Influence of Packaging on the Aroma Stability of Strawberry Syrup during Shelf Life

Abstract

Different types of packaging (glass bottle, PVC, and PET) were compared for the preservation of aroma quality of a strawberry syrup during shelf life. Esters, alcohols, and aldehydes were analyzed by solid-phase micro-extraction (SPME) and solvent extraction. During storage, hydrolysis of esters in acids and alcohols led to a modification of the aroma profile which can be explained by the replacement of "fruity" and "fresh" notes by "dairy note" in the syrup. Aroma compounds that are responsible for fruity notes, such as methyl cinnamate, methyl anthranilate, and methyl dihydrojasmonate, were strongly reduced after 90 days. This could be explained by a selective interaction of these compounds with the polymer matrix (PET or PVC). After 330 days, a later and important decrease of the "fruity notes" occurred in both PETs; so PVC2 and the glass bottle were found to be able to maintain a balanced aroma for long-term storage.

Sorption of aroma compounds in PET and PVC during the storage of a strawberry syrup

“…The decrease was more for short chain esters, and in particular for acetic acid esters and ethyl hexanoate ( Figure 1A) compared to more stable compounds ( Figure 1B). This reactivity is not related to the contact with polymer as it was previously found to occur during the storage of the syrup in a glass bottle (Ducruet et al, 2001). …”

“…By solvent extraction of the syrup or the packaging, these additives were extracted and co-eluted with the aroma compounds by GC. Thus, of the 38 aroma compounds previously identified in the syrup at the initial time of storage (Ducruet et al 2001), only 14 compounds can be quantified in both kinds of packaging and in the syrup over the 330-day storage period (Table 2).…”

“…In particular, lipids compete with polymers concerning the transfer of aroma compounds into polyolefins (Van Willige et al 2000a,b). Moreover, during long periods of storage of up to a year, changes in aroma composition were detected in the food matrix without any contact with the polymer (Ducruet et al 2001, Berlinet et al 2005. In this case it is important to understand how the reactivity of the aroma compound in the matrix can influence the absorption of the aroma compounds by the packaging material.…”

“…Although PET and PVC are known to be good barriers to oxygen, in comparison with polyolefins, PET (one of the most common packaging polymers) and PVC (which is not widely used to package flavoured drinks), have seldom been tested (Ducruet et al 2001 Berlinet et al 2005) for their barrier properties to aroma. The objective of the present study was to provide additional results on the sorption of aroma compounds in glassy polymers such as PET and PVC during long storage periods and to compare the kinetic sorption process with the degradation process, which also can reduce the amount of aroma.…”

Stability of volatile profile and sensory properties of passion fruit juice during storage in glass bottles

“…Chen et al (1982) (120 days). Ducruet et al (2001), studying the preservation of aroma quality of strawberry syrup during shelf life (225 days) in different types of packaging materials (glass, PVC, and PeT), observed that the decrease in the esters concentrations in glass bottles ranged from 40% -for ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, 3-methylbutyl 3-methylbutyrate -to 80% for ethyl butyrate, hexyl acetate, 3-(e)-hexenyl acetate and octyl acetate. The authors stated that the general decrease in ester concentrations could be explained by their hydrolysis and formation of the corresponding acids and alcohols.…”