Physicochemical Stability Enhancement of ?-carotene-rich O/W Nanoemulsions using a New Natural Emulsifier Developed from Pistacia lentiscus Fruit Residue

Abstract

A natural antioxidant-emulsifier was developed from oil pressed Pistacia lentiscus fruit and tested for oil-in-water nanoemulsions ?-carotene encapsulation. Five extracts were prepared, characterized and screened for their emulsifying capacity. The extract prepared with 75% ethanol (Ex-75%), displayed the highest antioxidant capacity (EC50 = 4.6 +- 0.2�mg/mL), which was significantly correlated with saponin and polyphenol contents (F = 22.30; P-value = 0.018). Under the same high-pressure homogenization conditions, Pistacia Ex-75% and the synthetic emulsifier (Tween-80) produced a comparable physically stable ?-carotene-rich nanoemulsions with d4,3 of 163.4 +- 2.5 and 158.4 +- 4�nm, respectively, and a similar monomodal size distribution following 90�days of storage at 25� C. However, Pistacia Ex-75% markedly improved the chemical stability of encapsulated ?-carotene during the storage period at both 5 and 25� C. These results suggest that Pistacia Ex-75% is effective as an antioxidant-emulsifier and could be used as a dual-purpose functional ingredient in emulsified products. 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.