Claudia Moggia

Development of aroma compounds and sensory quality of ‘Royal Gala’ apples during storage

Summary The effect of 1-MCP and CA storage on aroma production and consumer acceptance were investigated during storage of ‘Royal Gala’ apples. Fruit was harvested 132 d (Harvest 1) and 144 d (Harvest 2) after full bloom (DAFB), and stored under refrigerated air (RA; 0ºC; 90 – 95% RH), or in a controlled atmosphere (CA; 2.0 – 2.5 kPa CO2, 1.8 – 2.0 kPa O2), or treated at harvest with 625 nl l–1 1-methylcyclopropene (1-MCP) ) followed by RA storage. Ripening indices, aroma volatile production, and sensory quality were determined after 2, 4 and 6 months of storage, plus 7 d of simulated shelf-life. Butyl acetate and hexyl acetate were the most abundant esters produced by ‘Royal Gala’ apple, and hexanol, butanol, and 2-methyl butanol were the most abundant alcohols. Hexyl acetate, 2-methyl butyl acetate and butyl acetate were found to be major contributors to aroma. CA storage and 1-MCP-treatment reduced ethylene production, softening and acidity loss. Storage of apples under RA conditions gave the highest levels of volatiles, while CA and 1-MCP treatment depressed aromatic volatile production in the fruit. At harvest, volatile emission was higher in late-harvested apples than in fruit picked at commercial harvest. After RA storage, no improvement in volatile emission was observed in late-harvested fruit; however, under CA or 1-MCP treatment, late-harvested fruit retained higher odour values than fruit harvested earlier. There was a good correlation between volatile levels and aroma intensity perceived by taste panelists; similarly high correlations were found between ethylene levels and most of the odour-active compounds analysed. 1-MCP and CA-stored fruit were preferred by consumers in all trials, indicating that both treatments can ensure ‘Royal Gala’ apples maintain their preferred textural characteristics. Therefore, this technology could be used to retain the quality of ‘Royal’ Gala fruit, especially during long-term storage.

Effect of DPA [Diphenylamine] and 1-MCP [1-methylcyclopropene] on chemical compounds related to superficial scald of Granny Smith apples

Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following treatments: DPA (2,000 ppm); 1-MCP (1.2 ppm) and control (no treatment). All fruit was stored for 4 or 6 months at 0 deg C. A completely randomized factorial design was used (2 harvest dates by 3 postharvest treatments). Monthly measurements were made on maturity indices, ethylene production rate (EPR), scald related compounds (alpha-farnesene (AF), conjugated trienes (CT), total anti-oxidants (AO)), and cell membrane stability. Following 4 and 6 months of storage, plus 7 days at 20 deg C, scald was evaluated. After 6 months, DPA-treated fruit, from both harvests, showed similar firmness, EPR and AO, compared to the control. However, AF and CT were lower, and cell membrane stability higher. Conversely, 1-MCP-treated fruit showed a noticeable EPR suppression and AF inhibition, along with higher firmness, lower CT and AO, compared to the control and DPA. Furthermore, cell membrane stability was superior to that of the control and similar to that of the DPA. Treated fruit (DPA and 1-MCP) showed an important reduction in scald compared to the control. The effect of 1-MCP on the investigated compounds and the reduction in scald, confirms that ethylene plays a major role on its development.

Firmness at Harvest Impacts Postharvest Fruit Softening and Internal Browning Development in Mechanically Damaged and Non-damaged Highbush Blueberries (Vaccinium corymbosum L.)

Fresh blueberries are very susceptible to mechanical damage, which limits postharvest life and firmness. Softening and susceptibility of cultivars “Duke” and “Brigitta” to developing internal browning (IB) after mechanical impact and subsequent storage was evaluated during a 2-year study (2011/2012, 2012/2013). On each season fruit were carefully hand-picked, segregated into soft (<1.60 N), medium (1.61–1.80 N), and firm (1.81–2.00 N) categories, and then either were dropped (32 cm) onto a hard plastic surface or remained non-dropped. All fruit were kept under refrigerated storage (0°C and 85–88% relative humidity) to assess firmness loss and IB after 7, 14, 21, 28, and 35 days. In general, regardless of cultivar or season, high variability in fruit firmness was observed within each commercial harvest, and significant differences in IB and softening rates were found. “Duke” exhibited high softening rates, as well as high and significant r2 between firmness and IB, but little differences for dropped vs. non-dropped fruit. “Brigitta,” having lesser firmness rates, exhibited almost no relationships between firmness and IB (especially for non-dropped fruit), but marked differences between dropping treatments. Firmness loss and IB development were related to firmness at harvest, soft and firm fruit being the most and least damaged, respectively. Soft fruit were characterized by greater IB development during storage along with high soluble solids/acid ratio, which could be used together with firmness to estimate harvest date and storage potential of fruit. Results of this work suggest that the differences in fruit quality traits at harvest could be related to the time that fruit stay on the plant after turning blue, soft fruit being more advanced in maturity. Finally, the observed differences between segregated categories reinforce the importance of analyzing fruit condition for each sorted group separately.

Effect of the Cooling System and 1-MCP on the Incidence of Superficial Scald in Granny Smith Apples

A study was carried out to determine the effects of two cooling systems and the application of 1-methylcyclopropene (1-MCP, SmartFresh TM )�ontheincidenceofsuperficialscaldinapples�(Malus domestica Borkh.) cv. Granny Smith. Fruit were collected from a commercial orchard (Colbun, Maule Region, Chile) during 2004-2005 season. A completely randomized design was used in a 2 x 2 factorial arrangement, using cooling systems (normal and step-wise cooling) and application of 1-MCP (0 and 625 nL L -1 i.a.) as the main factors. Fruit from normal cooling were kept at 0 °C throughout the storage period (180 days). Step-wise cooling consisted of storing the fruit at 10 °C for 10 days; 4 °C for the next 20 days and 0 °C for the remaining 150 days. Every month, maturity indices and the chemicals, global antioxidant content (AO), α-farnesene�(AF)�andconjugatedtrienes�(TC),�weremeasured.�Incidenceofsuperficial� scald was determined after 180 days of storage, plus 10 days at 20 °C. The application of 1-MCP with both cooling systemswascapableofmaintainingfirmnessvaluesaround�8.2�kguptotheendofthestorageperiod,�aswellas� decreasingtheconcentrationofAF,�TCandAOduringstorage.�Incidenceofsuperficialscaldonfruitwith�1-MCP� was 0%, regardless of the type of cooling. Among treatments without 1-MCP, step-wise-cooling was more effective inpreventingsuperficialscald,�resultingin�1.3%�incidencecomparedto�75.6%�withthenormalcoolingsystem.� Nevertheless,�fromthefourthmonthonwardsfirmnesswaslowerthanthatrequiredforexport.

Use of Peroxyacetic Acid as Green Chemical on Yield and Sensorial Quality in Watercress (Nasturtium officinale R. Br.) Under Soilless Culture

The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment through the creation of biodegradable byproducts. In hydroponics, appropriate doses of peroxyacetic mixtures deliver these byproducts while also oxygenating the roots. Watercress producers who recirculate the nutritive solution can use these mixtures in order to increase oxygenation in the hydroponic system. The experiment took place between August and December 2009, beginning with the planting of the watercress seeds and concluding with the completion of the sensory panels. A completely random design was used, including three treatments and four repetitions, with applications of 0, 20 and 40 mg L−1 of the peroxyacetic mixture. Measured variables were growth (plant height, leaf length and stem diameter), yield (weight per plant and dry matter) and organoleptic quality (color and sensory panel). The application of 40 mg L−1 of the peroxyacetic mixture had a greater effect on the growth and development of the plants, which reached an average height of 29.3 cm, stem diameter of 3.3 mm and leaf length of 7.6 cm, whereas the control group reached an average height of only 20.2 cm, stem diameter of 1.9 mm and leaf length of 5.7 cm. The application of the peroxyacetic mixtures resulted in an improvement in growth parameters as well as in yield. Individual weights achieved using the 40 mg L−1 dose were 1.3 g plant−1 in the control group and 3.4 g plant−1 in the experimental group (62% yield increase). Sensory analysis revealed no differences in organoleptic quality.

Evolución de Madurez en Pre y Postcosecha y Potencialidad de Almacenaje de Peras Packham's Triumph

A B S T R A C T Packham’s Triumph pears (Pyrus communis L.) were evaluated from four weeks before harvest for maturity and ethylene production. Firmness and soluble solids showed the highest correlations (r = -0.97 y 0.98, respectively) with days after full bloom (DDPF). Ethylene production was low (< 0.07 mg kg -1 ) and was not correlated with DDPF. Fruit harvested with 7.8 (E1) and 7.0 kg (E2) were stored in conventional cold air (0°C) and two controlled atmosphere conditions (AC1: 2-2.5% O 2 /1-1.5% CO 2 and AC2: 1-1.3% O 2 / 0.5-0.8% CO 2 ), -1°C, for six months. Changes in maturity, and ethylene production were measured (monthly) and incidence of physiological disorders was assessed (after four and six months). Additionally, the ethylene production rate (TPE) was monitored for seven days at room temperature, after each storage period. Fruit from both harvests, stored under AC1 and AC2 were firmer, greener and had lower ethylene production than those of FC. There were no significant differences in ripening between AC1 and AC2. Ethylene accumulation was exponential and occurred earlier and with higher values in FC (900 mg kg -1 maximum at the 5 th month), with respect to AC (146 and 230 mg kg -1 for E1 and E2 at the end of the storage period). At room temperature, the TPE of the three storage conditions increased from the second month, but the climacteric peak was observed only in FC. After six months, fruit from FC and from both harvests developed superficial scald (17% for E1 and 20% for E2).

Studies with long term storage of cut flowers of Hydrangea macrophylla

Hydrangea macrophylla subsp. macrophylla var. macrophylla ha sido ampliamente cultivada como planta de jardin y planta en maceta. Adicionalmente, se han desarrollado e introducido recientemente en Chile cultivares de flor cortada, para su exportacion a Estados Unidos. Actualmente, las flores cortadas se transportan via aerea en cajas de carton, con un tubo con agua puesto en la base de sus tallos. Hay poca informacion disponible acerca del manejo poscosecha. Este estudio fue realizado con el fin de explorar la factibilidad de exportar varas florales de hortensia via maritima, cortadas en el estado de madurez clasico, tambien llamado estado antique. Se obtuvieron varas florales de un productor comercial ubicado en Chile Central. Se establecieron cuatro tratamientos: prefrio (varas puestas a 0,5 °C antes de empacar), prefrio + fungicida pyrimethanil o bisulfito de sodio y un grupo de flores sin prefrio (empaque inmediato). Se pusieron tubos con agua en la base de los tallos. Las varas fueron empacadas en cajas de carton y puestas en camara de frio a 0,5 °C. Despues de 20 dias de almacenamiento a 0,5 °C, la vida util (o vida en florero) fue de 7-9 dias. En contraste, un experimento adicional mostro que las varas que fueron almacenadas por 35 dias tuvieron una vida util de solo 2 dias. No hubo diferencia en cuanto a vida util entre varas con o sin prefrio. El promedio de absorcion de agua por vara fue de 43 ml. Se observo ataque de Botrytis solo en uno de los dos tratamientos sin fungicida, donde la incidencia fue de 12,5%, por lo que el efecto de los fungicidas no fue evaluado. Se concluyo que el transporte via maritima a Estados Unidos de flores cortadas en el estado antique seria tecnicamente posible.