Anderson Weber

Respiratory quotient: innovative method for monitoring ‘Royal Gala’ apple storage in a dynamic controlled atmosphere

Apples (Malus domestica, Borkh.) which are not stored at low temperature or in a properly controlled atmosphere (CA) may have a high metabolic rate during the postharvest stage resulting in losses in quality. The aim of this study was to evaluate the quality of ‘Royal Gala’ apple fruit stored in accordance with a new method of dynamic controlled atmosphere (DCA).The respiratory quotient (RQ) was monitored at two temperatures which were then compared using a commercially available technology based on chlorophyll fluorescence DCA (DCA-CF) and static CA. Ethylene production and respiration rates were lower in apples stored in DCA than in CA, as a result of lower 1-aminocyclopropane-1-carboxylate oxidase activity, especially in apples stored in DCA-RQ2. Flesh firmness of apples stored in DCA did not differ from those stored in CA. Apples stored at 1 °C had less flesh breakdown occurrence and a high percentage of healthy fruit. ‘Royal Gala’ stored at DCA-RQ2 had less flesh breakdown than apples stored in CA; however, the apples stored in DCA-CF did not differ from those stored in DCA-RQ2 and CA. Apples stored at the highest RQ value (6 and 4), especially at 0.5 °C, had low O2 injury occurrence after storage. However the increase in temperature to 1.0 °C, reduced the occurrence of this disorder. Therefore, storage in DCA-RQ2 at 1 °C or DCA-CF at 0.5 °C are the recommendations of preference for ensuring maintenance of quality in ‘Royal Gala’ apples after eight months of storage.

Estresse inicial por baixo oxigênio seguido do armazenamento em atmosfera controlada de maçãs 'Royal Gala'

The aim of this work was to evaluate the application of initial low oxygen stress and 1-methylcyclopropene (1-MCP) on quality maintenance of Royal Gala apples, when stored in a controlled atmosphere (CA). In order to do this, a lot of 50 % of the fruit was treated with 1-MCP (625 ppb) and one half of these, together with half of the fruit which did not receive the application of 1-MCP, were subjected to low oxygen stress (0.3 kPa for seven days) before being stored for seven months at 0.5 °C under the following CA conditions: 1.2 kPa O 2 + 2.0 kPa CO 2 ; 1.0 kPa O 2 + 2.0 kPa CO 2 ; 0.8 kPa O 2 + 1.0 kPa CO 2 ; 0.6 kPa O 2 + 1.0 kPa CO 2 e 0.5 kPa O 2 + 1.0 kPa CO 2 . After storage, and following a further seven days at 20 °C, analyses of fruit quality were carried out. The results show that initial low oxygen stress is not effective in maintaining quality, beyond increasing the occurrence of physiological disorders and decay. There was no big difference in the efficiency of the CA conditions used in this study on the conservation of fruit quality. The application of 1-MCP did not improve quality maintenance in fruit stored under ultralow oxygen, as seen at the lowest partial pressures (<1.0 kPa) used in this work.

Pré-resfriamento sobre a qualidade de pêssegos 'Chiripá'

The aim of this research was to evaluate the physic and chemical quality and the incidence of physiological disorders in Chiripa peaches submitted to different precooling forms. The treatments evaluated, were: [1] slow cooling in the storage chamber (-0.5°C e UR de 95%); [2] forced-air cooling (-1.5°C) until the pulp reached 0°C; [3] hydrocooling until the pulp reached 15°C; [4] hydrocooling until 10°C; [5] hydrocooling until 5°C; [6] hydrocooling until 1°C. The fruits were evaluated after 35 days at -0.5°C and more two and four days at 20°C. Lower ethylene synthesis during shelf-life at 20°C was verified in fruits submitted to both slow cooling and forced-air precooling. In those fruits, the succulence was significantly lower in the 4th day at 20°C, demonstrating an apparent relationship between the reduced ethylene synthesis and the largest wooliness incidence. Slow cooled fruits showed highest flesh firmness. All hydrocooling forms resulted in larger percentage of fruits with stains in the epidermis, possibly due to the low temperature of the precooler water. Therefore the precooling in water is not recommended for Chiripa peaches.

Manejo do etileno e sua relação com a maturação de maçãs 'Gala' armazenadas em atmosfera controlada

This research aimed to evaluate the quality of Gala apples submitted to different ways of ethylene handling, through inhibition of synthesis, inhibition of action and ethylene absorption in storage room, associated with two temperatures. The treatments originated from the combination between two temperatures (0.5 °C e -0.5 °C) and application of aminoethoxyvinylglycine (AVG), 1- methylcyclopropene (1-MCP) and ethylene absorption. All treatments were stored in controlled atmosphere with 1.2 kPa O2 + 2.5 kPa CO2. Ripening and quality evaluations were carried out after eight months of storage more seven days at 20 °C. Preharvest AVG application maintained fruit skin greener at the opening of storage rooms. After seven days at 20°C, the treatment with AVG resulted in greener skin, with lesser decay incidence, higher flesh firmness and less senescent breakdown incidence. The lower ethylene production of AVG-treated apples resulted in lower respiration and highest titratable acidity levels. The temperature of 0.5 °C maintained higher of the titratable acidity and reduced senescent breakdown incidence when compared with the temperature of -0.5 oC. The ethylene absorption and 1-MCP application were also efficient in the control of the senescent breakdown and loss of firmness, however less effective than AVG treatment.

Previsão de bitter pit em maçãs por meio da infiltração de Mg2+ e da aplicação de ethephon nos frutos

The effect of magnesium and calcium infiltration on bitter pit symptoms development in Gala apples was studied. It was also examined the efficiency of magnesium infiltration and the ripening hastening of Royal Gala apples as a predictive methods of bitter pit occurrence after storage. In the first experiment, Gala apples were infiltrated with MgCl2; CaCl2; or MgCl2 plus CaCl2. In the second experiment Royal Gala apples were infiltrated with MgCl2; or immersed into solution containing ethephon during five minutes. As a control a sample of each cultivar was stored in controlled atmosphere during 6 months plus eighteen days at 20°C. Fruits infiltrated with MgCl2 showed increased incidence and severity of bitter pit proportional to the MgCl2 concentration in the solution. Infiltration with CaCl2 prevents bitter pit-like symptoms. The ripening hastening of Royal Gala apples at harvest was effective on the bitter pit prediction after storage.