Detection of adulterated olive oil using multimode-singlemode-multimode (MSM) fiber structure

Abstract

A multimode-singlemode-multimode (MSM) fiber sensor is proposed and demonstrated for the detection of olive oil adulteration. The MSM fiber structure-based sensor uses a section of singlemode fiber (SMF), acts as the sensing probe, sandwiched between two sections of multimode fibers (MMFs) which act as generator and collector, respectively. The method used for the experiment relies on the interference between core and cladding modes in the singlemode fiber (SMF). The interference, in turn, offers information of transmission spectrum dips shift differently with the changes of the environmental characteristics. Six types of olive oil samples were adulterated with different percentages of palm oil which varies from 1% to 6%. The adulterated oil is then dropped until the sensing probe is completely immersed. The sensor is capable of showing a response to the refractive index (RT) variation with a high sensitivity of 0.225 dBm/% and a resolution of 0.05%. The proposed system could lead to the realization of a food frauds and adulterations sensing technology for food industries.