Rediscovery of cold pressed cardamom (Elettaria cardamomum L.) oil: a good source of fat-soluble bioactives with functional and health-enhancing traits

Abstract

Cardamom (Elettaria cardamomum) fruits or capsules are rich in bioactive phytochemicals with beneficial health impacts. Very few studies reported the chemistry and functionality of Elettaria cardamomum lipids, fixed oil, and cold pressed cardamom oil (CPCO). This work characterized CPCO for its lipid classes, fatty acids, phytosterols, tocols, total phenolics, antiradical potential (toward galvinoxyl and DPPH· radicals), antioxidative effects, and antimicrobial behavior (against foodborne bacteria and dermatophytic fungi). Neutral lipids were detected at the highest amount (ca. 96.6%), followed by glycolipids (ca. 2%) and phospholipids (ca. 1.3%). Oleic (C18:1, 43.7%), palmitic (C16:0, 21.6%), and linoleic (C18:2, 17.6%) were the major fatty acids in CPCO. The levels of monounsaturated fatty acids (MUFA), saturated fatty acids (SFA), and polyunsaturated fatty acids (PUFA) were 47%, 32%, and 21%, respectively. CPCO contained large amounts of unsaponifiables (16.4 g/kg). The total content of phytosterols was 222 mg/100 g oil, wherein β-sitosterol was the main compound, followed by sitostanol, campesterol, stigmasterol, Δ5-avenasterol, and citrostadienol. The total content of tocols was 2.38 mg/100 g of oil, and the contents (mg/100 g oil) of α-, β-, γ-, and δ-tocopherols in CPCO were 1.25, 0.08, 0.58, and 0.28, respectively. Besides, CPCO contained high amounts of total phenolics (3.9 mg GAE/g oil). CPCO exhibited better antiradical traits than extra virgin olive oil. The induction time (IT) recorded for sunflower oil (SFO) and CPCO blend (9:1, v/v) was 405 min, while the IT for blend) 8:2, v/v) was 532 min. Besides, CPCO showed broad antimicrobial effects against foodborne pathogens (Salmonella enteritidis, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli) and dermatophytic fungi (Trichophyton mentagrophytes and Trichophyton rubrum). It could be concluded that CPCO is a good source of lipid-soluble bioactives, making it a unique raw material for novel food, cosmetic, and pharmaceutical products.