oa Deciphering The Sources Of Population-wide Variation In The Date Fruit Metabolome

Dates are important dietary component in the Arab region. Dates production in Qatar is essential for the country's long term food security plan. In this project, we set to investigate the global sources of variation in the dates metabolome. To this end, fully ripened date samples from 138 different varieties were collected from 14 countries including Morocco, Algeria, Tunisia, Libya, Egypt, Sudan, Jordan, Saudi Arabia, UAE, Qatar, Pakistan, US, Iran and Iraq. In total, 402 different metabolites were measured using GC and LC platforms by two different collaborating centers and the resulting data subsequently analyzed using the multivariate analysis software kit Simca. The analysis revealed a global trend whereby certain dates varieties contained more amino acids and less carbohydrates, secondary metabolites, nucleotides and unsaturated fatty acids than other varieties. Integrating this dataset with another set of 30 samples from the same varieties but at the stage of pre and early-ripening revealed that the same metabolic signature underlies the differences between the varying stages of the fruit development process. In summary, at the population level, dates composition differs most according to the progression of the ripening process of the fruit. The local environment and the conditions of harvest and post harvest would directly affect the kinetics of the ripening and while some dates follow full natural ripening process, others might be artificially dried at the start of the ripening process owing to unfavourable weather conditions. Beside environment, genetic factors can also influence the ripening process as it was observed that the dry types of dates possess a metabolic profile similar to that of the soft types at the early phase of ripening. This is consistent with the fact that the dry types of dates typically go through a short ripening phase owing to their low moisture content. The metabolic differences between the soft and dry types of dates may have dietary implication for people with metabolic conditions such as diabetes.