Adding herbs and spices to vegetables made cafeteria diners more likely to choose them, and larger portions did not increase waste, offering a simple strategy to promote healthy eating habits.
Study: Spicing Up Vegetables: Consumer Attitudes and the Impact of Seasoning on Vegetable Consumption in a Cafeteria Setting. Image credit: Pixel-Shot.
Americans consume vegetables well below recommended amounts, spurring research on how to increase the acceptability of these foods. A recent paper published in the journal Nutrition Reviews suggests that adding seasoning to vegetables, coupled with larger servings, could increase vegetable consumption in commercial cafeterias.
Poor vegetable flavor perception limits healthy eating
Vegetables provide vitamins, dietary fiber, and a host of bioactive compounds that are essential to good health. A higher intake of fruits and vegetables is linked to lower rates of cancer, stroke, and cardiovascular disease. However, the national consumption of vegetables falls short of the recommended 2.5 cups per day for a 2000-calorie diet.
One major reason is the perception that vegetables lack sufficient flavor or appeal. Adding sugar, salt, or saturated fat to vegetables reduces their nutritional advantages, but spices and herbs could be used instead to season them. At least one study showed a nearly 20 % increase in vegetable consumption in an inner-city school cafeteria after this change was implemented.
Multiple studies explored seasoning and vegetable choices
The authors conducted their research in multiple linked studies. The first included focus groups, consumer surveys, and sensory testing, followed by three cafeteria-based experiments.
Focus groups
They conducted consumer focus groups to explore their attitudes and behaviors towards the use of vegetables, spices, and herbs, their preferences for these food components, and their plans to improve vegetable intake.
This showed that vegetable intake typically reflected flavor preferences and the family’s focus on healthy eating, which could be leveraged to increase the amount of vegetables eaten. People were interested in sampling flavored, versatile vegetable preparations that could offer teaching opportunities.
Consumer survey
The investigators then conducted a national consumer survey to collect quantitative data on current liking for spices and herbs, frequency of use, particularly in cooking vegetables, and whether they thought they could be used for this purpose. Participants were mostly White and were stratified by age group, income, education, and race.
The most popular spices and herbs were garlic, oregano, basil, and paprika, though this varied with community, age, income, location, and other background factors. This suggests that multiple factors interact to increase liking for vegetables through seasoning.
Approximately 86 % already use spices and herbs in home cooking of vegetables, with females being 60 % more likely to do so. Younger people used most of the 20 spices and seasonings in the survey. Notably, despite this, vegetable intake is generally subpar.
These findings suggest that interventions promoting herb and spice use may be particularly relevant among older adults, men, lower-income groups, and White participants.
Sensory experiments
Thirdly, the authors conducted sensory testing to compare liking for seasoned versus unseasoned vegetables. In a group of 749 participants, they compared the effects of seasoning on four types of vegetables: broccoli, cauliflower, carrots, and green beans.
Consistently, seasoned vegetables were preferred to unseasoned ones, indicating better sensory appeal. People had very different preferences for vegetables, whether they liked many vegetables or only specific types.
Cafeteria-based experiments
Finally, the researchers examined consumer behavior in a commercial cafeteria to test the conclusions from the previous phases of research.
In the initial phase, they conducted an observational cross-sectional study over three weeks (two testing weeks separated by one washout week) that offered carrots, green beans, and broccoli. The experiment consisted of offering all customers who bought a hot entrée a vegetable free of cost, seasoned or unseasoned. All customers knew they were participating in a study.
The vegetables offered varied by day of the week. On any given day, the seasoned and unseasoned versions of the vegetable had the same amounts of olive oil and salt. Seasoning blends were prepared by industry experts. Customers could not taste the vegetables before choosing between the seasoned and unseasoned options.
The authors compared current vegetable sales to previous purchase patterns for the same vegetable in the same cafeteria. At most, only 14 % of customers refused a free vegetable, and the seasoned version was chosen more often than the plain steamed counterpart. For instance, 67 % chose seasoned green beans and 22 % chose unseasoned green beans; 63 % chose seasoned broccoli and 31 % chose unseasoned broccoli.
The average waste from a 113.4g plate of vegetables was low overall, with waste generally remaining at 20 g or less, depending on preparation method. Seasoned broccoli produced the least waste at about 5 g per bowl, while seasoned carrots produced the most at about 20 g per bowl.
In a second study, the same vegetables in the same serving size were offered, but they had to be purchased separately at a modest cost ($1 per plate), similar to other vegetable side dishes sold there. Again, seasoned vegetables were purchased more often than unseasoned ones, except for carrots. Plate waste averaged about 6.5 g, irrespective of seasoning.
Next, participants were asked whether they would purchase a larger serving if it either cost the same or cost an additional $0.25. Most people (73 %) still said they would buy the larger size, though the chances differed by vegetable type. Liking did not differ between seasoned and unseasoned vegetables.
A third round of experiments examined whether larger serving sizes, combined with seasoning, could maintain consumer liking and encourage higher vegetable intake, using carrots, green beans, broccoli, and cauliflower. The serving size was 227 g, at $1 each. Again, seasoned vegetables were more likely to be bought, except for carrots. Liking responses were high overall, with no significant differences between the steamed and seasoned versions. The mean waste was as low as 5 g for steamed cauliflower and 30 g for seasoned carrots.
The researchers also noted a possible explanation for the high liking scores in the cafeteria studies despite the mixed differences between seasoned and unseasoned vegetables: participants may have rated the vegetables positively because they had selected those options themselves.
Seasoning and larger servings may raise vegetable intake
The authors conclude that increasing serving sizes and seasoning vegetables with spices and herbs could increase vegetable selection and intake in cafeteria settings. This twin strategy did not compromise customer satisfaction or create significant food waste. Future studies should examine even larger servings to identify the point at which further increases in consumption no longer occur.
Overall, the findings suggest that seasoning vegetables with herbs and spices alongside offering larger portions may be a viable strategy for increasing vegetable intake in commercial cafeteria settings.
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