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Efficient bioconversion of oleuropein from olive leaf extract to antioxidant hydroxytyrosol by enzymatic hydrolysis and high‐temperature degradation
Author(s) -
Liu Min,
Yong Qiang,
Yu Shiyuan
Publication year - 2018
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1002/bab.1651
Subject(s) - hydroxytyrosol , bioconversion , oleuropein , cellulase , chemistry , hydrolysis , enzymatic hydrolysis , antioxidant , food science , organic chemistry , polyphenol , fermentation
Hydroxytyrosol (HT), a powerful antioxidant, clears free radicals and exhibits many biological activities. Because contents of HT are low in natural sources, bioconversion of oleuropein (OLE) to HT is of increasing interest. A biotechnological process was investigated to produce HT from OLE presented in olive leaf extract. Enzymatic hydrolysis using two cellulases with high β‐ glucosidase activity, Novozymes CTec2 and commercial cellulase KDN (Qingdao, People's Republic of China) was carried out at 50 °C for 12 H followed by raising the temperature to 90 °C for chemical hydrolysis. After 48 H of hydrolysis, an OLE degradation rate of 100% and a HT yield of 86–88% were achieved. These cellulases degrade OLE and release a glucose molecule. Chemical hydrolysis at a high temperature promotes the cleavage of ester bond and the formation of HT. This process has a promising alternative for production of HT comparing with acid hydrolysis which not only causes significant pollution to the environment but also makes difficult to the subsequent separation.