Contribución a la implantación de una denominación de origen del aceite de oliva de Meknes (Marruecos): Estudio de la tipicidad del aceite de oliva de Meknes

This work was aimed at making a contribution to the study of Meknes Olive oil typicality in order to indentify it by a Protected Designation of Origin. Thus, the study has focused on 96 Moroccan Picholine olive oil samples coming from three areas of Meknes territory (Meknes Land, My Idriss Zerhoun and El Hajeb). The analytical determinations performed have been the evaluation of physico-chemical analyses (Acidity, Peroxides Index, K232 and K270), the chemical composition (total fatty acids content and pigments content) and the oxidative stability parameters (polyphenols content, tocopherols content and oxidative stability). Observed results reflect that there was no sample with chemical parameters out of the international established limits for Extra Virgin Olive Oils. Furthermore, average values were clearly lower than mentioned limits. Concerning the fatty acid composition, a media level of palmitic acid, a high level of oleic acid and a media level of linolein acid were noticed. Accrding to pigment content, the average concentrations of chlorophyll and carotenoid fraction in Meknes olive oil were 10.8 mg/kg and 8.5 mg/kg, respectively. As regards the stability parameters, results allow emphasizing a high content of total polyphenols, a media content of total tocopherol and a high oxidative stability. However, all of these parameters were analysed by one-way Anova technique in order to study their variation between the three areas of Meknes territory. The results demonstrate that at a level of confidence of 95 per cent no statistically significant difference was observed between olive oil samples of the three areas of Meknes territory regarding the physico-chemical analyses, the chemical composition and the oxidative stability parameters. Moreover, to compare Meknes olive oil commercialized with the results obtained, 12 olive oil samples, of the same mills of the sampling, have been taken and analysed. However, in addition to the chemical composition and the oxidative stability parameters, a sensorial analysis has been realised. The results show that the commercialized olive oils enter the rank of quality, composition and stability previously established for Meknes olive oil. From the organoleptic point of view, the samples have been classified within the Extra Virgin category since the median of the defects has been equal to 0 and the median of the fruity attribute has been greater than 5, emphasizing two categories: fruity intense and fruity media.