Effect of storage under extremely low oxygen on the volatile composition of ‘Royal Gala’ apples

Abstract

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).

1-methylcyclopropene effects on volatile profile and quality of 'Royal Gala' apples produced in Southern Brazil and stored in controlled atmosphere

“…In order to make the samples and determine the volatile profile a methodology proposed by BOTH et al (2014), using solid phase microextraction (HS-SPME) in the headspace of samples. The volatile compounds were only evaluated in the samples after 8 months of storage and 7 days of shelf life at 20°C.…”

“…The fiber remained exposed during 10min, at 250ºC, in a splitless mode for 2 initial min. Volatile compounds were separated and quantified in a polar fused silica capillary column CP-WAX 52 CB (Chrompack, USA; 60m×0.25mm×0.25μm) according to BOTH et al (2014). In the same conditions of the sample analyses, a series of homologous n-alkanes was analyzed, to calculate the Kovats Index (KI).…”

“…Concentration of each volatile compound was determined according to the concentration of the internal standard 3-octanol. The qualitative analyses of volatile compounds were carried out according to BOTH et al (2014).…”

“…Apple aroma depends of complex interaction between amounts of organic compounds. These organic compounds are significantly affected by the cultivar, duration and storage method employed (BOTH et al, 2014), preharvest treatment (SALLAS et al, 2011) and 1-MCP application (KONDO et al, 2005). For apples of 'Gala' group, such as 'Royal Gala', the 2-methylbutyl acetate is the most important contributor to sensorial quality (YOUNG et al, 1996).…”

Biochemistry of apple aroma: A review

“…Aldehydes are abundant in pre-climacteric apples (19), but aft er ripening, the content of some aldehydes becomes almost imper ceptible (9,20). However, when volatile content is determined in homogenized tissue (juice), high concentrations of some aldehydes are found, mostly hexanal and hexenals (21,22). Under hypoxic conditions apples can also produce acetaldehyde (23), which can be reduced to ethanol.…”