Removal of six pesticide residues in cowpea with alkaline electrolysed water

Reduction of pesticide residues in Chrysanthemum morifolium by nonthermal plasma-activated water and impact on its quality

This study investigated the efficiency of plasma-activated water (PAW) on the reduction of pesticides, namely, metribuzin and metobromuron, and the effect of PAW treatment on the quality of fresh chrysanthemums. The reduction efficiencies reached 74.3% for metribuzin and 38.2% for metobromuron after 240 s of PAW treatment. Compared with reverse osmosis (RO) water, PAW achieved significantly higher pesticide reductions because of its higher acidity, enhanced oxidizing ability, and increased formation of reactive species. Moreover, when compared with metobromuron, metribuzin was reduced more efficiently irrespective of the RO water or PAW treatments because of its higher water solubility, lower log octanol-water partition coefficient, and more oxidizable chemical structure. Additionally, the PAW treatment did not cause adverse changes to the chrysanthemums' color, total flavonoid content, radical scavenging, or metal chelating activities, but it did cause a slight decrease in the chrysanthemums' aroma compounds and total reducing power. This study successfully demonstrated the effectiveness of PAW for reducing pesticides in herbal flowers like chrysanthemums and reveals PAW's promising potential to treat foods with non-smooth surfaces.

Research trends and emerging physical processing technologies in mitigation of pesticide residues on various food products

The application of pesticides enhances food production vastly, and it cannot be prevented; longer fresh produce is contaminated with health-threatening pesticides even though traditional processing methods can remove these pesticides from food surfaces to a certain extent; novel emerging technologies such as cold plasma, ultrasound, electrolyzed water, and pulsed electric field could more effectively dissipate the pesticide content in food without the release of toxic residual on the food surface. The present review focuses on applying emerging technologies to degrade pesticide residues in great utility in the food processing industries. This review also discusses the pesticide removal efficacy and its mechanism involved in these technologies. The oxidation principle in cold plasma is recently gaining more importance for the degradation of pesticide residue in the food processing industries. Analysis of the emerging physical processing methods indicated greater efficacy in eradicating pesticide residues during agriculture processing. Even though the technologies such as EO (99% reduction in dimethoate), ultrasound (98.96% for chlorpyrifos), and irradiation (99.8% for pesticide in aqueous solution) can achieve promising results in pesticide degradation level, the rate and inactivation highly depend on the type of equipment and processing parameters involved in different techniques, surface characteristics of produce, treatment conditions, and nature of the pesticide. Therefore, to effectively remove these health-threatening pesticides from food surfaces, it is necessary to know the process parameters and efficacy of the applied technology on various pesticides.

Effectiveness of neutral electrolyzed water and copper oxychloride on fungi spores isolated from tropical fruits

The aim of this study was to assess the antifungal effectiveness of neutral electrolyzed water (NEW) to inhibit the spore germination of post-harvest fungi common in fruits, determine the required available chlorine concentration (ACC) of NEW and to compare it with copper oxychloride (CO) and sterile distilled water (SDW) in vitro. This study evaluated the biological effectiveness of NEW to inactivate pure cultures of 11 different fungi obtained from post-harvest tropical fruits with anthracnose, rottenness or necrosis symptoms. A conidial solution of 1 × 10⁴ spores/mL per culture was prepared and treated with a low, medium and high ACC of NEW (pH 7.0 ± 0.05, 12, 33 and 53 mg/L of ACC and ORP of 850 mV), CO at 0.3 g/L, or sterile distilled water as a control, for 3-, 5- and 10-min contact time. Spore germination of Alternaria alternata, Botrytis cinerea, Cladosporium australiense, Colletotrichum gloeosporioides and C. siamense, Fusarium solani and F. oxysporum, and Lasiodiplodia theobromae was inhibited in 100% by NEW at 12, 33 and 53 ppm ACC; 3,5 and 10 min contact time. Aspergillus niger and A. tamarii required 53 mg/L ACC to inhibit 100% of spore germination. NEW at 33 and 12 mg/L inhibited around 50% and <25% of A. niger spore germination, respectively. NEW at 53 mg/L ACC was the most efficient treatment against Rhizopus stolonifer but only inhibited spore germination in ∼25%. CO inhibited spore germination by 100% of A. alternata, B. cinerea, C. australiense, C. gloeosporioides, C. siamense and L. theobromae. However, CO inhibited <25% of spore germination of F. solani, F. oxysporum, A. niger, A. tamarii and R. stolonifer. NEW and CO had a significant effect on every fungus compared to a SDW treatment. SDW was the least effective treatment, followed by CO. NEW at 12 mg/L and 33 mg/L ACC were equally effective in eliminating the fungi, and more effective than CO. NEW at a concentration of 53 mg/L ACC was the most effective treatment. Results obtained in this study show that NEW has effectively inhibited spore germination of these species, and this treatment could be used as a substitute an ecological novel alternative to CO to avoid spore growth in the above-mentioned fruits.

Effects of electrolyzed water treatment on pesticide removal and texture quality in fresh-cut cabbage, broccoli, and color pepper

The effects of alkaline and acidic electrolyzed water (AlEW, AcEW) treatment on the removal of pesticides (phorate, chlorpyrifos, lambda-cyhalothrin, cyfluthrin, procymidone, and chlorothalonil) and texture quality of fresh-cut cabbage, broccoli, and color pepper were investigated. AlEW efficiently removed pesticides from color pepper, whereas AcEW was the optimal treatment for pesticide removal from cabbage and broccoli. AcEW resulted in greater losses of pyrethroid and organophosphates than fungicides, while AlEW was superior for removing fungicides. The best pesticide removal from cabbage (72.28%-91.04%) was achieved by continuous oscillation treatment, while intermittent oscillation for 20 min achieved optimal results for broccoli and color pepper (72.28%-90.11% and 72.24%-88.12%, respectively). No significant deterioration in texture was detected in samples treated with electrolyzed water for 5-25 min. The results suggest that electrolyzed water treatment is effective for removing organophosphate, pyrethroid, and fungicide residues from fresh-cut vegetables while not negatively affecting their texture quality.

Effect of plasma activated water and buffer solution on fungicide degradation from tomato (Solanum lycopersicum) fruit

This study investigated the effect of plasma-activated liquid (PAL) including plasma-activated water (PAW) and plasma-activated buffer solution (PABS) for the reduction of chlorothalonil (CTL) and thiram (THM) pesticide residues on tomato fruit. Results revealed that the PAL obtained by using atmospheric air as the feed gas, CTL residues were decreased to 85.3% and 74.2% and THM residues decreased to 79.47 and 72.21% after treatments with PAW₁₀ and PABS₁₀, respectively, and increasing the activation time caused a significant reduction in fungicide residues. In addition, CTL and THM residues were also decreased while increasing the activation time of PAL using Ar/O₂ as the feed gas, the concentrations of the CTL residues were decreased to 75.07 and 69.89% for PAW₁₀ and PABS₁₀, respectively and THM residues decreased to 65.89 and 61.91% for PAW₁₀ and PABS₁₀, respectively. Oxidation-reduction potential (ORP) and electrical conductivity (EC) were increased significantly after plasma treatment, while pH values of both solutions were decreased significantly with activation time. NO₃^- and NO₂^- concentrations of PAW increased significantly, while for PABS, NO₃^- concentration decreased but NO₂^-, with increasing the plasma activation time. Additionally, washing with PAW and PABS caused no notable negative impact on tomato fruit. Results confirmed that PAL treatments showed a significant reduction of CTL and THM fungicide residues (p < 0.05) in tomato without affecting the quality.

Interaction and multi-objective effects of multiple non-thermal treatments of sour cherry juice: pesticide removal, microbial inactivation, and quality preservation

BACKGROUND

The consumption of pesticide-contaminated sour cherries as fruit or juice has become a major health concern, and so the search for alternative processing technologies, such as pulsed electric fields (PEF), ozone (O), and ultrasonication (US) has intensified. The objectives of this experimental study of sour cherry juice were fourfold: (1) to quantify the removal efficiency of new processing technologies (PEF, O, US), and their combinations, for the pesticides chlorpyrifos ethyl, τ-fluvalinate, cyprodinil, pyraclostrobin, and malathion; (2) to detect their impact on physical, bioactive, and sensory properties; (3) to determine their microbial inactivation levels for Escherichia coli O157:H7, Bacillus cereus, Pseudomonas syringae subs. Syringae, and Penicillum expansum; and (4) to jointly optimize multiple responses of physical, quality, and sensory properties, pesticides, and microbial inactivation.

RESULTS

Except for all the O treatments, the physical, bioactive and sensory properties of sour cherry juice were not adversely affected by the treatments. The joint optimization suggested PEF1 (24.7 kV cm^-1 for 327 μs), PEF2 (24.7 kV cm^-1 for 655 μs), PEF2 + O + US, US, and PEF2 + O as the five best treatments. PEF2 + O + US best achieved both pesticide removal and microbial inactivation.

CONCLUSION

PEF2 + O + US provided promising reductions in pesticide and microbial loads. © 2019 Society of Chemical Industry.

Factors controlling the fate of pyrethroids residues during post-harvest processing of raw agricultural crops: An overview

Control of residual levels of synthetic pyrethroids in fresh fruits and vegetables as well as in foodstuff made of fresh agricultural produces is of utmost importance. Apart from the need to more control on application of pesticides by farmers, simple and effective postharvest practices by consumers and/or manufacturers usually applied to produces before consumption may enhance food safety from potentially harmful pesticide residues. The present review discusses the underline factors that control the effectiveness of crops postharvest treatments and the possible mechanisms of loss of pesticides during food processing. It is shown that the effectiveness of postharvest processes is controlled by various factors and that understanding such factors is essential for more control of residual pesticides. Though postharvest processes may lead to substantial reduction of residual pesticides, metabolites of broken pesticides are of great concern.

Comparison of Different Home/Commercial Washing Strategies for Ten Typical Pesticide Residue Removal Effects in Kumquat, Spinach and Cucumber

Home processing can reduce pesticide residues in agricultural products, and the common forms of treatment include washing, peeling, blanching, and cooking. In this study, the removal effects of tap water, micron calcium solution, alkaline electrolyzed water (AlEW), ozone water, active oxygen, and sodium bicarbonate on 10 typical pesticide residues in kumquat, cucumber, and spinach were investigated. The residue magnitudes were determined by chromatography–tandem mass spectrometry (GC-MS/MS, LC-MS/MS), combined with the QuEChERS pretreatment method. The model tests showed that the results of soaking and greenhouse were close. The removal effects of pesticide residues in kumquat and cucumber washing by alkaline electrolyzed water with a high pH value, micron calcium, and active oxygen solution were better than other washing solutions. The sodium bicarbonate solution, ozone water, and active oxygen solution were more effective in reducing pesticide residues in spinach than others. Active oxygen solution showed a better removal efficiency for the 10 pesticides than other treatments because of its alkalinity and oxidizability. Among the ten pesticides, pyrethroid pesticides had a higher removal rate. Additionally, chlorpyrifos were the most difficult to remove. For the majority of pesticides, the pesticide residue magnitudes showed a gradual reduction when increasing the washing time. The results indicated that alkaline solutions were effective for the reduction of pesticide residues when the washing time was longer than 15 min.

Optimisation of saponin extraction conditions with Camellia sinensis var. assamica seed and its application for a natural detergent

BACKGROUND

Camellia sinensis var. assamica seed cake (a by-product of tea-seed oil) is an abundant resource with poor utilisation. C. sinensis var. assamica seed saponin (CSS) is one kind of non-ionic surfactant. In this study, the CSS extraction conditions were optimised by response surface methodology (RSM) and then the CSS detergent was developed. Additionally, the safety and decontamination ability of the developed detergent were evaluated.

RESULTS

The optimised extraction conditions were including the extracting temperature of 40.04 °C, extraction time of 4.97 h, ethanol concentration of 64.11% and liquid-solid ratio of 14.57:1 mL g^-1 . The formula of the CSS detergent was as follows: 20% crude CSS, 0.3% oxidised tea polyphenols (OTPs), 0.2% nisin, 0.3% sodium dehydroacetate, 0.7% sodium alginate and 0.5% sodium polyacrylate. The LD₅₀ of the CSS detergent exceeds 14 g kg^-1 in mice, indicating the detergent was non-toxic. Both of the emulsifying and the pesticide residues removal abilities of the CSS detergent were significantly stronger than the commercial detergent.

CONCLUSION

A natural tea seed saponin detergent with good safety and decontamination ability was successfully developed. This can make better use of the tea seed cake, thereby creating added value in the tea seed oil industry. © 2017 Society of Chemical Industry.