Most of biobased polyols for polyurethanes are synthesized from vegetable oils. In the first part, the present review goes into details of these different synthetic routes to obtain polyols. First, olefinic functionalities of triglycerides could easily be epoxidized, leading to reactive epoxide groups. Second, triglycerides double bonds could undergo a wide ranges of reactions to yield polyols. Finally, the carbonyl group could also be used as a reactive group to yield various polyols. In the second part, the present review is dedicated to the commercial biobased polyols, and, based on the patent literature focuses on the industrial synthetic routes.

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From Vegetable Oils to Polyurethanes: Synthetic Routes to Polyols and Main Industrial Products

Review of analytical strategies in the production and upgrading of bio-oils derived from lignocellulosic biomass

Obesity and its comorbidities, including type 2 diabetes and cardiovascular disease, are straining our healthcare system, necessitating the development of novel strategies for weight loss. Lifestyle modifications, such as exercise and caloric restriction, have proven effective against obesity in the short term, yet obesity persists because of the high predilection for weight regain. Therefore, alternative approaches to achieve long term sustainable weight loss are urgently needed. Conjugated linoleic acid (CLA), a fatty acid found naturally in ruminant animal food products, has been identified as a potential anti-obesogenic agent, with substantial efficacy in mice, and modest efficacy in obese human populations. Originally described as an anti-carcinogenic fatty acid, in addition to its anti-obesogenic effects, CLA has now been shown to possess anti-atherosclerotic properties. This review summarizes the pre-clinical and human studies conducted using CLA to date, which collectively suggest that CLA has efficacy against cancer, obesity, and atherosclerosis. In addition, the potential mechanisms for the many integrative physiological effects of CLA supplementation will be discussed in detail, including an introduction to the gut microbiota as a potential mediator of CLA effects on obesity and atherosclerosis.

Conjugated linoleic acid effects on cancer, obesity, and atherosclerosis: A review of pre-clinical and human trials with current perspectives

Review of the roles of conjugated linoleic acid in health and disease

Conjugated linoleic acid (CLA) has drawn significant attention since the 1980s for its various biological activities. CLA consists mainly of two isomers, cis-9,trans-11 and trans-10,cis-12, and the mixture of these two (CLA mix or 50:50) has been approved for food as GRAS (generally recognized as safe) in the United States since 2008. Along with its original discovery as an anticancer component, CLA has been shown to prevent the development of atherosclerosis, reduce body fat while improving lean body mass, and modulate immune and/or inflammatory responses. This review summarizes the clinical trials involving CLA since 2012; additional uses of CLA for age-associated health issues are discussed; and CLA's potential health concerns, including glucose homeostasis, oxidative stress, hepatic steatosis, and milk-fat depression, are examined. With ongoing applications to food products, CLA consumption is expected to rise and close monitoring of not only its efficacy but also its known and unknown consequences ar...

Conjugated Linoleic Acid: Potential Health Benefits as a Functional Food Ingredient.

Conjugated linoleic acid (CLA) is found naturally in dairy and beef products at levels of 0.2% to 2% of the total fat. A more concentrated source of dietary CLA, low in saturated fat, would be highly desirable to obtain optimum CLA levels of about 3 g/d. We recently reported photoisomerization of soy oil with iodine catalysis to be a simple way of producing CLA in laboratory without high-energy input or expensive enzymes and microorganisms. However, a long irradiation time of 144 h has been a limitation for this technique to be of practical value. The objectives of this study were to build a pilot plant unit to rapidly produce high-CLA soy oil by photoirradiation and optimize the processing parameters to obtain high-CLA soy oil. Degassed oil with dissolved-iodine catalyst was irradiated by UV lamps in an illuminated laminar flow unit (ILFU). The ILFU consists of 2 borosilicate glass plates in a silicone lined stainless steel frame. The static mode of operation yielded 5.7% of total CLA isomers and performed twice as well than the continuous mode with 2.5% of total CLA. Irradiating oil in a static mode with reflective surfaces increased the CLA yields 3-fold to 16.4%. About 22% of total CLA isomers can be rapidly produced from soy oil linoleic acid with 0.35% iodine catalyst in a 0.5-cm-thick oil layer maintained at 48 degrees C for 12 h. The peroxide value and GC-MS analysis did not identify any volatile compounds characteristic of lipid oxidation. This study is a definitive step toward the commercialization of large-scale production of CLA-rich soy oil.

Pilot-scale production of conjugated linoleic acid-rich soy oil by photoirradiation.

Daily intake of conjugated linoleic acid (CLA), an anticarcinogenic, antiatherosclerotic, antimutagenic agent, and antioxidant, from dairy and meat products is substantially less than estimated required values. The objective of this study was to obtain CLA-rich soybean oil by a customized photochemical reaction system with an iodine catalyst and evaluate the effect of processing on iodine and iodo compounds after adsorption. After 144 h of irradiation, a total CLA yield of 24% (w/w) total oil was obtained with 0.15% (w/w) iodine. Trans,trans isomers (17.5%) formed the majority of the total yield and are also associated with health benefits. The isomers cis-9,trans-11 and trans-10,cis-12 CLA, associated with maximum health benefits, formed approximately 3.5% of the total oil. This amount is quite significant considering that total CLA obtained from dairy sources is only 0.6%. ATR-FTIR, 1H NMR, and GC-MS analyses indicated the absence of peroxide and aldehyde protons, providing evidence that secondary lipid oxidation products were not formed during the photochemical reaction. Adsorption processing vastly reduced the iodine and iodocompounds without CLA loss. Photocatalysis significantly increased the levels of CLA in soybean oil.

Photocatalytic production and processing of conjugated linoleic acid-rich soy oil.

Conjugated linoleic acid (CLA) is a collection of octadecadienoic fatty acids that have been shown to possess numerous health benefits. The CLA used in our study was produced by the photoisomerization of soybean oil and consists of about 20% CLA; this CLA consists of 75% trans–trans (a mixture of t8,t10; t9,t11; t10,t12) isomers. This method could be readily used to increase the CLA content of all soybean oil used as a food ingredient. The objective of this study was to determine the effects of trans–trans CLA-rich soy oil, fed as a dietary supplement, on body composition, dyslipidemia, hepatic steatosis, and markers of glucose control and liver function of obese fa/fa Zucker rats. The trans–trans CLA-rich soy oil lowered the serum cholesterol and low density lipoprotein–cholesterol levels by 41 and 50%, respectively, when compared to obese controls. Trans–trans CLA-rich soy oil supplementation also lowered the liver lipid content significantly (P < 0.05) with a concomitant decrease in the liver weight in the obese rats. In addition, glycated hemoglobin values were improved in the group receiving CLA-enriched soybean oil in comparison to the obese control. PPAR-γ expression in white adipose tissue was unchanged. In conclusion, trans–trans CLA-rich soy oil was effective in lowering total liver lipids and serum cholesterol.

trans-trans Conjugated linoleic acid enriched soybean oil reduces fatty liver and lowers serum cholesterol in obese zucker rats.

Conjugated linoleic acid (CLA) isomers in oils are currently measured as fatty acid methyl esters by a gas chromatography-flame ionization detector (GC-FID) technique, which requires approximately 2 h to complete the analysis. Hence, we aim to develop a method to rapidly determine CLA isomers in CLA-rich soy oil. Soy oil with 0.38-25.11% total CLA was obtained by photo-isomerization of 96 soy oil samples for 24 h. A sample was withdrawn at 30 min intervals with repeated processing using a second batch of oil. Six replicates of GC-FID fatty acid analysis were conducted for each oil sample. The oil samples were scanned using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and the spectrum was collected. Calibration models were developed using partial least-squares (PLS-1) regression using Unscrambler software. Models were validated using a full cross-validation technique and tested using samples that were not included in the calibration sample set. Measured and predicted total CLA, trans,trans CLA isomers, total mono trans CLA isomers, trans-10,cis-12 CLA, trans-9,cis-11 CLA and cis-10,trans-12 CLA, and cis-9,trans-11 CLA had cross-validated coefficients of determinations (R2v) of 0.97, 0.98, 0.97, 0.98, 0.97, and 0.99 and corresponding root-mean-square error of validation (RMSEV) of 1.14, 0.69, 0.27, 0.07, 0.14, and 0.07% CLA, respectively. The ATR-FTIR technique is a rapid and less expensive method for determining CLA isomers in linoleic acid photo-isomerized soy oil than GC-FID.

Measurement of conjugated linoleic acid (CLA) in CLA-rich soy oil by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR)

A 30-min, micro-base-catalyzed method for vegetable oil fatty acid methyl ester (FAME) preparation was developed using only 1 mg of oil sample by limiting the solvent volumes used. This method was primarily developed to quickly analyze fatty acid composition of CLA-rich soy oil but can be further applicable to pure vegetable oils. Existing base-catalyzed FAME preparation methods are not appropriate to use because they are either rapid but not micro, or micro but not rapid, or are rapid and micro but use acidification in the final step of FAME preparation, which would isomerize oils containing conjugated fatty acids. Serial dilutions of a mixed commercial FAME reference standard were prepared and analyzed by GC with a flame ionization detector (FID) with maximum instrument sensitivity. The novel method was also used to prepare soy oil FAMEs for GC-FID analysis. There were no statistically significant differences (P < 0.05) in fatty acid data from the FAME reference standard dilutions. Similarly, there was no statistical significant difference (P < 0.05) between results obtained for all the soy oil dilutions and the control method. This technique is a rapid method for preparing small pure oil samples as FAMEs for GC-FID analysis.

Vishal P. Jain

Papers

Pilot-scale production of conjugated linoleic acid-rich soy oil by photoirradiation.

Photocatalytic production and processing of conjugated linoleic acid-rich soy oil.

trans-trans Conjugated linoleic acid enriched soybean oil reduces fatty liver and lowers serum cholesterol in obese zucker rats.

Measurement of conjugated linoleic acid (CLA) in CLA-rich soy oil by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR)

A Rapid, Micro FAME Preparation Method for Vegetable Oil Fatty Acid Analysis by Gas Chromatography