Certain Food Proteins Reduce Bitterness and Pungency of EVOO

From Australia to Uruguay and California to Turkey, pro­duc­ers tell Olive Oil Times reporters that poten­tial cus­tomers are some­times put off by the bit­ter­ness and pun­gency of robust extra vir­gin olive oils.

These sen­sa­tions come from the polyphe­nols found in extra vir­gin olive oil, notably oleo­can­thal. Polyphenols are pow­er­ful antiox­i­dants and are respon­si­ble for many of the pro­duc­t’s health ben­e­fits.

Now, a team of researchers from the Monell Chemical Senses Center, where oleo­can­thal was first iden­ti­fied, have set out to study the rela­tion­ship between taste per­cep­tions and polyphe­nols more closely.

They dis­cov­ered that a food-derived pro­tein from egg yolks can reduce or elim­i­nate both the oral pun­gency detected in the throat and bit­ter sen­sa­tions of extra vir­gin olive oil when bound to the appro­pri­ate pro­tein. This, they argue, may widen the appeal of extra vir­gin olive oil to the unanointed.

As part of the study, extra vir­gin olive oil was placed into a may­on­naise-type mate­r­ial. Several hours later the oil-may­on­naise mix­ture was found to be less pun­gent and bit­ter. The researchers con­cluded that this elim­i­na­tion of bit­ter­ness and pun­gency occurs when pro­teins bind with oleo­can­thal and other phe­no­lic com­pounds.

“This demon­strates that phe­no­lic com­pounds and other reac­tive com­pounds often inter­act with pro­teins,” Catherine Peyrot des Gachons, a research asso­ciate at Monell, told Olive Oil Times.

“In pres­ence of cer­tain pro­teins, the pun­gent oleo­can­thal and the bit­ter-tast­ing phe­no­lic com­pounds could no longer acti­vate their respec­tive sen­sory recep­tors,” she added. ​“This means that the acti­va­tion of other phys­i­o­log­i­cal tar­gets might also be mod­i­fied, pos­i­tively (stronger acti­va­tion) or neg­a­tively (weaker acti­va­tion).

The researchers also found that the degree to which the pro­teins elim­i­nated the oral pun­gency detected in the throat and bit­ter­ness depended on the amount added. They argue that their find­ings will help pro­duc­ers bet­ter mar­ket their prod­ucts to con­sumers, rec­om­mend­ing that cer­tain extra vir­gin olive oils be used in cook­ing rather than fin­ish­ing, for exam­ple.

“The study shows the per­cep­tual char­ac­ter­is­tics of an extra vir­gin olive oil tasted in liq­uid form will evolve depend­ing on its culi­nary use, and pun­gency and bit­ter­ness might be sup­pressed,” Peyrot des Gachons said.

However, she stip­u­lated that bet­ter edu­ca­tion for con­sumers may also make the sen­sa­tions more palat­able. Learning that oral pun­gency detected in the throat and bit­ter­ness are directly asso­ci­ated with extra vir­gin olive oil’s health ben­e­fits may tip the scales for many con­sumers any­ways.

“What is fas­ci­nat­ing with a prod­uct like olive oil is the direct asso­ci­a­tion between the oil per­cep­tual prop­er­ties and its expected health-pro­mot­ing prop­er­ties,” Peyrot des Gachons said. ​“The com­pounds believed to be the most impor­tant for extra vir­gin olive oil health ben­e­fits are also those evok­ing bit­ter­ness and throat pun­gency.”

She added that the Monell Chemical Senses Center plans to con­tinue research­ing oleocanthal’s prop­er­ties and bet­ter under­stand­ing how it inter­acts with other food com­po­nents.

“We are par­tic­u­larly inter­ested in oleo­can­thal in our lab,” Peyrot des Gachons said. ​“We are now study­ing the nature of the inter­ac­tion of oleo­can­thal with dif­fer­ent pro­teins with the goal of under­stand­ing how it might impact the acti­va­tion of some of its phys­i­o­log­i­cal tar­gets.”

• Nature
• Phys.org