Food safety in Thailand 5: the effect of washing pesticide residues found in cabbages and tomatoes

Enhancing the Toxicity of Cypermethrin and Spinosad against Spodoptera littoralis (Lepidoptera: Noctuidae) by Inhibition of Detoxification Enzymes

The extensive use of wide-ranging insecticides in agricultural activities may develop resistance in insects. The dipping technique was utilized for examining changes in detoxifying enzyme levels in Spodoptera littoralis L. induced by cypermethrin (CYP) and spinosad (SPD) with and without a combination of three enzyme inhibitors: triphenyl phosphate (TPP), diethyl maleate (DEM), and piperonyl butoxide (PBO), at 70 μg/mL. PBO, DEM, and TPP showed 50% mortality against larvae at 236.2, 324.5, and 245.8 μg/mL, respectively. The LC₅₀ value of CYP on S. littoralis larvae reduced from 2.86 μg/mL to 1.58, 2.26, and 1.96 μg/mL, while the LC₅₀ value of SPD declined from 3.27 μg/mL to 2.34, 2.56, and 2.53, with the addition of PBO, DEM, and TPP, respectively, 24 h after treatment. Moreover, the activity of carboxylesterase (CarE), glutathione S-transferase (GST), and cytochrome P450 monooxygenase (Cyp 450) was significantly inhibited (p < 0.05) by TPP, DEM, PBO plus CYP, and SPD in S. littoralis larvae in comparison with tested insecticides alone. These findings suggested that three enzyme inhibitors play a major role in increasing the toxicity of CYP and SPD in S. littoralis and will provide insight into how to overcome insecticide resistance in insects.

Reduction in the Residues of Penthiopyrad in Processed Edible Vegetables by Various Soaking Treatments and Health Hazard Evaluation in China

Tomato and cucumber are two vital edible vegetables that usually appear in people's daily diet. Penthiopyrad is a new type of amide chiral fungicide, which is often used for disease control of vegetables (including tomato and cucumber) due to its wide bactericidal spectrum, low toxicity, good penetration, and strong internal absorption. Extensive application of penthiopyrad may have caused potential pollution in the ecosystem. Different processing methods can remove pesticide residues from vegetables and protect human health. In this study, the penthiopyrad removal efficiency of soaking and peeling from tomatoes and cucumbers was evaluated under different conditions. Among different soaking methods, heated water soaking and water soaking with additives (NaCl, acetic acid, and surfactant) presented a more effective reduction ability than other treatments. Due to the specific physicochemical properties of tomatoes and cucumbers, the ultrasound enhances the removal rate of soaking for tomato samples and inhibits it for cucumber samples. Peeling can remove approximately 90% of penthiopyrad from contaminated tomato and cucumber samples. Enantioselectivity was found only during tomato sauce storage, which may be related to the complex microbial community. Health risk assessment data suggests that tomatoes and cucumbers are safer for consumers after soaking and peeling. The results may provide consumers with some useful information to choose better household processing methods to remove penthiopyrad residues from tomatoes, cucumbers, and other edible vegetables.

Removal of pesticide residues from apple and tomato cuticle

Pesticide residues are always an unsolved problem in the world despite all kinds of prevention measures. The present research work is based on a scientific hypothesis, i.e., "The removal of average pesticide residue is inversely proportional to the thickness of cuticle." The effects of boron-containing products and plant-based surfactants were tested for the removal of five pesticides (lambda-cyhalothrin, chlorpyrifos, diflubenzuron, metaflumizone, acetamiprid) on tomatoes and apples. Boron-containing products were able to remove the pesticide residues on average between 58.0 and 72.6% in tomatoes and 33.2-58.8% in an apple. While plant-based surfactants removed residues on average between 58.5 and 66.6% in tomatoes and 41.0-53.2% in an apple. The highest removal rate was 72% with etidot at 1%. The solution of 1% C8-C10 provided 66.6% average removal for tomatoes. Less removal was achieved in apples. For an apple, Log K_ow and molecular mass (independent variables) were significant with p < 0.01, and the coefficient of determination (R²) was > 0.87. However, the multiple linear regression analysis for ground colemanite was significant with R² of 0.96. In tomatoes, neither Log K_ow nor molecular mass as significant. The correlation was found between the physical and chemical properties of pesticides, but it is estimated that the thickness of the cuticle is effective in removing pesticides.

Effect of Thermal and Non-Thermal Processing on Nutritional, Functional, Safety Characteristics and Sensory Quality of White Cabbage Powder

This study was aimed to improve nutritional, functional and consumer safety aspects of cabbage powder (CP). White cabbage (Brassica oleracea var. capitata f. alba) was dehydrated to CP following microwave heating, blanching, alkali or acid washing treatments. The results for nutrients and mineral composition of raw and processed CP elucidated raw CP to exhibit significantly (p < 0.05) higher amounts of protein (12.2%), dietary fiber (25.2%), Na (52 mg/100 g), Ca (355 mg/100 g), K (286 mg/100 g), Fe (14 mg/100 g) and Zn (32 mg/100 g). Among different processing techniques, microwave treatment resulted in a higher rate of reduction for alkaloids, oxalates, tannins and phytates contents, i.e., 77%, 85%, 85%, and 86%, respectively. Likewise, microwave treatment was found more effective in reducing residual levels of neonicotinoids, pyrethroids, organophosphates including imidacloprid, cypermethrin, bifenthrin, chlorpyrifos and deltamethrin in cabbage in the range of 0.98−0.12 ppm, 1.22−0.23 ppm, 1.03−0.15 ppm, 1.97−0.43 ppm, and 2.12−0.36 ppm, respectively. CP supplementation at the rate of 5% in unleavened flatbreads was observed to maintain textural and sensory attributes of the product. The results suggest microwave heating as a cost-effective technique to reduce toxicants load in cabbage powder. Further, ~5% supplementation of CP in wheat flour may also improve nutritional and functional properties of the baked goods.

Boiling, Blanching, and Stir-Frying Markedly Reduce Pesticide Residues in Vegetables

Nowadays, a lot of produce (fruits and vegetables) sold in many countries are contaminated with pesticide residues, which cause severe effects on consumer health, such as cancer and neurological disorders. Therefore, this study aims to determine whether cooking processes can reduce the pesticide residues in commonly consumed vegetables (Chinese kale and yard long beans) in Thailand. For cooking experiments, the two vegetables were cooked using three different processes: boiling, blanching, and stir-frying. After the treatments, all cooked and control samples were subjected to extraction and GC-MS/MS analysis for 88 pesticides. The results demonstrated that pesticide residues were reduced by 18–71% after boiling, 36–100% after blanching, and 25–60% after stir-frying for Chinese kale. For yard long beans, pesticide residues were reduced by 38–100% after boiling, 27–28% after blanching, and 35–63% after stir-frying. Therefore, cooking vegetables are proven to protect consumers from ingesting pesticide residues.

The present situation of pesticide residues in China and their removal and transformation during food processing

Pesticide residues are one of the most important issues affecting food safety. In this review, the general situation of pesticide residues in fruits and vegetables based on the background of the Chinese fruit and vegetable industry is first described. On the basis of primary processing of agricultural products, the effects of processing methods on the removal and metabolism of pesticide residues are reviewed in this paper. In addition, the transformation mechanism of pesticides in crops and in the environment is discussed. Finally, this study summarizes the development trend of pesticide-residue monitoring methods. With the prohibition of a large number of pesticides in China, the risk of pesticide residues is gradually reduced. However, some highly toxic pesticides can still be detected. Furthermore, the development of high-resolution mass spectrometry screening methods and rapid and intelligent detection instruments is the development trend for pesticide monitoring in the future.

Assessing Pesticide Residue and Spray Deposition in Greenhouse Eggplant Canopies to Improve Residue Analysis

Pesticide residue analysis is critically important for ensuring food safety and regulating international trade. In a greenhouse setting, we assessed pesticide residue and exposure patterns using liquid chromatography-mass spectrometry and Allura Red tracer analysis. Our results show significant effects of eggplant canopy position and spray concentration on deposition parameters. Specifically, spray coverage, spray density, deposition, and residue were generally greater for leaves in the higher canopy. Deposition and residue, unlike spray coverage and spray density, linearly correlated with spray concentration. Pesticide residues on leaves linearly correlated with depositions on artificial targets, and a correction factor was constructed to estimate residues from tracer depositions. This comparative analysis suggests that tracer analysis using Allura Red in combination with artificial targets is a time- and cost-saving alternative to conventional residue analysis for assessing spray parameters under high-volume spraying scenarios. A better understanding of pesticide residue and spray patterns will not only enhance the safety of our food supply chain but also improve pest control efficacy within the sustainable integrated pest management framework.

A Cross-Sectional Investigation of Cardiovascular and Metabolic Biomarkers among Conventional and Organic Farmers in Thailand

Pesticide exposure has been implicated as a risk factor for developing a wide range of adverse health issues. Some examples are metabolic syndromes, including diabetes. This study investigated the relationship between current occupational use of pesticides and metabolic and cardiovascular biomarker levels among organic and conventional farmers in Thailand. In total, 436 recruited farmers were divided into two groups: conventional farmers (n = 214) and organic farmers (n = 222). Participants, free of diabetes, were interviewed and submitted to a physical examination. Serum samples were collected for clinical laboratory analyses, i.e., serum glucose and lipid profiles (triglycerides, total cholesterol, high-density lipoproteins, and low-density lipoproteins). Potential risk factors such as smoking, alcohol consumption, and heavy exercise were significantly different between the two groups. There were significant differences in terms of the years of pesticide use, pesticide use at home, sources of drinking water, and distance between the farmers’ homes and farms between the groups. After adjusting for confounders, current conventional farmers had significantly higher abnormal body mass index (BMI), waist circumference, body fat percentage (% body fat), triglyceride, total cholesterol, and low-density lipoprotein values as compared to organic farmers. Conventional farmers had higher risk of many metabolic and cardiovascular risk factors as compared to organic farmers, putting them at higher risk of metabolic diseases in the future.