Quality criteria for edible argan oil Results from a market survey Bertrand Matthäus und Ludger Brühl Max Rubner-Institut, Bundesforschungsinsitut für Ernährung und Lebensmittel Schützenberg 1; D-3756 Detmold, email: bertrand.matthaus@mri.bund.de
Why the definition of quality criteria is necessary qualitas State, grade or value Quality criteria describe how a product is or should be constituted They serve as basis for the business quality criteria The definition of quality criteria are the measure of all things, because without specification of demands we have product no quality producer consumer
Where is quality of vegetable oils defined? Regulation (EC) No 178/: No food stuff dangerous to health and/or unfit for consumption may be placed on the market Edible oils Codex Alimentarius Sensory evaluation Composition Peroxide value Acid value Contaminants National standards Guideline for edible fats and oils (Germany) Canola standard (Canola Council of Canada) Moroccan standard N.M. 8.5.9 Quality seals Award of the German Agricultural Society
Identity criteria and quality features for the assessment of edible oils Identity criteria Fatty acid composition Tocopherol composition Sterol composition Contaminants PAH (Benzo(a)pyrene) Phthalates Pesticides 3-MCPD esters Quality features Sensory evaluation Content of free fatty acids Peroxide value Anisidine value Totox value Content of chlorophyll Oxidative stability Content of steradienes Smoke point The sensory evaluation of the oil is one of the most important quality features for edible oils! Bioactive compounds Tocopherols Sterols Canolol Q1/Q9
Sensory evaluation form for cold pressed argan oil typical attributes 1 3 4 5 nutty (roasty) atypical attributes Roquefort cheese rancid wood-like bitter burnt musty yeast-like fusty others
Intensity of the sensory perception [ = not perceptible; 4 = strong perceptible] Intensity of the sensory perception [ = not perceptible; 4 = strong perceptible] Sensory evaluation of different argan oil from the Swiss and German market nutty roasty burnt Roquefort cheese fusty 4 3 4 3 1 nutty roasty 1 1 1 3 4 5 6 7 8 9 1 11 1 13 14 15 16 17 1 = Cooperative Tighanimine Tilahia = Cooperative Female Taitmatine
Roquefort Roquefort Roquefort Roquefort Effect of processing of the sensory quality during storage A nutty B nutty 1 roasty 1 roasty C fusty nutty 3 1 Storage time weeks weeks D roasty fusty 3 nutty 1 roasty A: unroasted, mech. extracted B: roasted, mech. extracted C: roasted, trad. extracted D: roasted, goats, trad. extracted fusty fusty
Content [%] Identity of argan oil (I) SFA Oleic acid Linoleic acid Linolenic acid Ratio linoleic acid/ linolenic acid Argan oil 45 34,1 34:1 Rapeseed oil 6.6 58 1 :1 Olive oil 14 7 8,9 9.6:1 18 16 14 1 1 8 6 4 Triacylglycerol composition
Tocopherol content [mg/kg] Content [mg/kg] Content [mg/kg] Identity of argan oil (II) 5 45 9 8 7 6 5 4 3 1 4 35 3 5 15 1 5 α-tocopherol γ-tocopherol δ-tocopherol -T -T -T -T P-8 -T3 -T3 -T3 15 1 5 Grapeseed oil Rapeseed oil Linseed oil Sunflower oil Soybean oil Olive oil Wheat germ oil Hempseed oil
Peroxide value [meq O /kg], anisidine value, totox value Peroxide value, anisidine value and totox value 3 5 15 1 5 Peroxide value Anisidine value Totox value German Guidelines for Edible Fats and Oils, 11 Argan oil, virgin, fine, Moroccan standard N.M. 8.5.9 Argan oil, virgin, extra, Moroccan standard N.M. 8.5.9 Rossell, 1989 Frankel, 5 16 1 3 11 14 13 7 1 9 8 6 15 5 4 1 17 Sample number
Oxidative stability, free fatty acids and smoke point Sample number Oxidative stability [h] Predicted shelf-life [days] month before the best before date Free fatty acids [g/1 g] Smoke point [ C] 1 5.7 4.53 6. 54.4 3 1. 436.33 184 4 5.1 17 4.9 5 9.7 413 8.53 179 6 5.6 39 6.7 7 6.3 71.1 8 5.6 4 1.19 9 9.4 4 4.48 1 9. 39 9.3 177 11 6. 64 1.69 1 5.1 18 4.64 165 13 6.7 84 4 1.16 163 14 6.1 59 15.4 16 15 4.6 198 1.5 171 16 9.4 399 1.45 168 17 5.8 49 6.64 155
Content of hydrocarbons [mg/kg] Content of mineral oil saturated hydrocarbons 7 6 5 4 3 1 11 1 1 15 3 17 8 1 7 16 13 5 6 9 14 4 Sample number
Summary A constant high quality is important for the further success of argan oil on the international level. Especially the sensory quality needs some further improvement. The occurrence of attributes like fusty or Roquefort cheese but also burnt resulting from the choice of improper raw material can endanger the whole success. The identity of argan oil can easily be ensured by systematically monitoring of the tocopherol, sterol and triacylglycerols composition. Results from oxidative stability and oxidative state recommend a shelflife of only one year for cold-pressed argan oil. Unusual high contents of mineral oils from external sources can be a problem.
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