Project start: 01.01.2020
Project end: 30.06.2022
Sponsor: Forschungskreis der Ernährungsindustrie e.V.

A health-conscious diet containing beneficial plant compounds continues to be very popular with consumers. Fruit juices provide health-relevant ingredients such as vitamins, minerals and secondary plant substances. In addition to positive nutritional effects, certain bioactive plant substances (polyphenols) from fruits and juice (e.g. cranberry, apple, grape) have also shown caries-protective effects in previous studies (inhibition of caries bacteria, biofilm formation, pH drop, enzyme activity of amylase and glucosyltransferase). However, these effects have not been sufficiently demonstrated by in vivo studies, yet. Particularly human intervention studies are lacking. Since caries is still a widespread disease in all age groups and juice, due to its sugar content, poses a risk for the development of caries, a polyphenol-rich juice with caries-inhibiting effects would strengthen the healthy characteristics of juice. In addition, the results will provide a counterbalance to the sugar debate that is currently weighing on the fruit juice industry. In conventional juice production, the polyphenol concentration in the juice is relatively low because a large proportion of the polyphenols remain in the pomace or low-polyphenol raw materials are used. Production techniques that can be used to increase the natural polyphenol content in the juice and polyphenol-rich raw materials offer the possibility of developing juices with caries-inhibiting properties. Since juices with high polyphenol concentrations can lead to a bitter and astringent taste and usually also correlate with a high acid content, these factors must also be taken into account. The aim of the project is to produce a juice mixture using different polyphenolic fruits with different polyphenol profiles (apple, quince, speierling (Sorbus domestica)), which has both optimal caries inhibiting effects and good sensory properties.