Lab Test Would Define the Sensory Profile of Olive Oil by Analyzing Its Molecules

Researchers and olive oil pro­duc­ers in Italy are one step closer to com­plet­ing a new sci­en­tific pro­ce­dure for iden­ti­fy­ing the volatile com­pounds of extra vir­gin olive oil.

The goal is to add a lab­o­ra­tory analy­sis to the rou­tine tests done by extra vir­gin olive oil tast­ing pan­els to con­firm qual­ity and deter­mine organolep­tic char­ac­ter­is­tics.

The Italian Association of the Edible Oil Industry (Assitol) asked pro­duc­ers and lab­o­ra­to­ries across Italy to par­tic­i­pate in the last test­ing phase.

“We are talk­ing about a new ana­lytic sys­tem capa­ble of eval­u­at­ing the sen­so­r­ial pro­file of extra vir­gin olive oil,” Anna Cane, pres­i­dent of Assitol’s olive oil group, told Olive Oil Times.

According to cur­rent European Union reg­u­la­tions and International Olive Council stan­dards, eval­u­at­ing the qual­ity of extra vir­gin olive oil requires a panel test.

“It is a method based on human abil­i­ties, as it requires at least eight expert tasters who fol­low an estab­lished pro­ce­dure,” Cane said. ​“Their sen­so­r­ial organs con­sti­tute the equip­ment of the panel test analy­sis.”

“The new analy­sis tool is based on sci­en­tif­i­cally-sound tech­nol­ogy,” she added. ​“It allows us to extract the volatile com­pounds of extra vir­gin olive oil and iden­tify the spe­cific mol­e­cules, which come in hun­dreds.”

According to Assitol, the whole sec­tor would ben­e­fit from the new analy­sis pro­ce­dure once it is per­fected and trans­lated into a legal stan­dard. One of the advan­tages would be the abil­ity to ana­lyze a large num­ber of sam­ples from dif­fer­ent sup­pli­ers.

“The new method might allow a first screen­ing of the sam­ples to exclude those that do not fit the desired pro­files quickly,” Cane said. ​“It could greatly speed up the pro­ce­dures and sup­port the panel test oper­a­tions.”

Additionally, Assitol believes this approach would improve the infor­ma­tion given to con­sumers.

“Today, we have lim­ited options to include sen­so­r­ial indi­ca­tions on extra vir­gin olive oil labels,” Cane said. ​“We can only use ​‘fruity,’ ​‘bit­ter’ and ​‘piquant’ as they are those deter­mined by the sole legal ana­lytic sys­tem, the panel test.”

As many con­sumers are not yet aware of extra vir­gin olive oil organolep­tic qual­i­ties, most pro­duc­ers only use the attribute ​“fruity” on their labels, shun­ning ​“bit­ter” and ​“piquant,” or pun­gency.

“That means that extra vir­gin olive oils on sale are not suf­fi­ciently dif­fer­en­ti­ated,” Cane said. ​“In the future, we could have an ana­lytic tool capa­ble of detect­ing herba­ceous, arti­choke, almond or many other pos­i­tive attrib­utes.”

“That could even help develop a new reg­u­la­tion on extra vir­gin olive oil label­ing,” she added. ​“To dis­play sen­so­r­ial attrib­utes on the label, today, those attrib­utes must have been cer­ti­fied by an ana­lytic sys­tem defined by law.”

The new labels could also sup­port extra vir­gin olive oil sales through dif­fer­ent chan­nels, includ­ing food ser­vice. ​“Restaurants are the ambas­sadors of local qual­ity prod­ucts through­out the coun­try,” Cane said.

Many restau­rants in Italy fea­ture dif­fer­ent wines expertly paired with each meal. ​“Recently in Umbria, a maitre d’ spent 10 min­utes explain­ing to my friends and myself the beauty of a Riesling bot­tle of wine, so we ordered it,” Cane said. ​“When I asked him for some extra vir­gin olive oil, he just put a bot­tle on the table.”

“When we asked him to tell us some­thing about that extra vir­gin olive oil as he had done for the wine, he told us he did not know any­thing about it,” she added. ​“That is an exam­ple of how much we need to reach a new level of com­mu­ni­ca­tion for extra vir­gin olive oil.”

Assitol empha­sized how pro­duc­ers could also deploy the new sys­tem to eval­u­ate olive oil blends along­side the panel test.

“It could help eval­u­ate the pro­file of the blend a com­pany aims to bring onto the mar­ket and ver­ify that the prod­uct falls within the given stan­dard,” Cane said. “[It would be] a lab­o­ra­tory con­fir­ma­tion which comes on top of the panel test results.”

Cane also cited other poten­tial advan­tages of the new sys­tem, such as allow­ing a pro­ducer to ver­ify the sta­bil­ity of extra vir­gin olive oil over time.

“It could prob­a­bly also be used to char­ac­ter­ize monocul­ti­var extra vir­gin olive oil,” she said. ​“There are many oppor­tu­ni­ties related to this new method.”

Assitol ben­e­fited from a series of ear­lier aca­d­e­mic research when it started its task force focused on devel­op­ing the new method in 2018. However, only a few olive oil pro­duc­ers and experts par­tic­i­pated in the first test­ing phase.

“One of the most rel­e­vant chal­lenges has been iden­ti­fy­ing how a spe­cific mol­e­cule was related to the organolep­tic feed­back and which mol­e­cules cor­re­sponded to a pos­i­tive attribute or a neg­a­tive one, a defect,” Cane said.

As a result of the ongo­ing sci­en­tific research and the com­ple­tion of the first test­ing phase, Assitol is now ask­ing the whole indus­try to join in the devel­op­ment efforts.

The new test­ing phase is seen as cru­cial to com­plete the new approach. ​“In the new test­ing phase, we will be look­ing for a def­i­nite reli­a­bil­ity of the infor­ma­tion, a repro­ducibil­ity of the ana­lytic data and broad­en­ing the num­ber of involved lab­o­ra­to­ries,” Cane said.

For an ana­lytic sys­tem to be val­i­dated, it must com­ply with spe­cific repro­ducibil­ity require­ments.

“The new method must be con­sid­ered an addi­tion to what we already have, which is the panel test,” Cane said. ​“The panel test has been cru­cial in improv­ing the prod­ucts end­ing up on the shelves.”

“In indus­tries such as wine, cof­fee, tea or choco­late, this ana­lytic approach based on volatile com­pounds has been stud­ied and detailed more than in the olive oil sec­tor,” she added.

“That explains the rel­e­vance of this research, as it adds to the panel test, a legal con­trol method that other food sec­tors do not have at their dis­posal,” Cane con­tin­ued. ​“The new approach strength­ens the panel test’s work.”

According to Cane, most of the machin­ery needed for the new analy­sis method is likely already avail­able in many lab­o­ra­to­ries. ​“Besides the right equip­ment, though, you also need to have the trained tech­ni­cian oper­at­ing it,” she said.

The goals of the new method are sim­i­lar to the European Union’s Oleum project, which is also in its final stages of devel­op­ment.

“The ana­lytic sys­tem is very sim­i­lar to Oleum,” Cane con­firmed. ​“There is no com­pe­ti­tion to deter­mine which sys­tem is bet­ter. We all want the same result as soon as pos­si­ble; meth­ods required by the cur­rent needs of the olive oil mar­ket.”

“And that means quick and reli­able con­trol and ver­i­fy­ing sys­tems, with repro­ducible results world­wide, sus­tain­able and inex­pen­sive,” she con­cluded.