Kanario Millicent, Matofari Joseph Wafula, Nduko John Masani
Department of Dairy and Food Science and Technology, Egerton University, P.O Box 536-20115 Egerton, Kenya.
J Food Prot. 2025 Jun 23;88(7):100521. doi: 10.1016/j.jfp.2025.100521. Epub 2025 Apr 24.
In Kenya, the extensive use of agrochemicals in potato farming raises concerns about pesticide residues in potato tubers and products. This study aimed to document the pesticide application practices of potato farmers in Nyandarua County, Kenya and evaluate the effect of the practices on pesticide residue levels in raw potato tubers. Also, the study evaluated the effect of various heat processing methods on the pesticide residue levels in potatoes. A cross-sectional survey using semi-structured questionnaires was conducted on 275 randomly selected farmers. Alongside, raw Shangi potato variety samples (n = 16) from respective farmers were analyzed for some of the most commonly used pesticide residues using LC-MS/MS and GC-MS/MS. The study found that 98.8% of farmers use synthetic pesticides, with 96.4% using fungicides, 68.2% insecticides, and 28.7% herbicides. Common fungicides contained mancozeb, metalaxyl, and cymoxanil as the main active ingredients. Insecticides contained α-cypermethrin and imidacloprid, while herbicides had glyphosate and 2,4-D as the main active ingredients. These chemicals were used either alone or in mixtures. Only 11.85% of farmers adhered to the recommended manufacturer's application rates, with the majority relying on advice from agrochemical retailers (74.63%) or other farmers (13.32%). The frequent mixing of pesticides and weekly applications were also common practices. Residue analysis revealed that adherence to the manufacturer's instructions resulted in lower residue levels. Mixing pesticides and frequent applications led to higher residues, particularly for fungicides containing azoxystrobin. Longer preharvest intervals generally reduced residue levels. Most of the pesticide residues were below the EU and Codex Maximum Residue Limits (MRLs) in potatoes, however, the banned insecticides containing chlorpyrifos and fenitrothion were found at levels exceeding the EU and Codex MRLs of 0.01 mg/kg. Processing methods such as frying, baking, boiling, and steaming significantly reduced pesticide residues, below the Codex MRLs. Frying and boiling were particularly effective for most pesticides. However, baking, roasting, and frying were not effective in reducing chlorpyrifos and fenitrothion below EU and Codex MRLs. The findings highlight the need for farmer education on proper pesticide use and adherence to recommended practices to minimize residue levels and ensure food safety.
在肯尼亚，马铃薯种植中大量使用农用化学品引发了对马铃薯块茎及产品中农药残留的担忧。本研究旨在记录肯尼亚尼亚达鲁瓦县马铃薯种植户的农药施用情况，并评估这些做法对生马铃薯块茎中农药残留水平的影响。此外，该研究还评估了各种热处理方法对马铃薯中农药残留水平的影响。使用半结构化问卷对275名随机挑选的农户进行了横断面调查。同时，使用液相色谱 - 质谱联用仪（LC - MS/MS）和气相色谱 - 质谱联用仪（GC - MS/MS）对来自各农户的16份尚吉马铃薯品种生样本中的一些最常用农药残留进行了分析。研究发现，98.8%的农户使用合成农药，其中96.4%使用杀菌剂，68.2%使用杀虫剂，28.7%使用除草剂。常见杀菌剂的主要活性成分包括代森锰锌、甲霜灵和霜脲氰。杀虫剂含有高效氯氰菊酯和吡虫啉，而除草剂的主要活性成分是草甘膦和2,4 - D。这些化学品单独或混合使用。只有11.85%的农户遵守制造商推荐的施用量，大多数农户依赖农用化学品零售商的建议（74.63%）或其他农户的建议（13.32%）。频繁混合农药和每周施用也是常见做法。残留分析表明，遵守制造商的说明会使残留水平降低。混合农药和频繁施用会导致残留量增加，尤其是对于含有嘧菌酯的杀菌剂。较长的收获前间隔通常会降低残留水平。大多数农药残留在马铃薯中的含量低于欧盟和食品法典委员会的最大残留限量（MRLs），然而，发现含有毒死蜱和杀螟硫磷的禁用杀虫剂含量超过了欧盟和食品法典委员会0.01毫克/千克的MRLs。油炸、烘焙、煮和蒸等加工方法显著降低了农药残留量，使其低于食品法典委员会的MRLs。油炸和煮对大多数农药特别有效。然而，烘焙、烘烤和油炸对于将毒死蜱和杀螟硫磷降低到欧盟和食品法典委员会的MRLs以下并不有效。研究结果凸显了对农民进行正确使用农药及遵守推荐做法的教育的必要性，以尽量减少残留水平并确保食品安全。
