Addition Of Limonene Research Articles

Identification of characteristic compounds of sweet orange oil and their sweetening effects on the sucrose solution with sweetness meter, sensory analysis, electronic tongue, and molecular dynamics simulation

The characteristic aroma compounds of five-fold sweet orange oil were analyzed using gas chromatography–mass spectrometry combined with the odor aroma value (OAV) method. The results indicated that limonene, linalool, dodecanol, (E,E)-2,4-decadienal, (E)-citral, linalool, (E)-2-decenal, and geraniol are important contributors. The sweetening effects of key compounds on sucrose solutions were experimentally investigated. The results showed that the sweetness effects of five compounds (limonene, citronellal, geraniol, β-sinensal and β-caryophyllene) were better than those of (E)-citral, linalool and octanal. Molecular dynamics implied that the hydrogen bonding residues of the T1R2/T1R3-sucrose system were converted from LYS65, GLU302, ASP278, and SER144 to ASP278, SER144, ASP142, and ASP213 after the addition of limonene. Meanwhile, the hydrophobic interaction forces of the system are significantly enhanced. The total energy of the T1R2/T1R3-sucrose system decreased from −32.08 kcal/mol to −63.57 kcal/mol. The synergistic sweetening mechanism of characteristic aroma compounds of sweet orange oil on sucrose was revealed.

The effects of limonene on the crystallization of palm oil

This study aimed to evaluate how the addition of limonene in different concentrations (1–10 g/100 g) influences the crystallization of palm oil (PO). An extensive study of the crystallization behavior of PO and its blends was performed using nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), polarized light microscopy (PLM), and X-ray diffraction. Adding limonene to PO reduced its solid fat content (SFC) and delayed crystallization, with a more pronounced effect at higher concentrations (7.5 and 10 g/100 g). The samples’ microstructure changed from spherulites in pure PO to agglomerated granular crystals at higher concentrations (7.5 and 10 g/100 g). Regarding polymorphism, the samples containing limonene showed a slight sign of acceleration over time, and after 60 days all samples, including PO, had predominance of the β form. It can be affirmed that reducing the SFC of PO substantially contributes to mitigating its post-hardening.

Preparation and Characterisation of Gellan Gum Hydrogel containing Curcumin and Limonene

Success in wound treatment requires careful assessment on the wound and suitable wound dressing. In this project a novel incorporation of both curcumin and limonene into gellan gum hydrogel have been done. This system is believed to have a better permeation of curcumin to the target area. The samples prepared are denoted as GGTF for gellan gum thin film, Cur-GGTF for curcumin gellan gum thin film. Samples of Cur-GGTF incorporated with limonene with three different concentrations of 0.0005 M, 0.0006 M and 0.0007 M are known as CurLim-GGTF05, CurLim-GGTF06 and CurLim-GGTF07, respectively. The hydrogels were crosslinked by calcium ion. From the FTIR analysis, all of the expected functional groups from the gellan gum, curcumin and limonene were found present in the hydrogel samples. The TGA-DTG analysis has proven that the incorporation of limonene into hydrogels has decreased the thermal stability of the hydrogels. The addition of limonene has caused a hike in the gel fractions of the hydrogels. The water vapour transmission rate (WVTR) and swelling test showed that the introductions of high concentrations of limonene into the hydrogels have hampered the absorption of water molecules thus causing the swelling degree to decrease.

Investigation of thermo-mechanical, chemical and degradative properties of PLA-limonene films reinforced with cellulose nanocrystals extracted from Phormium tenax leaves

Poly(lactic acid) (PLA) bio-nanocomposite films modified with limonene as plasticizer and reinforced with cellulose nanocrystals (CNC) extracted from agro-waste, such as Phormium tenax leaves, have been prepared by using a twin-screw microextruder and characterized.The extraction of cellulose was carried out by chemical treatment followed by sulphuric acid hydrolysis process. Binary and ternary films containing the plasticizer (20wt.%) and/or the CNC (1 and 3wt.%) were produced and characterized in terms of morphological, thermal, mechanical and wettability properties. The effect of CNC content and the combination with the specific plasticizer on the structural properties of PLA films were also investigated.The addition of limonene into the PLA matrix reduces, as expected, the glass transition temperature of the films, and affects the mechanical properties of the films, increasing the plastic response of PLA. Disintegration study was also carried out under simulated composting conditions in a laboratory-scale test at 58°C, 50% of humidity and in aerobic conditions, demonstrating that the presence of both plasticizer and CNC can alter the degradation rate of developed PLA-based formulations. The successful production of PLA biodegradable nanocomposites incorporating cellulosic material from agro-waste suggested the possible application of these new bio-nanocomposites for active food packaging.

Properties and Stability of Spray-Dried and Freeze-Dried Microcapsules Co-Encapsulated with Fish Oil, Phytosterol Esters, and Limonene

The objectives of this study were to investigate the properties and stability of microcapsules containing fish oil co-encapsulated with phytosterol ester and limonene, prepared by spray-drying and freeze-drying methods. Whey protein isolate and soluble corn fiber were used as wall materials in the encapsulation process. The properties of microcapsules, including structure, glass transition, volatile/non-volatiles retention, microencapsulation efficiency, oxidation stability, color measurement, and sensory profiles, were evaluated after drying and during a seven-day accelerated storage trial. The finding reveals that drying methods have an effect on the retention of volatile fraction and the physical structure of the wall matrix consisted of WPI and SCF, consequently influencing the storage stability of the powders. Significantly higher retention of volatile fraction (p < 0.05) and lower surface oil were found in the spray-dried samples, resulting in the higher microencapsulation efficiency. However, samples dehydrated by both methods have good redispersion properties, showing no statistical significance (p > 0.05). The oxidation of the encapsulated oils was comparable for both spray- and freeze-dried samples during the seven-day accelerated storage trial but the loss of limonene flavor was significantly higher in the freeze-dried samples (p < 0.05). Sensory evaluation indicated that the addition of limonene could mask the unpleasant fishy odor in the co-encapsulated microcapsules. Overall, freeze drying did not produce powders with superior properties and did not show better protection towards the core materials than spray drying.

Linalool Dehydratase-Isomerase, a Bifunctional Enzyme in the Anaerobic Degradation of Monoterpenes

Castellaniella (ex Alcaligenes) defragrans strain 65Phen mineralizes monoterpenes in the absence of oxygen. Soluble cell extracts anaerobically catalyzed the isomerization of geraniol to linalool and the dehydration of linalool to myrcene. The linalool dehydratase was present in cells grown on monoterpenes, but not if grown on acetate. We purified the novel enzyme ∼1800-fold to complete homogeneity. The native enzyme had a molecular mass of 160 kDa. Denaturing gel electrophoresis revealed one single protein band with a molecular mass of 40 kDa, which indicated a homotetramer as native conformation. The aerobically purified enzyme was anaerobically activated in the presence of 2 mm DTT. The linalool dehydratase catalyzed in vitro two reactions in both directions depending on the thermodynamic driving forces: a water secession from the tertiary alcohol linalool to the corresponding acyclic monoterpene myrcene and an isomerization of the primary allylalcohol geraniol in its stereoisomer linalool. The specific activities (V(max)) were 140 nanokatals mg(-1) for the linalool dehydratase and 410 nanokatals mg(-1) for the geraniol isomerase, with apparent K(m) values of 750 μm and 500 μm, respectively. The corresponding open reading frame was identified and revealed a precursor protein with a signal peptide for a periplasmatic location. The amino acid sequence did not affiliate with any described enzymes. We suggest naming the enzyme linalool dehydratase-isomerase according to its bifunctionality and placing it as a member of a new protein family within the hydrolyases (EC 4.2.1.X).

Impact of Limonene on the Physical Properties of Reduced Fat Chocolate

AbstractThe addition of limonene, a low molecular weight hydrophobic compound, to chocolate was reported to decrease the hardness and the viscosity of chocolate, facilitating the production and improving the eating quality of reduced fat chocolate. The objective of this study is to understand the functionality of limonene in decreasing the viscosity and the hardness of chocolate, a fat (cocoa butter)‐based particulate suspension. This study shows that chocolate hardness was decreased because limonene mixes with cocoa butter, affects its crystallization pattern and decreases its solid fat content. After checking that limonene does not significantly affect the continuous phase volume fraction, we show that limonene decreases chocolate viscosity by decreasing the viscosity of the continuous phase, cocoa butter. The addition of low quantities of limonene in cocoa butter leads to a great decrease in the liquid fat viscosity. The dependence of the viscosity on the ratio of cocoa butter to limonene analyzed using Kay’s equation seems to indicate that limonene mixes with and within the cocoa butter triglycerides, diluting the fat and leading to a decrease in the overall fat viscosity.

角質細胞間脂質リポソームの融合に及ぼすＣａ｀２＋´イオンおよびＬｉｍｏｎｅｎｅの影響

The effects of the addition of Ca2+ ion and/or limonene on the fusion of stratum corneum lipid liposomes (SCLL) were investigated. SCLL were prepared with ceramide, palmitic acid, cholesterol and cholesterolsulfate. The fusion of SCLL was estimated by using of fluorescent probes in terms of the fusion of the membrane and the mixing of the inner phase of liposomes. The Ca2+ ion, which was often used to induce the fusion of liposomes, induced the fusion of SCLL dependently on its concentration. Furthermore, the addition of limonene to SCLL before the addition of Ca2+ ion promoted the fusion of SCLL, while the addition of tricaprylin or liquid paraffin gave no effect on the fusion of SCLL. In order to elucidate the factors which bring about the promotion of the fusion, microfluidity of the liposome membrane and the zeta potential of the liposome were studied. Both the increasing microfluidity near the hydrophilic moiety of the liposome membrane by the addition of limonene and the decreasing of surface charge of the liposome by the addition of limonene and Ca2+ ion were considered to contribute to the promotion of the fusion of SCLL.