Effect of Packaging Design and Materials On the Aroma Profile of ‘Chester' Blackberries Under Retail Conditions

Aroma, a complex chemical pattern where compounds such as alcohols, esters, aldehydes, ketones, acids and others are involved, plays a key role in the appeal of fresh produces. Extrinsic factors such as packaging can significantly affect this quality parameter. In this study, the effects of four different packaging systems on the evolution of the aroma profile of ‘Chester’ blackberries during storage at low temperature are compared. ‘Chester’ blackberries were packaged in packages differing in design: open and enclosed, and in material: bio-based and petroleum-based, and then were stored at 3^oC for three weeks. The main aroma volatile compounds of ‘Chester’ blackberries were identified by gas chromatography-mass spectrometry (GC-MS) and solid-phase microextraction (SPME) fiber as ethanol, ethyl acetate, hexanal, trans-2-hexenal, 2-heptanone, ethyl hepanoate, 2-ethyl-1-hexanol, D-limonene, 1-hexanol, and nonanal. The quantitative analyses of these compounds during storage were performed by gas chromatography equipped with a flame ionization detector (GC-FID) and SPME fiber. In addition, oxygen and carbon dioxide permeabilities of the packages were measured using an 8100 Oxygen analyzer, and a Permatran ™ C 4/41 analyzer in order to determine the permselectivity of the different materials. The levels of most aroma compounds decreased during storage, with the most pronounced decreases observed for ethanol, hexanal, trans-2-hexenal, 1-hexanol, 2-heptanone, and ethyl hepanoate. This trend was not observed for ethanol and 2-heptanone in the open design package. In addition, this package consistently showed higher quantities of each volatile, which can be attributed to a higher moisture loss of the berries in the open system and therefore a higher concentration of the aroma compounds. Comparing fruit from packages of the same material but different design, revealed significant differences in volatile concentrations during the first week of storage, after which these differences became insignificant. Fruit from packages of different material but same design showed similar trends in volatile compound levels. This can be attributed to the same permselectivity calculated for the bio-based and petroleum-based material. No effect of design or material was observed on D-limonene, 2-ethyl-1-hexanol, and nonanal