Rapid de-carbonation in canned carbonated soft drink beverages

Abstract

Carbonated beverages are engineered to contain a defined quantity range of CO2 dissolved into the product to optimize consumer preference. Carbonation level is an integral component of carbonated soft drink beverages that significantly contributes to positive sensory attributes of sodas; the mouthfeel and taste that the consumer expects. Rapid de-carbonation is a phenomenon in which the carbonation level of a canned carbonated soft drink beverage rapidly decreases to unacceptable levels, determined by consumer best taste limits, in less than 10 minutes of opening the can. Rapid de-carbonation leads to a range of negative experiences for the consumer. This phenomenon is classified into three types of rapid de-carbonation: gushing, foaming, and active. The objective of this thesis is to investigate factors that contribute to rapid de-carbonation through exploring the interactions between internal can coating morphology, beverage chemistry, and physical characteristics contributed by filling and processing conditions. Each of these factors has been studied separately in the past by the beverage, can, and coating industry. The factors were studied simultaneously to evaluate the effect on the rapid de-carbonation phenomena as well as the interaction between each factor. Specific levels, or conditions, of each factor were identified as a stress factor: high initial carbonation level, high water mineral content level, and a specific coating morphology. The results show that while each separate factor increased the rate of de-carbonation; however, when the stress factors were combined the effect was not only additive but synergistic. The carbonation loss increased by more than 1.5x when compared to a system that had lowest amount of engineered stress factors. Physical and chemical interactions between the beverage and coatings that were previously regarded as inert were observed. After the cans were filled, there were morphological changes in the can coating and deposits high in nitrogen were detected. These deposits were found to be more pervasive on the epoxy-based coatings versus the acrylic-based coatings. These findings can help the can and beverage industry better understand the interactions between beverage and packaging and how these interactions play a role in the widely elusive rapid de-carbonation phenomenon.