`Soil May Have Most Impact on Certain Olive Oil Phytosterol Levels


Soil May Have Most Impact on Certain Olive Oil Phytosterol Levels

Jun. 9, 2014
By Louise Taylor

Recent News

Phy­tos­terols are plant com­pounds that resem­ble cho­les­terol. The high­est con­cen­tra­tions are found in veg­etable oils, beans and nuts. There are over 200 dif­fer­ent phy­tos­terols, includ­ing steryl glu­co­side and other sterol deriv­a­tives. Phy­tos­terol deriv­a­tives have been sci­en­tif­i­cally proven to lower plasma and LDL cho­les­terols by com­pet­ing with cho­les­terol for absorp­tion in the diges­tive tract.

The authors of a study recently pub­lished in the Jour­nal of Agri­cul­tural and Food Chem­istry com­pared dif­fer­ent olive cul­ti­vars, orchard loca­tions, farm­ing meth­ods and sam­pling times in a bid to deter­mine which ele­ments influ­ence steryl glu­co­side lev­els in olive oils. Ini­tial find­ings sug­gest that pedo­cli­mate – mean­ing soil water, nutri­ents, and aer­a­tion – could have the most sig­nif­i­cant impact on steryl glu­co­side con­cen­tra­tions.

Researchers at the Insti­tuto de la Grasa, CSIC (Insti­tute of Fats and Fat Deriv­a­tives of the Span­ish National Research Coun­cil) ana­lyzed vir­gin oils obtained from the Cor­ni­cabra, Man­zanilla Cacereña, Man­zanilla Castel­lana, and Picual olive vari­eties grown in eight dif­fer­ent orchards sit­u­ated around the out­skirts of Madrid near the Man­zanares River. The orchards were typ­i­cally planted with 300 trees per hectare and both tra­di­tional and organic farm­ing meth­ods were included in the study. Fruit was hand­picked and oil was extracted within 24 hours of har­vest­ing to ensure high qual­ity. An Aben­cor® ham­mer mill was used to crush the olives, with 700 g of oil paste processed per hour. Forty-four oil sam­ples were ana­lyzed.

Fruit vari­ety and farm­ing method proved less sig­nif­i­cant than char­ac­ter­is­tics of the soil – the pedo­cli­mate – on lev­els of steryl glu­co­sides. Another inter­est­ing find­ing was the pres­ence of a wider vari­ety of steryl glu­co­side deriv­a­tives in the olive oils than has pre­vi­ously been observed. The method­ol­ogy used in the study was effi­cient and cost-effec­tive, and thus could eas­ily be applied to the rou­tine test­ing of steryl glu­co­side lev­els in olive oils.

Because they pre­vent the absorp­tion of reg­u­lar dietary cho­les­terol while remain­ing not eas­ily absorbed them­selves, steryl glu­co­sides together with other phy­tos­terols induce lower total cho­les­terol lev­els, which in turn can reduce risk for heart dis­ease, stroke and heart attack. This study con­tributes to the moun­tain of evi­dence demon­strat­ing that olive oil, with its con­cen­tra­tions of essen­tial fatty acids and minor com­pounds includ­ing phy­tos­terols and antiox­i­dants, is a strate­gic food ele­ment for man­ag­ing and reduc­ing cho­les­terol lev­els and asso­ci­ated health risks, as well as many other ail­ments. /end/

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