Polyphenolic profile, processing impact, and bioaccessibility of apple fermented products

Abstract

Health-promoting foods have become increasingly popular due to intensified consumer interest and awareness of illnesses. There is a global market for apple fruits, which are affordable, nutritious, tasty, and produced in large quantities for direct consumption as well as food processing to make derived products. The food matrix of apples is suitable for fermentation, besides containing a high amount of phenolics and polyphenols. Fermentation of apples is one of the most common methods of preserving apple fruit and its byproducts. With different fermentation techniques, apple fruit can be used to make a wide range of products, such as fermented apple juice, cider, liqueurs, apple cider, apple vinegar and fermented apple solids, because it is not only a low-cost and simple method of processing the fruit, but it can also sometimes increase the bioavailability of nutrients and the levels of components that can improve health and sensory quality. To understand the health benefits of food products and how the fermentation process impacts polyphenols, it is also crucial to observe the effects of digestion on polyphenol bioaccessibility. Polyphenolic profile changes can be observed via both in vitro and in vivo digestion methods; however, in vitro digestion methods have the advantage of observing every step of gastrointestinal track effects and have less cost as well. In this review, the polyphenolic profile, processing impact, and bioaccessibility of apple-fermented products is assessed, with most available studies showing polyphenol profiles and bioaccessibility in apple varieties and fermented apple products.

Keywords:

• Apple
• fermentation
• apple fermented products
• polyphenols
• bioaccessibility

Acknowledgments

The authors are grateful to the Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The research leading to these results was supported by Warsaw University of Life Sciences Own Scholarship Fund (BWM/376/2022), by MICINN supporting the Ramón y Cajal grant for Jianbo Xiao (RYC-2020-030365-I) and M.A. Prieto (RYC-2017-22891) that supports the contract of P. Garcia-Oliveira; and by Xunta de Galicia for supporting the program EXCELENCIA-ED431F 2022/01 that supports the work of J. Echave. The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Bio Based Industries Consortium.