The aim of the present work was to compare the effect of ultralow oxygen (ULO) with dynamic controlled atmosphere (DCA) and controlled atmosphere (CA) on the post storage quality of 'Royal Gala' and 'Galaxy' apples after long-term storage. Two experiments were carried out with 'Royal Gala' and 'Galaxy' apples, in the years 2012 and 2013, respectively. A higher internal ethylene concentration was observed in fruits stored under CA; intermediate concentration in fruits under ULO; and the lowest by fruits stored under DCA-CF (DCA based on chlorophyll fluorescence). Flesh firmness was higher in fruits stored under DCA-CF and ULO differing from CA, in the year 2012, but in 2013 fruits stored under ULO showed the highest flesh firmness, differing from CA fruits. DCA-CF is efficient in quality maintenance of 'Royal Gala' and 'Galaxy' apples. Both 'Gala' mutants stored under ULO show a similar quality maintenance to those stored under DCA-CF.

The aim of this work was to assess the profile of volatile compounds in 'Royal Gala' apples stored under controlled atmosphere (CA), with O(2) levels ranging from 1.0kPa to as low as 0.5kPa during 8months (0.5°C), followed by 7days of shelf-life at 20°C. Volatile compounds were collected via solid-phase microextraction (HS-SPME) and analysed by gas chromatography. Straight and branched-chain esters exhibited a distinct pattern. The emission of straight-chain esters decreased under extremely low O(2) (0.5kPa), while branched-chain esters were not significantly affected in such condition. 2-Methyl-butyl acetate, a significant contributor to the 'Royal Gala' aroma, was higher in intermediate O(2) concentration, suggesting that lowering the O(2) levels down to 0.7kPa does not negatively affect the volatile composition of 'Royal Gala' apples, as compared to the standard CA (1.0kPa O(2)). The remaining volatile compounds were not strongly affected by storing fruits under extremely low O(2).

-The objective of this work was to evaluate the effect of growth regulators on gas diffusion and on metabolism of 'Brookfield' apple, and to determine their correlation with quality characteristics of fruit stored in controlled atmosphere. A completely randomized design was used with four replicates. After eight months of storage, the effects of water (control), aminoethoxyvinylglycine (AVG), AVG + ethephon, AVG + naphthaleneacetic acid (NAA), ethephon + NAA, sole NAA, 1-MCP, ethylene absorption by potassium permanganate (ABS), AVG + ABS, and of AVG + 1-MCP -applied at different rates and periods -were evaluated on: gas diffusion rate, ethylene production, respiratory rate, internal ethylene concentration, internal CO 2 content, mealiness, and intercellular space. Fruit from the control and sole NAA treatments had the highest mealiness occurrence. Growth regulators significantly changed the gaseous diffusion through the pulp of 'Brookfield' apple, mainly in the treatment AVG + ABS, which kept the highest gas diffusion rate. NAA spraying in the field, with or without another growth regulator, increased ripening metabolism by rising ethylene production and respiration rate, and reduced gas diffusion during shelf life. AVG spraying cannot avoid the ethephon effect during the ripening process, and reduces both the internal space and mealiness incidence, but it is not able to induce ethylene production or to increase respiration rates.Index terms: Malus domestica, aminoethoxyvinylglycine, ethylene absorption, fruit quality, 1-methylcyclopropene. Efeito de reguladores de crescimento na difusão de gases e no metabolismo de maçãs 'Brookfield' em armazenamento em atmosfera controladaResumo -O objetivo deste trabalho foi avaliar o efeito de reguladores de crescimento na difusão de gases e no metabolismo de maçãs 'Brookfield', e determinar sua correlação com características dos frutos armazenados em atmosfera controlada. Utilizou-se o delineamento experimental inteiramente casualizado com quatro repetições. Após oito meses de armazenamento, os efeitos de água (controle), aminoetoxivinilglicina (AVG), AVG + ethephon, AVG + ácido naftalenoacético (ANA), ethephon + ANA, somente ANA, 1-MCP, absorção de etileno por permanganato de potássio (ABS), AVG + ABS, e de AVG + 1-MCP -aplicados em diferentes doses e épocas -foram avaliados sobre: taxa de difusão de gases, produção de etileno, taxa respiratória, concentração interna de etileno, concentração interna de CO 2 , polpa farinácea e espaço interno. Frutos dos tratamentos controle e ANA sozinha apresentaram a maior ocorrência de polpa farinácea. Os reguladores de crescimento modificaram significativamente a difusão gasosa pela polpa de maçãs 'Brookfield', principalmente no tratamento AVG + ABS, que manteve a maior taxa de difusão de gases. A aplicação de ANA no campo, com ou sem outro regulador de crescimento, acelerou o metabolismo de amadurecimento, pelo aumento na produção de etileno e na taxa respiratória, e reduziu a difusão de gases durante a vida de prateleira. Ap...

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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 O 2 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.

The effects of dynamic controlled atmosphere (DCA) storage based on chlorophyll fluorescence (DCA-CF) and respiratory quotient (DCA-RQ) on the quality and volatile profile of 'Royal Gala' apple were evaluated. DCA storage reduces ACC (1-aminocyclopropane-1-carboxylate) oxidase activity, ethylene production and respiration rate of apples stored for 9months at 1.0°C plus 7days at 20°C, resulting in higher flesh firmness, titratable acidity and lesser physiological disorders, and provided a higher proportion of healthy fruit. Storage in a regular controlled atmosphere gave higher levels of key volatiles (butyl acetate, 2-methylbutyl acetate and hexyl acetate), as compared to fruit stored under DCA-CF, but fruit stored under DCA-RQ 1.5 and RQ 2.0 also showed higher amounts of key volatile compounds, with increment in ethanol and ethyl acetate, but far below the odour threshold. Storage in DCA-CF reduces fruit ester production, especially 2-methylbutyl acetate, which is the most important component of 'Royal Gala' apple flavour.

Growth regulators are used in the production of apples worldwide, especially to extend the harvest period and maintain postharvest quality. This study aimed to investigate the effects of applying aminoethoxyvinylglycine (AVG) in isolation as well as in combination with other growth regulators and postharvest techniques on the harvest quality and storage potential of 'Brookfield' apples (Malus domestica), a 'Gala' strain. Fruit receiving AVG only had the highest starch content and the highest titratable acidity at harvest. After 8 months of storage, the AVG + 1-MCP (1-methylcyclopropene) and AVG + ABS (ethylene absorption) conserved higher flesh firmness than to all the other treatments. Naphthaleneacetic acid (NAA) application induced ACC oxidase enzyme activity at harvest, but not after storage. AVG application, with or without the aid of another technique, did not decrease the red skin color of 'Brookfield' apples. Low mealiness and a high healthy fruit percentage was obtained when the fruits were submitted to pre-harvest AVG application combined with NAA, 1-MCP and ABS. Internal carbon dioxide had an inverse correlation with the quantity of healthy fruit and was directly correlated with mealiness.Keywords: Malus domestica, postharvest quality, skin color, ethephon, naphthaleneacetic acid IntroductionThe application of growth regulators is necessary either to advance or to delay the fruit harvest in the field, due to the short period that fruit remains naturally at the correct maturation stage. Besides the short harvest period, another problem is that the harvest is carried out manually and requires a lot of time and manual labor. Thus, growth regulators are frequently used in the orchards.The main growth regulator applied in the field is aminoethoxyvinylglycine (AVG) which is used to delay the harvest in order to avoid pre-harvest fruit drop (McFadyen et al., 2012;Yildiz et al., 2012). AVG blinds the active site of ACC (1-aminocyclopropane-1-carboxylate) synthase enzyme and inhibits ethylene production and maturation events initiated by this plant hormone (Yu and Yang, 1979;Huai et al., 2001). Despite the benefits promoted by AVG application, it decreases the red skin color of 'Gala' apples (Malus domestica) (Steffens et al., 2006). However, this reduction of red skin color has not yet been proven in 'Gala' mutants.Another growth regulator used extensively is ethephon, mainly to advance the fruit harvest. Its application allows for an early harvest of the fruit, and also increases the red color of fruit skin Steffens et al., 2006;Ban et al., 2007). However, ethephon application may decrease organoleptic quality and decrease the storage potential of fruit after harvest, especially in terms of declines in flesh firmness (Steffens et al., 2006;Ban et al., 2007). As well as the application of ethephon, naphthaleneacetic acid (NAA) is also used during apple production. Its application reduces pre-harvest fruit drop in apples (Yuan and Carbaugh, 2007; Unrath et al., 2009), oranges (Zur and Goren, 1977) ...

The objective of this study was to evaluate the interaction between controlled atmosphere (CA), CA+1-methylcyclopropene (1-MCP) and dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) with three fruit maturity stages at harvest (early harvest date, optimal harvest date and late harvest date) on 'Galaxy' apple metabolism and quality after harvest and 9months storage plus 7days of shelf life at 20°C. Fruit stored under dynamic controlled atmosphere monitored by respiratory quotient 1.3 (DCA-RQ 1.3) showed lower ethylene production, respiration rate, mealiness and higher flesh firmness in comparison to CA stored fruit, but did not differ from those treated with 1-MCP. The dynamic controlled atmosphere monitored by respiratory quotient 1.5 (DCA-RQ 1.5) increased the acetaldehyde, ethanol and ethyl acetate concentration, regardless of the fruit maturity at harvest. The storage of 'Galaxy' apple under DCA-RQ 1.3 is efficient in keeping quality regardless of the maturity stage at harvest.