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Bell peppers (Capsicum annuum L.) are prone to chilling injury (CI) when stored at temperatures below 7 °C. Melatonin, a natural plant regulator, plays a critical role in defending against different pre- and post-harvest abiotic stresses, including those associated with cold storage. This study aimed to assess the effects of applying exogenous melatonin alone and in combination with a commercial wax on the CI tolerance, postharvest life, and potential biomarker search of red bell peppers. In the initial experiment, the effective melatonin concentration to reduce CI effects was determined. Peppers were sprayed with either distilled water (control) or a melatonin aqueous solution (M100 = 100 μM or M500 = 500 μM) and then stored for 33 d at 4 °C, followed by 2 d at 20 °C. The M500 treatment proved to be more effective in reducing fruit CI incidence (superficial scalds) and metabolic rate, while weight loss, softening, and color were comparable to the control. A second experiment assessed the potential synergistic effects of a combined melatonin and commercial wax treatment on pepper CI and quality. Fruits were sprayed with distilled water (control), melatonin (M500), commercial wax (Wax), or the combined treatment (Wax + M500) and stored for 28 d at 4 °C, followed by 2 d at 20 °C. The Wax + M500 was the most effective in significantly reducing the incidence of fruit CI symptoms and calyx fungal infection. Furthermore, this combined treatment enhanced fruit weight loss prevention compared with individual melatonin or wax treatment. Also, Wax + M500-treated peppers exhibited notable proline accumulation, indicative of a metabolic response counteracting the cold effects, resulting in better fruit stress acclimation. This treatment also preserved the peppers’ color and antioxidant capacity. In summary, these findings highlight the suitability of applying a combined Wax + M500 treatment as a highly effective strategy to enhance the CI tolerance of peppers and extend their postharvest life.

El arroz es un cultivo de importancia en Ecuador y uno de los cereales más consumidos en este país. Sin embargo, bajo ciertas condiciones, puede contaminarse y contener toxinas exógenas como las micotoxinas. En este sentido, la presente investigación se realizó con la finalidad de levantar información sobre la presencia de las micotoxinas zearalenona y aflatoxina total en arroz sin cáscara, mediante el uso del método inmunológico ELISA, debido a que estos contaminantes comprometen la inocuidad de los alimentos y representan un riesgo para la salud pública. Para ello, se tomaron 41 muestras de los cantones con mayor superficie sembrada de arroz del Ecuador y se analizaron con el método de inmunoensayo ELISA competitivo. Los resultados revelaron la presencia de zearalenona en rangos de concentración entre 1-20 μg/kg para el 34 % de las muestras y de 41-60 μg/kg para el 2 % de las muestras; por otro lado, no se detectó la presencia de aflatoxina total en las muestras recolectadas. Se concluye que se detectó la presencia de la micotoxina zearalenona en varias muestras de arroz, pero ventajosamente todas las muestras positivas arrojaron valores por debajo del límite máximo establecido por la Unión Europea (Reglamento (CE) N° 1881/2006 de la Comisión) de 100 μg/kg para zearalenona y de 4 μg/kg para aflatoxina total.

Honey is one of the oldest sweetening foods and has economic importance, making this product attractive to adulteration with cheap sugars. This can cause a critical problem in the honey industry and a possible health risk. The present work has the aim of evaluating the authenticity of honey commercialized in two different provinces of Ecuador (Pichincha and Loja) by performing physicochemical and spectroscopic analyses. For this study 25 samples were collected from different places and markets and characterized by water, sucrose, reducing sugars and electric conductivity measurement. Also, their Raman and Infrared (IR) spectra were recorded and analysed using a Principal Component Analysis (PCA) in order to verify the quality of the honeys. In addition, a screening of several pesticides was performed in order to verify possible chemical threats to human health and honey bees. It was found that 8 samples have a deviation from the Standard established parameters. Two of them have a high difference in the content of sucrose and reducing sugars, which are located deviated from all the other samples in the PCA of the applied vibrational spectroscopy (IR/Raman), shaping two clear clusters. The results show that Raman and IR spectroscopy is appropriate techniques for the quality control of honey and correlates well with the physicochemical analyses.