MCPD and Glycidol in Edible Oils Post Refining Formation, Decomposition and Analysis SGS Germany GmbH J. Kuhlmann

Transcription

1 MCPD and Glycidol in Edible Oils Post Refining Formation, Decomposition and Analysis SGS Germany GmbH J. Kuhlmann 1

2 Introduction, & Glycidol: Derivates of glycerol free : non-genotoxic carcinogen MCPD fatty acid esters release most of MCPD during digestion (3-Chloropropane-1,2-diol) (2-Chloropropane-1,3-diol) free glycidol: reproductive toxicity [1B] germ cell mutagenicity [2] carcenogenicity [1B etc. glycidyl fatty acid esters release glycidol completely during digestion [Classification according to Regulation (EC) No 1272/28 [EU-GHS/CLP]] - HCl + HCl Glycidol 2

3 (fatty acid) bound Glycidol & MCPD in oils & fats Introduction crude oil refining refined oil Bound MCPD & Glycidol are generated mainly during deodorisation at high temperatures. The vast majority of refined oils & fats contain bound MCPD & glycidol potential of contaminant formation is dependant upon the oil type & quality degree of formation is dependant upon refining conditions mono esters are more volatile and might get into equilibrium of formation evaporation 3

4 Introduction Precursors of bound Glycidol & MCPD in natural oils Mono(acyl)glycerides / Di(acyl)glycerides / Tri(acyl)glycerides e.g. > 2 C - H 2 O/-FA bound glyicdol Glycidyl fatty acid esters mono esters rather volatile and less stable < 2 C + HCl* bound MCPD e.g. *natural sources e.g. FeCl x, chlorinated phytosphingosines 1) 2- & fatty acid esters - H 2 O/-FA 1-/2- mono esters << 1,2-/1,3- di esters less volatile and highly stable Glycidylpalmitate -1,2-bis-pamitoyl ester 1) K. Nagy et al.: Mass-defect filtering of isotope signatures to reveal the source of chlorinated palm oil contaminants; Food Addit. Contam. 211, 28,

5 Analytical approach glycidol fatty acid(s) 3-MBPD Indirect analysis by SGS 3-in-1 method (identical to AOCS Official Method Cd 29b-13) Oil containing a complex mixture of 2- & - & glycidyl mono- & diesters SGS 3-in-1 -method: -better glycidol-precision as DGF C-VI 18 (1) -lowest LOQs -covers bound & free analytes -higher troughput in comparison to direct analysis ester cleavage (alkaline, mild) matrix clean-up (e.g. (l/l) - extraction) derivatisation (e.g. HFBA/acetone/PBA) Glycidol GC-MS 5

6 Analytical approach glycidol fatty acid(s) 3-MBPD Indirect analysis by SGS 3-in-1 method (identical to AOCS Official Method Cd 29b-13) Oil containing a complex mixture of 2- & - & glycidyl mono- & diesters SGS 3-in-1 -method: -better glycidol-precision as DGF C-VI 18 (1) -lowest LOQs -covers bound & free analytes -higher troughput in comparison to direct analysis ester cleavage (alkaline, mild) Glycidol transformation into MBPD! matrix clean-up (e.g. (l/l) - extraction) derivatisation (e.g. HFBA/acetone/PBA) Glycidol Glycidol as 3-MBPD GC-MS 6

7 Formation of bound MCPD and glycidol Analyte formation by simple heat treatment of oils & fats Temperature induced formation of and glycidol in edible oils and fats Analyte conce entration Temperatureramping. 27 C 2 C ca. 2 min 15 min 7

8 Formation of bound MCPD and glycidol Glycidol Analyte formation by simple heat treatment of oils & fats Temperature Temperature induced induced formation formation of of glycidol and glycidol in edible in edible oils andoils fats and fats Glycidol[ [mg/kg] Analyte conce entration C LOQ:,1 mg/kg Liquid frying Temperature-. fat Butter,3 % saltramping Sunflower oil- margarine Spreadfat; butter-rapeseedoil, 1 % salt Vegetable Margarine,.3 % salt Butter, unsalted Spread fat; butter-rape seed oil, unsalted Clarified butter Crude palm oil Olive oilrefined+ e.v. 27 C X Olive oile.v.+ 3 % NaCl Refined sunflower oil Refined coconut fat Olive oil extra virgin Refined rape seed oil Cold press. sunflower oil Refined safflour oil Cold press. rape seed oil ca. 2 min 15 min -The generation of bound glycidol starts at apr. 25 C by heating of various oils, fats and spread fats - The glycidol-formation ability of various oils, fats & spreads is very similar except for crude palm oil 8

9 Formation formation by simple heat treatment of oils & fats Temperature induced formation of bound in edible oils and fats 3,6 3-MC CPD [mg/kg] 2,4 1,2 Crude palm oil X Olive oil e.v. + 3 % NaCl refined oils LOQ:.1 mg/kg ca. 2 min 15 min non-refined oils; Olive rape seed - sunflower There was no significant formation of bound observed when different pristine or refined oils were heated up to 27 C, Refined - except rape seed foroil crude palm Refined oilpalm oil Olive oil ref. & e.v. High loads of sodium chloride present during heating of olive oil caused medium levels of bound 3- MCPD Refined sunflower oil 9

10 Temperature induced formation of in edible oils and fats Formation formation by simple heat treatment of spreads etc. 13 Butter,3 % salt [m mg/kg] 97, ,5 Liquid frying fat, 1.5% salt Vegetable Margarine,.3 % salt Butter, unsalted Sunflower oil based margarine Clarified butter ca. 2 min 15 min High loads of bound were generated; salt content correlated to MCPD-formation The formation of bound started at apr. 17 C 19 C 1

11 Temperature induced formation of in edible oils and fats Formation formation by simple heat treatment of spreads etc. 13 SpreadfatA; butter-rapeseedoil, 1 % seasalt Butter,3 % salt [m mg/kg] 97, ,5 Spread fat C; butter-rape seed oil Liquid frying fat, 1.5% salt Spread fat B; butter-rape seedoil, 1 % salt Vegetable Margarine,.3 % salt Butter, unsalted Sunflower oil based margarine Clarified butter ca. 2 min 15 min High loads of bound were generated; salt content correlated to MCPD-formation The formation of bound started at apr. 17 C 19 C The observed generation slopes were different in dependancy upon the spread composition 11

12 [mg/k kg] Formation Chemically induced formation of bound MCPD in olive oil Generation of bound glycidol and MCPD during heat treatment of customary extra virgine oliveoilcontaining,13 % FeCl. 3 6 H 2 O ca. 2 min 15 min 12

13 Formation Chemically induced formation of bound MCPD in olive oil Generation of bound MCPD during heat treatment of customary extra virgine olive oil containing,7 % AlCl. 3 6 H 2 O [mg/k kg] ca. 2min 2 min 13

14 [mg/k kg] Formation Chemically induced formation of bound MCPD in olive oil Generation of of ofboundmcpd glycidol and duringheattreatmentoffryingfaton MCPD treatment treatment customary customary extra palmoilbasein virgine extra olive virgine oil oliveoilcontaining,13 presenceof2.1 containing,7 % AlCl %. FeCl H 3 2 O6 H 2 O sum MCPD ca. 2min ca. ca. min 2 min 2 min 15 min 14

15 Formation Chemically induced formation of bound MCPD in olive oil Generation Generation of of bound of ofboundmcpd glycidol and duringheattreatmentoffryingfaton MCPD treatment treatment customary frying customary extra palmoilbasein fat virgine on extra olive virgine oil base oliveoilcontaining,13 presenceof2.1 containing,7 of % 5 AlCl %. FeCl.. AlCl H 3 2 O6 H 2 O [mg/k kg] sum sum MCPD ca. 2min ca. ca. min 2 min 2 min 15 2 min AlCl 3. 6 H 2 O acted as much stronger MCPD-precurser than FeCl 3. 6 H 2 O Around 23 C starts to isomerise into to generate an equilibrium of apr. 2:1 ratio With waterfree AlCl 3 bound is generated already at room temperature ( 1%) 15

16 Formation Can bound MCPD be generated during industrial or individual frying of foods? Olive oil extra virgin Olive oil in parts refined Butter Liquid paraffine frying oil bound bound bound glycidol x 3! analyte mg/kg f start start afo: after frying of m.t.: moderate temperature h.t.: high temperature 16

17 Formation Can bound MCPD be generated during industrial or individual frying of foods? 2 Shift of analyte contents in frying oils after theire use for private houshold frying of various foods mg/kg 1,5 1,5 -,5 Glycidol Glycidol 17

18 Formation Can bound MCPD be generated during industrial or individual frying of foods? 2 Fomation of bound MCPD during industrial frying 16 mg/kg bound bound bound glycidol Unter certain conditions private or industrial frying may be a relevant source of bound MCPD as well. 18

19 Removal Is removal of the analytes in edible oils by acid treatment in the heat feasible? Determination of bound glycidol and MCPD during heat treatment of frying fat on palm oil base 2 15 glycidol [mg/kg] 1 temp.-ramping 5 ca. 35 min 3 min 4 h 19

20 Removal [mg/kg] Is removal of the analytes in edible oils by acid treatment in the heat feasible? Determination of ofboundglycidol and andmcpd duringheattreatmentofrefinedpalmoilin treatment frying fat on oil presenceof.7 base % AlF. 3 3 H 2 O glycidol glycidol temp.-ramping Glycidol minimum: 23 C ca. 35 min ca. 3 min 3 min 2 min4 h 2

21 Removal [mg/kg] g] Is removal of the analytes in edible oils by acid treatment in the heat feasible? Determination of ofboundglycidol and andmcpd duringheattreatmentofrefinedpalmoilin treatment frying fat on oil presenceof.7 base % AlF % H. 33 BO 3 H 32 O glycidol glycidol glycidol temp.-ramping Glycidol Glycidol minimum: minimum: 23 C 25 C ca. 35 min ca. 3 min 3 min 2 min4 h Glycidyl esters can be removed in oils & fats by heating in presence of certain inorganic salts/acids 21

22 Stability Long-term stability of analytes during sample storage Repeated analysis of one & the same sample: Reference oil: mix rape seed oil /palm oil (stored at room temperature),8 mg g/kg,6,4,2, glycidol 22

23 Stability Long-term stability of analytes during sample storage Repeated analysis of one & the same sample: Reference oil: mix rape seed oil /palm oil (stored at room temperature) 1 RBD Palm oil: 3 aliquotsstoredatdifferent stored at different temperatures (RT vs.6 C vs.-2 C) mg g/kg,8,6 mg/ /kg,4,2, 12, 12, 1, 1, 8, 8, 6, 6, 4, 4, 2, 2,,, -2 C / RT / 6 C / C -2 C C / Glycidol RT RT / Glycidol 6 C C / Glycidol glycidol 6 C / Glycidol RT / Glycidol -2 C / Glycidol 6 C / RT / -2 C / Bound MCPD seems to be of high long-term stability whereas bound glycidol can exhibit significant decomposition at low temperatures in some cases. 23

24 Conclusions The formation of bound MCPD is not only related to high temperature deodorisation In presence of suitable precusors/catalysts/reactands bound MCPD might be formed as well at medium temperatures e.g. during frying of food, especially fish & meat The reaction of waterfree AlCl 3 with oils can be used as easy snthesis of bound As many others before we found no easy way to remove bound once it has appeared in oils & fats Bound glycidol seems to have a minimum in stability at temperatures around 6 C. On the other hand it might be removed at high temperatures by the presence of certain inorganic acidic components. 24

25 SGS Germany GmbH Dr. Jan Kuhlmann Weidenbaumsweg 137 D-2135 Hamburg Tel.: +49 () mobile: +49 () Thank you for your kind attention! 25