Edible fats and oils are among the basic components of the human diet, along with carbohydrates and proteins, and they are the source of high energy and essential fatty acids such as linoleic and linolenic acids. Edible fats and oils are used in for pan- and deep-frying, and in salad dressing, mayonnaise and processed foods such as chocolates and cream. The physical and chemical properties of edible fats and oils can affect the quality of oil foods and hence must be evaluated in detail. The physical characteristics of edible fats and oils include color, specific gravity, refractive index, melting point, congeal point, smoke point, flash point, fire point, and viscosity, while the chemical characteristics include acid value, saponification value, iodine value, fatty acid composition, trans isomers, triacylglycerol composition, unsaponifiable matters (sterols, tocopherols) and minor components (phospholipids, chlorophyll pigments, glycidyl fatty acid esters). Peroxide value, p-anisidine value, carbonyl value, polar compounds and polymerized triacylglycerols are indexes of the deterioration of edible fats and oils. This review describes the analytical methods to evaluate the quality of edible fats and oils, especially the Standard Methods for Analysis of Fats, Oils and Related Materials edited by Japan Oil Chemists' Society (the JOCS standard methods) and advanced methods.
An efficient synthetic protocol based on a new concept named “the pseudo-intramolecular process” is developed. Substrates are brought closed to each other by forming a salt, and this spatial proximity facilitates an efficient reaction like an intramolecular process, despite actually proceeding via an intermolecular pathway. This concept can be widely applied in organic synthesis. For instance, α-aryl-β-keto esters undergo a transacylation with amines accompanied by high efficiency, regioselectivity, and chemoselectivity. On the other hand, α-nitro-β-keto nitriles react via a tandem cyclization to afford polyfunctionalized azaheterocyclic compounds, which cannot be easily prepared by alternative methods. These synthetic protocols are practically useful because each reaction can be conducted without using any special reagent under mild reaction conditions through only simple experimental manipulations.
Oleic acid is a commercially valuable compound and has many positive health effects. Determining optimum conditions in a physical separation process is an industrially significant point due to environmental and health related concerns. Molecular distillation avoids the use of chemicals and adverse effects of high temperature application. The objective of this study was to determine the molecular distillation conditions for oleic acid to increase its purity and distillation yield in a model fatty acid mixture. For this purpose, a short-path evaporator column was used. Evaporation temperature ranged from 110 to 190℃, while absolute pressure was from 0.05 to 5 mmHg. Results showed that elevating temperature generally increased distillation yield until a maximum evaporation temperature. Vacuum application also affected the yield at a given temperature, and amount of distillate increased at higher vacuums except the case applied at 190℃. A multi-objective optimization procedure was then used for maximizing both yield and oleic acid amounts in distillate simultaneously, and an optimum point of 177.36℃ and 0.051 mmHg was determined for this purpose. Results also demonstrated that evaporation of oleic acid was also suppressed by a secondary dominant fatty acid of olive oil – palmitic acid, which tended to evaporate easier than oleic acid at lower evaporation temperatures, and increasing temperature achieved to transfer more oleic acid to distillate. At 110℃ and 0.05 mmHg, oleic and palmitic acid concentrations in distillate were 63.67% and 24.32%, respectively. Outcomes of this study are expected to be useful for industrial process conditions.
Fully hydrogenated expanded press soybean oil (FHEPSO) rich in naturally bioactive components was prepared using Palladium on Carbon (Pd/C) catalyst. Interesterified fat was prepared from binary blends of FHEPSO and cold press corn oil (CPCO) with FHEPSO/CPCO mass ratios of 50:50, 40:60 and 30:70. Lipozyme RM IM (6 wt% of total substrate) was used in a supercritical CO2 system to catalyze the transesterification. The fatty acid compositions had no significant changes in the fats before and after interesterification, and trans-fatty acid (TFA) was not detected. The fatty acid compositions within triacylglycerol (TAG) were rearranged, and the amounts of trisaturated and triunsaturated TAG decreased, whereas that of mixed TAG increased as a result of interesterification. The enzymatic interesterified fats (EIEF) had a lower solid fat content (SFC), broader melting and plasticity ranges compared to the noninteresterified blend (NIB). According to X-ray diffraction (XRD), the predominant crystal form had changed from β to β’. EIEF contained 0.33-0.51 g/100 g phospholipids, 88.6-105.6 mg/100 g total tocopherols, and 916-1053 mg/100 g total phytosterols, which could confer health benefits. The results indicated that EIEF may have a potential use in trans-free margarine stock preparation.
Oil content and bioactive properties of almond and walnut kernels were investigated in developing almond and walnut kernels at 10 days intervals. The oil contents of almond and walnuts after the first harvest (1.H) stage changed between 46.2% and 55.0% to 39.1% and 70.5%, respectively (p<0.05). Oleic acid contents of almond and walnut oils ranged from 71.98% (1.H) to 78.68% (5.H) and 10.51% (1.H) to 16.78% (2.H) depending on harvest (H) times, respectively (p<0.05). In addition, linolenic acid contents of walnut and almond oils were found between 62.35% and 67.78%, and 12.02% and 17.65%, respectively. The almond kernel oil after the first harvest stage contained 1.045, 1.058, 1.018, 0.995 and 0.819 mg/kg ɑ-tocopherol, respectively. γ-Tocopherol contents of walnut oil changed between 1.364 (3.H) and 2.954 mg/kg (1.H). The β-sitosterol contents of both almond and walnut oils were found between 1956.6 (5.H) and 2557.7 (1.H), and 1192.1 (3.H) and 4426.4 mg/kg (1.H). The study exhibited the presence of high percentage of oleic and linoleic for almond and walnut, respectively, and γ-tocopherol and β-sitosterol.
We have developed an artificial skin that mimics the morphological and mechanical properties of human skin. The artificial skin comprises a polyurethane block possessing a microscopically rough surface. We evaluated the tactile sensations when skin-care cream was applied to the artificial skin. Many subjects perceived smooth, moist, and soft feels during the application process. Cluster analysis showed that these characteristic tactile feels are similar to those when skin-care cream is applied to real human skin. Contact angle analysis showed that an oil droplet spread smoothly on the artificial skin surface, which occurred because there were many grooves several hundred micrometers in width on the skin surface. In addition, when the skin-care cream was applied, the change in frictional force during the dynamic friction process increased. These wetting and frictional properties are important factors controlling the similarity of artificial skin to real human skin.
Behaviors of cationic and nonionic mixed micelles in the form of hexadecyltrimethylammonium bromide (HDABr) and hexadecyltrimethylammonium bromide-Polyethylene glycol hexadecyl ether (C16E20), in the presence of inert salts (NaBr and 3,5-dichlorosodium benzoate), by the use of reaction probe between Pp and ionized PhSH (Pp = piperidine and PhSH = phenyl salicylate), has been reported in this work. The values of RXBr (RXBr denotes ion exchange constants obtained in the presence of micelles of different structural features) or KXBr (KXBr denotes ion exchange constants obtained in the presence of micelles of the same structural features) for 3,5-Cl2C6H3CO2– were almost the same at three different [HDABr]T (0.006, 0.010 and 0.015 M). The average value of RXBr or KXBr determined, in the presence of pure HDABr micelles, using semi empirical kinetic (SEK) method appeared to be almost 2½-fold larger (RXBr or KXBr = 198) than that in the presence of mixed HDABr-C16E20 micelles (RXBr or KXBr = 78). Rheological measurements indicated the existence of wormlike/twisted micelles and vesicle at 0.015 M pure HDABr, various [3,5-Cl2C6H3CO2Na], and 25 and 35℃ whereas there were evidence of only spherical micelles in the presence of mixed HDABr-C16E20 ([HDABr]T = 0.015 M and [C16E20]T = 0.006 M) at both temperatures.
It has been reported that a lot of receptors localize in lipid raft domains and that the microfluidity of these domains regulates the activation of these receptors. In this study, we focused on the lipid raft and in order to evaluate the physicochemical effects of surfactants on microfluidity of lipid membranes, we used liposomes comprising of egg-yolk L-α-phosphatidylcholine, egg-yolk sphingomyelin, and cholesterol as a model of cell membranes containing raft domains. The microfluidity of the domains was characterized by fluorescence spectrometry using 1,6-diphenyl-1,3,5-hexatriene and 2-dimethylamino-6-lauroylnaphthalene. Among several surfactants, dialkylammonium-type cationic surfactants most efficiently increased the microfluidity. It is therefore concluded that (1) the electrostatic interaction between the cationic surfactant and eggPC/eggSM/cholesterol liposome could be important, (2) surfactants with alkyl chains more effectively inserted into membranes than those with acyl chains, and (3) cationic surfactants with lower Tm values have a greater ability to increase the fluidity.
The tuber of the konjac plant is a source enriched with GlcCer (kGlcCer), and has been used as a dietary supplement to improve the dry skin and itching that are caused by a deficiency of epidermal ceramide. Previously, we showed chemoenzymatically prepared konjac ceramide has a neurite-outgrowth inhibitory effect that is very similar to that of Sema3A and is not seen with animal-type ceramides. While, it has been unclear whether kCer may act on Sema3A or TrkA signaling pathway. In the present study, we showed kCer induces phosphorylation of CRMP2 and microtubules depolymerization via Sema3A signaling pathway not TrkA. It is concluded that kCer may be a potential Sema3A-like agonist that activates Sema3A signaling pathway directly.
Konjac ceramide (kCer) can be prepared by a chemoenzymatic method as previously published (Usuki, S.; Tamura, N.; Sakai, S.; Tamura, T.; Mukai, K.; Igarashi, Y. Biochem. Biophys. Rep. 5, 160-167 (2016)). Thus prepared kCer showed an activation effect on Sema3A signaling pathway to induce phosphorylation of CRMP2 and microtubule depolymerizaion, resulting in opposing NGF-induced neurite outgrowth. In the present study, we have shown that kCer is a potential Sema3A-like ligand that has a competitive effect on Sema3A binding to a cell surface receptor Nrp1, but animal-type ceramides have no effect on Sema3A binding to Nrp1. In addition, kCer showed a direct molecular interaction with Nrp1, but animal-type ceramides, C16Cer, C18Cer, and C24Cer show no specific bindings to Nrp1. Further, kCer showed an additive effect to activate the Sema3A signaling pathway together with low-dose Sema3A but a reversed effect to inhibit this pathway when combined with high-dose Sema3A.
In this study, we prepared calcium silicate at different molar ratios (Ca:Si=1:3, 1:6, and 1:9 refer to CAS-30S, CAS-60S, and CAS-90S, respectively) with water addition. The adsorbent characteristics (specific surface area, pore volume, mean pore diameter, and elemental analysis) were measured and the effect of water addition on the adsorbent surface for the prevention of deterioration was evaluated. In addition, the deterioration of soybean oil (SO) subjected to heating and aeration was investigated based on the acid value (AV) and carbonyl value (CV). The specific surface area increased in the order CAS-60S (160.51 m2/g) < CAS-30S (182.61 m2/g) < CAS-90S (204.19 m2/g). Deterioration of SO could be induced by heating and aeration with AV and CV of 1.4 mg/g and 102.9 µmol/g, respectively. The adsorbent (CAS-30S and CAS-90S) with water addition (25% and 50%) was found to decrease the AV, indicating that a small amount of water addition to adsorbent surface is important for the decreasing of AV. In addition, the correlation between the decrease in AV and the specific surface area is strongly positive (R value: 0.968). The adsorption mechanism is thought to involve interactions between the polar compounds (free fatty acids) in the SO (nonaqueous phase) and the water layer (containing calcium ions released from the adsorbent) on the adsorbent surface. In summary, the data obtained in this study provide useful information for preventing the deterioration of SO and prolonging the oil life cycle.
Karanja oil (KO) is widely used for synthesis of bio-fuel karanja oil methyl ester (KOME) due to its competitive price, good energy values and environmentally friendly combustion properties. Bio-lubricant is another value added product that can be synthesized from KO via chemical modification. In this work karanja oil trimethylolpropane ester (KOTMPE) bio-lubricant was synthesized and evaluated for its viscous flow behaviour. A comparison of viscous flow behaviours of natural KO and synthesized bio-fuel KOME and bio-lubricant KOTMPE was also made. The aim of this comparison was to validate the superiority of KOTMPE bio-lubricant over its precursors KO and KOME in terms of stable viscous flow at high temperature and high shear rate conditions usually encountered in engine operations and industrial processes. The free fatty acid (FFA) content of KO was 5.76%. KOME was synthesized from KO in a two-step, acid catalyzed esterification followed by base catalyzed transesterification, process at 65°C for 5 hours with oil-methanol ratio 1:6, catalysts H2SO4 and KOH (1 and 1.25% w/w KO, respectively). In the final step, KOTMPE was prepared from KOME via transesterification with trimethylolpropane (TMP) at 150°C for 3 hours with KOME-TMP ratio 4:1 and H2SO4 (2% w/w KOME) as catalyst. The viscosity versus temperature studies were made at 0–80°C temperatures in shear rate ranges of 10–1000 s–1 using a Discovery Hybrid Rheometer, model HR–3 (TA instruments, USA). The study found that viscosities of all three samples decreased with increase in temperature, though KOTMPE was able to maintain a good enough viscosity at elevated temperatures due to chemical modifications in its molecular structure. The viscosity index (VI) value for KOTMPE was 206.72. The study confirmed that the synthesized bio-lubricant KOTMPE can be used at high temperatures as a good lubricant, though some additives may be required to improve properties other than viscosity.
Shimatogarashi (Capsicum frutescens) is a typical chili pepper domesticated in southern Japan. Important traits of Shimatogarashi peppers, such as color; proportion of organic acids, capsaicinoids, and aromatic compounds; and antioxidant activity in three stages of maturity (green (immature), orange (turning), and red (mature) stages) were characterized. The results indicated that the concentration of organic acids, including ascorbic, citric, and malic acid, increased during ripening. In addition, the amount of capsaicinoids, which are responsible for the pungent taste of chili peppers, increased as the fruit matured to the orange and red stages. The volatile compound profile of Shimatogarashi was dominated by the presence of esters, which mainly contributed to fruity notes. The total amount of volatile compounds analyzed by gas chromatography-headspace solid-phase microextraction (GC-HS-SPME), especially esters, decreased as the fruit changed in color from green to red. This was in contrast to the amount of terpenoids, especially limonene, which increased at the red stage, denoting a change in flavor from fruity to a more citrus-like aroma. Based on the total phenolic content (TPC), the oxygen radical absorbance capacity (ORAC) and the diphenylpicrylhydrazyl (DPPH) free radical method, the antioxidant capacity of Shimatogarashi showed an increase at the mature red stage. However, while the red stage showed higher pungency and antioxidant capacity as well as an attractive color, the results of aromatic compound analysis revealed that the immature green stage had the advantages of having pleasant fruity smell, making it suitable for use in condiments.