Effects of Fruit Position in Standard Place Pack Cartons and Gamma 1 Irradiation on the Postharvest Quality of ‘Barnfield’ Navel Oranges

The objective of this study was to determine if oranges in the top and bottom layers within a Standard Place Pack were impacted differently by irradiation after long-term storage. ‘Barnfield’ Navel oranges were packed in Standard Place Pack cartons and treated with 0, 0.15, or 1 kGy of gamma irradiation. The fruit were stored for 3 weeks at 5 °C and then for 1 week at 20 °C. After storage, the fruit from the top and bottom layers were separately evaluated for quality. The development of stem-end rind breakdown (SERB) was the main cause of quality loss and was greater in irradiated fruit in the top layer. Fruit in the bottom layer showed more physical damage (flattening) but lower incidence of SERB. The changes in individual sugar content were minimal but significant for layer. The content of individual organic acids was consistently lower in irradiated fruit from the bottom layer. Layer type showed a stronger effect on phenolic compounds than irradiation dose. The tristimulus color, total soluble solids, titratable acidity, and firmness of fruit were not influenced by irradiation dose or layer type. The results show that damage in irradiated Navel oranges depends on dose and layer, with the top layers showing greater physiological damage and bottom layers showing more physical damage

Flavonoids: Important Biocompounds in Food

Flavonoids are secondary metabolites in plants that show some desirable characteristics. These compounds can be grouped in different classes on the basis of their basic structure. It has been reported that flavonoids are important for human health because of their antioxidant, antibacterial, antiviral, and anti‐inflammatory activities and because they act as free radical scavengers as they are potential reducing agents that protect from oxidative damage, which are conferred by the content of hydroxyl groups. In recent years, flavonoids have been investigated based on their ability to reduce the incidence of many diseases, to inhibit cell damage, to repair DNA process and to reduce oxidative stress. Besides, flavonoids have been demonstrated to have cardioprotective effects, have potential to improve coronary vasodilatation and prevent LDLs from oxidizing and also showed potential neuroprotective effects. Moreover, flavonoids have been used in the food industry due to their ability to preserve foods, to provide colour and flavour and to make dietary supplements, among other important industrial applications

EFECTO DE RECUBRIMIENTOS COMESTIBLES DE QUITOSANO EN LA REDUCCIÓN MICROBIANA Y CONSERVACIÓN DE LA CALIDAD DE FRESAS

Se evaluó el efecto de recubrimientos comestibles (RC) de quitosano (Q) (1 y 2 %) con o sin la adición de aceite esencial de canela (AC) (0,03, 0,07 y 0,1 %) sobre los cambios en aceptabilidad, fenoles totales, capacidad antioxidante y población microbiana en fresas. Fresas sin recubrimiento se utilizaron como control. Frutos tratados fueron almacenados por 15 días a 5°C y se evaluaron cambios en la calidad a intervalos de 3 días. Fresas tratadas y control no mostraron diferencias en el contenido de fenoles totales y capacidad antioxidante. Todos los tratamientos redujeron significativamente la población microbiana con respecto al control. RC con Q 2 % + AC 0,1 % redujo en mayor magnitud el crecimiento microbiano (2 Log ufc/g) sin afectar la calidad después de 14 días a 5°C, seguido del RC de Q 1 % + AC 0,1 % con 1,5 Log ufc/g de reducción y vida de anaquel de 15 días. El control presentó 8 días de vida de anaquel; todos los recubrimientos presentaron la mayor aceptabilidad en comparación con el control. Estos resultados indican que los RC de quitosano con aceite de canela pueden prolongar la vida de anaquel de fresas por 15 días a 5ºC

The barrier properties and potential use of recycled-LDPE films as a packaging material to preserve the quality of Jalapeño peppers by modified atmospheres

The permeation of O2, CO2 and water vapor through recycled-LDPE films of five different thicknesses (35.2, 44.2, 50.5, 63.8 and 88.9 μm) were studied at 7 °C and 23 °C. These films were used to pack intact Jalapeño peppers, which were stored at 7 °C for 4 weeks. The quality of the peppers and the gas composition inside of the packages were evaluated weekly during the storage interval. Film thickness affected the permeation of the tested gases, being such effect more notorious at 23 °C than at 7 °C. The CO2 levels inside of the pepper packages depended strongly on the film thickness, but the O2 levels were similar in all packages. The modified atmosphere packaging inhibited the postharvest changes in color, firmness, weight loss, ascorbic acid, total phenols and overall quality of the peppers. Fermentative metabolites accumulated during storage, although the levels of such compounds were low and did not affect the quality of the peppers

Productos alternativos a la aminoetoxivinilglicina para el control de la producción de etileno en manzana 'Golden Delicious'

Chihuahua produce el 66 % de la manzana (Malus x domestica Borkh) a nivel nacional, siendo el cultivar ‘Golden Delicious’ el de mayor superficie plantada. La necesidad de controlar la maduración de la fruta para programar la cosecha, ha condicionado el uso de productos a base de la aminoetoxivinilglicina (AVG), un inhibidor de la síntesis del etileno, y por lo tanto de la maduración de los frutos climatéricos. Este producto es eficaz, pero de alto costo. En este estudio se evaluó la eficiencia de productos alternativos al AVG de menor costo. Se asperjaron manzanos ‘Golden Delicious’ en precosecha durante el ciclo 2008, con los tratamientos: ácido salicílico (AS; 1, 0.1 y 0.01 μM), cobalto (40, 60 y 80 mg Co++·L-1), ácido cítrico (AC; 533 mg·L-1) y AVG (123 mg·L-1) y agua como testigo. Los tratamientos de AS (0.01 y 1.0 μM) y de AC redujeron significativamente la concentración interna de etileno en los frutos, en comparación con el testigo, y a un nivel similar al AVG, con concentraciones de etileno de 0.6, 0.6, 0.4, 1.7 y 0.4 ppm, respectivamente. Los tratamientos con cobalto, a 40 y 80 mg Co++·L-1, retrasaron el pico climatérico en tres semanas. Los tratamientos con AS y cobalto indujeron frutos con color de cáscara más verde y con menor concentración de sólidos solubles, indicando un estado menos avanzado de maduración. Los tratamientos precosecha con AS, AC, y cobalto, representan una herramienta en el control de la maduración de manzanas ‘Golden Delicious’. Abstract Chihuahua produces 66 % of the apple (Malus x domestica Borkh) production in Mexico, being ‘Golden Delicious’ apple cultivar the most widely planted. The need to control fruit maturation in order to schedule harvest has made the use of aminoethoxyvinylglicine (AVG) almost a must, since it is an efficient ethylene synthesis inhibitor, and therefore a retardant of the maturation process in climacteric fruits; however it is an expensive product too. In this trial the effectiveness of alternative products to AVG, at a lower sell price, were evaluated. ‘Golden Delicious’ apple trees were sprayed before harvest during the 2008 season with: salicylic acid (AS; 1.0, 0.1 and 0.01 μM), cobalt (40, 60 and 80 mg Co++·L-1), citric acid (AC; 533 mg L-1), AVG (123 mg·L-1) and water as control. The treatments with AS (0.01 and 1.0 μM) and with AC reduced the internal concentration of ethylene in the fruit respect to control, and to a similar level as AVG did it, with internal ethylene concentration of 0.6, 0.6, 0.4, 1.7 and 0.4 ppm, respectively. Treatments with cobalt at 40 and 80 mg Co++·L-1 delayed in three weeks the climacteric peak. AS and cobalt produced fruits with greener peel and lower level of soluble solids, indicating a less advanced maturation stage. Therefore, the preharvest treatments with AS, AC and cobalt offer to growers a tool to control the maturation of ‘Golden Delicious’ apple fruits. Keywords: Malus x domestica, citric acid, salicylic acid, cobalt