Effects of Heat-Cooking with Edible Fats and Oils on the Levels of 3-Chloro-1, 2-Propanediol Fatty Acid Esters (3-MCPDEs), 2-Chloro-1, 3-Propanediol Fatty Acid Esters (2-MCPDEs) and Glycidyl Fatty Acid Esters (GEs) in Processed Foods.

This study investigated the effect of cooking on the levels of 3-chloro-1, 2-propanediol esters (3-MCPDEs), 2-chloro-1, 3-propanediol esters (2-MCPDEs) and glycidyl esters (GEs) in deep-fried rice cracker, fried potato, croquette, fish fillet, chicken fillet and cooking oils (rice bran oil and palm oil). The levels of 2-/3-MCPDE in rice cracker fried with rice bran oil and the used oil remained about the same, while the levels of GEs in them fell with frying time. The levels of 2-/3-MCPDEs in fried potato, croquette, fried fish and chicken cutlet fried with rice bran oil and palm oil respectively fell with frying time, while the level of GEs in them remained about the same. The levels of 2-/3-MCPDEs and GEs in fried rice cooked with rice bran oil were under the method limit of quantification. These results provide insights the cooking has no influence with the levels of 2-/3-MCPDEs and GEs in cooked foods.

Differences in the Compositions of Vitamin E Tocochromanol (Tocopherol and Tocotrienol) in Rice Bran Oils Produced in Japan and Other Countries.

In this study, we investigated the compositions of vitamin E tocochromanol [tocopherol (Toc) and tocotrienol (T3)] in crude and refined rice bran oil (RBO) produced in Japan and other countries, including Brazil, Thailand, and Vietnam, based on high-performance liquid chromatography analysis. All RBO analyzed contained α-, ß- and γ-Toc and α-, γ- and δ-T3. Japanese crude RBO, although not refined RBO, also contained ß-T3. Furthermore, total Toc contents in both Japanese crude and refined oils were found to be higher than those in the crude and refined RBO from other countries. Total T3 contents in Japanese crude RBO were similar to those in the crude RBO from Brazil and Vietnam. The α-Toc and α-T3 contents in Japanese crude and refined RBO were considerably higher than those in the crude and refined RBO produced in other countries, whereas in contrast, γ-Toc and γ-T3 contents in Japanese crude and refined RBO were lower. Consequently, the ratios of total α-Toc and α-T3 contents to total γ-Toc and γ-T3 contents in Japanese crude and refined RBO (1.75 and 1.91, respectively) were notably higher than those in the crude and refined RBO produced in other countries. Similarly, the ratios of total Toc to total T3 in Japanese crude and refined RBO were higher than those in the crude and refined RBO produced in other countries. These results accordingly indicate that the ratio of total α-Toc and α-T3 contents to γ-Toc and γ-T3 contents could be used as an effective index to discriminate between the RBO produced in Japan and that produced in other countries.

Effects of Cultivars and Geography in China on the Lipid Characteristics of Camellia oleifera Seeds.

New cultivars of Camellia oleifera have been developed and planted in southern China. However, lipid characteristics of their seed oils were still unclear. In this study, nine C. oleifera fruits were collected from different cultivars in different planting regions, and the lipid characteristics, such as oil content, fatty acid composition, triacylglycerol composition, tocopherol content and sterol composition were investigated for their seed oils. The oil content in Yuekexia-2 was the lowest (11.6%), while those in other cultivars ranged from 22.3% to 29.6%. The major fatty acids of C. oleifera seed oils (COSOs) were palmitic acid (16:0, 8.4-11.5%), oleic acid (18:1, 76.3-80.5%), and linoleic acid (18:2, 7.9-12.2%), respectively. Trioleoylglycerol (OOO) was the most abundant triacylglycerol specie (more than 50%) in the COSOs. COSOs contained 21.2-36.4 mg/100 g of α-tocopherol. Seven sterols and squalene were found in all COSOs, while the COSOs showed significant differences in their contents of unsaponifiable matters. The planting region and the cultivar type significantly affected some of the lipid characteristics with the C. oleifera seeds.

Determination of γ-Oryzanol in Refined Rice Bran Oil by Nuclear Magnetic Resonance Method.

γ-Oryzanol contained as a minor component in rice bran oil (RBO) is a group of phytosterol ferulates. The existence of γ-oryzanol in rice bran oil is very interesting because of the special biological functions. The methods to determine γ-oryzanol in crude RBO include the absorptiometry, thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). However, those methods need much solvent and long operating time. Moreover, some of those methods are not able to apply to refined RBO because of the low sensitivity. We have developed the method to determine γ-oryzanol in refined RBO using proton nuclear magnetic resonance (1H-NMR). Refined RBO had a specific chemical shift due to the methoxy group of ferulate in γ-oryzanol at 3.9 ppm on the 1H-NMR spectrum. The intensity of the chemical shift due to the methoxy group of ferulate was consistent with the amounts of γ-oryzanol in refined RBO. This NMR method was able to quickly and easily determine γ-oryzanol in refined RBO.

Lipid Characteristics of Camellia Seed Oil.

Camellia oleifera, C. japonica and C. sinensis are three representative crops of the genus Camellia. In this work, we systematically investigated the lipid characteristics of these seed oils collected from different regions. The results indicated significant differences in acid value (AV), peroxide value (PV), iodine value (IV), saponification value (SV) and relative density of the above-mentioned camellia seed oils (p < 0.05). The C. japonica seed oils showed the highest AV (1.7 mg/g), and the C. sinensis seed oils showed the highest PV (17.4 meq/kg). The C. japonica seed oils showed the lowest IV (79.9 g/100 g), SV (192.7 mg/g) and refractive index (1.4633) of all the oils, while the C. sinensis seed oils showed the lowest relative density (0.911 g/cm3). The major fatty acids in the camellia seed oils were palmitic acid (16:0), oleic acid (18:1) and linoleic acid (18:2); the oleic acid in C. oleifera and C. japonica seed oils accounted for more than 80% of the total fatty acids. The oleic acid levels in the C. oleifera and C. japonica oils were higher than those in the C. sinensis seed oils, while the linoleic acid levels in the former were lower than those in the latter one. Differences also exist in the triacylglycerol (TAG) composition, although the most abundant TAG molecular species in the camellia seed oils was trioleoylglycerol (OOO). Seven sterol species, squalene and α-tocopherol were detected in the camellia seed oils, however, the contents of tocopherol and unsaponifiable molecules in the C. oleifera and C. japonica seed oils were significantly lower than those in the C. sinensis seed oil. These results demonstrated that the varieties of Camellia affected the seed oil lipid characteristics.

Seeds of Centranthus ruber and Valeriana officinalis Contain Conjugated Linolenic Acids with Reported Antitumor Effects.

Conjugated linolenic acids (CLNs) are naturally occurring fatty acids that are believed to have anticancer properties. In this study, we examined various plant seeds from herbs to discover seed oils containing CLNs. The ultraviolet spectra of total lipids from these seeds were measured. An absorption maximum around 270 nm was observed in seed oils belonging to the Valerianaceae family (Centranthus ruber and Valeriana officinalis). When the fatty acid compositions of these seed oils were measured, CLNs were detected. By silica column chromatography, neutral lipids (NLs), glycolipids, and phospholipids were eluted from seed oils of C. ruber and V. officinalis. Then, fatty acid compositions of these fractions were measured. This revealed that most of the CLNs in these seed oils existed in the NL fraction. When the NL fractions of these seed oils were reacted with lipase, CLNs showed good sensitivity to lipase hydrolysis. This suggested that the CLNs in the seed oils of C. ruber and V. officinalis existed predominantly at the sn-1,3 position of triacylglycerol and less at the sn-2 position. These results suggested that the CLNs from the seed oils of C. ruber and V. officinalis could easily be taken up by cancer cells as free fatty acids and had good potential as antitumor substances.

Analytical Methods to Evaluate the Quality of Edible Fats and Oils: The JOCS Standard Methods for Analysis of Fats, Oils and Related Materials (2013) and Advanced Methods.

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.

Autoxidation of Fish Oil Blended with Rice Bran Oil.

Effects of rice bran oil on the oxidative and flavor stability of fish oil were investigated by the gas liquid chromatography-head space method. When fish oil blending with different ratio of rice bran oils was oxidized at room temperature in the dark, volatile compounds produced during autoxidation was measured by gas liquid chromatography. The amounts of volatile compounds were decreased with increased the ratio of blended rice bran oil as well as peroxide value. The level of propanal and acrolein which gave unpleasant flavor was also decreased with increased the ratio of blended rice bran oil. Especially, the level of propanal and acrolein and peroxide value were remarkably decreased when blending more than 75% of rice bran oil. Blending of rice bran oil improved the oxidative and flavor stabilities of fish oil.

Decomposition products of glycidyl esters of fatty acids by heating.

In this study, decomposition products of glycidyl palmitate (GP) of fatty acids heated at high temperature such as deep frying were investigated. When GP and tripalmitin (TP) were heated at 180 and 200 °C, they were decreased with heating time. The weight of GP was less than that of TP, although both GP and TP were converted to polar compounds after heating. The decomposition rate of GP was higher than TP. Both GP and TP produced considerable amounts of hydrocarbons and aldehydes during heating. Aldehydes produced from GP and TP included saturated aldehydes with carbon chain length of 3-10, while hydrocarbons consisted of carbon chain length of 8-15. It was observed that major hydrocarbons produced from GP during heating were pentadecane. Moreover, the level of carbon dioxide (CO2) released from GP was higher than that of TP. It was suggested that fatty acids in GE might be susceptible to decarboxylation. From these results, GP might be quickly decomposed to hydrocarbons, aldehydes and CO2 besides polar compounds by heating, in comparison with TP.

Antioxidant effects of pH-regulating agents on the thermal deterioration of vegetable oils.

pH-Regulating agents, such as sodium tartrate, disodium succinate, and trisodium citrate, were investigated for their antioxidant activities during the thermal deterioration of vegetable oils. Refined rapeseed and rice bran oils, supplemented with pH-regulating agents and α-tocopherol (0.1%) were heated at 180℃. After heating, acid values (AVs), carbonyl values (CVs), polar material contents, and color (absorbance at 420 nm) of each sample were measured. All pH-regulating agents gave rise to reduced AVs, CVs, and polar material contents of vegetable oils during heating relative to samples not containing a pHregulating agent. Rapeseed and rice bran oils supplemented with sodium tartrate showed the lowest AVs, CVs, polar material contents and absorbances at 420 nm after heating. Sodium tartrate not only retarded the hydrolysis, thermal oxidation, polymerization, and coloration of both oils while heating at high temperatures, but it also showed antioxidant activity at the supplementation level of 0.01%. The antioxidant activity of sodium tartrate was higher than that of α-tocopherol during the deterioration of vegetable oils. Sodium tartrate was particularly effective retarding hydrolysis while heating at high temperatures, resulting in increase of AVs of vegetable oils. Sodium tartrate is therefore expected to be an effective antioxidant for the thermal deterioration of fats and oils during deep-fat frying.

Rapid determination of saponification value and polymer content of vegetable and fish oils by terahertz spectroscopy.

A rapid method for determining the saponification value (SV) and polymer content of vegetable and fish oils using the terahertz (THz) spectroscopy was developed. When the THz absorption spectra for vegetable and fish oils were measured in the range of 20 to 400 cm⁻¹, two peaks were seen at 77 and 328 cm⁻¹. The level of absorbance at 77 cm⁻¹ correlated well with the SV. When the THz absorption spectra of thermally treated high-oleic safflower oils were measured, the absorbance increased with heating time. The polymer content in thermally treated oil correlated with the absorbance at 77 cm⁻¹. These results demonstrate that the THz spectrometry is a suitable non-destructive technique for the rapid determination of the SV and polymer content of vegetable and fish oils.

Reconsideration of laparoscopic cholecystectomy.

We describe the surgical method of cases showing a distended gallbladder. Because the most important thing does not cause biliary tract injury, it is to find orientation carefully. The frequency of incidental gallbladder cancer was in 7 (0.7%) of the 983. Only cholecystectomy is necessary to be performed for Tis or T1 cancer, and surgery has to be changed to radical surgery for T2 cancer or deeper invasion. Laparoscopic cholecystectomy is already an established standard operation. In the presence of acute or severe chronic inflammation, special attention should be paid to these points.

Supplementation of DHA-rich microalgal oil or fish oil during the suckling period in mildly n-3 fatty acid-deficient rat pups.

Long-chain polyunsaturated fatty acids (LC-PUFA), particularly arachidonic acid (ARA) and docosahexaenoic acid (DHA), are considered critical for the development of infants and are commonly supplemented in infant formulae. In this study, two common sources of n-3 LC-PUFA, fish oil (FO) and DHA-rich microalgal oil (DMO), were fed to rat pups of mildly n-3 PUFA-deficient dams to compare changes in LC-PUFA of tissue phospholipids. The milk from dams fed a n-3 PUFA-deficient diet contained less n-3 LC-PUFA than that of dams fed a control diet (AIN-93G). The pups' were given orally 1 mg/g weight of either FO or DMO for 17 days between the ages of 5 and 21 days, the pups were weaned, and sacrificed 1 week later for analysis of fatty acid compositions of brain, heart, kidney, spleen, and thymus phospholipids. Although both FO and DMO brought about a recovery in the tissue DHA levels compared to those of the control group (pups from AIN-93G-fed dams), DMO was more effective at restoring tissue LC-PUFA status because it was richer in DHA than FO. FO had a slightly lower PUFA level than that required to bring the LC-PUFA status completely to normal levels in this experiment, and EPA did not accumulate in tissues under the conditions tested here. These results demonstrate the effectiveness of ingesting either FO or DMO in the pre-weaning period for improving mild n-3 PUFA deficiency.

Determination of triacylglycerol composition in vegetable oils using high-performance liquid chromatography: a collaborative study.

Triacylglycerol (TAG) composition in vegetable oils was collaboratively analyzed in 9 laboratories using high-performance liquid chromatography (HPLC) equipped with a refractive index detector. Dococyl (C22) and triacontyl (C30) silica columns were used for analysis. The TAG molecular species in soybean, rapeseed, and palm oils were individually separated on the chromatogram. The collaborative study demonstrated that TAG composition in vegetable oils could be analyzed based on partition numbers (PN) between 38 and 50. In conclusion, the HPLC method using C22 and C30 silica columns would be useful for determining the TAG composition (%) in vegetable oils.

Terahertz absorption spectra of Fatty acids and their analogues.

Absorption spectra in the terahertz (THz) region between 10 and 400 cm(-1) were measured for fatty acids and their analogues at room temperature. Saturated fatty acids such as palmitic and stearic acids had some sharp peaks, while unsaturated fatty acids such as oleic, linoleic and linolenic acids had two distinct peaks at 247 and 328 cm(-1). These peaks apparently derived from the carboxylic group because oleyl alcohol had no distinct peak. The THz absorption spectra of fatty acids may be affected by the crystalline as well as the chemical structure. The THz absorption spectra of oleic acid esters depended on ester types, although all oleic acid esters had some peaks due to the ester group. THz absorbance of fatty acids positively correlated with concentration. Based on these results, THz spectrometry may be a good analytical method for the non-destructive qualitative and quantitative evaluation of fatty acids and their analogues.

Effects of non-methylene-interrupted polyunsaturated fatty acid, sciadonic (all-cis-5,11,14-eicosatrienoic acid) on lipid metabolism in rats.

We investigated effects of the non-methylene-interrupted polyunsaturated fatty acid, sciadonic acid (all-cis-5,11,14-eicosatrienoic acid), on the lipid metabolism in rats, to identify the mechanism for the plasma and hepatic triacylglycerol-lowering effects of Japanese torreya (Torreya nucifera) seed oil. Sciadonic acid was isolated from torreya seed oil by the combination of urea-adduct with lipase-esterification. Sprague-Dawley (SD) male rats were fed with experimental diets containing 5% and 10% sciadonic acid based on corn oil for 2 weeks. The serum and liver triacylglycerol levels were lower in the rats fed with sciadonic acid. Considerable amounts of sciadonic acid were detected in the triacylglycerol and phospholipid in both the serum and liver of the rats fed with sciadonic acid. These observations demonstrate that sciadonic acid could modify the lipid metabolism in rats.

Estimation of total carbonyl compounds in roasted and dried foods by the tentative method using 1-butanol as a solvent.

Total carbonyl compounds in oils extracted from roasted and dried foods were estimated by the tentative method using 1-butanol instead of benzene as a solvent. Oils extracted from dried foods had generally showed higher carbonyl value (CV) than those from roasted foods. The CV estimated by the tentative method had a good correlation with that by the conventional method in oils extracted from roasted and dried foods, although the former did not always correlate with the latter for roasted and dried foods. It was expected that the tentative method using 1-butanol could be substituted for that using benzene and be useful for evaluating the quality of oils in roasted and dried foods.

Long-term supplementation of docosahexaenoic acid-rich, eicosapentaenoic acid-free microalgal oil in n-3 fatty acid-deficient rat pups.

Rat pups deficient in n-3 fatty acids received an oral administration of docosahexaenoic acid (DHA)-rich, eicosapentaenoic acid (EPA)-free microalgal oil (DMO) or fish oil (FO). DMO administration almost restored liver EPA to the level of the control diet-fed dam's pups, but FO administration did not. This suggests that EPA could be recovered in the liver, even though EPA-free DMO was supplemented.

Effects of Japanese Torreya (Torreya nucifera) seed oil on the activities and mRNA expression of lipid metabolism-related enzymes in rats.

The mechanism for the plasma and liver triacylglycerol-reducing effects of Japanese torreya (Torreya nucifera) seed oil containing sciadonic acid (all-cis-5, 11, 14-eicosatrienoic acid) is reported. Male SD rats were fed experimental diets containing 10% torreya, corn, or soybean oil for 4 weeks, and the activities and mRNA expression of the enzymes involved in lipid metabolism were measured in the liver. The activities of some hepatic enzymes involved in fatty acid synthesis were lower in the rats fed torreya oil.

Adsorption of bisphenol A by lactic acid bacteria, Lactococcus, strains.

Ten strains of the genus Lactococcus were examined for their ability to remove bisphenol A [2, 2-bis(4-hydroxyphenyl)propane; BPA], which is known as an endocrine disrupter. Nine strains of the lactococci tested could remove BPA from media during growth, although the removal ratio was below 9%. When BPA was incubated with lyophilized cells of lactococci for 1 h, the concentration of BPA in the media was decreased by 9-62%. Especially, the highest removal ratio of BPA was observed for Lactococcus lactis subsp. lactis 712. The lactococci could adsorb BPA but not degrade it, because the lactococci maintained the ability to remove BPA from the medium after autoclaving. When the lyophilized cells of L. lactis subsp. lactis 712 were also incubated with six analogues of BPA, they effectively adsorbed hydrophobic compounds such as 2, 2'-diphenylpropane and bisphenol A dimethylether. The BPA-adsorbing ability of lactococci could be due to the hydrophobic binding effect. The removal ratio of BPA by L. lactis subsp. lactis 712 was increased after treatment with sodium dodecyl sulfate and decreased after digestion with trypsin. These results suggest that the hydrophobic proteins on cell surface may be involved in the BPA-adsorbing ability of lactococci.