CHEMICAL CHARACTERIZATION OF CAMELINA SEED OIL By ANUSHA SAMPATH A Thesis submitted to the Graduate School-New Brunswick Rutgers, The State University of New Jersey In partial fulfillment of the requirements For the degree of Master of Science Graduate Program in Food Science Written under the direction of Professor Thomas G. Hartman And approved by ________________________ ________________________ ________________________ ________________________ New Brunswick, New Jersey [May, 2009] ABSTRACT OF THE THESIS Chemical characterization of Camelina Seed Oil By ANUSHA SAMPATH Thesis Director: Professor Thomas G. Hartman, Ph.D Camelina sativa (L).Crantz also known as false flax, Dutch flax is an ancient oil seed crop that belongs to the Brassicaceae family. Camelina oil pressed from the seeds of this crop has a unique aroma. Eighteen camelina oil samples were analyzed for fatty acid composition (13 unrefined, 2 deodorized and 3 refined samples). Eight of these samples were analyzed for unsaponifiables content, free fatty acids and volatiles and semi-volatile compounds. Seven camelina seed samples were analyzed for volatile and semi-volatile compounds as well to determine the suitability of these products in animal feed formulations. Fatty acid composition was obtained by the trans-esterification of the triacylglycerols in the oil to their methyl esters and 21 different fatty acids with chain length from C-14 to C-24 were identified. The major fatty acids were α-linolenic, linoleic, oleic, eicosenoic and palmitic acid and three fatty acids, namely tricosanoic, pentadecanoic and heptadecanoic are being first reported here. ii The unsaponifiables fraction in camelina oil samples ranged between 0.45-0.8% and 21 compounds were identified. The major compounds identified were β-sitosterol, campesterol, cholesterol, phytol, squalene and brassicasterol which accounted for 80-90% of the unsaponifiable content in camelina oil. A total of 168 and 306 volatile and semi-volatile compounds were identified in the headspace of camelina seeds and oil respectively. Homologous series of lipid oxidation derived compounds like aldehydes, ketones, alcohols, furans and hydrocarbons dominate the aroma and favor profile of the oil and seeds. Sulfur compounds (methyl mercaptan, dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide), naturally occurring 3-alkyl-2-methoxy pyrazines, terpenes, short chain free fatty acids and maillard reaction products were also identified in camelina seeds. The presence of 2-sec-butyl-3- methoxy pyrazine, aldehydes and alcohols (with green notes) and sulfur compounds like 2, 4, 5-trithiahexane and 1-butene-4-isothiocyanato in some camelina oils, may be responsible for the unique aroma of this oil. The information from this study may potentially be used by camelina oil producers as supporting data for the chemical characteristics of the oil produced in Montana, USA. Camelina oil can serve as a good vegetable source of α-linolenic acid provided it gets the much awaited GRAS certification. iii ACKNOWLEDGEMENT I would like to extend my sincere thanks and regards to my advisor Dr.Thomas Hartman, for providing me the opportunity to work on this project. He has provided me with extensive support and guidance while working on this study and during the entire time I have worked in the Mass-Spectrometry laboratory. I would like to specially thank Dr.Chi Tang Ho and Dr.Henryk Daun for having consented to be a part of my defense committee. I also sincerely appreciate their valuable time and inputs. I would like to thank Dr.Wudeneh Letchamo who has been responsible for co-ordinating this project with GNG (Great Northern Growers, Montana) and providing us with samples of camelina seeds and oil. I would like to thank the lab staffs Dr.Bin Khong Khoo and Joseph Lech for their guidance and support. I would also like to mention my special appreciation to Dr.Bin Khoo for having guided me throughout the time I have worked in the Mass-Spectrometry lab with his patience and eagerness to help students. I would also like to thank all my friends in the graduate school who have given constant support and encouragement. My special mention goes to my dear friends Poornima and Kasi Sundaresan for their constant encouragement and support. I would like to thank my family for having given me the support to work on my thesis and helping me achieve my goal. Finally I would like to thank God for giving me the strength to pursue such a wonderful opportunity. Anusha Sampath iv TABLE OF CONTENTS ABSTRACT---------------------------------------------------------------------------------ii ACKNOWLEDGEMENT---------------------------------------------------------------iv TABLE OF CONTENTS-----------------------------------------------------------------v LIST OF TABLES-------------------------------------------------------------------------x LIST OF FIGURES---------------------------------------------------------------------xiii 1. INTRODUCTION-------------------------------------------------------------------------1 1.1 Background on Camelina sativa-------------------------------------------------1 1.2 Geographical distribution of Camelina sativa----------------------------------8 1.3 Camelina Seed Processing-------------------------------------------------------10 1.4 Refining of Vegetable Oils------------------------------------------------------12 1.5 Type of Camelina Oil------------------------------------------------------------14 1.6 Uses and applications of Camelina seeds and oil-----------------------------15 1.6.1 Camelina seeds-----------------------------------------------------------15 1.6.2 Camelina Oil-------------------------------------------------------------15 1.6.3 Camelina Meal-----------------------------------------------------------18 2. LITERATURE REVIEW--------------------------------------------------------------19 2.1 Fatty acid composition-----------------------------------------------------------19 2.2 Unsaponifiables fraction---------------------------------------------------------20 2.3 Flavor and Aroma compounds--------------------------------------------------21 3. HYPOTHESIS AND OBJECTIVE OF THE RESEARCH---------------------23 3.1 Hypothesis of the research-------------------------------------------------------23 v 3.2 Objectives of the research-------------------------------------------------------24 4. MATERIALS AND METHODS------------------------------------------------------25 4.1 Characterization of fatty acids in Camelina Oil------------------------------25 4.1.1 Sample Materials--------------------------------------------------------25 4.1.2 Chemicals and reagents-------------------------------------------------27 4.1.3 Trans-esterification of fatty acids--------------------------------------27 4.1.4 Instrumentation-----------------------------------------------------------27 4.2 Unsaponifiables fraction extraction and identification----------------------30 4.2.1 Sample Materials--------------------------------------------------------30 4.2.2 Chemical reagents-------------------------------------------------------30 4.2.3 Isolation and characterization of unsaponifiables fraction in Camelina oil-----------------------------------------------------------31 4.3 Free fatty Acids-------------------------------------------------------------------34 4.3.1 Sample materials---------------------------------------------------------34 4.3.2 Chemical reagents-------------------------------------------------------34 4.3.3 Determination of free fatty acids--------------------------------------34 4.4 Volatiles and semi-volatiles-----------------------------------------------------36 4.4.1 Volatiles identification using Purge & Trap thermal Desorption method ------------------------------------------------------36 4.4.1.1 Sample Materials-----------------------------------------------36 4.4.1.2 Other materials--------------------------------------------------37 4.4.1.3 Identification of volatiles and semi-volatiles in Camelina oil-----------------------------------------------------38 vi 4.4.1.4 Identification of volatiles and semi-volatiles in Camelina seeds--------------------------------------------------39 4.4.2 Volatiles identification using Static headspace method in camelina seed ---------------------------------------------------------42 5. RESULTS AND DISCUSSION--------------------------------------------------------43 5.1 Fatty Acid Composition----------------------------------------------------------43 5.1.1 Fatty acid methyl ester (FAMES) standard components----------43 5.1.2 Fatty acids in Camelina Oil---------------------------------------------43 5.2 Unsaponifiables fraction---------------------------------------------------------56 5.2.1 Calculation and determination of unsaponifiable fraction---------56 5.2.2 Identification of unsaponifiable components by GC-MS----------58 5.3 Free Fatty Acids-------------------------------------------------------------------69 5.4 Volatiles and Semi-volatiles identification------------------------------------71 5.4.1 Identification of volatiles and semi-volatiles in camelina Seeds ----------------------------------------------------------------------71 5.4.2 Identification of volatiles and semi-volatiles in individual Camelina seed samples--------------------------------------------------80 5.4.2.1 Volatiles and semi-volatiles in Sample Ligena 1 Seeds by static and dynamic headspace methods-----------80 5.4.2.2 Volatiles and semi-volatiles in Sample Ligena 1A Seeds by static and