Development of an eco-sustainable biotechnological process for making low sugar fruit juices and puree

Because of industrialization and globalization of food systems, food processing has evolved substantially during the last half-century. Adverse impacts on nutritional dietary quality have appeared, such as greater levels of free sugars, energy density lower levels of protein and fiber, and high fat content (Chen et al., Nutrition J 2020). Excess sugar bingeing is dangerous for the human body, contributing to the epidemic of obesity and overweight (Witek et al., Nutrients 2022). Reduction of sugar in sugar-sweetened food chain remains a significant topic necessitating a sustainable, affordable and effective strategy for control. Recently microbe-driven processes appeared as a natural tool for the creation of novel 100% fruit-based products with a reduced sugar content, such as pure juices and natural fruit juices. Depending on the process selected, production of alcohol could be a possible drawback (Sahin et al., Food Res Int 2019). Therefore, fermentation can meet the requirements of sustainability and functionality, but in order to get desirable properties of fermented product it must necessarily be monitored and guided towards targeted properties through starters-assisted fermentation.

Within the framework of the general objectives mentioned above, high sugary fruit substrates will be selected to be exploited through fermentation by decreasing sugar content and preserving the nutritional, rheological and sensory features similar or improved compared to the fresh products. In parallel, lactic acid bacteria and yeasts will be screened for their high pro-technological performance (adaptation and acidification) also by phenomic approach and functional properties (reduction of fructose, glucose, sucrose and ethanol, release of antioxidants, bioactive peptides, hydroxy fatty acids, phenolic and other antimicrobial compounds). The effect of other bioprocessing treatments (e.g., use of food grade enzymes) on such functional properties will be investigated as well. This screening will help in establishing pre-treatments of fruit substrates suitable to optimize the microbial fermentation. Fermented fruits (e.g., juices and puree) will be evaluated in terms of nutritional (sugar content), rheological (viscosity and texture), sensory (aroma compounds), and functional (bioactive compounds, antioxidants and antimicrobial compounds) attributes. Finally, the shelf-life of these products will be assessed monitoring the spoilage microorganisms during the storage up to the spoilage thresholds using the more appropriate traditional culture dependent methods in relation to food physico-chemical characteristics.

This project will define a biotechnological protocol for the production of a low-sugar plant-based formulation with a high caloric content and which, at the same time, preserves the nutritional, rheological and sensory properties similar or improved compared to the fresh products. These fermented products will satisfy consumers and industrial needs for healthy diet, especially given the high risk of non-communicable diseases. The results of this project will confirm the power of fermentation in reducing sugars, extending shelf-life and enriching food formulation beneficial microbial metabolites. The most interesting results will be published in scientific journals.