Degradation Trends of Some Insecticides and Microbial Changes during Sauerkraut Fermentation under Laboratory Conditions

Role of Lactic Acid Bacteria in Insecticide Residue Degradation

Lactic acid bacteria are gaining global attention, especially due to their role as a probiotic. They are increasingly being used as a flavoring agent and food preservative. Besides their role in food processing, lactic acid bacteria also have a significant role in degrading insecticide residues in the environment. This review paper highlights the importance of lactic acid bacteria in degrading insecticide residues of various types, such as organochlorines, organophosphorus, synthetic pyrethroids, neonicotinoids, and diamides. The paper discusses the mechanisms employed by lactic acid bacteria to degrade these insecticides, as well as their potential applications in bioremediation. The key enzymes produced by lactic acid bacteria, such as phosphatase and esterase, play a vital role in breaking down insecticide molecules. Furthermore, the paper discusses the challenges and future directions in this field. However, more research is needed to optimize the utilization of lactic acid bacteria in insecticide residue degradation and to develop practical strategies for their implementation in real-world scenarios.

Probiotic bacteria alleviate chlorpyrifos-induced rat testicular and renal toxicity: A possible mechanism based on antioxidant and anti-inflammatory activity

Chlorpyrifos (CPF) has caused many potential toxicities in nontarget organisms. Fewer studies have been conducted on the effects of lactic acid bacteria (LAB) in mitigating tissue damage induced by CPF in vivo. Therefore, we investigated CPF renal and testicular toxicity and the alleviating effect of probiotic lactobacilli, based on antioxidant and anti-inflammatory activity, on induced toxicity in an animal model. Biochemical assays showed that CPF induced oxidative stress along with a change in superoxide dismutase (SOD) and catalase (CAT) activity in a tissue-dependent manner. After treatment with CPF, testicular and renal levels of TNF-α were significantly reduced and enhanced, respectively, compared to the control group. The probiotic treatment restored renal and testicular TNF-α levels and modulated and blocked the increasing effect of CPF on renal IL-1β levels. Testicular IL-1β levels in the probiotic-treated and CPF groups demonstrated similar values. Exposure to CPF significantly induced renal histopathological damage that, of course, was completely inhibited by treatment with Lactobacillus casei and the LAB mixture. In summary, CPF showed significant toxicological effects on oxidative stress and the inflammation rate in CPF-exposed rats. Therefore, supplementation with probiotic bacteria may alleviate CPF renal toxicity and mitigate its oxidative stress and inflammation effects.

Residue changes and processing factors of thirteen pesticides during different tomato pickle processes

Tomatoes grown in an experimental greenhouse were sprayed with 13 selected pesticides at the recommended field doses, and used for pickle processing. Three different pickle processing techniques (natural fermentation, starter added fermentation and canning) were applied during the trials. Two strains of Lactobacillus plantarum were used as starter cultures in starter added fermentation trials. Changes in pesticide residues, pH levels and microbiological populations were periodically analysed and processing factors (PFs) were calculated at the end of the processing period. Yeasts-moulds and enterobacteria were not detected in any of the trials. Mesophilic aerobic bacteria were detected during both fermentation treatments (natural and starter added), whereas lactic acid bacteria were only observed in starter added trials. The initial pH levels of brines in all treatments were measured as 2.7 at the beginning of the processes and changed depending on the type of treatment. Lower pH values were detected in starter added treatments. Following the harvest day, significant reductions were observed in pesticide concentrations during both types of fermentation (natural and starter added) trials (p < .01) with the exception of bifenazate and abamectin. But on the contrary, residue changes were not significant (p > .05) throughout the canning process. Since bifenazate and abamectin are more stable at lower pH, their residue levels were not affected by the methods applied during fermentation processes. Only PF of canning process for bifenazate was higher than 1 and calculated as 1.17. All other PF values were lower than 1, indicating that the treatments caused degradation of the active compounds. Processing methods affected the pesticide residue levels in different ways, as a result of various degradation mechanisms.

Biotransformation of carbendazim in cowpea pickling process

Carbendazim, a systemic fungicide, is one of the most commonly detected pesticides in cowpeas. Pickled cowpea is a fermented vegetable product with unique flavor favored in China. The dissipation and degradation of carbendazim were investigated in the pickled process. The degradation rate constant of carbendazim in pickled cowpeas was 0.9945 and the half-life of the carbendazim was 14.06 ± 0.82 d. Seven transformation products (TPs) were identified in the pickled process. Furthermore, the toxicity of some TPs show more harmful to three aquatic organisms (TP134) and rats (all the identified TPs) than carbendazim. And most of the TPs posed more development toxicity and mutagenicity than carbendazim. 4 out of 7 TPs were discovered in the real pickled cowpea samples. These results shed light on the degradation and biotransformation of the carbendazim in the pickled process, to better understand the potential health risk of pickled food and evaluate the environmental pollution.

Microbial Detoxification of Residual Pesticides in Fermented Foods: Current Status and Prospects

The treatment of agricultural areas with pesticides is an indispensable approach to improve crop yields and cannot be avoided in the coming decades. At the same time, significant amounts of pesticides remain in food and their ingestion causes serious damage such as neurological, gastrointestinal, and allergic reactions; cancer; and even death. However, during the fermentation processing of foods, residual amounts of pesticides are significantly reduced thanks to enzymatic degradation by the starter and accompanying microflora. This review concentrates on foods with the highest levels of pesticide residues, such as milk, yogurt, fermented vegetables (pickles, kimchi, and olives), fruit juices, grains, sourdough, and wines. The focus is on the molecular mechanisms of pesticide degradation due to the presence of specific microbial species. They contain a unique genetic pool that confers an appropriate enzymological profile to act as pesticide detoxifiers. The prospects of developing more effective biodetoxification strategies by engaging probiotic lactic acid bacteria are also discussed.

Effect of alkali treatment and natural fermentation on the residue behaviour of malathion and malaoxon during table olive production

Pesticide use is indispensable for combating diseases occurring during olive cultivation. However, this has led to challenges of pesticide residues in consumer products as a result of pesticide application errors and the methods used during processing and preservation. This work aimed to identify the effects of table olive processing and preservation techniques on the concentrations of malathion and its degradation product malaoxon. For this purpose, olive trees in an experimental olive orchard were sprayed homogeneously with malathion at a dose of 975 mg L^-1 and processed as (i) vacuum-packed, (ii) alkali treated and (iii) directly brined for natural fermentation. The changes in microbial growth, pH-acidity and pesticide (malathion and malaoxon) concentrations were monitored regularly during the experiment. Lactic acid bacteria, yeast and mould growth were not detected in any of the treatments. Mesophilic aerobic bacteria and enterobacteria were the dominant microbial groups in all non-sprayed treatments, but no enterobacteria growth was detected in sprayed treatments. Lower pH values were observed in the brines of natural fermentation treatments of both sprayed and non-sprayed olives. The independent effects of time and processing method and their interactions on malathion and malaoxon concentrations were found significant (p < .05). During the experiments, the highest reduction in malathion concentration was observed in alkali treated samples (95-99%), followed by naturally fermented (77-88%) and vacuum-packed samples (74-76%). Processing factors for all treatments were lower than 1.

The Complex Role of Lactic Acid Bacteria in Food Detoxification

Toxic ingredients in food can lead to serious food-related diseases. Such compounds are bacterial toxins (Shiga-toxin, listeriolysin, Botulinum toxin), mycotoxins (aflatoxin, ochratoxin, zearalenone, fumonisin), pesticides of different classes (organochlorine, organophosphate, synthetic pyrethroids), heavy metals, and natural antinutrients such as phytates, oxalates, and cyanide-generating glycosides. The generally regarded safe (GRAS) status and long history of lactic acid bacteria (LAB) as essential ingredients of fermented foods and probiotics make them a major biological tool against a great variety of food-related toxins. This state-of-the-art review aims to summarize and discuss the data revealing the involvement of LAB in the detoxification of foods from hazardous agents of microbial and chemical nature. It is focused on the specific properties that allow LAB to counteract toxins and destroy them, as well as on the mechanisms of microbial antagonism toward toxigenic producers. Toxins of microbial origin are either adsorbed or degraded, toxic chemicals are hydrolyzed and then used as a carbon source, while heavy metals are bound and accumulated. Based on these comprehensive data, the prospects for developing new combinations of probiotic starters for food detoxification are considered.

Validation of LC-MS/MS method for simultaneous determination of chlorpyrifos, deltamethrin, imidacloprid and some of their metabolites in maize silage

In this study, a validation of a multi-residue analysis method was performed for the simultaneous analysis of chlorpyrifos (CHL), deltamethrin (DEL) and Imidacloprid (IMI) residues and some of their metabolites in maize silage, by LC MS/MS. Extraction was conducted with acetonitrile acidified with 1% acetic acid. To avoid the matrix effect, a matrix matched calibration was used. The method was validated according to the SANTE/12682/2019 Guidelines. Selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), trueness (recovery %) and precision (intra-day and inter-day) parameters were evaluated in line with the SANTE document. The linearities of all compounds were quite confident (R²≥ 0.98) and no interference was observed. The LOD and LOQ values were between 2.76 µg kg^-1 to 53.61 µg kg^-1 and 9.19 µg kg^-1 to 178.71 µg kg^-1, respectively. The recovery, repeatability RDS_r and reproducibility RDS_R values of compounds were calculated between 93.7-109.2%, 1-15%, and 1-13%, respectively. Consequently, results obtained with the evaluation of all parameters were found to be compatible with the SANTE validation criteria, so the method was reliable, effective and easy to use for the detection of insecticides and metabolites in maize silage with LC MS/MS.

A Lab-in-a-Syringe Device Integrated with a Smartphone Platform: Colorimetric and Fluorescent Dual-Mode Signals for On-Site Detection of Organophosphorus Pesticides

Herein, a portable lab-in-a-syringe device integrated with a smartphone sensing platform was designed for rapid, visual quantitative determination of organophosphorus pesticides (OPs) via colorimetric and fluorescent signals. The device was chiefly made up of a conjugate pad labeled with cetyltrimethylammonium bromide-coated gold nanoparticles (CTAB-Au NPs) and a sensing pad modified by ratiometric probes (red-emission quantum dots@SiO₂ nanoparticles@green-emission quantum dots, rQDs@SiO₂@gQDs probe), which was assembled through a disposable syringe and reusable plastic filter. In the detection system, thiocholine (Tch), the hydrolysis product of thioacetylcholine (ATch) by acetylcholinesterase (AchE), could trigger the aggregation of CTAB-Au NPs, resulting in a significant color change from red to purple. Then, CTAB-Au NPs flowed vertically upward and bound to the rQDs@SiO₂@gQDs probe on the sensing pad, reducing the fluorescence resonance energy transfer effect between CTAB-Au NPs and gQDs. Meanwhile, rQDs embedded in SiO₂ NPs remained stable as internal reference fluorescence, achieving a color transition from red to green. Thus, based on the inhibition of AChE activity by OPs, a colorimetric and fluorescent dual-mode platform was constructed for on-site detection of OPs. Using glyphosate as a model, with the support of a color recognizer application (APP) on a smartphone, the ratio of red and green channel values could be utilized for accurate OP quantitative analysis ranging from 0 to 10 μM with a detection limit of 2.81 nM (recoveries, 90.8-122.4%; CV, 1.2-3.4%). Overall, the portable lab-in-a-syringe device based on a smartphone sensing platform integrated sample monitoring and result analysis in the field, implying great potential for on-site detection of OPs.