“Água-mel” is a honey-based product produced in Portugal for ancient times. Several attributes have been reported to “água-mel” particularly in the alleviation of simple symptoms of upper respiratory tract. Samples of “água-mel” from diverse beekeepers from different regions of Portugal were studied in what concerns antimicrobial, antioxidant and antiviral properties. The amounts of phenol and brown pigment were also evaluated and correlated with the antioxidant activities. A great variability on the levels of these compounds was found among samples which were responsible for the variability detected also on the antioxidant activities, independent on the method used. Generally, antioxidant activity correlated better with brown pigments’ amount than with phenols’ content. The antimicrobial activity found for “água-mel” samples confirm the virtues reported by popular findings. In addition, this work also reveals the antiviral properties of “água-mel” evidenced by a decrease on the infectivity of the Qβ bacteriophage.

Água-mel is a honey-based traditional product typically produced in southern Portugal. The evolution of some parameters during its production using two distinct containers (aluminium and stainless steel with a water cooling system) and two heating sources (gas heating and electricity) were evaluated. All parameters, except moisture, increased over time, reaching a ‘plateau’ after 8 h of heating. Moisture, free acidity, HMF (hydroxymethylfurfural), colour, melanoidins, phenols and glucose depended on the producer and procedure for obtaining água-mel. Kinetic parameters and correlation coefficients were determined. In general, changes in parameters during água-mel production followed zero- and/or first-order kinetics, depending on the producer and heating system.

RESUMEN El chile de agua es una hortaliza endémica de los Valles Centrales de Oaxaca, que a pesar de su importancia económica y para la nutrición humana, su contenido de compuestos bioactivos está poco estudiado. El objetivo fue determinar el contenido de compuestos bioactivos en el fruto del chile de agua (Capsicum annuum L.), cultivado en macrotúneles con diferentes materiales de cubierta. Plántulas de chile de agua del genotipo “Ejutla” fueron cultivadas con acolchado plástico y fertirriego, en macrotúneles con cubiertas de plástico transparente, plástico verde y malla blanca. Cada cubierta correspondió a un tratamiento y el cultivo a cielo abierto fue el testigo. Se utilizó un diseño experimental completamente al azar con tres repeticiones. Las variables respuesta fueron a) climáticas: temperatura, humedad relativa y radiación fotosintéticamente activa integrada (RFAI); b) compuestos bioactivos: fenoles totales, flavonoides y capacidad antioxidante. La temperatura diurna, nocturna y humedad relativa bajo plástico verde aumentaron 28.0, 6.7 y 0.5 % con respecto a campo abierto. La RFAI en campo abierto superó en 28.3 % a los materiales de cubierta. El plástico verde incrementó significativamente la concentración de fenoles totales y capacidad antioxidante, superando al testigo en 489.1 y 39.0 %, respectivamente. La concentración de flavonoides totales de los frutos cultivados en campo abierto fue mayor en al menos 47 % a los materiales de cubierta evaluados. La concentración de fenoles de los frutos de chile de agua y la capacidad antioxidante se incrementan cuando se cultivan en macrotúneles con cubierta de plástico verde. | SUMMARY The “Chile de agua” is an endemic vegetable of the central valleys of Oaxaca, but despite its importance in the economic and human nutrition field, its bioactive compounds has been poorly studied. The objective of this research was to determine the content of bioactive compounds into the fruit of the “Chile de agua” (Capsicum annuum L.), grown under macro tunnels with different cover materials. Seedlings of the “Ejutla” genotype were planted in soil with plastic mulch and fertigation under macro tunnels using transparent and green plastic covers, and white mesh. Each cover corresponded to a treatment, and the open-air cultivation was the control. The response variables were grouped into a) climatic: temperature, relative humidity and Integrated Photosynthetically Active Radiation (IPAR); b) bioactive compounds: total phenols, flavonoids and antioxidant capacity. The daytime and nighttime temperatures and relative humidity under green plastic cover increased 28.0, 6.7 and 0.5 % with respect to the control. The IPAR in open-air cultivation exceeded the cover materials by 28.3 %. The green plastic significantly increased the concentration of total phenols and antioxidant capacity by 489.1 and 39.0 % with respect to the control. The concentration of total flavonoids of the fruits grown in open-air cultivation was greater than at least 47 % to the cover materials evaluated. The phenols concentration of “Chile de agua” fruits and their antioxidant capacity increased when they are grown in macro tunnels with green plastic covers.