Strategies to Broaden the Applications of Olive Biophenols Oleuropein and Hydroxytyrosol in Food Products

Abstract

Oleuropein (OLE) and hydroxytyrosol (HT) are olive-derived phenols recognised as health-promoting agents with antioxidant, anti-inflammatory, cardioprotective, antifungal, antimicrobial, and antitumor activities, providing a wide range of applications as functional food ingredients. HT is Generally Recognised as Safe (GRAS) by the European Food Safety Authority (EFSA) and the Food and Drug Administration (FDA), whereas OLE is included in EFSA daily consumptions recommendations, albeit there is no official GRAS status for its pure form. Their application in food, however, may be hindered by challenges such as degradation caused by processing conditions and undesired sensorial properties (e.g. the astringency of OLE). Among the strategies to overcome such setbacks, the encapsulation in delivery systems and the covalent and non-covalent complexation are highlighted in this review. Additionally, the synthesis of OLE and HT derivatives are studied to improve their applicability. All in all, more research needs however to be carried out to investigate the impact of these approaches on the sensory properties of the final food product and its percussions at the gastrointestinal level, as well as on bioactivity. At last limitations of these approaches at a scale of the food industry must also be considered.

Role of Hydroxytyrosol and Oleuropein in the Prevention of Aging and Related Disorders: Focus on Neurodegeneration, Skeletal Muscle Dysfunction and Gut Microbiota

“…Lipophilic derivatives [ 57 , 58 , 59 , 60 , 61 ] and novel compounds were synthetized without modifying the catecholic moiety to be tested in vitro and in vivo as antioxidant, anticancer, anti-inflammatory, and neuroprotective agents [ 62 , 63 , 64 , 65 ]. Emerging research is devoted to developing drug delivery systems based on liposomes [ 66 ] and nanotechnology [ 67 ] for a better bioavailability and improved biological activities of both HTyr and OLE [ 68 ].…”

Nanoscale Technologies in the Fight against COVID-19: From Innovative Nanomaterials to Computer-Aided Discovery of Potential Antiviral Plant-Derived Drugs

“…A small natural polyphenol which has antiviral activity is hydroxytyrosol [ 103 ], which can be captured in the hydrophobic cavity of -cyclodextrins [ 206 ]. The study evidenced that -cyclodextrin interacts with Spike and ACE2 proteins; moreover, hydroxytyrosol interacts with Spike and ACE2 proteins, even if -cyclodextrin results a better inhibitor than hydroxytyrol against ACE2 protein.…”

A comprehensive review on polarity, partitioning, and interactions of phenolic antioxidants at oil–water interface of food emulsions

“…The applications of hydroxytyrosol in emulsified systems may be hindered by challenges such as degradation caused by processing conditions. To overcome such shortcomings, the noncovalent and covalent complexations of hydroxytyrosol have been reported to play a significant role in its antioxidant properties (Monteiro et al, 2021). Pham et al (2019) prepared the hydroxytyrosolflaxseed protein isolate complexes as an emulsifier in oilin-water emulsions and found that the complexes showed an antioxidant activity of 80% inhibition against the formation of hydroperoxides at 20 • C, compared to the activity of 18% for the emulsions with flaxseed protein isolate alone.…”

“…The applications of hydroxytyrosol in emulsified systems may be hindered by challenges such as degradation caused by processing conditions. To overcome such shortcomings, the noncovalent and covalent complexations of hydroxytyrosol have been reported to play a significant role in its antioxidant properties (Monteiro et al., 2021). Pham et al.…”