ABSTRACT
Objective@#To develop an approach for simultaneous detection of multi-mycotoxins in fresh fruits, so as to provide technical supports for mycotoxins surveillance in fresh fruits.@*Methods@#Fresh fruits were collected from markets and homogenized. Then, 2 g of fresh fruits were added with 10 mL of 0.1% formic acid ( 99∶1, v/v ) in acetonitrile and wortexed for 10 min. Following extraction with 1 g of sodium chloride and 4 g of anhydrous sodium sulfate, samples were centrifuged and 5 mL of the supernatant was cleaned up with 25 mg C18. Following centrifugation, the supernatant was dried under nitrogen. The residue was dissolved in 300 μL of methanol-acetonitrile mixture solution ( 1∶1, v/v ), and mixed evenly in 700 μL of the distilled water. Samples were then eluted in gradient series of 0.1% formic acid and 5 mmol ammonium formate and methanol-acetonitrile mixture solution ( 1∶1, v/v ). The 15 mycotoxins were determined using liquid chromatography-tandem mass spectrometry ( LC-MS/MS ) with electrospray ion source (ESI+/ESI-) under multiple reaction monitoring. In addition, a matrix-matched standard curve was employed for quantitative analysis.@*Results@#There was a good linear relationship for 15 mycotoxins at concentrations of 0.25 to 10 ng/mL ( R2>0.992 ), the LC-MS/MS method showed the detection limits of 0.1-1.0 μg/kg, the spiked recovery rates of 71.68%-117.50%, and the relative standard deviations ( RSDs ) of 0.01%-13.60%. The detection rate of mycotoxins was 27.09% in 203 fresh fruits sold in markets.@*Conclusions@#The optimized LC-MS/MS method can be used for simultaneous determination of multi-mycotoxins in fresh fruits.
ABSTRACT
O crescente interesse da população pela promoção da saúde vem despertando a atenção dos consumidores por alimentos ricos em antioxidantes, combinado com a praticidade do consumo de sucos de frutos processados. O presente trabalho objetivou quantificar e avaliar a capacidade antioxidante de compostos fenólicos e ácido ascórbico em frutas in natura e polpas congeladas. As frutas in natura e polpas congeladas obtidas na região de Lavras - MG foram submetidas à quantificação de compostos fenólicos e ácido ascórbico e os respectivos extratos acetônico-etanólico e acetônico-metanólico. Foram determinadas suas atividades antioxidantes pelos métodos radicalares DPPH e ABTS. O extrato acetônico-metanólico foi mais efetivo para extrair os compostos antioxidantes das amostras. Apenas as polpas congeladas de acerola apresentaram uma redução do teor de compostos fenólicos em relação ao fruto. Para o teor de ácido ascórbico, houve uma redução nas polpas congeladas de acerola e goiaba. As amostras de acerola apresentaram os maiores teores de compostos fenólicos, ácido ascórbico e atividade antioxidante em relação aos demais frutos analisados.
The growing public interest in health- promotion, has called the attention of consumers for foods rich in antioxidants, combined with the practicality of the consumption of processed fruit juices. Therefore, this study aimed to quantify and evaluate the antioxidant capacity of phenolic compounds and ascorbic acid in fruits "in natura" and frozen pulps. The fruits "in natura" and frozen pulps from region of Lavras-MG, underwent quantification of phenolic compounds, ascorbic acid and the corresponding extracts acetonic-ethanolic and acetonic-methanolic. Their antioxidant activities were evaluated by DPPH and ABTS radical methods. The extract acetonic-methanolic was more effective to extract the antioxidant compounds from samples. Only frozen acerola pulps showed lower content of phenolic compounds in relation to fruit. For ascorbic acid, there was a reduction in the frozen pulp of acerola and guava. Acerola samples showed higher content of phenolic compounds, ascorbic acid and antioxidant activity compared to other fruits analyzed.