Analysis of Total SO2 Loss in Bag-in-Box Wine Packaging During 9-Month Storage

Analysis of Total SO2

An analysis of total SO2 was conducted at both the beginning and end of the experiment to assess the impact of storage on the SO2 concentration in the wine. The results, shown in Table 4, represent the findings after a 9-month storage period.

Results and Discussion

The data indicate only minor differences in total SO2 levels between the various bag types, with one exception: bag F, where the total SO2 concentration was consistently 20-30 mg/L lower than in the other bags. Wine from bag F also exhibited lower levels of free SO2, although the differences in free SO2 between bags from other groups were minimal.

The observed loss of total SO2 in the wine can be attributed to two main factors: oxidation and a slight release of bound SO2 into its free form. The results demonstrate an overall loss of total SO2 ranging from 30-40 mg/L over the 9-month period, which averages out to a loss of approximately 3-4.5 mg/L per month.

Comparison with Previous Studies

This rate of SO2 loss is consistent with previous research. Studies by Bach and Hess indicated similar findings, where the monthly loss of total SO2 in wines stored in Bag-in-Box (BIB) packaging from Zewathener and Sieger was 4.3 mg/L and 3.4 mg/L, respectively. The results in this study, therefore, align with those observed in earlier investigations of total SO2 loss in bagged wines.

Conclusion

In summary, the loss of total SO2 during a 9-month storage period was generally consistent across different BIB packaging types, with the exception of bag F. The average loss of total SO2 in the study was similar to the findings of prior studies, confirming that oxidation and the release of bound SO2 are key contributors to the decrease in total SO2 levels in stored wines.