Cielo Char

Effect of emulsification on the antimicrobial activity of carvacrol

This work focuses on the emulsification of carvacrol for its incorporation into juices with the aim of retaining antimicrobial activity while enhancing the stability of the oil in aqueous systems. Carvacrol was emulsified (CA-E) using capsul® (1:2 emulsion) and its antimicrobial activity was determined on Escherichia coli and Lactobacillus plantarum. The combined effect of CA-E and pH reduction to 4.5 was assessed on different juices. The sensitivity of L. plantarum to carvacrol was not affected by emulsification, whereas E. coli presented higher minimal inhibitory concentrations. Combined treatments improved the effect: 0.5 µL/mL CA-E increased from 0.2 to 2.1 log reductions of E. coli. Carvacrol emulsion (1.0 µL/mL) successfully inactivated E. coli in apple and orange juices, attaining undetectable levels (<1 log CFU/mL). The efficacy of carvacrol emulsion was improved by acidification; therefore, its incorporation at low doses in acidic foods may be a useful alternative for multiple applications.

Optimisation of minimal processing variables to preserve the functional quality and colour of carrot juice by means of the response surface methodology

Combined processes based on acidification (pH: 4.5, 5.0, 5.5) and mild thermal treatments (T: 56, 58, 60°C) at different exposure times (t: 2, 4, 6 min) were optimised using the response surface methodology to improve the functional quality of carrot juice. The effects on aand b-carotenes, total antioxidant activity (TAA) and colour parameters were assessed. All combinations exhibited higher aand b-carotenes than untreated juice due to an increase on the extractability during processing. T was the most influential factor increasing carotenes as T increased. Conversely, TAA was more affected by pH. The maximum TAA was observed at pH 4.5 at 56°C. Moreover, samples with the lowest pH were the most luminous with highest a* and b*. The combination of pH 4.5 at 60°C, 4 min simultaneously showed high carotenes and TAA, resulting a good alternative to improve the functional quality and colour of carrot juice.

Role of flower preservative solutions during postharvest of Hydrangea macrophylla cv. Bela

Hydrangea macrophylla (hydrangea) is widely used as an ornamental plant and cut flower due to its inflorescence, which is composed of colored bracts. As cut flowers, hydrangeas show a postharvest life of up to 1 month at 2 °C, but little is known about their postharvest life during air shipment. This study was aimed at evaluating the effect of Triton X-100 (surfactant) and ClO2 (biocide) during an air shipment simulation of hydrangea harvested at two floral stages of development: fresh and antique. Vase life, fresh weight loss (FWL) and solution uptake were evaluated after an air shipment simulation. Furthermore, bacterial counts and microscopic observation of the bracts were performed in order to understand the water relations of hydrangea during vase life. The longest vase life was observed in antique hydrangeas, and the control (deionized water) was the best treatment, reaching up to 32.7 days in this floral stage. FWL was faster when using Triton X-100 (3.83 days to lose 20% of FW) compared to deionized water (8.75 days). However, this flower preservative was efficient at promoting solution uptake (31.96 mL). Bacterial plugging did not appear to occur considering that the high presence of microorganisms counted did not affect solution uptake or vase life. The presence of stomata on the bracts seems to be crucial for the dehydration of the inflorescence, a problem that was not solved by the higher water uptake promoted by Triton X-100. Thus, deionized water was the best treatment, and the effect of flower preservatives in order to extend vase life of hydrangea cut flowers was insignificant. Hydrangea macrophylla (hortensia) es ampliamente utilizada como planta ornamental y flor de corte debido a su inflorescencia compuesta por bracteas coloreadas. Como flor de corte, las hortensias presentan una vida en postcosecha de hasta un mes a 2°C pero poco se conoce sobre su postcosecha durante un envio aereo. Este estudio tuvo como objetivo evaluar el efecto de Triton X-100 (surfactante) y ClO2 (biocida) durante una simulacion de envio aereo de hortensias cosechadas en dos estados de desarrollo floral: ‘fresh’ y ‘antique’. Durante esta simulacion aerea se evaluo vida en florero, perdida de peso fresco y captura de solucion. Ademas, se realizo un conteo de bacterias y observaciones microscopicas de las bracteas para entender las relaciones hidricas durante la vida en florero. La vida en florero mas prolongada se observo en hortensias ‘antique’ y el control (agua deionizada) fue el mejor tratamiento alcanzando hasta 32,7 dias en este estado floral. La perdida de peso fresco fue mas rapida cuando se utilizo Triton X-100 (3,83 dias para perder 20% of peso fresco) en comparacion con el agua deionizada (8,75 dias). Sin embargo, este preservante floral fue eficiente en promover la captura de solucion (31,96 mL). El taponamiento por bacteria no fue sugerido para esta especie considerando que la alta presencia de microorganismos contabilizados no afecto la captura de solucion y la vida en florero. La presencia de estomas en las bracteas parece ser crucial para la deshidratacion de la inflorescencia, problema que no fue resuelto por la mayor captura de solucion promovido por el Triton X-100. Agua deionizada fue el mejor tratamiento y el efecto de preservantes florales fue insignificante para extender la vida en florero de flores de hortensia.

Rol de las soluciones preservantes de flores durante la postcosecha de Hydrangea macrophylla cv. Bela

Hydrangea macrophylla (hydrangea) is widely used as an ornamental plant and cut flower due to its inflorescence, which is composed of colored bracts. As cut flowers, hydrangeas show a postharvest life of up to 1 month at 2 °C, but little is known about their postharvest life during air shipment. This study was aimed at evaluating the effect of Triton X-100 (surfactant) and ClO2 (biocide) during an air shipment simulation of hydrangea harvested at two floral stages of development: fresh and antique. Vase life, fresh weight loss (FWL) and solution uptake were evaluated after an air shipment simulation. Furthermore, bacterial counts and microscopic observation of the bracts were performed in order to understand the water relations of hydrangea during vase life. The longest vase life was observed in antique hydrangeas, and the control (deionized water) was the best treatment, reaching up to 32.7 days in this floral stage. FWL was faster when using Triton X-100 (3.83 days to lose 20% of FW) compared to deionized water (8.75 days). However, this flower preservative was efficient at promoting solution uptake (31.96 mL). Bacterial plugging did not appear to occur considering that the high presence of microorganisms counted did not affect solution uptake or vase life. The presence of stomata on the bracts seems to be crucial for the dehydration of the inflorescence, a problem that was not solved by the higher water uptake promoted by Triton X-100. Thus, deionized water was the best treatment, and the effect of flower preservatives in order to extend vase life of hydrangea cut flowers was insignificant. Hydrangea macrophylla (hortensia) es ampliamente utilizada como planta ornamental y flor de corte debido a su inflorescencia compuesta por bracteas coloreadas. Como flor de corte, las hortensias presentan una vida en postcosecha de hasta un mes a 2°C pero poco se conoce sobre su postcosecha durante un envio aereo. Este estudio tuvo como objetivo evaluar el efecto de Triton X-100 (surfactante) y ClO2 (biocida) durante una simulacion de envio aereo de hortensias cosechadas en dos estados de desarrollo floral: ‘fresh’ y ‘antique’. Durante esta simulacion aerea se evaluo vida en florero, perdida de peso fresco y captura de solucion. Ademas, se realizo un conteo de bacterias y observaciones microscopicas de las bracteas para entender las relaciones hidricas durante la vida en florero. La vida en florero mas prolongada se observo en hortensias ‘antique’ y el control (agua deionizada) fue el mejor tratamiento alcanzando hasta 32,7 dias en este estado floral. La perdida de peso fresco fue mas rapida cuando se utilizo Triton X-100 (3,83 dias para perder 20% of peso fresco) en comparacion con el agua deionizada (8,75 dias). Sin embargo, este preservante floral fue eficiente en promover la captura de solucion (31,96 mL). El taponamiento por bacteria no fue sugerido para esta especie considerando que la alta presencia de microorganismos contabilizados no afecto la captura de solucion y la vida en florero. La presencia de estomas en las bracteas parece ser crucial para la deshidratacion de la inflorescencia, problema que no fue resuelto por la mayor captura de solucion promovido por el Triton X-100. Agua deionizada fue el mejor tratamiento y el efecto de preservantes florales fue insignificante para extender la vida en florero de flores de hortensia.