The effects of soybean storage under controlled atmosphere at different temperatures on lipid oxidation and volatile compounds profile.

This study aimed to evaluate the effects of low oxygen partial pressure (pO2) and high carbon dioxide partial pressure (pCO2) combined with different temperatures on the oil acidity and peroxide values of two soybean cultivars (NA 5909 RG and FEPAGRO 37 RR). The volatile compounds correlated to lipid oxidation were also evaluated. Soybeans were stored for seven months under ambient and controlled atmosphere (CA) conditions at three temperatures (20, 25, and 30 °C). Storage under ambient conditions increased acidity and peroxide value regardless of the temperature. CA storage with low pO2 reduced oil acidity and its combination with high pCO2 had no positive effects on oil acidity and peroxide values. Grains of FEPAGRO 37 RR stored under ambient air showed higher 1-octne-3-ol amount compared to CA. The higher storage temperature increased (E)-2-heptenal and decanal amount in grains of cultivar NA 5909 RG. In addition, the ambiente air storage provide higher γ-Butyrolactone in relation to CA storage. Moreover, in both cultivars the CA storage technique provides lower (E)-2-hexenal content. This compound, together with hexanal are potential lipid deterioration markers of soybeans. CA storage is a promising tool for soybean grains preservation and the effect is mainly due to the oxygen reduction, with no additional effect of CO2 increasing.

Effect of dynamic controlled atmosphere monitored by respiratory quotient and 1-methylcyclopropene on the metabolism and quality of 'Galaxy' apple harvested at three maturity stages.

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.