Thermal Properties of Monoglycerides from Nephelium Lappaceum L. Oil, as a Natural Source of Saturated and Monounsaturated Fatty Acids

Abstract

The present paper studied the transformations of reserve lipids (RLs) of the species Nephelium lappaceum Linn (N. Lappaceum). The triacylglycerols (TAGs) in this species are composed of C18:1, C20:0, and C20:1 fatty acids (FAs). The transition from native triglycerides to pure monoglycerides (MGs) was explored. It has been shown how the physical and physicochemical properties of MGs were influenced by the effect of the FA composition, consisting of saturated and unsaturated fatty acids. In organic process, the first step was lipase-catalyzed hydrolysis of native triglycerides. The second step was the chemically catalyzed esterification of hydrolyzed free fatty acids into MGs. Both steps were carried out in organized media used as microreactors. These transformations increased the melting temperatures from 22 °C to 51 °C and decreased the crystallization temperature from 22 °C to −1 °C, from long-chain TAGs to MGs (C20:0 and C20:1). By monitoring the saturated/unsaturated FA ratio in the lipotransformation into MGs, it was possible to control the composition of binary and ternary mixtures and, therefore, control the physical and physicochemical properties of the systems. This may be very useful for applications in the food, cosmetics, and pharmaceuticals industries.

Characterization of three varieties of Malaysian rambutan seed oil

“…Based on results, rambutan seed oils are completely liquid at normal ambient temperature because SFC at that temperature was 0%. These results are in good agreement with SFC results of rambutan seed fat found by Romain et al 29 .…”

“…These values are within the range of slip melting point (25.1°C to 51.3°C) and (24.8°C and 50.6°C) of various rambutan varieties that were reported by Kheiri and Mohd Som 28 and Chai et al 7 . Similar to the findings in this study, Romain et al 29 reported that the melting point of rambutan seed fat is 24°C. Sonwai and Ponprachanuvut 12 and Manaf et al 6 reported that rambutan seed fat has melting point of 39.2°C and 41.55°C, respectively.…”

“…This is because of high content of saturated fatty acids in TAG profile of Serjan. Romain et al 29 reported that the rambutan seed fat melted completely at below 30°C. However, studies by Manaf et al 6 and Sonwai and Ponprachanuvut 12 showed that the complete melting point of rambutan seed fat was 40°C and 41.55°C, respectively, while Chai et al 7 reported that the complete melting temperature of the 11 varieties of rambutan seed fat was between 24.8°C and 50.6°C.…”

Characteristics of fat, and saponin and tannin contents of 11 varieties of rambutan (Nephelium lappaceumL.) seed

“…The SFI of rambutan seed fat samples was determined according to the method described by Lee et al [10] and Romain et al [20] The amounts of solids in rambutan seed fats as a function of the temperature were derived from the heating thermogram of the respective fat sample. By using the PYRIS data processing software, the partial peak areas (%) of the melting peaks against temperature were calculated and correlated with solid percentages, considering that, at 0% of partial area, samples were 100% solids.…”

Characterization of insoluble material isolated from Colombian palm oil biodiesel

“…This may have been due to impurities that coeluted with the monopalmitin, such as monostearin [15]. When present, even at low concentrations, impurities displace DSC peak temperatures and impart complex features to melting and crystallization profiles that may not be easy to interpret, such as broad peaks and shoulders not separable from peaks [26]. Even so, the similitude in the DSC curve between F1Hz1 and the monopalmitin standard is evident, and therefore F1Hz1 was confirmed to be composed of monopalmitin.…”