DIFFERENTIATION OF CHIA, FLAX AND SESAME: POLYPHENOL FINGERPRINTING BY HPLC-ESI-qTOF (MS).

BRIGANTE, F.; LUCINI MAS, A; PIGNI, N; BARONI M.V.; MARTINEZ, M.; WUNDERLIN D.A.

Parma

Congreso; FOODINTEGRITY 2017 CONFERENCE; 2017

Nowadays, there is awidespread preference for the consumption of foods that, in addition to itsnutritional properties, provide components that could reduce the risk ofcertain diseases, leading to the concept of "functional food". Chia, flax and sesameseeds are a great source of polyphenols and have greatly increased theirpopularity among consumers due to their beneficial properties like reducingcancer risk, diabetes and heart disease, among others. The antioxidant activity shown by these compounds is responsible of the mentioned properties. These seeds can be added to processed foods to increase their nutritional value. Food integrity is thestate of being whole, complete, undiminished or in perfect state in terms ofquantity and quality, and this quality means to reach specific standards insensory, microbiological and origin aspects of foodstuffs. There is a gap in theavailable scientific information to evaluate food attributes for complex foods.Many times it is difficult to assess the presence of a particular ingredient ofnutritional importance within a complex food. So far, when a food product canbe sold for a premium price because of its characteristics, it is of paramount importance that label claims and declarations on origin and identity can be certified. The aim of this work was to find polyphenols within each seed, which could be used as authenticity biomarkers in complex foods contaning these seeds. For this study we used defatted chia, flax and sesame flour obtained after oil extraction. Polyphenols were extracted by sonication of defatted flour with ethanol 50% andidentified and quantified by liquid chromatography coupled with time of flightmass spectrometry detection (HPLC-ESI-qTOF). The identification was done by MS spectra, UV-Vis spectra and exact mass comparison and quantification was performed by external calibration curves using structurally related compounds Nineteen polyphenols were found in the sesame flour, of which eleven were lignans (derivatives ofEnterolactone and Enterodiol), five phenolic acids (being these the majorityones); and only three flavonoids which were (-)-Epigallocatechin-3-gallate, Apigenin, Apigenin-6-C-glucoside. On the other hand, fourteencompounds were found in chia flour and all of them were phenolic acids beingthe majority derived from Caffeic acid (e.g. Salviaflaside and Rosmarinic acid). Finally, fifteen compounds were found in flax flour, six were phenolic acids (mainly Caffeic acid derivatives such as caffeoyl-fructosyl-glucosideand Rosmarinic acid hexoside), one was Quinic acid and eight were flavonoids derived from Quercetin mostly. There were ubiquitous compounds in the analyzed seeds such as Rosmarinicacid and Quinic acid. On the other hand, each seed showed distinctive compounds.In the case of sesame flour the lignans (e.g. Sesamolin, 7-Hydroxymatairesinol,Matairesinol-rhamnoside); in the case of the flax flour the flavonoids (Cyanidin-3-glucoside, Eriodictyol-7-glucoside, Gallocatechin, amongothers) and in the case of chia some phenolic acids like Caftaric acid,Fertaric acid, Salvianolic acids, Sagerinic acid and Danshensu. Therefore, these key polyphenols could be used to differentiate eachseed as well as markers of authenticity in complex foods. Further research isneeded to evaluate the stability of these proposed markers after food processing.