Conducted by researchers at the Monell Center, a non-profit independent scientific research institute in Philadelphia, the study (published in the journal of Physiology & Behavior) examined 393,568 unique food reviews of 67,553 products posted by 256,043 Amazon customers over a 10-year period using data posted on an open-source data science site.
Researchers analyzed words related to taste, texture, odor, spiciness, cost, health, and customer service, and then computed the number of reviews that mentioned each of these categories. Taste was mentioned in over 30% of consumer food reviews pointing to the importance sensory experience plays in food purchases.
"Sweet was the most frequently mentioned taste quality and the reviewers definitively told us that human food is over-sweetened," said lead author of the study Danielle Reed, PhD, a behavioral geneticist at the Monell Center. "This is the first study of this scale to study food choice beyond the artificial constraints of the laboratory,"
Scientists found that sweet taste was mentioned in 11% of product reviews, almost three times more often than bitter. Saltiness was rarely mentioned, a somewhat surprising finding in light of public health concerns about excess salt consumption, noted researchers.
Narrowing it down, the study found that over-sweetness was mentioned in almost 1% of Amazon food products reviews, regardless of category, using the phrase 'too sweet'. When looking at reviews that referred to sweet taste, the researchers found that over-sweetness was mentioned 25 times more than under-sweetness.
Products getting less sweet and growing consumer acceptance
In line with the study's analysis of nearly 400,000 Amazon food product reviews is the larger industry trend of consumers reducing their sugar intake and showing a preference for less sweet products. According to IFIC's annual food and health survey, two-thirds of American consumers said that they are either limiting or avoiding sugar entirely in their diet. While the push to reduce sugar intake is largely driven by health concerns, consumers' palates are evolving to prefer the taste of less sweet products.
In Mattson's 10 Macro Trends Driving Food & Beverage Innovation in 2019 report, the innovation consultancy said: "It’s inevitable that our collective tongues will be awash in less sweet stuff in the near and distant future. This means that our palates will adjust to start liking things that are less sweet. Getting 'less sweet' right is about creating a new type of deliciousness that appeals to both adults and kids."
Further analysis
Researchers also looked at responses to the 10 products that received the widest range of ratings, as defined by the variability in the number of stars the product received to better understand consumer responses and sensory perceptions of various food products. Scientists found that
"Genetic differences in taste or olfactory receptor sensitivity may help account for the extreme reactions that some products get," said Dr Reed.
Product reformulation, differing perceptions of the sweetness profile, and a product's smell all contributed to differences in opinion on a particular product.
"Looking at the responses to polarizing foods could be a way to increase understanding of the biology of personal differences in food choice," added Dr Reed.
How big data can advance sensory science
"Reading and synthesizing almost 400,000 reviews would essentially be impossible for a human team, but recent developments in machine learning gave us the ability to understand both which words are present and also their underlying semantic meaning," said study coauthor Joel Mainland, PhD, an olfactory neurobiologist at the Monell Center.
Researchers added that this study's findings demonstrate how big data can advance the emerging field of sensory nutrition -- a field that integrates sensory science with nutrition to improve human health -- as similar mehtods can help inform approaches to personalized nutrition matching healthy products with an individual's personal sensory preferences.