Separation and identification of isomeric conjugated fatty acids by high‐performance liquid chromatography with photodiode array detection

Husain, Sajid; Devi, K. Sita

doi:10.1007/bf02537128

Cited by 10 publications

(4 citation statements)

References 11 publications

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“…It may also act as a growth promoting agent . An analytical technique for separating the two isomers has not been perfected (Belury, 1995;Husain and Devi, 1993) and therefore it is not possible to determine the biological significance of the independent isomers. In this report, CLA refers to both the cis-9,trans-11 and trans-9,cis-11 isomers of octadecadienoic acid.…”

Section: Introductionmentioning

confidence: 99%

Osmotic‐Convective Dehydrofreezing Process for Drying Kiwifruit

Robbers

Singh

Cunha

1997

Journal of Food Science

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Osmotic and convective dehydrofreezing were studied to determine sugar concentration, ascorbic acid loss, and texture changes in dried and dehydrofrozen kiwifruit. Two concentrations of sucrose (60Њ and 72Њ Brix) were used as osmotic solutions after convective air drying. Time needed to reach desired moisture was reduced with combined drying compared with osmotic drying. Firmness was evaluated by the maximum force from a back extrusion test. A reduction in maximum force was observed after freezing, as compared with fresh and dried fruit. Addition of ascorbic and citric acid as antioxidants in the osmotic solution prevented browning, and significant loss of ascorbic acid during osmotic drying. Air drying at 30ЊC produced distinguishable color changes.

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Section: Introductionmentioning

confidence: 99%

Osmotic‐Convective Dehydrofreezing Process for Drying Kiwifruit

Robbers

Singh

Cunha

1997

Journal of Food Science

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“…It is imperative to mention that Husain and Sita [3] established the structure of conjugated trienoic fatty acid by HPLC from different sources of Momordica charantia and identified the molecule as ·-elaeostearic acid.…”

Section: Introductionmentioning

confidence: 99%

Nutritional Characteristics of Oil Containing Conjugated Octadecatrienoic Fatty Acid

Dhar¹,

Bhattacharyya²

1998

Ann Nutr Metab

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The nutritive value of conjugated octadecatrienoic fatty acid (C18:3 Δ9,11,13α-elaeostearic acid) as occurs in karela seed (Momordica charantia) oil was studied. When rats were fed at the 20% level for 6 weeks, the growth pattern of rats and the food efficiency ratio showed a slightly significant difference compared to the group raised on linseed oil with non-conjugated octadecatrienoic acid (C18:3 Δ9,12,15α-linolenic acid) as control. The concentrations of total cholesterol, triglyceride, VLDL-cholesterol, LDL-cholesterol and LDL/HDL-cholesterol in serum were significantly higher in karela oil than in linseed oil. The liver lipid profile showed no difference. The total lipid as well as phospholipid concentrations of heart lipid were significantly higher in karela oil. The brain weight of the linseed oil group was significantly higher than the karela group. The brain phospholipid concentration of the karela oil group was significantly higher than that of the linseed oil group.

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“…The total methyl esters of these oils as obtained were spotted on preparative silica gel TLC plates (Merck F254) and developed twice with hexane/diethyl ether (94:6). TLC yielded two close but well-resolved bands (15) at an R f of 0.44 and 0.50 ( Fig. 1) as obtained upon densitometric scanning of the plate at 254 nm under absorption/reflection mode using HPTLC (Model 4.05; CAMAG, Muttenz, Switzerland).…”

Section: Methodsmentioning

confidence: 99%

TLC as a tool for quantitative isolation of conjugated trienoic FA

Devi

2003

J Americ Oil Chem Soc

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Conjugated trienoic FA-α-eleostearic, β-eleostearic, and punicic acids-were preferentially isolated in pure form from the total methyl esters of the respective oils by simple silica gel TLC using hexane/diethyl ether as the mobile phase (94:6). The subsequent saponification of the separated methyl ester fractions upon cooling at -20°C yielded individual acids in crystalline form. Melting points, conventional UV spectroscopy, and GLC confirmed the identity of the conjugated trienoic FA. The method finds potential application in benchscale reaction optimization using pure FA and in the preparation of standard reference materials of these acids, as these oils are widely used in the coatings industry.Paper no. J10335 in JAOCS 80, 315-318 (April 2003).Conjugated trienoic FA such as α-eleostearic, punicic and licanic acids are an industrially important group of compounds found in vegetable oils. They are not very common in yeasts, bacteria, fish oil, or animal fats, but conjugated dienoic, trienoic, and tetraenoic FA and their oxygenated derivatives are encountered in various seed oils in abundance (1-3). The oils containing these FA are very important raw materials in the manufacture of organic coatings and polymers (4-7), as the conjugated unsaturation facilitates good polymerization and imparts adhesive properties when properly treated. As these acids are heat and light sensitive, they cannot be stored for long times and thus standard reference materials are difficult to procure. The isolation and purification of conjugated acids were effected by the crystallization technique devised by earlier workers (8). Silver-ion TLC was used to achieve separation of conjugated esters from other esters (9). Also, the separation of positional and geometrical isomers was facilitated by HPLC by using the silver-ion mode again (10). Further, the characterization of hydroxy eicosatetraenoic acids and conjugated dienes was carried out by a UV spectroscopic method (11). The analysis of carotenoids using nonaqueous reversed-phase HPLC with photodiode array (PDA) detection was accomplished by Tan et al. (12). However, isolation by direct silica gel TLC has not been reported before for the enrichment of α-eleostearate.Four varieties of bittergourd [Momordica charantia: varieties, Long Green Monsoon, Summer Crop (S.C), Coimbatore Long (C.L), and Local] and one variety of snake gourd (Trichosanthus anguina) were studied in our laboratory for the content of conjugated FA in the respective seed oils, and different analytical methods were used for identification and quantification. Interestingly, simple TLC yielded very useful results because the methyl esters of the above oils, when separated by TLC using normal silica gel plates, presented wellresolved bands accounting for approximately 96% of conjugated trienoic FA of any geometrical configuration. We first attempted to isolate α-eleostearate in clean form by using hexane/ether (94:6) as the mobile phase system to monitor the biosynthetic pathway of conjugated FA (13). We extended this wor...

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Separation and identification of isomeric conjugated fatty acids by high‐performance liquid chromatography with photodiode array detection

Cited by 10 publications

References 11 publications

Osmotic‐Convective Dehydrofreezing Process for Drying Kiwifruit

Osmotic‐Convective Dehydrofreezing Process for Drying Kiwifruit

Nutritional Characteristics of Oil Containing Conjugated Octadecatrienoic Fatty Acid

TLC as a tool for quantitative isolation of conjugated trienoic FA

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