Víctor Escalona

Shelf-life of fresh blueberries coated with quinoa protein/chitosan/sunflower oil edible film

BACKGROUND The aim of this study was to evaluate quinoa protein (Q), chitosan (CH) and sunflower oil (SO) as edible film material as well as the influence of this coating in extending the shelf-life of fresh blueberries stored at 4 °C and 75% relative humidity. These conditions were used to simulate the storage conditions in supermarkets and represent adverse conditions for testing the effects of the coating. The mechanical, barrier, and structural properties of the film were measured. The effectiveness of the coating in fresh blueberries (CB) was evaluated by changes in weight loss, firmness, color, molds and yeast count, pH, titratable acidity, and soluble solids content. RESULTS The tensile strength and elongation at break of the edible film were 0.45 ± 0.29 MPa and 117.2% ± 7%, respectively. The water vapor permeability was 3.3 × 10(-12) ± 4.0 × 10(-13) g s(-1) m(-1) Pa(-1). In all of the color parameters CB presented significant differences. CB had slight delayed fruit ripening as evidenced by higher titratable acidity (0.3-0.5 g citric acid 100 g(-1)) and lower pH (3.4-3.6) than control during storage; however, it showed reduced firmness (up to 38%). CONCLUSION The use of Q/CH/SO as a coating in fresh blueberries was able to control the growth of molds and yeasts during 32 days of storage, whereas the control showed an increasing of molds and yeast, between 1.8 and 3.1 log cycles (between 20 and 35 days).

Quality of tomato slices disinfected with ozonated water

Fresh-cut industry needs novel disinfectant to replace the use of chlorine. Ozone is one of the most powerful oxidizing agents and is applied in gaseous or aqueous form for sanitation purposes. However, the strong oxidative effect could affect the nutritional and sensorial quality, in particular, when time of washing is extended. For that reason, the overall impact of ozonated water (0.4 mg/L) dipping applied during 1, 3 and 5 min compared to control washed in water during 5 min was studied in tomato slices stored during 14 days at 5 ℃. According to the results, ozonated water treatment of 3 min achieved the best firmness retention, microbial quality (mesophilic, psychrotrophic and yeas load) and reduced the consumption of fructose and glucose. The use of ozonated water did not affect the total acidity, pH, total solid soluble, organic acid as ascorbic, fumaric or succinic acid and the sensorial parameters, which were only affected by storage time. However, the poor appearance, aroma and overall quality obtained in all treatments prevented shelf life of 14 days and the quality at acceptable levels was established in 10 days at 5 ℃. It is recommended to wash tomato slices with 0.4 mg/L ozonated water for 3 min only. Extending treatment duration did not improve the microbiological quality, possibly due to the extra time permitting the ozone to react with other components of the fruit tissue, undermining the antimicrobial benefits.

Modified atmosphere packaging as a method to extend postharvest life of tulip flowers

ABSTRACT Tulip is one of the most important cut flowers in the world market and abscission of the tepals is this species’ most common symptom during vase life. To prevent these symptoms and extend postharvest life, passive and active modified atmosphere packaging (MAP) was applied at 0°C. Respiratory rate (CO2 Kg−1h−1), ethylene production (µL kg−1h−1) and concentration of CO2 and O2 (%) inside the packaging were evaluated during storage, while fresh weight loss (FWL) (%) and vase life (days) were assessed. Flowers stored using MAP performed significantly better than conventional packaging. A lower FWL (only up to 0.3%) was observed on MAP while FWL was as high as 18 to 21% for conventional packaging after 20 and 31 days, respectively. Vase life was 5.7 and 6.0 days for active and passive MAP, respectively compared to 3.3 days for conventional packing. Thus, MAP successfully extended postharvest life of tulip flowers.

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.

Application of calcium and antibrowning agent effect on total phenol content and antioxidant capacity of fresh cut 'Packham's Triumph' pears packaged in modified atmosphere

Modified atmosphere (MA) packaging combined with antibrowning agents could preserve the quality of fresh cut pears. The aim of this work was to determine the combined effect of calcium propionate (PCa), ethylenediaminetetraacetic acid (EDTA), cysteine (CIS) and citric acid (AC) on respiration rate, total phenols content, antioxidant capacity and sensory properties of fresh cut pears. The control showed the lowest respiration rate during storage at 5°C. All treatments showed an increase of CO2 production, which might be related to the 12 expected deterioration of fresh cut pears, development of senescence and increased microbial growth. The total phenols content varied from 1.47 to 2.49 mg GAE·gfw−1. After 1 day at 5°C, the total phenols content of all treatments was reduced, especially in those fresh cut pears treated with PCa + EDTA + CIS + AC by 67% as compared to fresh peeled fruit (2.65 mg GAE·gfw −1). The antioxidant capacity of fresh cut pears treated with PCa + EDTA + CIS + AC and PCa + EDTA + CIS showed a higher antioxidant capacity (1.13 and 1.04 mg trolox eq·gfw −1, respectively) in comparison to the control (0.58 mg trolox eq·gfw −1) after day 1 of storage, even though this value was reduced by around 0.9 mg trolox eq·gfw−1 in comparison to the freshly peeled pear. The application of antibrowning agents and calcium propionate maintain the bacterial growth below the maximum levels allowed by Chilean regulation and reduced the typical flavour of pears. The chosen commercial film achieved high CO2 and low O2 levels although neither off–flavour nor off–odour was found along storage.

Oxidative enzymes and functional quality of minimally processed grape berries sanitised with ozonated water

Thompson Seedless (TS) and Black (BS) grapes sanitised with 2, 4, 6, 8 mg L 1 O3 or NaOCl (100 mg L ) were stored 21 days at 5 °C. Ozonated water stimulated the respiration rate, especially after 5 days of storage, and increased superoxide dismutase and catalase activity compared to NaOCl-sanitised grapes. Total polyphenol content (TPC) was 23–50% higher in TS and 18.5–28% higher in BS samples sanitised with ozonated water. Twofold higher total antioxidant capacity (TAC) was registered in TS at all of the evaluated O3 doses while the doses of 6 and 8 mg L 1 increased TAC by 19–30% in BS. The use of ozonated water as a sanitising method, especially at 6 and 8 mg L 1 doses, improved the functional quality and maintained low microbial counts on fresh-cut grapes being a good alternative for the industry.

Compositional changes on colored and light-yellow-fleshed potatoes subjected to two cooking processes

ABSTRACT Five potatoes varieties both raw and microwave (800 W, 8 min) and fried (180°C, 5 min) were evaluated. Colored-fleshed potatoes showed between 2- and 2.5-fold higher total polyphenols (TP, 2880.5–3241.6 mg GAE/kg DW) than the light-yellow. Chlorogenic acid was predominant. However, related to the others identified phenols, microwave and fried presented different phenolic profile. Vitamin C and total antioxidant capacity were also higher on colored ones with values in the range of 260.7–511.6 mg AA/kg DW and 344.1–527.8 mg GAE/kg DW respectively. Microwave and frying reduced TPs and vitamin C. Conversely, microwave increased total antioxidant capacity in 1–2-fold while frying reduced more than half compared to raw potatoes. Microwave and fried-colored potatoes represent an interesting alternative compared to light-yellow potatoes due to its contribution of phytochemicals to the consumer’s diet.

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.