60°C, was compared with mercerization treatment. The observed variation of the tensile properties is partially due to modifications caused at the cross section of the fibers due to the treatments, and also by structural modifications caused by removing fiber’s constituents or by promoting structural modifications due to shrinking of cell wall. Although much more aggressive to the environment mercerization was much more effective to enhance the mechanical properties of the fiber.

Analytical approach, dissipation pattern and risk assessment of pesticide residue in green leafy vegetables: A comprehensive review.

The category of 'leafy vegetables' comprises a wide range of plants, including cabbage, lettuce, leeks, spinach, Swiss chard and kale, and it forms a significant component of the human diet. Typically, leafy vegetables are low in calories and fat, are great sources of vitamins, protein, dietary fibre and minerals (including iron, calcium, and nitrates), and are rich in phytochemicals. To counter the impact of pests on vegetables, a broad variety of pesticides are used. Because of their large surface areas, leafy vegetables are expected to have high residual pesticide levels. As such, a sound analytical approach is needed to detect and quantify residue levels that are equal to or lower than the maximum residue limits, thus rendering the products safe for consumption. Overall, leafy vegetables consumed raw (after a tap water wash only), boiled or steamed contribute 2% of total vegetable consumption globally, and they might have a comparatively greater influence on health than cereal ingestion. Consequently, in this review paper, we highlight the importance of leafy vegetables, the pesticides that are commonly used on them and various analytical techniques, including sample preparation, extraction, clean-up and final detection. The effects on dissipation patterns, pre-harvest residue limits and safety/risks imposed by various pesticides are also reviewed and discussed. In conclusion, environmentally friendly extraction methods coupled with high-throughput techniques with greater reproducibility and lower uncertainty are needed for quantifying residues in leafy vegetables at very low concentrations. Commercial and household food preparation, such as washing, peeling, blanching and cooking are effective in removing most of the pesticide residues that are loosely attached on vegetables.

Effects of household washing on bacterial load and removal of Escherichia coli from lettuce and "ready-to-eat" salads.

Customer demands for fresh salads are increasing, but leafy green vegetables have also been linked to food‐borne illness due to pathogens such as Escherichia coli O157:H7. As a safety measure, consumers often wash leafy vegetables in water before consumption. In this study, we analyzed the efficiency of household washing to reduce the bacterial content. Romaine lettuce and ready‐to‐eat mixed salad were washed several times in flowing water at different rates and by immersing the leaves in water. Lettuce was also inoculated with E. coli before washing. Only washing in a high flow rate (8 L/min) resulted in statistically significant reductions (p < .05), “Total aerobic count” was reduced by 80%, and Enterobacteriaceae count was reduced by 68% after the first rinse. The number of contaminating E. coli was not significantly reduced. The dominating part of the culturable microbiota of the washed lettuce was identified by rRNA 16S sequencing of randomly picked colonies. The majority belonged to Pseudomonadaceae, but isolates from Enterobacteriaceae and Staphylococcaceaceae were also frequently found. This study shows the inefficiency of tap water washing methods available for the consumer when it comes to removal of bacteria from lettuce. Even after washing, the lettuce contained high levels of bacteria that in a high dose and under certain circumstances may constitute a health risk.

Assessment of some home processes for decontamination of insecticide residues in vegetables

The present investigation was conducted at “Residue Analysis Laboratory” Department of Entomology, College of Agriculture, Raipur (C.G.) during 2009-2010 on Assessment of insecticide residues in vegetables. The indiscriminate use of pesticide on vegetables possesses serious residue problems in humans, animals and environment. The residue is above the Maximum Residue Limit values. Contamination may occur mainly due to harvest of crops before the recommended waiting period. The household processing is the preparation of food using like washing, peeling, cooking, trimming or hulling is reduce to some extent of toxicity from food material. This present results revealed that out of different home processing procedures, tap water wash for 15 minutes was found to be the best for decontamination of endosulfan residues on tomato to an extent of 89.59 per cent followed by hot water treatment (84.24 %). How to view point the article : Ayam, Arvind Kumar, Sahu, Arun, Tekam, Doman Singh, Sahu, Chandramani and Koshta, V.K. (2017). Assessment of some home processes for decontamination of insecticide residues in vegetables. Internat. J. Plant Protec., 10(1) : 83-86, DOI : 10.15740/ HAS/IJPP/10.1/83-86

Microbiological quality of lettuce (Lactuca sativa) irrigated with wastewater in Addis Ababa, Ethiopia and effect of green salads washing methods

BackgroundIn Addis Ababa, where irrigation water for vegetable production is commonly derived from the highly polluted Akaki river, information on microbial contamination of water and irrigated vegetable is scanty. An assessment was done to determine the microbiological quality of irrigation water and lettuce harvested from 10 urban farming sites of Addis Ababa. The efficacy of 5 lettuce washing methods were also assessed. A total of 210 lettuce and 90 irrigation water samples were analyzed for faecal coliform and helminth eggs population levels.ResultsThe mean faecal coliform levels of irrigation water ranged from 4.29-5.61 log10 MPN 100 ml−1, while on lettuce, the concentrations ranged from 3.46-5.03 log10 MPN 100 g−1. Helminth eggs and larvae were detected in 80% of irrigation water and 61% of lettuce samples. Numbers ranged from 0.9-3.1 eggs 1000 ml−1 and 0.8-3.7 eggs 100 g−1 wet weight for irrigation water and lettuce, respectively. The helminth eggs identified included those of Ascaris lumbricoides, Hookworm, Enterobius vermicularis, Trichuris trichiura, Taenia and Strongloyides larvae. Ascaris lumbricoides and Hookworm were most prevalent in both irrigation water and lettuce samples. Compared with the WHO recommendations and international standards, the faecal coliform and helminth eggs levels in irrigation water and lettuce samples exceeded the recommended levels. Irrespective of the tested washing methods, faecal coliform and helminth eggs levels were somehow reduced. Among the washing methods, potable tap water washing - rinsing (2 min) followed by dipping in 15 000 ppm vinegar solution for a minute supported the highest faecal coliorm reduction of 1.7 log10 units, whereas lowest reduction of 0.8 log10 units was achieved for the same procedure without vinegar.ConclusionCompared with international standards, both faecal coliform and helminth eggs levels exceeded recommended thresholds in water and lettuce, but still in a potential risk range which can be easily mitigated if farmers and households are aware of the potential risk. Aside preventing occupational exposure, potential risk reduction programs should target households which have so far no guidance on how best to wash vegetables. The result of the present study suggest that the vinegar based washing methods are able to reduce faecal coliform towards low level while the physical washing with running water may help to substantially decrease potential risk of helminth parasitic infections.

Flubendiamide: Residues and Risk Assessment in Tomato Solanum lycopersicum

Flubendiamide belongs to a new chemical class, the phthalic acid diamides, widely used on tomato in India for the management of fruit borers. Flubendiamide is registered for use in India on tomato, but Maximum Residue Limits are not available as per Food Safety and Standards Authority of India. A research project was taken to study the dissipation pattern of flubendiamide on tomato cv. Nirupama in both open fields and poly-houses, when applied twice @ 48 g a.i. ha−1, first spray was given 50 days after planting (fruit initiation) followed by the second spray at 10 days interval as per the farmers practice. Flubendiamide residues were quantified through regular sampling till the residues are below the determination level (BDL) of 0.05 mg kg−1 following the validated QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method. The qualitative and quantitative analysis of flubendiamide were performed on HPLC-PDA and LC-MS/MS. Initial deposits of 1.23 mg kg−1 were detected in the tomato samples collected from poly-house, which dissipated to BDL at the 10th day with half-life of 6.18 days. In open fields, deposits of 0.90 mg kg−1dissipated to BDL at the 7th day with half-life of 6.07 days, and indicated that dissipation was slow in poly-house when compared to the open fields due to various factors. MRL of 3 mg kg−1in polyhouse tomato and 2 mg kg−1 in open field tomato is recommended based on the OECD (Organization for Economic Co-operation and Development) calculator and chronic hazard exposure assessment taking into consideration of average body weight, national per capita tomato consumption and acceptable daily intake (ADI) of flubendiamide. Among the various decontamination methods tested, veggy wash was found very effective in removing flubendiamide residues to the extent of 65.39% which can be recommended as risk mitigation method for food safety, followed by 4%acetic acid solution (61.63%) and tap water wash was least effective (17.71%) in removing flubendiamide residues from tomato.

Reduction of Shiga Toxin-Producing E. coli and Salmonella Typhimurium on Cattle Hides by Spray Treatment with “Fit-L” (Levulinic Acid plus Sodium Dodecyl Sulfate)

The efficacy of levulinic acid plus sodium dodecyl sulfate (SDS) at different concentration to inactivate STEC and Salmonella Typhimurium on cattle hides in vitro and in vivo as a surface spray treatment was determined. A mixture of six isolates of STEC, including serovars O26, O45, O103, O111, O121, and O157 (10 8 CFU/ml) and a mixture of 5 strains of S. Typhimurium (108 CFU/ml) were sprayed on the surface of 10 x 10-cm sections of cattle hide. The inoculated hides were dried under a hood at 21˚C for 72 h or held 4˚C for 24 h. The hides were treated by surface spray with a commercial microbicide (Fit-L) at different concentrations at 45 psi for 15 s. Water only applied at 45 psi for 15 sec was used as the negative control. Sponge samples of the hides were collected at 1, 3, and 5 min after treatment and enumerated for STEC and Salmonella. For STEC-contaminated hides, treatment of Fit-L diluted at 1:11 (v/v) in tap water (4% levulinic acid plus 0.4% SDS for 5 min reduced STEC populations by 3.7 log CFU/cm 2 , when compared with the water only treatment. For S. Typhimurium-contaminated hides, treatment of Fit-L reduced the Salmonella population by 4.6 log CFU/cm2. Scrubbing hides with a brush for 30 s followed by Fit-L spray treatment further reduced Salmonella contamination by 0.5 log/cm2. Fit-L product diluted in tap water at 1:22 (v/v, 2% levulinic acid plus 0.2% SDS) was used as a surface wash for live beef cattle. Results revealed that surface spray of cattle with Fit-L reduced the E. coli population by 3.4 log CFU/cm2 at 5 min when compared with the tap water wash only control. No adverse effects for the cattle were observed after the spray treatment.