New research shows why your glass bottle of orange juice is bad for the planet

A study from the University of Massachusetts Amherst refutes the widely held belief that glass is the most sustainable packaging for orange juice, showing that cartons are the best choice. Price influences consumers’ purchasing decisions more than sustainability claims, underscoring the importance of affordable, sustainable packaging. Reducing food waste is highlighted as a more effective sustainability measure than packaging choice.

The University of Mass Amherst survey aims to give the food industry a better understanding of consumer attitudes toward sustainable packaging and guide them toward more environmentally friendly options.

A new study has found that while consumers prefer glass due to its perceived sustainability, contrary to popular belief, cartons are actually the most energy-efficient and sustainable packaging option for single-serve orange juice.

Which type of packaging for a 12-ounce single container of orange juice would you choose as the most sustainable option:

1. Aluminium/cans made from recycled material;
2. Cardboard described as biodegradable/compostable;
3. Glass, 100% recyclable; or
4. Plastic that is described as biodegradable/compostable?

If you were one of the U.S. consumers surveyed by food scientists in a study conducted at the University of Massachusetts Amherst, you would prefer glass and believe it is the most sustainable choice. And you are all wrong.

“Glass was the most sought-after and most valued type of packaging,” says Nomzamo Dlamini, lead author of the article recently published in the journal sustainability. Dlamini, a PhD student in food science, recently visited South Africa as a Fulbright scholar from the University of Pretoria, studying in the UMass Amherst lab of Alissa Nolden, assistant professor of food science. “But it turns out that glass is actually one of the least sustainable packaging when you look at the entire life cycle,” Dlamini added.

Nomzamo Dlamini, a PhD student in food science, recently visited South Africa as a Fulbright scholar from the University of Pretoria and studied at UMass Amherst. Photo credit: UMass Amherst

Misconceptions and realities regarding packaging sustainability

When asked which types of packaging they consider to be the most to least sustainable, consumers overall answered: glass, cardboard, aluminum and plastic.

Although the sustainability of food packaging varies depending on the product and packaging type, the size and weight of the container, and other variables, in the case of single-serve orange juice, a carton would be the most sustainable, followed by plastic, then cans, and finally glass.

This even surprised Dlamini. “I was shocked when I read in the experts’ life cycle assessment that so much energy is needed to produce and recycle glass – much more than to produce or recycle plastic,” she says.

The study states: “The production and end-of-life impacts of plastic are lower than those of glass. Plastic is lighter and therefore requires less energy to transport. In addition, the aseptic sealing process of plastic containers using steam is less energy intensive than the autoclave system used for glass.”

Consumer decisions and impact on the industry

The study aimed to understand consumers’ motivations behind their packaging choices, taking into account price, lifestyle and other attitudes. The data can, in turn, help industry experts understand what consumers think, believe and prefer, and educate them on how to make more sustainable choices.

“We developed a questionnaire using a method called conjoint analysis, which mimics a real-world situation where you are presented with different options and you have to make a compromise,” says Dlamini. “And we try to understand what is important to people at the end of the day. The basic idea of ​​the study was to understand what people think and what influences their decisions.”

Nolden points out that although many consumers expressed an intention to purchase sustainable packaging, the most important motivating factor was ultimately price – particularly the lowest price – followed by packaging type and product and packaging promises.

The ideal orange juice alternative – selected from the 847 adult consumers who participated in the online survey – cost $1.10 per 12 fluid ounces, was packaged in glass, was produced locally and was labeled as 100 percent recyclable.

The message to the food industry is that consumers are motivated to choose sustainable packaging as long as the price is right. “These sustainable packaging options should be clearly labelled as such, effective (e.g. not defective or as durable as conventional packaging) and affordable to increase consumer motivation and their acceptance of sustainable packaging for food and beverages,” the paper says.

Ultimately, sustainable food consumption is about more than just choosing the optimal packaging.

“Although packaging choices contribute to overall environmental impacts, the most effective and practical way consumers can contribute to sustainability efforts is by reducing or avoiding food waste,” the paper concludes.

Reference: “Unpacking Consumer Preferences: Perceptions and Sustainability of Packaging Material for Orange Juice” by Nomzamo N. Dlamini, Emily J. Mayhew and Alissa A. Nolden, July 19, 2024, sustainability.
DOI: 10.3390/su16146202