The soggy truth: paper straws fall short, but packaging can deceive consumers
New research finds bioplastic polylactic acid straws outperform paper in user tests, but their "biodegradable" label is misleading. Consumer preference, it turns out, is strongly influenced by the type of beverage lid
image: Bio-based alternatives to plastic drinking straws: are they more environmentally benign and consumer preferred?
Credit: Yinglin Liang, Jiazhou He & Min Zhuang
The Search for a Better Straw
As bans on single-use plastics expand globally, paper and bioplastic straws have become common replacements. Yet, consumer complaints about their performance are frequent. A new study by researchers at Guangdong University of Technology and China University of Petroleum-Beijing systematically compared the properties of paper, polylactic acid PLA, and traditional polypropylene PP plastic straws to understand their real-world performance and environmental impact. The findings reveal a complex picture where the best-performing alternative has its own environmental drawbacks, and consumer satisfaction is shaped by more than just the straw itself.
The Paper Problem: Absorption and Unpleasant Taste
The investigation confirmed what many consumers have experienced: paper straws struggle with liquids. The study showed that paper straws can absorb up to 30% of their weight in water after just 10 minutes of soaking. This high absorption is due to their porous, open-fiber structure. This not only causes the straw to soften and lose its integrity but also leads to ion leaching, which can impart an unpleasant taste to the beverage. Lead author Yinglin Liang and the team found that while these leached ions pose no health risk, they can negatively affect the drinking experience.
Bioplastics Perform Like Plastic
In contrast, PLA straws, made from plant-based materials like corn starch, demonstrated superior performance. Their compact, nonporous polymer surfaces prevented water absorption and ion leaching, performing much like traditional plastic straws in cold and room-temperature drinks. Physically, they were stiffer and more durable than paper straws. However, the researchers noted a significant weakness: PLA straws soften and lose their mechanical strength at temperatures above 55°C, making them unsuitable for hot beverages like coffee or tea.
The Biodegradability Question
A major selling point for PLA straws is their claim of being biodegradable. The research team tested this by burying paper, PLA, and PP plastic straws in natural soil for 30 days. While the paper straws showed clear signs of biodegradation, the PLA straws showed almost no change, with a mass loss of less than 0.3%. Their condition was nearly identical to the non-biodegradable PP plastic straws. The study explains that PLA requires high-temperature industrial composting facilities to break down, a condition rarely met in typical waste streams, meaning they often persist in the environment just like conventional plastics.
What Consumers Really Care About
To connect lab results with real-world use, the team conducted a survey with 68 participants. The results showed that the two factors most influencing a consumer's willingness to purchase a drink were the ease of inserting the straw into the lid and whether the straw fractured in the process. Surprisingly, factors like mouthfeel or the straw becoming soggy had an insignificant effect on purchase intent. A straw that can reliably pierce a sealed lid without breaking is what matters most to beverage buyers.
The Power of Packaging
The most unexpected finding related to beverage packaging. The consumer survey revealed that paper straws were liked almost as much as PLA straws when used with drinks that had open-ended lids. However, when the data was filtered for only fully sealed lids, the satisfaction score for paper straws dropped dramatically from 4.16 to 3.46 out of 5, while PLA straws maintained a high score of 4.70. This demonstrates that the choice of lid can mask the functional weaknesses of paper straws, effectively misleading consumers about their performance. According to corresponding author Jinxing Ma, this suggests merchants can improve customer experience by simply using packaging that is easier to pierce.
Corresponding Author:
Jinxing Ma
Original Source:
https://doi.org/10.1007/s44246-023-00062-4
Contributions:
Yinglin Liang: Investigation, Software, Writing, Original draft. Jiazhou He: Investigation, Methodology. Min Zhuang: Investigation, Methodology. Fayuan Chen: Conceptualization, Writing–review. Kui Yang: Supervision, Resourcing; Jinxing Ma: Conceptualization, Project administration. Supervision, Writing-review & editing.