Background

Rapid growth of global population leads to an increase in food demand and food processing. Enormous amounts of root vegetable side streams (RVSS) are generated annually. Despite being a rich source of nutrients and bioactive components, RVSS are used as animal feeds or disposed in landfills. A large number of studies have been carried out to explore the potential of food application and value-addition to RVSS. However, the literature and research findings are scattered. This review aims to systematically examine the data in the literature as the current state-of-the-art in order to support future research for valorizing RVSS.

Scope and approach

This paper carries out a comprehensive review of the scientific literature on valorization of RVSS in terms of processing technologies, high-value compounds, biological activities, and potential application in food, nutraceutical, and pharmaceutical products. The main challenges and development perspectives of utilizing RVSS are also discussed.

Key findings and conclusions

Fractions enriched with proteins, fibers and bioactive compounds can be obtained from RVSS by conventional and green extraction methods. Incorporating proteins from the leaves, and fibers from the peels and pomaces enhanced nutritional values and the functionality of food products. Phenolic compounds, carotenoids, and other bioactive compounds in RVSS presented high antioxidant, antimicrobial, hypoglycemic and anticancer activities, showing good potential in the application of nutraceuticals and pharmaceuticals. Future research should focus on in-depth understanding of RVSS composition and the bioaccessibility of the beneficial components. Safety assessment of the RVSS-derived ingredients/fraction should also be further explored.