Effect of growth regulators on 'Brookfield' apple gas diffusion and metabolism under controlled atmosphere storage

Abstract

-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...

Effect of growth regulators application on the quality maintenance of 'Brookfield' apples

“…According to figure 1a, ethephon application after NAA reduced the negative effect of spraying NAA alone. Brackmann et al (2014) verified a similar response in 'Brookfield' apples after long-term storage under controlled atmosphere. These authors verified a significant reduction of ethylene production, respiration rate and mealiness incidence.…”

“…These results go against the findings proposed by Steffens et al (2006), that no significant quality reduction was found through ethephon application after AVG in 'Gala' apples. On the other hand, Brackmann et al (2014) found a significant increment in mealiness incidence by the ethephon application after AVG in 'Brookfield' apples. Another research carried out with 'Brookfield' apples found that ethephon application after AVG reduced healthy fruits amount and flesh firmness, without a significant increment in red skin color (Brackmann et al, 2015).…”

“…The ethephon application can also neutralize the negative effect of AVG on the red skin color development of 'Gala' apples (Steffens et al, 2006), but there is a lack of studies evaluating its effect on 'Brookfield' apples. In addition to the products applied during preharvest, on postharvest other technologies are also employed, such as 1-MCP application and LE (Brackmann et al, 2014). However, there are very few studies evaluating the effect of the growth regulators application, either alone or combined, on quality at harvest and postharvest.…”

“…The container was closed during about 2 hours and thereafter 2 aliquot of 1 mL were taken of and injected into a gas chromatograph model Star 3400CX (Varian, Palo Alto, CA, USA) equipped with a flame ionization detector (FID) and a Porapak N80/100 column. The temperature of injector, column and detector were 140, 90 and 200 respectively, results were expressed in µL C 2 H 2 kg -1 h -1 ; c) respiration rate: evaluated by the determination of CO 2 production of the same fruits of ethylene production analysis, results expressed in mL CO 2 kg -1 h -1 ; d) titratable acidity: determined by the titration, with a 0.1 N NaOH solution, of 10 mL juice diluted in 100 mL distillated water until pH 8.1, results showed in meq 100 mL -1 ; e) iodine starch (0-10) and f ) soluble solids (°Brix) were evaluated according to the methodology proposed by Steffens et al (2006); IEC (µL L -1 ), ICO 2 (mL 100 mL -1 ), internal space (g 100 g -1 ) and gas diffusion rate (mL CO 2 m -2 s -1 ) were evaluated according to the methodology proposed by Brackmann et al (2014); red skin color index (0-3) was assessed subjectively through the identification of the skin area with red color, according to a scale of 0-3: 0 = <25% of the fruit's skin was red; 1 = ≥25% up to 50% of the fruit's skin was red; 2 = ≥50% up to 75% of the fruit's skin was red; 3 = ≥75% of the fruit's skin was red. Mass loss (%): evaluated by weighting the fruits before and after storage; mealiness (%), flesh breakdown (%), healthy fruits (%), decay incidence (%): evaluated by counting the fruits with these characteristics in relation to the total number of fruits; flesh firmness (N): evaluated by the insertion of an 11 mm tip in the two opposite sides of the equatorial region, where the skin was previously removed.…”

“…Perhaps, the low IEC, ethylene production and respiration rate in fruits treated with AVG result in lower cell wall degrading enzyme activity, once these enzymes are started by ethylene (Nishiyama et al, 2007;Payasi et al, 2009;Wei et al, 2010), leading in fruits with high flesh firmness and low physiological disorders. The high quality of these fruits is due to the lower ethylene production, respiration rate, IEC and ICO 2 , since great part of these variables have an inverse correlation with quality, especially physiological disorders and gas diffusion rate (Brackmann et al, 2014). Previous researches have verified the maintenance of quality through AVG application in some apple cultivars (Brackmann et al, 2014(Brackmann et al, , 2015Steffens et al, 2006;Wang & Dilley, 2001;Yuan & Carbaugh, 2007;.…”