Ivan Sestari

Inibição da ação do etileno retarda o desenvolvimento de injúrias de frio em tangor 'Murcott'

The blockage of ethylene-dependent signaling may affect the quality of tropical fruit in a positive or negative way after cold storage. Hence, the role of ethylene on chilling injury in tangor Murcott and the responses related to injuries resistance were the aims of this study. Fruit were treated for 12h with 500nL L-1 of 1 methylcyclopropene (1-MCP) or immersed into solutions containing 2000nL L-1 ethephon or salicylic acid for 5min before storage at 1°C for 90 days. As a control fruit were stored at 1°C. Chilling injury symptoms were anticipated and intensified when fruit were treated with ethephon or salicylic acid. On the other hand, the ethylene inhibition by 1-MCP delayed symptoms and resulted in the lowest injury index and percentage of fruit decay at the end of storage. At 45 days the superoxide dismutase (SOD) activity was intensified, however, in lower intensity in salicylic acid treated fruit. Afterwards, SOD activity decrease in all the treatments, though at 90 days the intensity was slightly superior to that at the initial 30 days of storage. During storage period it were not observed significantly alterations in putrescine (Put) and spermine (Spm) levels in flavedo tissues. In contrast, spermidine (Spm) levels were more affected by chilling stress.

Armazenamento de pêssegos cv. "Granada" em atmosfera controlada, visando ao transporte a longas distâncias

This research was aimed at evaluating controlled atmosphere (CA) and temperature conditions for storing of cv. Granada peach fruit harvested at two ripening stages aiming the transport of fruit for distant market, such as Europe. Treatments evaluated were six storage conditions and two ripening stages. The storage conditions were: [1] cold storage (20.8kPa de O2 +<0.5kPa de CO2); controlled atmosphere (CA) conditions with [2] 6.0kPa de O2 + 15.0kPa de CO2; [3] 1.0kPa de O2 + 3.0kPa de CO2; [4] 1.0kPa de O2 + <0.5kPa de CO2, all at +0.5°C. Moreover, CA with 2.0kPa O2 + 5.0kPa CO2 was evaluated both at [5] +0.5°C and [6] -0.5°C. Fruits were harvested either at the breaking stage or at the half-ripe ripening stage and stored in the conditions cited above. The harvest of cv. Granada peaches in the breaking stage (greeny background color of the skin) is the most suitable, because although not affecting the physical and chemical quality, these fruits showed a reduced incidence of flesh browning and rot. For short-term storage (25 days), controlled atmosphere did not significantly improve fruit quality in relation to cold storage.

1-metilciclopropeno e salicilato de metila reduzem injúrias por frio em nêspera 'Fukuhara' refrigerada

This study was carried out whit the objective to verify the effect of 1-methylcyclopropene (1-MCP) and methyl salicylate (MeSA) in chilling injury control of Fukuhara loquat fruit. It was applied four concentrations of 1-MCP (0, 50, 500 e 5,000nL L-1) and 0,01mM of MeSA associated or not to 500nL L-1 of 1-MCP. The fruit were stored at 1°C during 60 days. The variables analyzed were flesh firmness, pH, titratable acidity, soluble solids content, ascorbic acid content and activity of polyphenol oxidase (PPO). After 60 days of cold storage, there was no development of internal browning in fruit treated with 1-MCP and MeSA. Fruits without treatment showed higher levels of internal browning and high activity of PPO enzyme. All treatments showed increase of flesh firmness during cold storage.

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.

Remoção da adstringência de caquis 'Giombo' com subdosagens de etanol

The objective of this research was to evaluate ethanol sub-doses efficacy on the astringency removal of Giombo. Additionally, it was evaluated the influence of temperature and ethanol exposure time on fruit deastringency. Thus, experiments were carried out with different exposition times (6, 12, 24 and 36h) and ethyl alcohol concentrations (1.75; 3.5 e 7mL kg-1 or 0.3 and 0.6mL L-1 of chamber). Fruit exposition to ethanol concentration of 1.75mL during 12 h was sufficient to remove completely the persimmon fruit astringency. After the treatment application, the fruits needed 4 days to become suitable to consumption. The process of tannin polymerization is not influenced by cold storage.

Qualidade de pêssegos cv. "Eldorado" tratados com aminoetoxivinilglicina e ethephon e armazenados em atmosfera controlada

The effect of preharvest application of aminoethoxyvinylglycine (AVG) and ethephon combined with controlled atmosphere (CA) storage conditions on peach fruit (cv. Eldorado) quality maintenance and chilling injury prevention was investigated, aiming at the maritime transport. Treatments evaluated were preharvest application of AVG (125g ha-1 and 250g ha-1 at 15 or 21 days before harvest), ethephon (140g ha-1 7 days before harvest), and control, combined with two CA conditions (1.0kPa O2 + 3.0kPa CO2 and 2.0kPa O2 + 5.0kPa CO2 at 0°C). After 24 days of CA storage plus 2 and 4 days of shelf-life at 15°C, preharvest application of ethephon stimulated fruit ripening by increasing ethylene production and decreasing both flesh firmness and titratable acidity. Application of AVG did not delay fruit ripening. However, fruit treated with 125g ha-1 of AVG at 15 days before harvest showed lower incidence of internal browning than ethephon-treated and control fruit. Furthermore, storage of fruit under CA with 2.0kPa O2 + 5.0kPa CO2 allowed higher titratable acidity and lower incidence of internal browning.

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.

Métodos para predição de bitter pit em maçãs 'Fuji' e 'Braeburn'

Experiments were carried out with objective to evaluate the efficiency of methods for bitter pit prediction in Fuji and Braeburn apples sampled at two harvest dates. Fruits from 6 orchards, three for each cultivar, were sampled earlier (20 days before harvest) and at commercial harvest date. The prediction methods assessed were: infiltration of apples with 0.10M MgCl2 solution containing 0.01% Tween-20 and 0.4M sorbitol; and immersion of fruits in 2.500nL L-1 ethephon solution plus 0.01% Tween-20. Four replications of 25 fruits of each orchard were stored on controlled atmosphere (CA) during five months plus 12 days at 20°C in order to assess the real bitter pit occurrence. Both methods showed incidence and severity similar to real bitter pit occurrence after storage for both cultivars sampled 20 days before harvest. On the other hand, none method was able to predict the incidence of bitter pit after CA storage for fruits sampled at commercial harvest. The magnesium infiltration and immersion of fruits on ethephon only are efficient to predict bitter pit incidence on fruits when sampled 20 days before commercial harvest.

Thidiazuron affects the quality of 'Gala' apples stored under controlled atmosphere

This work was carried out aiming to evaluate the effect of thidiazuron (TDZ) on the quality of Gala apples stored under controlled atmosphere (CA) conditions. Plants were sprayed at full bloom with TDZ at 0, 10, 20, or 40g ha-1 (a.i.). Harvested fruits were then stored in CA with 1.0+2.5, 1.5+2.5 and 1.5+5.0 (kPa O2+kPa CO2), both at 0.5°C. In addition, the partial pressure of 1.5kPa of O2+2.5kPa of CO2 was also evaluated at -0.5°C. Higher flesh firmness and titratable acidity was obtained by applying 20 or 40g ha-1 TDZ. Furthermore, these TDZ doses decreased the respiration rate as well as the occurrence of flesh breakdown, mealiness and decay. The application of TDZ at doses ranging from 20 to 40g ha-1 maintains higher fruit quality for up to 8 months under CA. In addition, the storage of Gala apples under CA with 1.0kPa O2+2.5kPa CO2 at 0.5°C results in higher flesh firmness and titratable acidity. Moreover, this CA condition reduces the incidence of flesh breakdown, mealiness and postharvest decay in Gala apple fruits.