Impact of incorporating olive leaves during the industrial extraction of cv. Arbequina oils on the physicochemical–sensory quality and health claim fulfillment

Abstract

The effect of olive leaves addition (1%, w/w, cvs. Arbequina or Santulhana), during the industrial extraction of Arbequina oils, on their physicochemical, color, phenolic profile, and sensory characteristics, was studied. Leaves' incorporation reduced the primary oxidation (peroxide value by 33% and K 232 by 17%) and increased the oxidative stability (19%), with the impact being more pronounced for Arbequina leaves. For these latter oils, leaves incorporation increased the total phenolic content (293 ± 9 mg GAE/kg), which became richer in secoiridoid derivatives (143.7 ± 3.0 mg/kg). Also, only Arbequina oils extracted with their own leaves supported the health claim regarding the protection of blood lipids against oxidative stress (hydroxytyrosol and tyrosol derivatives content greater than 5 mg per 20 g of olive oil). On the other hand, the incorporation of leaves from cvs. Arbequina and Santulhana during extraction enhanced the bitterness (55-59%) and decreased the pungency (25-33%). Santulhana leaves promoted an increase of the green-fruitiness (5.3 ± 0.5), while Arbequina leaves enhanced the oils' sweetness (7.0 ± 0.4). Moreover, a potentiometric laboratory-made electronic tongue was applied, as a taste sensor device, being capable of successfully discriminating Arbequina oils extracted without or with addition of leaves, allowing the identification of (un)deliberated leaves incorporation during oils' extraction. Lastly, it was found that the quality and composition of Arbequina oils industrially extracted were leaf cultivar dependent, with the low level of phenolics of control oils promoted by the incorporation of Arbequina leaves.

The potential of wild olive leaves (Olea europaea L. subsp. oleaster) addition as a functional additive in olive oil production: the effects on bioactive and nutraceutical compounds using LC–ESI–QTOF/MS

“…Accordingly, the extraction of bioactive compounds for the development of functional meals becomes a barrier, necessitating the identification of potent natural component sources to enhance the availability of healthier food choices. In this regard, one method to valorizing the enormous spectrum of bioresources is for the food industry to investigate innovations that disrupt the way we eat food [ 25 ], [ 33 ].…”

“…Various studies have recently proved the utility of natural antioxidants as oxidation inhibitors in edible oils [ 33 , 41 ]. Previous research has looked at enriching edible oils, such as olive oil, using olive leaf extracts to increase its organoleptic quality and oxidative stability.…”

“…Previous research has looked at enriching edible oils, such as olive oil, using olive leaf extracts to increase its organoleptic quality and oxidative stability. Also, Marx et al [ 33 ] signaled that olive leaves are rich in phenolic compounds and their extract has an antioxidant potential. Olive leaves are commonly considered as a byproduct with a lot of opportunity for value addition [ 1 , 33 ].…”

“…Also, Marx et al [ 33 ] signaled that olive leaves are rich in phenolic compounds and their extract has an antioxidant potential. Olive leaves are commonly considered as a byproduct with a lot of opportunity for value addition [ 1 , 33 ]. Phytochemicals from olive leaves can be recovered for valorization in food items, resulting in high added-value compounds [ 33 ].…”

“…Olive leaves are commonly considered as a byproduct with a lot of opportunity for value addition [ 1 , 33 ]. Phytochemicals from olive leaves can be recovered for valorization in food items, resulting in high added-value compounds [ 33 ].…”