Assessment of metabolic, mineral, and cytotoxic profile in pineapple leaves of different commercial varieties: A new eco-friendly and inexpensive source of bioactive compounds.

Pineapple is among the most produced and consumed fruits worldwide, and consequently, its agroindustrial production/processing generates high amounts of agricultural waste, which are routinely discarded. Thus, it is crucial to seek alternatives to reuse this agricultural waste that are in high availability. Therefore, this work aims to evaluate the chemical composition of a specific residue (leaves) of seven commercial varieties of pineapples, to attribute high added value uses, and to evaluate its potential as a source of secondary metabolites and minerals. Thereby, twenty-eight metabolites were annotated by UPLC-QTOF-MS, including amino acids, organic acids, and phenolic compounds. The following minerals were quantitatively assessed by ICP-OES: Zn (5.30-19.77 mg kg), Cr, Cd, Mn (50.80-113.98 mg kg), Cu (1.05-4.01 mg kg), P (1030.77-6163.63 mg kg) and Fe (9.06-70.17 mg kg). In addition, Cr and Cd (toxic materials) present concentration levels below the limit of quantification of the analytical method (LOQ and LOQ = 0.02 mg kg) for all samples. The multivariate analysis was conceived from the chemical profile, through the tools of PCA (principal component analysis) and HCA (hierarchical cluster analysis). The results show that pineapple leaves have similarities and differences concerning their chemical composition. In addition, the cytotoxicity assays of the extracts against tumor and non-tumor strains shows that the extracts were non-toxic. This fact can corroborate and enhance the prospection of new uses and applications of agroindustrial co-products from pineapple, enabling the evaluation and use in different types of industries, such as pharmacological, cosmetic, and food, in addition to the possibility of being a potential source of bioactive compounds.