Ponto de compensação anaeróbico para o armazenamento de maçãs ‘Maxi Gala’ em atmosfera controlada dinâmica e sua relação com o nível de CO2

Abstract

At prolonged apple storage, dynamic controlled atmosphere monitored by the respiratory quotient (DCA-RQ) condition has its efficient attested when compared to conventional controlled atmosphere (CA), whetter with or without 1-methylcyclopropene application on overall quality maintenance, with higher aroma volatile compounds maintenance, also when compared to DCA monitored by chlorophyll fluorescence (DCA-CF). Although, DCA-RQ is a hardware dependent for the RQ determination, which encumbers this technic. Thus, we proposed to develop a simple and low cost methology which can be comercialy applied. Therefore, two experiments were conduced to test the apple storage under a DCA monitored by the anaerobic compensation point (DCA-ACP), where only the apple respiration is required to monitore the lowest oxygen limit (LOL) tolerated by the fruit. This storage condition was comared to DCA-RQ 1.3, DCA-CF, and to conventional CA (1.2 kPa O2 + 2.0 kPa CO2) with or without 1-methylcyclopropene (1-MCP) application. Also, the different carbon dioxide concentrations (0.4, 1.2, 1.6 and 2.0 kPa CO2) effect on DCA-ACP storage condition was evaluated. On the first experiment, DCA conditions were conduced with 1.2 kPa CO2, where compared to DCA-ACP was compared to conventional CA wit and without 1-MCP application, DCA-CF and DCA-RQ 1.3. On the second experiment, the effect of the CO2 concentration of 0.4, 1.2, 1.6, and 2.0 kPa on DCA-ACP storage were compared to conventional CA and DCA-CF (with 1.2 kPa CO2) on overall apple quality concervation. Apples of the ‘Maxi Gala’ apples were evaluated after 9 months of storage at 2.0 °C plus 7, 14, and 21 days of shelf life at 20 °C. At the first experiment, the conditions of DCA-CF, DCA-RQ 1.3, DCA-ACP and CA + 1-MCP maintained lower ethylene productions and higher healphy fruit after 14 days of shelf life. After 21 days, DCA-ACP and DCA-RQ 1.3 stored apple mainteined higher number of healphy fruit. After 7 days of shelf life, apples stored under CA maintained higher ‘Gala’ important aroma volatile compounds like 2methylbutyl acetate and hexyl acetate. The DCA-ACP maintained higher hexyl acetate concentration when compared to CA + 1-MCP, DCA-CF, and DCA-RQ 1.3, although lower than CA. DCA-ACP maintained higher (E)-2-hexenal concentration, and DCA-RQ 1.3 and DCA-ACP maintained higher 2-metyl butanal after 14 days of shelf life. On the second experiment, ‘Maxi Gala’ apple storage under DCA-ACP with 1.2 and 1.6 kPa CO2 resulted in higher flesh firmness maintenance, healphy fruit, and lower mealiness incidence after 14 and 21 days of shelf life when compared to CA, DCA-CF, and DCA-ACP with 0.4 and 2.0 kPa CO2. Apples stored under CA presented higher fruit senescence as a result of the higher mealiness incidence, as a responce to the higher respiration rate, internal ethylene concentration and higher ACC oxidase activity, besides lower healphy fruit maintenance.