Effect of CaCl₂ enrichment on fatty acid profile in Rocha pears^†

Human malnourishment is a current problem of society and agronomic biofortification is a procedure that wishes to tackle these mineral deficits in human diets by increasing a specific nutrient on the edible part of food crops. Calcium is an important mineral element that performs structural functions, and thus can help prevent the development of pathologies such as osteoporosis. Thereby, this work aims to study the impact of calcium enrichment on fatty acid content in Rocha pears. Thus, an agronomic enrichment workflow with seven foliar sprays of CaCl₂ (with concentrations between 4 - 8 kg/ha), was performed in an orchard located in the West region of Portugal. Besides Ca enrichment assessment in fruits (with a portable x-ray fluorescence analyzer) at harvest, fatty acids (FA) quantification and FA profile (acquired with a gas–liquid chromatograph, coupled to a flame ionization detector (GC-FID)), DBI and lipoperoxidation values (with a spectrophotometer) were also attained. Increases of Ca in sprayed fruits reached 7.6 % to 44.3 %. For FA related parameters, no significant differences were observed, suggesting that Ca sprays did not impact these parameters. Total fatty acids (TFA), double bond index (DBI) and lipoperoxidation values varied between 0.72 - 0.74 g/100 g FW, 8.13 - 9.83 and 2.23 - 3.18 µM /g FW respectively. The following FA profile was attained: C18:2 > C16:0 > C18:3 > C18:0 > C18:1 > <C16:0. No significant differences were observed. In summary, CaCl₂ can be used to increase Ca levels in fruits allowing the production of fruits with prophylactic characteristics, while the concentrations from this study did not impact their FA content. Overall, this suggests that cell compartmentation and membranes regular functioning were maintained, suggesting the absence of lipid decay, and avoiding a potential increase in storage losses.