Evaluation of a berry-based beverage for intervention studies

Abstract

With increasing age, it is common to experience decline in some cognitive abilities. To some degree, this is a natural cause of changes in structure and function in the brain. However, the cognitive decline can sometimes be extensive and develop into Alzheimer’s disease and other types of dementia that heavily impacts the life quality of the affected individual.
Various approaches to curb the development and progression of cognitive decline have been investigated. Managing diet is one of them. Research indicates that consumption of foods rich in antioxidants could have a positive effect of cognitive function. Different types of antioxidants are for example found in large amounts in many species of fruits, vegetables, and berries. Nordic berries such as lingonberries and bilberries are examples of berries that are hypothesized to have positive effects on cognition, and these are currently being investigated further.
Lingonberries and bilberries are rich in polyphenols and bilberries in particular contain high levels of anthocyanins. They also contain vitamin C. In this project, a Nordic berry-based beverage aimed to be used in clinical studies on cognition was characterized. Analysis using the Folin-Ciocalteu method showed that a fresh beverage contained around 4580 mg GAE/l phenolics. Analysis using the pH differential method indicated that the beverage contains 1390 mg/l anthocyanins when freshly made. Both these values decrease considerably when the beverage is stored, although they are better preserved the lower the storage temperature.
One hedonic and one analytical sensory test was performed with panelists recruited from Aventure AB to characterize sensory properties and acceptability of berry-beverages and compared to a reference drink. The analytical test assessed the perceived sweetness, acidity, intensity of berry flavour and aroma, viscosity and smoothness of the test beverage and the reference drink. The hedonic test evaluated the liking of the aroma, appearance, taste, berry flavour, texture, mouthfeel and overall liking. In this setting, there was no significantly stronger preference for one of the two drinks.
Furthermore, a comparison in blood glucose response between the two beverages was carried out by letting a test person wear a continuous blood glucose monitor for a week and drinking the two beverages on different days. No clear differences in trends regarding peak area could be identified between the beverages, but there seems to be a difference in the shape of the curves.
It is possible that Nordic berries also could have effects on mood. Hence, mood assessment was performed using questionnaires with different mood parameters that the subjects graded the intensity of in the given moment. The assessment was done once before and twice after drinking a beverage containing either berries or reference drink. No indications of effects on mood were found in this project.
For a successful study product, it is of great importance that it has an acceptable flavour and is possible to ingest in the intended amounts, that the concentration of bioactive compounds is high and preserved over time. The aim of this master thesis was to investigate if this is the case for this specific study product.

Popular Abstract

As a person gets older, not only the body changes, but also the brain. The changes in structure and function of the brain result in alterations in for example memory and processing speed. These changes are referred to as the cognitive decline. A minor cognitive decline that does not interfere with the quality of life is a normal part of aging. For example, it is normal that a child that plays memory with her grandmother will win easily. However, when the decline is so extreme that it heavily impacts the life of the affected individual, it can be a sign of dementia. Different types of dementia are common among elderly, but can also develop in younger individuals, and the effects of the disease are devastating both for the individual and the people close to the person.
One possible way of restricting or suppressing cognitive decline is diet management. Some foods have been suggested to improve cognitive functions. One of these are Nordic berries, in which lingonberries and bilberries are two examples. In this project, a beverage based on lingonberries and bilberries as well as a corresponding reference beverage was characterized with respect to health promoting components, sensory qualities, and effect on mood. The beverages are aimed to be used in both acute and chronic studies on cognitive function.
Different analyses showed that the beverage was very rich in phenolics and anthocyanins. The analyses were performed on both freshly made beverage and similar beverages that had been stored at different temperatures for two years. The results showed that all the concentration of the compounds that were previously mentioned decreased notably after storage. The decline was more profound the higher the storage temperature. It can therefore be concluded that the beverage should ideally be consumed fresh, and if it is necessary to store it for a longer period of time, it should be kept as cold as possible.
Results from sensory evaluations showed that the properties of the test drink and reference drink are perceived differently. The reference drink is perceived as sweeter, less acidic and more artificial. Despite this, the general preference was not significantly stronger for one of the beverages.
A mood assessment to evaluate if the test beverage had effects on the mood was carried out during the project. No differences in mood between people that consumed the berry-based drink and the reference drink could be identified. The mood assessment was done in parallel with a breakfast study aimed to evaluate the study design used in the clinical trials. The study showed that the majority of the subjects thought that the time that was given to finish the beverage and the breakfast consisting of two slices of white bread, butter, cheese, and cucumber were reasonable. Some participants thought it was difficult to finish the volume of the beverage that was served. The test drink for the reason that it was too acidic and filling, and the reference drink because it was too sweet.
Additionally, blood glucose was measured in a test person during a week to investigate if there was indications that the test drink and reference drink gave different responses in blood glucose. Such differences could be identified in the shape of the peaks, but not the peak area. However, since the measurements were only carried out on one test person, this should be further investigated in the future.

• author: Medin, Vilma
• supervisor: Juscelino Tovar
• organization: Food Technology and Nutrition (M.Sc.)
• course: KNLM05 20221
• year: 2022
• type: H2 - Master's Degree (Two Years)
• subject: Agriculture and Food Sciences
• keywords: Applied Nutrition and Food Chemistry, nordic berries, cognition, bioactive compounds
• language: English
• id: 9091570
• date added to LUP: 2022-07-01 13:30:50
• date last changed: 2022-07-01 13:30:50