Change of fatty acid esters of MCPD and glycidol during restaurant deep frying of fish nuggets and their correlations with total polar compounds

2020 ◽  
Vol 55 (7) ◽  
pp. 2794-2801
Author(s):  
Lirong Xu ◽  
Yuanbo Zhang ◽  
Mengyue Gong ◽  
Jianhua Huang ◽  
Qingzhe Jin ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6030
Author(s):  
Zhanglan He ◽  
Kangzhuo Yang ◽  
Zhipeng Liu ◽  
Mingzhe An ◽  
Zongwei Qiao ◽  
...  

Wuliangye baijiu is one of the most famous baijiu in China, with a rich, harmonic aroma profile highly appreciated by consumers. Thousands of volatiles have been identified for the unique aroma profile. Among them, fatty acid esters have been identified as the main contributors to the aroma profile. In addition, many non-ester minor compounds, many of which are more polar than the esters, have been identified to contribute to the characteristic aroma unique to Wuliangye baijiu. The analysis of these minor compounds has been challenging due to the dominance of esters in the sample. Thus, it is desirable to fractionate the aroma extract into subgroups based on functional group or polarity to simplify the analysis. This study attempts a new approach to achieve simultaneous volatile extraction and fractionation using tandem LiChrolut EN and silica gel solid-phase extraction (SPE) columns. A baijiu sample (10 mL, diluted in 40 mL of water) was first passed through the LiChrolut EN (1.0 g) column. The loaded LiChrolut EN column was then dried with air and coupled with a silica gel (5.0 g) SPE column with anhydrous Na2SO4 (10.0 g) in between. The volatile compounds were eluted from the LiChrolut EN column and simultaneously fractionated on the silica gel column based on polarity. The simultaneous extraction and fractionation technique enabled the fractionations of all fatty acid esters into less polar fractions. Fatty acids, alcohols, pyrazines, furans, phenols, hydroxy esters, and other polar compounds were collected in more polar fractions. This technique was used to study the volatile compounds in Wuliangye, Moutai, and Fengjiu baijiu. In addition to fatty acid esters, many minor polar compounds, including 2,6-dimethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-3,5-dimethylpyrazine, p-cresol, and 2-acetylpyrrole, were unequivocally identified in the samples. The procedure is fast and straightforward, with low solvent consumption.



2014 ◽  
Vol 31 (2) ◽  
pp. 95-101
Author(s):  
Xiaobo YAN ◽  
Shaoming WU ◽  
Nan LI ◽  
Huadong LV ◽  
Wusheng FU


1994 ◽  
Vol 59 (4) ◽  
pp. 833-840
Author(s):  
Slavomír Pirkl

The phase transitions and effective optical rotary power of saturated and monounsaturated aliphatic esters of cholesterol with 18 and 22 carbon atoms in the chain have been described. The effect of cis/trans isomerism on these properties is discussed.



1992 ◽  
Vol 70 (6) ◽  
pp. 448-454 ◽  
Author(s):  
Ewa Świeżewska ◽  
T. Chojnacki ◽  
W. J. Jankowski ◽  
K. Singh ◽  
J. Olsson

The long chain polyprenols composed of 30 and more isoprene units from leaves of plants belonging to the genera Potentilla and Rosa have been described. They occur in the form of fatty acid esters. The composition of polyprenol mixture was species dependent and its content reached ca. 0.5% wet weight. Large scale preparation of individual polyprenols from a natural polyprenol mixture was performed using time-extended liquid chromatography on the hydrophobic gel Lipidex-5000.Key words: long chain polyprenols, Rosaceae.



Author(s):  
R E Pauls ◽  
B Pease

Abstract An ionic liquid (IL) 111 column was compared with other commonly employed stationary phases including polydimethyl siloxane and polyethylene glycol for the separation of fatty acid monomethyl and dimethyl esters. The fatty acid esters employed in this study were derived from metathesis reactions of vegetable oils both with and without olefins. The IL 111 column demonstrated enhanced performance compared with conventional columns for the separation of these esters. These advantages included significantly enhanced retention of dimethyl esters relative to monomethyl esters, excellent cis/trans isomer separation and the ability to analyze higher carbon number dimethyl esters. As a result, these columns are highly suited for the analysis of mixtures of mono- and dimethyl fatty acid esters found in lipid metathesis reaction products or to determine monofunctional impurities in samples of commercial dimethyl esters.



ACS Omega ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 3227-3231
Author(s):  
Chizuru Kogame-Asahara ◽  
Hitomi Iguchi ◽  
Kenichiro Honda ◽  
Hajime Shigemitsu ◽  
Toshiyuki Kida


2009 ◽  
Vol 287 (7) ◽  
pp. 795-799 ◽  
Author(s):  
Hidetaka Noritomi ◽  
Kenji Kagitani ◽  
Yasutaka Muratsubaki ◽  
Satoru Kato


1996 ◽  
Vol 73 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Tomomichi Okano ◽  
Naoyuki Egawa ◽  
Masami Fujiwara ◽  
Masahiro Fukuda


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