Pesticide residues on lettuce (Lactuca sativa L.) in Cundinamarca-Colombia.

Lettuce is Colombia's most widely cultivated leafy vegetable, but in the absence of good agricultural practices, there is the risk of some pesticide residues that affect its safety and quality. This work aimed to identify the pesticides used by farmers for the lettuce crop, the iceberg variety (Lactuca sativa var. capitata), in some municipalities of Cundinamarca (Colombia) and to investigate their residues by sampling and analysis. The farmers reported in the survey 44 active ingredients, most fungicides (54%), while the laboratory analysis showed 23 chemical compounds (52% insecticides, 39% fungicides and 9% herbicides). In addition, dithiocarbamates, procymidone and some organophosphates were among the active ingredients that exceeded the maximum residue limits (MRLs). About 80% of the identified pesticides were not registered with the regulatory entity Instituto Colombiano Agropecuario (ICA) for their use in lettuce, but some were in commercial products legally registered in Latin American and Caribbean countries.

Food neophobia, risk perception and attitudes associations of Brazilian consumers towards non-conventional edible plants and research on sale promotional strategies.

Non-conventional edible plants (NCEP) are plants or parts of plants that are not usually consumed by the population and have limited geographic distribution. This study investigated the consumption of NCEP, the influence of Food Neophobia and risk perception on Brazilian consumers attitudes as well as purchase preferences to determinate the best sale promotional strategy. Participants (n = 271) answered the online questionnaire that consisted of socio-demographic questions, items about consumption (open questions), Food Neophobia Scale, risk perception (to assign the level risk) and attitudes towards NCEP (using 5-point Likert scale). Fisher's exact test was used to investigate possible associations. Task purchase choice was evaluated using the Best-Worst Scale. The most consumed conventional leafy vegetables were collard greens (Brassica oleracea L. var. acephala D.C) (95.6%) and lettuce (Lactuca sativa) (88.5%). As for NCEP, taioba (Xanthosoma taioba E.G) (26.7%), bertalha (Basela alba L.) (23.3%) and beldroega (Portulaca oleracea L.) (14.1%) were the most cited leafy vegetables. High food neophobia individuals demonstrated to try NCEP if its nutritional value and safety are proven, showing a demand for such strategy, this would increase the consumption of these vegetables. The perception of a high risk was also associated with the inclusion of NCEP in the diet. The inclusion of NCEP at the moment of purchase, even at a higher price, presented higher scores when compared to the purchase of only conventional vegetables, at lower prices. Despite this, the price can still be a limiting factor and the search for promotional strategies should be reinforced to increase the commercialization of NCEP at street markets.

Prevalence of helminths in fresh vegetables: a narrative literature review.

The consumption of fresh vegetables is related to healthy lifestyle habits present in culinary preparations in different regions. The presence of pathogenic parasites in these foods can cause gastrointestinal disorders. Thus, the objective of the present study was to carry out a narrative review of the literature on the prevalence of helminths in fresh vegetable samples. The analysis of the studies published from 2016 to 2022 showed that hookworms and Ascaris lumbricoides are the most common pathogenic helminths in fresh vegetable samples, with a prevalence of up to 73.8% and 55.1%, respectively. In addition, studies have shown associations between the presence of helminths and pathogenic protozoa. The results obtained in this review indicate the urgent need to implement actions at all stages of the vegetable production chain, from the water used in planting irrigation to cleaning before sale to the final consumer. © 2022 Society of Chemical Industry.

Electrochemical and Spectrophotometric Methods for Polyphenol and Ascorbic Acid Determination in Fruit and Vegetable Extracts.

RESEARCH BACKGROUND: Fresh-cut fruits and vegetables are considered sources of antioxidant compounds. However, their shelf life is limited due to nutritional, quality and safety deterioration. Therefore, in recent decades, various methods have been reported for food processing and preservation, as well as for the determination of antioxidant compounds, due to their many benefits when consumed. The aim of the present work is to compare the performance of electrochemical and spectrophotometric methods in the analysis of the content of polyphenolic compounds and ascorbic acid in extracts from fruits (eggplant), edible roots (carrot) and leaves (rocket, lettuce and chard), and evaluate their capability to detect small changes in the antioxidant content in the eggplant extracts previously irradiated with different UV-C light intensities. EXPERIMENTAL APPROACH: Polyphenolic compounds and ascorbic acid were determined by electrochemical and spectrophotometric methods. An enzymatic biosensor and a nanocomposite sensor were used for polyphenolic compounds and ascorbic acid, respectively, in electrochemical measurements, while Folin-Ciocalteu and Kampfenkel methods were used for spectrophotometric measurements. RESULTS AND CONCLUSION: Results obtained through the different methodologies were comparable and consistent with each other. Both methods allowed determining the content of ascorbic acid and polyphenolic compounds in the fruit and vegetable extracts. Moreover, both techniques enable the detection of the analyte concentration changes in samples exposed to different UV-C intensities and storage days. Finally, it was observed that the antioxidant capacity depends on the type of food, treatment and storage period. NOVELTY AND SCIENTIFIC CONTRIBUTION: Both methodologies were suitable for the quantification of analytes; however, the electrochemical sensors provided higher specificity and selectivity, applicable to different fruit and vegetable matrices, obtaining results with higher precision, in shorter time and with a smaller sample volume, minimizing the economic costs because of the lower consumption of reagents.

Parasitological analysis of green leaf lettuce cultivated in different production systems / Análise parasitológica em alfaces cultivadas em diferentes sistemas de produção

This study analysed parasite contamination in green leaf lettuce (Lactuca sativa), grown in different cultivation systems (conventional, organic, and hydroponic), from a family farmer cooperative in the municipality of Presidente Prudente, São Paulo, Brazil. Samples were collected at weekly intervals during five months, totalling 180 vegetable samples (60 samples of leaf lettuce from each cultivation system). Lettuce leaves were washed with 0.5% Extran MA 02, and the resulting fluid subjected to sedimentation and centrifugal flotation for recovery of parasite structures. Overall, 71 samples (39.4%) were contaminated with at least one parasite structure, 34 (47.9%) from lettuce grown in the hydroponic system, 20 (28.2%) from the organic system, and 17 (23.9%) from the conventional system. Entamoeba spp. cysts were the most common parasite structures found in the leafy vegetables, with the highest cyst counts found in the hydroponic system (p = 0.003). It is concluded that, regardless of the cultivation system (conventional, organic, or hydroponic), there is a possibility of green leaf lettuce contamination by intestinal parasites. Measures that improve sanitary conditions during production, as well as proper hygiene during the preparation of raw leafy vegetables, may be important to reduce contamination and consequent transmission of parasite diseases from raw leafy vegetable consumption.(AU)

O presente estudo analisou a contaminação parasitológica em alfaces crespas (Lactuca sativa) cultivadas em diferentes sistemas de produção (convencional, orgânico e hidropônico), fornecidas por uma cooperativa de produtores da agricultura familiar, no município de Presidente Prudente, São Paulo. As coletas foram repetidas em intervalos semanais, durante um período cinco meses, totalizando 180 amostras de hortaliças (60 amostras de alface por tipo de produção). As folhas das alfaces foram lavadas com Extran MA 02 a 0.5% e o fluído resultante submetido às técnicas de sedimentação e de centrífugo-flutuação, para recuperação das estruturas parasitárias. Observou-se que do total de 180 amostras, 71 (39,4%) estavam contaminadas por pelo menos uma estrutura parasitária, sendo 34 (47,9%) das alfaces cultivadas no sistema hidropônico, 20 (28,2%) no orgânico e 17 (23,9%) no sistema convencional. Cistos de Entamoeba spp. foram as estruturas parasitárias mais frequentes nas hortaliças, com maior contagem de cistos naquelas produzidas no sistema hidropônico (p=0,003). Conclui-se que independentemente do sistema de cultivo (convencional, orgânico e hidropônico), existe a possibilidade de contaminação de alfaces por enteroparasitos. Medidas que propiciem a melhoria na qualidade higiênico-sanitária na produção, assim como a adequada higienização das verduras antes do consumo in natura podem ser importantes para a redução da contaminação e consequente transmissão de doenças parasitárias peloconsumo “in natura” de hortaliças.(AU)

Parasitological analysis of green leaf lettuce cultivated in different production systems / Análise parasitológica em alfaces cultivadas em diferentes sistemas de produção

This study analysed parasite contamination in green leaf lettuce (Lactuca sativa), grown in different cultivation systems (conventional, organic, and hydroponic), from a family farmer cooperative in the municipality of Presidente Prudente, São Paulo, Brazil. Samples were collected at weekly intervals during five months, totalling 180 vegetable samples (60 samples of leaf lettuce from each cultivation system). Lettuce leaves were washed with 0.5% Extran MA 02, and the resulting fluid subjected to sedimentation and centrifugal flotation for recovery of parasite structures. Overall, 71 samples (39.4%) were contaminated with at least one parasite structure, 34 (47.9%) from lettuce grown in the hydroponic system, 20 (28.2%) from the organic system, and 17 (23.9%) from the conventional system. Entamoeba spp. cysts were the most common parasite structures found in the leafy vegetables, with the highest cyst counts found in the hydroponic system (p = 0.003). It is concluded that, regardless of the cultivation system (conventional, organic, or hydroponic), there is a possibility of green leaf lettuce contamination by intestinal parasites. Measures that improve sanitary conditions during production, as well as proper hygiene during the preparation of raw leafy vegetables, may be important to reduce contamination and consequent transmission of parasite diseases from raw leafy vegetable consumption.

O presente estudo analisou a contaminação parasitológica em alfaces crespas (Lactuca sativa) cultivadas em diferentes sistemas de produção (convencional, orgânico e hidropônico), fornecidas por uma cooperativa de produtores da agricultura familiar, no município de Presidente Prudente, São Paulo. As coletas foram repetidas em intervalos semanais, durante um período cinco meses, totalizando 180 amostras de hortaliças (60 amostras de alface por tipo de produção). As folhas das alfaces foram lavadas com Extran MA 02 a 0.5% e o fluído resultante submetido às técnicas de sedimentação e de centrífugo-flutuação, para recuperação das estruturas parasitárias. Observou-se que do total de 180 amostras, 71 (39,4%) estavam contaminadas por pelo menos uma estrutura parasitária, sendo 34 (47,9%) das alfaces cultivadas no sistema hidropônico, 20 (28,2%) no orgânico e 17 (23,9%) no sistema convencional. Cistos de Entamoeba spp. foram as estruturas parasitárias mais frequentes nas hortaliças, com maior contagem de cistos naquelas produzidas no sistema hidropônico (p=0,003). Conclui-se que independentemente do sistema de cultivo (convencional, orgânico e hidropônico), existe a possibilidade de contaminação de alfaces por enteroparasitos. Medidas que propiciem a melhoria na qualidade higiênico-sanitária na produção, assim como a adequada higienização das verduras antes do consumo in natura podem ser importantes para a redução da contaminação e consequente transmissão de doenças parasitárias peloconsumo “in natura” de hortaliças.

Standardization of a method for the detection of helminth eggs and larvae in lettuce.

Despite reports that food-borne parasitic infections have been increasing worldwide, the methodologies employed to detect food contamination by helminths are still largely based on methodologies used to detect these pathogens in feces and water. This study sought to improve the diagnosis of parasitic contaminants in lettuce by standardizing a method for detecting helminth eggs and larvae and estimating their percentage of recovery. Sanitized lettuces were artificially contaminated with different amounts of Ascaris suum and hookworm eggs and larvae. To standardize the method, we tested liquid extractors, vegetable washing steps, and spontaneous sedimentation times. Higher percentages of egg and larvae recovery were obtained using 1 M glycine as the liquid extractor, manual shaking for 3 min and 2 h of sedimentation. Five different levels of artificial contamination (ten replicates each; n = 50) were tested using these standardized conditions, yielding an average recovery of 62.6 % (±20.2), 51.9 % (±20.0), and 50.0 % (±27.3) for A. suum eggs, hookworm eggs, and larvae, respectively. Tests were performed with a different matrix to evaluate the performance of the method. Furthermore, collaborative analytical studies performed by different laboratories produced satisfactory results. The method for the identification of helminth eggs and larvae proposed in this study proved to be simpler and more efficient than previously published procedures, thereby demonstrating its potential contribution to health surveillance and epidemiological studies.

Evaluation of Minerals, Phytochemical Compounds and Antioxidant Activity of Mexican, Central American, and African Green Leafy Vegetables.

The green leafy vegetables Cnidoscolus aconitifolius and Crotalaria longirostrata are native to Mexico and Central America, while Solanum scabrum and Gynandropsis gynandra are native to Africa. They are consumed in both rural and urban areas in those places as a main food, food ingredient or traditional medicine. Currently, there is limited information about their nutritional and phytochemical composition. Therefore, mineral, vitamin C, phenolic and flavonoid concentration, and antioxidant activity were evaluated in multiple accessions of these leafy vegetables, and their mineral and vitamin C contribution per serving was calculated. The concentrations of Ca, K, Mg and P in these leafy vegetables were 0.82-2.32, 1.61-7.29, 0.61-1.48 and 0.27-1.44 mg/g fresh weight (FW), respectively. The flavonoid concentration in S. scabrum accessions was up to 1413 µg catechin equivalents/g FW, while the highest antioxidant activities were obtained in C. longirostrata accessions (52-60 µmol Trolox equivalents/g FW). According to guidelines established by the US Food and Drug Administration, a serving size (30 g FW) of C. longirostrata would be considered an excellent source of Mo (20 % or more of the daily value), and a serving of any of these green leafy vegetables would be an excellent source of vitamin C. Considering the importance of the minerals, phytochemicals and antioxidants in human health and their presence in these indigenous green leafy vegetables, efforts to promote their consumption should be implemented.

Teores de vitamina K em hortaliças consumidas na cidade de São Paulo / Levels of vitamin K in vegetables consumed in the city of São Paulo

Estudos sobre a vitamina K têm evidenciado seu papel na manutenção da saúde óssea e vascular. A atuação desta vitamina em tecidos extra-hepáticos não é considerada na recomendação dietética da DRI de 2001, sendo reconhecidas necessidades maiores para função óssea em pessoas acima dos 60 anos e em indivíduos que fazem uso de medicamentos antivitamina K. Visando colaborar com pesquisas futuras, onde o conhecimento do teor de vitamina K1 é relevante, além de contribuir com dados para Tabela Brasileira de Composição de Alimentos - TBCA-USP, o presente trabalho foi conduzido para determinação do teor de filoquinona (vitamina K1) de hortaliças consumidas na cidade de São Paulo. As hortaliças analisadas foram escolhidas após a conclusão de um inquérito alimentar realizado, com adultos e idosos, num projeto de pesquisa desenvolvido junto ao Departamento de Alimentos e Nutrição Experimental da FCF/USP visando a análise da ingestão diária de vitamina K. Desta forma, foram analisadas as hortaliças mais consumidas por esses grupos, submetidas ou não ao processo de cocção. Estas amostras foram adquiridas diretamente na CEAGESP - Companhia de Entrepostos e Armazéns Gerais de São Paulo. As metodologias empregadas na determinação da filoquinona (vitamina K1) foram extração e purificação pelo método líquido-líquido utilizando solventes orgânicos e quantificação através da Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados mostraram que as amostras de hortaliças de colorações verdes mais escuras apresentaram os maiores teores da vitamina como: salsa 491,05 µg/100g; espinafre 375,01 µg/100g, quando comparados com as amostras de colorações verdes mais claras as quais como é o caso da alface americana 113,42 µg/100g e a couve-flor 32,55 µg/100g. A maioria das hortaliças analisadas apresentaram variações entre as diferentes épocas do ano e quando comparadas com dados da literatura

Studies on vitamin K have shown its role in maintaining bone and vascular health. The role of this vitamin in extrahepatic tissues is not considered in the dietary recommendation of DRI 2001. Increased need for vitamin K intake is recognized for the bone function in people over age 60 and individuals who use anti-vitamin K drugs. Aiming at supporting future research, where knowledge of vitamin K1 is relevant, and contribute data to the Brazilian Table of Food Composition - TBCA-USP, this study was conducted to determine the level of phylloquinone (vitamin K1) of vegetables consumed in the city of São Paulo. The vegetables studied were chosen after completion of a nutrition survey carried out with adults and elderly people, a research project developed by the Department of Food and Experimental Nutrition FCF / USP aimed at analyzing the daily intake of vitamin K. Therefore, we analyzed the most consumed vegetables by these groups submitted or not to the cooking process. These samples were acquired directly at CEAGESP - General Warehouses Company of São Paulo. The methodologies employed in the determination of phylloquinone (vitamin K1) were extraction and purification method using liquid-liquid organic solvents followed by High Performance Liquid Chromatography (HPLC). The results showed that the samples of darker green vegetables showed the highest levels of vitamin such as parsley (491.05 µg/100g) and spinach (375.01 µg/100g), when compared with samples of lighter coloration (e.g. 113.42 µg/100g lettuce, and 32.55 µg/100g cauliflower). Most vegetables analyzed showed variation in results when compared to the different seasons and the literature data

Carotene and provitamin A content of vegetables sold in Viçosa, MG, Brazil, during spring and winter / Caroteno e provitamina A teor de hortaliças comercializadas em Viçosa, MG, Brasil, durante a primavera e o inverno

This study investigated the α- and β-carotene content and provitamin A value of four leafy vegetables sold at local and street markets in Viçosa, MG, Brazil, in the spring and winter of 2002. Carotenoids were analyzed by high-performance liquid chromatography. α-Carotene was detected in all samples sold during spring, but was only present in a few samples of smooth and curly lettuce and kale in winter. β-Carotene was found in marked quantities in all leafy vegetables analyzed. Duncan's test (α = 5 percent) showed significantly higher α-carotene content in curly lettuce and vitamin A value in large-leaved watercress in the spring. Mean β-carotene content and vitamin A value were 7544, 8751, 2584, 2792, 8193, and 5338 μg/100 g and 666, 760, 227, 238, 698, and 460 μg RAE/100 g in large-leaved and hydroponic watercress, smooth and curly lettuce, kale and spinach, respectively. All leafy vegetables analyzed represent important sources of provitamin A and supply an important part of the daily requirements of children and adults.

Investigou-se o conteúdo de α e β-caroteno e avaliou-se o valor pro-vitamínico A de quatro hortaliças folhosas comercializadas em mercados locais e feira- livre de Viçosa, MG durante a primavera e o inverno de 2002. Os carotenóides foram analisados por Cromatografia Líquida de Alta Eficiência (CLAE). O α-caroteno foi detectado em todas as amostras analisadas na primavera, porém no inverno, somente algumas amostras de alface crespa e lisa, e couve apresentaram tal carotenóide. O β-caroteno foi encontrado, em quantidades apreciáveis, em todas as hortaliças folhosas analisadas. O teste de Duncan (α=5 por cento) detectou que o conteúdo de α-caroteno em alface crespa e o valor de vitamina A em agrião de folha larga foram estatisticamente superiores na primavera. Os teores médios de β-caroteno e de valor de vitamina A para agrião de folha larga e hidropônico, alface crespa e lisa, couve e espinafre foram: 7544; 8751; 2584; 2792; 8193; 5338 μg/100g e 666; 760; 227; 238; 698; 460 μg RAE/100g, respectivamente. Todas as hortaliças folhosas analisadas constituem importantes fontes de provitamina A e suprem grande parte das recomendações diárias de crianças e adultos.

Carotenos e provitamina A em bertalha e ervas aromáticas comercializadas em Viçosa, Estado de Minas Gerais, durante as quatro estações do ano / Carotenes and provitamin A in basella and aromatic herbs marketed in Viçosa, Minas Gerais State, during the four seasons of the year

Este estudo teve como objetivos investigar o teor de alfa-caroteno, beta-caroteno e calcular o valor de vitamina A em hortaliças comercializadas no mercado formal e informal de Viçosa, Estado de Minas Gerais, bem como avaliar a influência das quatro estações do ano e do local de comercialização sobre o conteúdo desses nutrientes. As hortaliças (bertalha, cebolinha, coentro, manjericão e salsa) foram analisadas utilizando-se a cromatografia líquida de alta eficiência (CLAE). Devido ao conteúdo inexpressivo de alfa-caroteno em todas as amostras, foi possível quantificar apenas o beta-caroteno. Não se verificou diferença estatisticamente significativa (alfa = 0,05) no conteúdo de beta-caroteno das hortaliças entre os diferentes estabelecimentos, nem entre as estações do ano. As hortaliças mostraram-se excelentes fontes de provitamina A, e se consumidas regularmente, contribuem de forma importante na adequação diária de vitamina A para adultos e crianças. Além disso, esses alimentos são acessíveis à população por apresentarem baixo custo e serem facilmente encontrados.

This study aimed to investigate the level of alpha-carotene, beta-carotene and to calculate the value of vitamin A in vegetables sold at local markets and informal markets of Viçosa, Minas Gerais State, as well as to evaluate the seasonal and commercial effects on the content of these pigments. The vegetables (basella, green onion, cilantro, sweet basil and parsley) were analyzed through high-performance liquid chromatography (HPLC), being alpha-carotene the only pigment present in all the analyzed samples. No significant statistical differences (beta = 0.05) were found in the contents of beta-carotene of the vegetables either among the different stores, or among the different seasons. The vegetables analyzed are great provitamin A sources and, if eaten on a regular basis, they can fit the daily requirements of vitamin A for adults and children. Besides, these foods are very accessible due to their low cost and availability in the market.