Healthy Cocktail Adds to Sensory Experience of Juice

30 Mar 2016 --- New research has found that adding a cocktail of lime, fiber and stevia to fruit juice can increase both its nutritional value as well as promote sensory experience.

The effect on the sensory experience of adding these three ingredients to juice was investigated. Results were published in the journal Food Research International. This trinity of ingredients means that it is possible to make a tasty fruit beverage that is both low in sugar and high in fiber.

"We used this particular drink to investigate a novel mixed product instead of a well known product which people know and have clear expectations towards in terms of the sensory experience," postdoc Line Holler Mielby from the Department of Food Science at Aarhus University told NutritionInsight.

Fruit juice contains a number of beneficial vitamins, but often has high sugar and low fiber contents. The challenge is to increase the nutritional value of the juice without spoiling the taste. The team of scientists devised a solution to the problem of combining sweetness with healthiness by adding stevia for sweetness and β-glucans for fiber with a dash of lime to adjust the taste.

Super sweetness joins fiber for health
A high intake of sugar is one of the factors contributing to obesity and lifestyle diseases, but cutting out sugar can be difficult. To satisfy the desire for something sweet while limiting our consumption of sugar, stevia – a natural sweetener – can be used.

Stevia is the only approved natural sweetener in Europe. From a health and technological viewpoint, the effects of using stevia have been purely positive, explains Mielby.

Unfortunately, however, a characteristic of stevia is its effect on taste. Therefore, juice containing stevia has a tendency to leave a bitter aftertaste.

Mielby explained further: "The reason for applying stevia is due to its potential as a natural sweetener compared to other sweeteners. Also, we were interested in masking the negative aftertaste of stevia. Other sweeteners may also have negative tastes/after tastes, but these are not the same as stevia."

Earlier research results have shown that fiber in food has a number of health-promoting effects. Fiber products that have a positive effect on health include β-glucans – which are naturally occurring in oats, for example. However, β-glucans also have an adverse effect on flavor as they give the food product a slightly metallic and stale smell.

The sensory experience is important
Foods should not only be healthy, but should also give the consumer a good sensory experience. Foods should have satisfying sensory characteristics, since these characteristics will determine whether the consumer will buy the product again. The product should leave a good all-round impression, explains Mielby.

Adding healthy fiber and low-calorie sweeteners to food will not work if they have a negative effect on the flavor. A remedy has to be found for this and in this instance the choice fell on lime. In the study the scientists used an apple-cherry juice to which varying quantities of lime, β-glucans and stevia were added. The aim was to characterize the sensory experience of the juice.

The results showed that the addition of lime to the apple-cherry juice could counterbalance the adverse impact on taste of the stevia and β-glucans. The taste of lime in the juice concealed not only the aftertaste of stevia but also the smell of staleness and metals imparted by the β-glucans and improved the experience of drinking fruit juice containing β-glucans.

Could other juices be used to gain the same effect? "We did not compare lemon juice and lime juice," Mielby told NutritionInsight. "However, lemon juice would definitely have an effect on the overall sensory experience." Whether this is similar or not has not been explored, as yet.

With the increasing popularity of functional food, it would be interesting to examine the effects in other food products such as breakfast cereals that have a high sugar and low fiber content. In relation to the addition of β-glucans to food it would also be relevant to examine other eating experiences, for example satiety, says Mielby.

by Kerina Tull