Study of the Chemical Composition of Carica papaya L. Seed Oils of Various Geographic Origins

Abstract

The papaya plant (Carica papaya L.) is tree-like fruit plant cultivated throughout the tropics and subtropics. The aim of this study was to compare the physicochemical properties, fatty acid, sterols, and triterpenic alcohols composition of Carica papaya L. seed oils grown in a typical geographical location and Carica papaya L. seed oils grown in an untypical geographical location in greenhouse conditions (Saratov Region, Russia). The oils were extracted from the seeds of Carica papaya L. fruits collected in Kenya, the Dominican Republic, Angola, Ghana, and Brazil, as well as from the seeds of fruit plants grown in a similar environment (Russian Federation, Saratov). Parameters such as the oil yield, refractive index, peroxide value, iodine value, saponification value, and acid value of the extracted Carica papaya L. seed oils were determined. The qualitative and quantitative chemical compositions of the seed oils were determined by a combination of mass spectrometry and NMR spectroscopy. The profiles as well as the content of fatty acids, sterols, triterpenic alcohols, and benzyl isothiocyanate were established. The saponifiable fraction of the oils is mainly represented by triglycerides (98.7–99.4%), while di-(0.4–1.1%) and monoglycerides (0.1–0.3%) are also present but in smaller amounts. The content of sterols and triterpene alcohols was (537.5–918.2) mg/100 g of oil (0.54–0.92%), and up to 75% of the fraction was represented by β-sitosterol (55.9–66.7%) and its saturated analogue-sitostanol (11.0–15.7%). The physicochemical properties and the fatty acid, sterol, and triterpenic alcohol composition of seed oils from Carica papaya L. fruits, cultivated in Russia, is in the quantitative range of other samples, which suggests that Carica papaya L. can be grown in Russia for obtaining the seed oil.