IMPACT OF BEVERAGE COMPOSITION AND ALUMINUM CAN PACKAGING QUALITY ON BEVERAGE FAILURE
Aluminum cans potentially offer many benefits compared to glass packaging including convenience, lower environmental impact, and lower cost of shipping (EPA, 2022; Jacoby, 2019). In the context of a standard 750 mL bottle of wine, a corkscrew and glasses are needed for consumption and the wine needs to be consumed within a few days to avoid undesirable characteristics caused by oxidation. Glass bottles can be up to 60% of the total package weight of bottled wines, leading to higher shipping costs and emissions during transit to the beverage producer and to the consumer (Zhang, 2021). Aluminum is infinitely recyclable and is recycled at a greater frequency than glass and plastic in the United States (EPA, 2022). To ensure a long shelf-life within aluminum cans, a polymeric liner is applied to the inside of the can to prevent the beverage from reacting with the aluminum, and vice versa (Robertson, 2013). Other work has looked at the corrosivity of compounds with bare aluminum, or has examined the corrosion resistance of polymeric liners, but little work has been done on the variability of package quality on both off-aroma formation (H2S generation in canned wine) and aluminum can corrosion (Grandle & Taylor, 1996; Soares et al., 2019). Both off-aroma formation and can corrosion shorten the shelf-life of canned beverages that are growing in popularity, such as wine, hard cider, ready-to-drink (RTD) cocktails, kombuchas, and energy drinks. This thesis investigates the level of variability within different polymeric liner types and across different can manufacturers. The relative impact of the package quality on product shelf-life is contrasted with the impact of differences in concentration of corrosive beverage components. By addressing the technical challenges of preventing aluminum-beverage interactions, this work hopes to provide valuable implications for the beverage packing industry, sustainability initiatives, and consumer satisfaction. Chapter 2 investigates the amount of H2S off-aroma produced in canned wines when stored in the current “gold-standard,” BPA epoxy lined cans versus a new alternative BPA-NI epoxy liner that exhibits much lower endocrine activity. A BPA-NI epoxy liner was used from two different can manufacturers to elucidate the variability within can manufacturer. Three different beverage solutions were used, building off previous work to identify whether free SO2 or molecular SO2 leads to H2S formation. In Chapter 3, a BPA-NI epoxy liner is compared to acrylic liners from two different producers. Beverage solutions with varying concentrations of potentially corrosive compounds were utilized to determine what components lead to high levels of can corrosion, leading to product failure. Future directions for work on aluminum canned beverage failure are proposed in Chapter 4.