Table olives and health: a review

Abstract

Table olives, a product of olive tree (Olea europaea L.), is an important fermented product of the Mediterranean Diet. Agronomical factors, particularly the cultivar, the ripening stage and the processing method employed are the main factors influencing the nutritional and non-nutritional composition of table olives and their organoleptic properties. The important nutritional value of this product is due to its richness in monounsaturated fat (MUFA), mainly oleic acid, fibre and vitamin E together with the presence of several phytochemicals. Among these, hydroxytyrosol (HT) is the major phenolic compound present in all types of table olives. There is a scarcity of in vitro, in vivo and human studies of table olives. This review focused comprehensively on the nutrients and bioactive compound content as well as the health benefits assigned to table olives. The possible health benefits associated with their consumption are thought to be primarily related to effects of MUFA on cardiovascular health, the antioxidant (AO) capacity of vitamin E and its role in protecting the body from oxidative damage and the anti-inflammatory and AO activities of HT. The influence of multiple factors on composition of the end product and the potential innovation in the production of table olives through the reduction of its final salt content was also discussed.

Keywords: ALS, amyotrophic lateral sclerosis; AO, antioxidant; Alpha-tocopherol; BP, blood pressure; CVD, cardiovascular disease; DM-II, Diabetes Mellitus 2; EFSA, European Food Safety Authority; FM, fat mass; GSH, glutathione; HDL-c, high-density lipoprotein cholesterol; HT, hydroxytyrosol; LDL-c, low-density lipoprotein cholesterol; MD, Mediterranean Diet; MUFA, monounsaturated fat; Mediterranean Diet; Monounsaturated fat; NO, nitric oxide; NaCl, sodium chloride; NaOH, sodium hydroxide; Nrf2, nuclear factor erythroid 2-related factor 2; OL, oleuropein; OO, olive oil; PKC, protein kinase C; PUFA, polyunsaturated fat; Phenolic compounds; RDA, Recommended Dietary Allowance; ROS, reactive oxygen species; TC, total cholesterol; TG, triacylglycerol; TG, triglyceride; Table olives; Ty, tyrosol; WHO, World Health Organization; cv, cultivar; e.p, edible portion; α-TOH, alpha-tocopherol.