Immobilized Naringinase as a Suitable Biocatalyst and an Environment-Friendly Approach for De-bittering of Citrus Juices: Recent Developments and Future Perspectives

Naringin is one of the important flavonoids that occurs naturally in citrus fruits and contributes bitterness to citrus fruit juices. Chemical methods can reduce the bitterness in citrus juices, but these methods have several drawbacks. Biologically, the naringin-mediated bitterness can be reduced by naringinase-mediated hydrolysis of naringin. The naringinase (E.C.3.2.1.40) is an enzyme complex that hydrolyses naringin and produces the tasteless product naringenin. The naringinase-mediated treatment of citrus juices is promising for the juice industry in dealing with the natural bitterness of citrus juices. The enzymatic treatment of citrus juices is an environment-friendly approach that fits with sustainable food processing. Enzyme immobilization increases the reusability of enzymes along with improved catalytic efficiency, stability, and reusability. Various immobilization supports have been investigated for naringinase immobilization. Results have supported the promising role of immobilized naringinase in the food industry for de-bittering citrus juice without affecting its health benefits. Also, the end product (naringenin) produced due to naringin hydrolysis has various health benefits. This review summarizes recent trends in the immobilization of naringinase for effective hydrolysis of naringin in citrus juices, which leads to de-bittering of citrus juice, including advanced nanomaterials. This first review article focuses on immobilized naringinase as a biocatalyst for potent industrial applications in de-bittering citrus juice. The advantages of naringinase over chemical methods and the health benefits of the end product have also been discussed.