Obesity, which results from an imbalance between energy intake and energy expenditure, has become a major health risk factor worldwide, causing numerous and various diseases such as diabetes, hypertension, and cardiovascular diseases. Fucoxanthin, a specific carotenoid in brown algae, has garnered much attention for its anti-obesity and anti-diabetic effects attributable to a unique mechanism. Fucoxanthin induces uncoupling protein 1 (UCP1) expression in white adipose tissue (WAT). That inner membrane mitochondrial protein, UCP1, can dissipate energy through oxidation of fatty acids and heat production. Furthermore, fucoxanthin improves insulin resistance and ameliorates blood glucose levels through down-regulation of adipocytokines related to insulin resistance in WAT and up-regulation of glucose transporter 4 (GLUT4) in skeletal muscle. Algae fucoxanthin is a beneficial compound for the prevention of the metabolic syndrome.
Mannosylerythritol lipids (MELs) are a glycolipid class of biosurfactants produced by a variety yeast and fungal strains that exhibit excellent interfacial and biochemical properties. MEL-producing fungi were identified using an efficient screening method for the glycolipid production and taxonomical classification on the basis of ribosomal RNA sequences. MEL production is limited primarily to the genus Pseudozyma, with significant variability among the MEL structures produced by each species. Outside of Pseudozyma, one recently isolated strain, Ustilago scitaminea, has been shown to exhibit abundant MEL-B production from sugarcane juice. Structural analyses of these compounds suggest a role for MELs in numerous cosmetic applications. MELs act as effective topical moisturizers and can repair damaged hair. Furthermore, these compounds have been shown to exhibit both protective and healing activities, to activate fibroblasts and papilla cells, and to act as natural antioxidants. In this review, we provide a brief summary of MEL research over the past few decades, focusing on the identification of MEL-producing fungi, the structural characterization of MELs, the use of alternative compounds as a primary carbon source, and the use of these compounds in cosmetic applications.
Trimethylolpropane triesters are biodegradable synthetic lubricant base oil alternative to mineral oils, polyalphaolefins and diesters. These oils can be produced from trimethylolpropane (TMP) and fatty acid methyl esters via chemical or enzymatic catalyzed synthesis methods. In the present study, a commercial palm oil derived winter grade biodiesel (ME18) was evaluated as a viable and sustainable methyl ester source for the synthesis of high oleic trimethylolpropane triesters (HO-TMPTE). ME18 has fatty acid profile containing 86.8% oleic acid, 8.7% linoleic acid with the remaining minor concentration of palmitic acid, stearic acid and linolenic acid. It’s high oleic property makes it superior to produce synthetic lubricant base oil that fulfills both the good low temperature property as well as good oxidative stability. The synthetic base oil produced had a viscosity of 44.3 mm2/s at 40°C meeting the needs for ISO 46 oils. It also exhibited an excellent viscosity index of 219 that is higher than some other commercial brands of trimethylolpropane trioleate. Properties of base oil such as cloud point, density, acid value, demulsibility and soap content were also examined. The oil was then used in the formulation of tapping oil and appraised in term of adaptability, stability and field test performance.
A comparative study was done on the production of different medium chain fatty acid (MCFA) rich mustard oil using a stirred tank batchreactor (STBR) and packed bed bio reactor (PBBR) using three commercially available immobilised lipases viz. Thermomyces lanuginosus, Candida antarctica and Rhizomucor meihe. Three different MCFAs capric, caprylic and lauric acids were incorporated in the mustard oil. Reaction parameters, such as substrate molar ratio, reaction temperature and enzyme concentration were standardized in the STBR and maintained in the PBBR. To provide equal time of residence between the substrate and enzyme in both the reactors for the same amount of substrates, the substrate flow rate in the PBBR was maintainedat 0.27 ml/min. Gas liquid chromatography was used to monitor the incorporation of MCFA in mustard oil. The study showed that the PBBR was more efficient than the STBR in the synthesis of structured lipids with less migration of acyl groups. The physico-chemical parameters of the product along with fatty acid composition in all positions and sn-2 positions were also determined.
In this study, the interfacial properties of biosurfactant rhamnolipid were investigated and were applied to remove adsorbed heavy metal ions from sand surfaces with flushing operations. The surface tension-lowering activity, micelle charge characteristic, and foaming ability of rhamnolipid were identified first. For rhamnolipid in water, the negatively charged characteristic of micelles or aggregates was confirmed and the foaming ability at concentrations higher than 40 mg/L was evaluated. By using the rhamnolipid solutions in a batch washing approach, the potential of applying the interfacial properties of rhamnolipid to remove adsorbed copper ions from sand surfaces was then demonstrated. In rhamnolipid solution flushing operations for sand-packed medium, higher efficiency was found for the removal of adsorbed copper ions with residual type than with inner-sphere interaction type, implying the important role of interaction type between the copper ion and the sand surface in the removal efficiency. In addition, the channeling effect of rhamnolipid solution flow in the sand-packed medium was clearly observed in the solution flushing operations and was responsible for the low removal efficiency with low contact areas between solution and sand. By using rhamnolipid solution with foam to flush the sand-packed medium, one could find that the channeling effect of the solution flow was reduced and became less pronounced with the increase in the rhamnolipid concentration, or with the enhanced foaming ability. With the reduced channeling effect in the flushing operations, the removal efficiency for adsorbed copper ions was significantly improved. The results suggested that the foam-enhanced rhamnolipid solution flushing operation was efficient in terms of surfactant usage and operation time.
In this work, novel γ-butyrolactone-type monomeric and dimeric (gemini) surfactants with a semifluoroalkyl group [Rf– (CH2)3–; Rf = C4F9, C6F13, C8F17] as the hydrophobic group were successfully synthesized. Dimethyl malonate was dimerized or connected using Br(CH2)sBr (s = 0, 1, 2, 3) to give tetraesters, and they were bis-allylated. Radical addition of fluoroalkyl using Rf–I and an initiator, i.e., 2,2’-azobisisobutyronitrile for C4F9 or di-t-butyl peroxide for C6F13 and C8F17, was perform at high temperature, with prolonged heating, to obtain bis(semifluoroalkyl)-dilactone diesters. These dilactone diesters were hydrolyzed using KOH/EtOH followed by decarboxylation in AcOH to afford γ-butyrolactonetype gemini surfactants. Common 1 + 1 semifluoroalkyl lactone surfactants were synthesized using the same method. Their surfactant properties [critical micelle concentration (CMC), γCMC, pC20, ΓCMC, and AG] were investigated by measuring the surface tension of the γ-hydroxybutyrate form prepared in aqueous tetrabutylammonium hydroxide solution. As expected, the CMC values of the gemini surfactants were more than one order of magnitude smaller than those of the corresponding 1 + 1 surfactants. Other properties also showed the excellent ability of the gemini structure to reduce the surface tension. These surfactants were easily and quantitatively recovered by acidification. The monomeric surfactant was recovered in the γ-hydroxybutyric acid form, and the gemini surfactant as a mixture of γ-butyrolactone and γ-hydroxybutyric acid forms.
In this study, the effects of the degree of hydrolysis on the interfacial and emulsifying properties of soybean peptides were evaluated based on surface and interfacial tension, dynamic light scattering (DLS), and freeze-fracture transmission electron microscopy (FF-TEM) analyses. Of the five evaluated soybean peptides (SP95, SP87, SP75, SP49, and SP23), those with higher degrees of hydrolysis (SP95 and SP87) did not exhibit noticeable surface-active properties in water, whereas those with relatively low degrees of hydrolysis (SP75, SP49, and SP23) exhibited remarkable surface tension-lowering activity. The latter set (SP75, SP49, and SP23) also formed giant associates with average sizes ranging from 64.5 nm to 82.6 nm above their critical association concentration (CAC). Moreover, SP23 with the lowest degree of hydrolysis exhibited excellent emulsifying activity for soybean oil, and FF-TEM analysis demonstrated that the emulsions were stabilized by a lamella-like multilayer peptide structure on the oil droplets that prevented coagulation. The peptide with the lowest degree of hydrolysis (SP23) was effective not only for soybean oil emulsification, but also for the emulsification of liquid paraffin and silicon oil that are generally difficult to emulsify.
Monoalkyl sulfosuccinate is an anionic surfactant having two types of hydrophilic groups in one molecule, carboxylic acid group and sulfonic acid group, resulting in three ionization states depending on its pH. In state I, both carboxylic acid and sulfonic acid groups are not ionized; in state II, only sulfonic acid group is ionized; and in state III, both carboxylic acid and sulfonic acid groups are ionized. The ionization state affects the hydrophile-lipophile balance (HLB) of the surfactant, an index of the distribution coefficient of water/oil ratio of the surfactant. The decrease in HLB promotes the adsorption of the surfactant to the oil/water interface and improves the interface activity. State II has high emulsifying property for high interface activity but low water solubility. In contrast, state III has low emulsifying property for low interface activity but high water solubility. We applied the pH responsiveness of monoalkyl sulfosuccinate to the dispersion granulation method to change the state from II to III in a mild range of pH (weak acidity and weak alkalinity). Consequently, we successfully developed a novel dispersion granulation method that decreased the amount of surfactant needed for emulsifying resin solution by employing state II for its high emulsifying property, and we also reduced the amount of surfactant remaining on resin particles after the washing process by employing state III for its high water solubility.
The low-cost substrates from food industry, including maize starch hydrolysate and soybean meal hydrolysate, were used to produce docosahexaenoic acid (DHA) by Schizochytrium limacinum OUC88. Glucose derived from maize starch hydrolysate was used as the carbon source and soybean meal hydrolysate as the nitrogen sources. In 10L bioreactor fermentation, by using the soybean meal hydrolysate as the main nitrogen source, the biomass of Schizochytrium limacinum OUC88 reached 85.27 g L–1, and the yields of DHA was 20.7g L–1. As a comparison, when yeast extract was used as the main nitrogen source, the yields of biomass and DHA were 68.93 g L–1 and 13.3 g L–1, respectively. From the results of this study, these hydrolysates can provide all the nutrients required for high-density cultivation of S. limacinum OUC88 and DHA production, that will improve the economical and competitive efficiency of commercial DHA production.
Pangasius micronemus (Black Pangasius sp.) and Pangasius nasutus (Fruit Pangasius sp.) are two species of silver catfish widely consumed in Malaysia. The present study evaluated fatty acid profiles of fish muscles in these two Pangasius sp. from different farms and locations to determine which species or location is better in term of lipid quality. The results showed MUFAs (Monounsaturated fatty acid) content was highest (35.0-44.4%) followed by SFA (Saturated fatty acid) [32.0-41.5%] and PUFAs (polyunsaturated fatty acids) [9.3-19.3%]. P. micronemus of Sg. Kanchong displayed higher palmitic acid (SFA; 29.0%) than P. nasutus from Peramu (23.5%). In contrast, oleic acid (MUFA) revealed highest in P. nasutus (38.1%) while lowest in P. micronemus of Sg. Kanchong (29.7%). Additionally, utmost PUFAs belonged to P. micronemus of Sg. Kanchong (19.3%) and lower most in P. nasutus from Peramu (9.3%). P. micronemus presented with a higher EPA (eicosapentaenoic acid) [1.0-1.4%], DHA (Docosahexaenoic acid) [1.7-2.8%] and LA (Linoleic acid) [11.8-12.0%] than P. nasutus (EPA; 0.3%, DHA; 1.0%, LA; 4.8%). However, P. nasutus established higher GLA (gamma-linolenic acid) [0.4%] than P. micronemus (0.04-0.06%). Both Pangasius sp. can be regarded as good supplies of omega-3 and omega-6. Overall, P. micronemus from Sg. Kanchong is the best choice among all for reason high in EPA and DHA.
We compared the physiological activities of sesame seeds rich in lignans from three varieties (Gomazou, Maruhime and Maruemon), and those from a conventional cultivar (Masekin) in rats. The sum of the values of fat-soluble lignans (sesamin and sesamolin) in seeds of Gomazou, Maruhime and Maruemon varieties was approximately double the value in Masekin. Seeds from Maruemon contained fat-soluble lignan most exclusively as sesamin while other varieties contained sesamin and sesamolin at about a 2:1 ratio. After a 16 d experiment, sesame seeds, added at 200 g/kg to the experimental diets, increased the activity and mRNA levels of fatty acid oxidation enzymes. Increases were stronger with seeds rich in lignans than with seeds from Masekin. In contrast, sesame seeds lowered the activity and mRNA levels of lipogenic enzymes. However, sesame seeds from all the varieties were comparable in affecting these parameters. Serum triacylglycerol concentrations were lower in rats fed diets containing sesame seeds rich in lignans than in those fed a diet free of sesame seeds or a diet containing seeds from the Masekin variety. Serum malondialdehyde (a marker of lipid peroxidation) was lower in rats fed diets containing sesame seeds rich in lignans than in those fed a sesame seed-free diet or Masekin diet. It is apparent that sesame seeds rich in lignans, irrespective of lignan composition, more profoundly affect hepatic fatty acid oxidation and serum triacylglycerol levels and possibly attenuate oxidative stress. Therefore, consumption of sesame seeds rich in lignans hopefully results in physiological activity to promote health.
The Essential oil (EO) of Nigella sativa (black cumin) was extracted from the crude oil and the volatile constituents were characterized using gas chromatographic analysis. The EO was formulated in water-based microemulsion system and its antibacterial activity against six pathogenic bacteria was evaluated using the agar well diffusion method. This activity was compared with two other well known biologically active natural and synthetic antimicrobials namely eugenol and Ceftriaxone®. Results showed that N. sativa EO microemulsion was highly effective against S. aureus, B. cereus and S. typhimurium even at the lowest tested concentration of that EO in the microemulsion (100.0 μg/well). Interestingly, the EO microemulsion showed higher antibacterial activity than Ceftriaxone solution against S. typhimurium at 400.0 μg/well and almost comparable activity against E. coli at 500.0 μg/well. No activity was detected for the EO microemulsion against L. monocytogenes and P. aeruginosa. Eugenol which was also formulated in microemulsion was less effective than N. sativa EO microemulsion except against P. aeruginosa. The synthetic antibiotic (Ceftriaxone) was effective against most of the six tested bacterial strains. This work is the first report revealing the formulation of N. sativa EO in microemulsion system and investigating its antibacterial activity. The results may offer potential application of that water-based microemulsion in controlling the prevalence of some pathogenic bacteria.
We prepared pH-sensitive anionic liposomes composed solely of anionic bilayer membrane components that were designed to promote efficient release of entrapped agents in response to acidic pH. The pH–sensitive anionic liposomes showed high dispersion stability at neutral pH, but the fluidity of the bilayer membrane was enhanced in an acidic environment. These liposomes were rather simple and were composed of dimyristoylphosphatidylcholine (DMPC), an anionic bilayer membrane component, and polyoxyethylene sorbitan monostearate (Tween 80). In particular, the present pH-sensitive anionic liposomes showed higher temporal stability than those of conventional DMPC/DPPC liposomes. We found that pHsensitive properties strongly depended on the molecular structure, pKa value, and amount of an incorporated anionic bilayer membrane component, such as sodium oleate (SO), dimyristoylphosphatidylserine (DMPS), or sodium β-sitosterol sulfate (SS). These results provide an opportunity to manipulate liposomal stability in a pH-dependent manner, which could lead to the formulation of a high performance drug delivery system (DDS).