Analysis of Monoglycerides, Diglycerides, Sterols, and Free Fatty Acids in Coconut (Cocos nucifera L.) Oil by ³¹P NMR Spectroscopy

Abstract

Phosphorus-31 nuclear magnetic resonance spectroscopy ( (31)P NMR) was used to differentiate virgin coconut oil (VCO) from refined, bleached, deodorized coconut oil (RCO). Monoglycerides (MGs), diglycerides (DGs), sterols, and free fatty acids (FFAs) in VCO and RCO were converted into dioxaphospholane derivatives and analyzed by (31)P NMR. On the average, 1-MG was found to be higher in VCO (0.027%) than RCO (0.019%). 2-MG was not detected in any of the samples down to a detection limit of 0.014%. On the average, total DGs were lower in VCO (1.55%) than RCO (4.10%). When plotted in terms of the ratio [1,2-DG/total DGs] versus total DGs, VCO and RCO samples grouped separately. Total sterols were higher in VCO (0.096%) compared with RCO (0.032%), and the FFA content was 8 times higher in VCO than RCO (0.127% vs 0.015%). FFA determination by (31)P NMR and titration gave comparable results. Principal components analysis shows that the 1,2-DG, 1,3-DG, and FFAs are the most important parameters for differentiating VCO from RCO.

Quality characteristics of virgin coconut oil: Comparisons with refined coconut oil

“…Also, VCO can be differentiated from RCO using the test for % volatile matter volatile at 120 °C, % FFA and peroxide value. In particular, RCO gives off much fewer volatiles and has lower % FFA and peroxide value when compared to VCO [7]. VCO contains low amounts of proteins, ranging from ND to 0.12 % (LOD = 0.01 %) while no proteins could be detected in RCO [8].…”

Larval Feeding Stimulants for a Rutaceae-Feeding Swallowtail Butterfly, Papilio xuthus L. in Citrus unshiu Leaves

“…1-Monoacylglycerols are known to coexist with triglycerides as minor components in plants (Dayrit et al, 2008). We have identified lipids 7 and 8 in leaves of another favorite larval host of P. xuthus, Zanthoxylum piperitum (Rutaceae), in a non-host Orixa japonica (Rutaceae), and in carrot Daucus carota (Apiaceae) in substantial quantities (unpublished data), suggesting that 1-monoacylglycerols may be present universally among larval host plants of several Papilio species.…”

Virgin Coconut Oil and Its Antimicrobial Properties against Pathogenic Microorganisms: A Review

“…The extraction process of VCO does not involve the use of thermal or chemical and also exposure to very high temperatures or UV treatments, making it more beneficial with all of the natural active components such as antioxidants, vitamins, and polyphenols are being retained [14,15]. On the other hand, RCO is produced by the extraction of the oil from dried coconut flesh, followed by chemical refinement, bleaching, and deodorization processes [16]. Due to the refining process, the RCO lacks the taste and fragrance of coconut while VCO, which never undergo any refining process, has a distinct coconut flavour and aroma compared to CO and [10].…”

“…The non-food application of coconut oil is acknowledged in the production of soaps, rubbers, elastomers, and also derivatives such as alkanolamides [8]. Generally, coconut oil is available in three major forms, which are refined coconut oil (RCO), copra oil (CO), and virgin coconut oil (VCO) [9,10].…”