Karteikarten
Margarine & Spreads processing
Karten in diesem Stapel (12)
- 1What is margarine?Margarine is 80% fat. Water in fat emulsion. Water dispersed phase; fat continuous phase – stable crystalline network.
Fats and oils built of fatty acids:
CH3CH2COOH – Can be saturated (C-C) or unsaturated (C=C).
Saturated FA are straight and pack together closely = denser = solid at room temp
Unsaturated FA have a kink and do not pack together closely = liquid at room temp = oil
FAs (x3) form Triglycerides with Glycerol, releasing 3 H2O molecules. - 2General FA compositionMargarine = mainly made of monounsaturated FA as opposed to sunflower oil, whose main component is Polyunsaturated FA. Sunflower oil has a higher chance of rancidity due to it’s polyunsaturation – the more double bonds present, the higher chance of rancidity as free radicals formed and higher chance of oxidative rancidity. Marg much lower chance of rancidity.
- 3Margarine fat requirementsFat groups must contain at least 10% fat content, but <90%. Must be a W/O emulsion, fit for human consumption with milk content no higher than 3% above fat content. Must remain solid at 20oC.
Margarine: 80% - <90% fat
¾ Fat Margarine: ~ 60% fat content
½ Fat Margarine: ~ 40% fat content - 4Margarine raw materialsOil/Fat: combo of the 2
Emulsifier: mono-&di-glycerides, lecithin. Dispersed in continuous phase (fat/oil)
Milk/Protein: Whey, Albumin, Casein, Caseinate, Soy Protein Isolate.
Preservatives: salts – sorbic acid/benzoic acid and their salts. protect against microbial spoilage.
Flavour: Synthetic butter flavour (ketones and aldehydes etc), salt
Vitamins/colours: Mandatory Vit A fortification, Vit D optional. B-Carotene and vit A also help with colour enhancement. - 5OIL REFININGDegumming – Removal of phospholipids (in process flow - GUM out), important by-product is lecithin. Separate the 2 phases by centrifugation.
Neutralisation – Removal of FA using alkali. Soap produced so centrifuge to remove soap.
Bleaching – Removal of pigments using activated charcoal which is absorbent.
Deodorisation – Removal of volatiles and odours by steam distillation under vacuum.
Hydrogenation – optional step in oil refining:
- Converts double bonds to single bonds by adding H2 and using a Ni catalyst.
- Increases melting pt
- Lowers degree of unsaturation = more resistant to auto-oxidation.
- Changes plastic properties of fat
- Partial hydrogenation can lead to formation of trans fatty acids. - 6oil processing flow
- 7optional steps in oil processingInteresterification – modify fats by changing the position of FAs in relation to glycerol molecules. Can help achieve wide melting range and better balance of properties. Use chemical catalysts and high temps.
Fractionation – separating different fat fractions based on melting pts.
Crystals form through selective crystallisation based on mpts of fat. - 8EMULSIFICATIONTo produce finely dispersed aqueous phase in melted oil, by continuously blending oil and aqueous phases by dosing pump/metering devices.
- 9CRYSTALLISATIONSlow formation of fat crystals from melt by cooling. 2 types: Crystal nucleation and crystal growth. 3 forms a, B’, B
a = least stable, small
B’ = finer
B = most stable, course.
[Crystallisation creates the w/o emulsion. Needs to be very controlled to prevent creating crystals that give a grainy texture/wrong spreadability. aim for B’?] - 10MARGARINE FLOW DIAGRAM
- 11Scraped surface heat exchanger in margarine productionSuitable for higher viscosity and crystalline products.
Concentric pipe heat exchangers with agitated rotating scraper blades in inner pipe. (Multiple different scraper blades available). Refrigerant in annular space. - 12SFISolid Fat Index => proportion of fat in solid form in product (amount of solid fat as a % of total fat). Gives the crystallinity of the fat important to give the right kind of spreadabiity of margarine typically 20% at 20oC.
Should have easy spreading at 4-10oC so SFC must not exceed 35% at 10oC.
Packaging at 5-10oC. SFC of 15% at 15oC for easy packing.
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- Beschreibung
- 4 th yr Food Science SEM 1 (9. Margarine and Spreads Processing) Karteikarten am Margarine & Spreads processing, erstellt von Lizzy Cottam am 11/01/2017.
- Erstellt von
- Lizzy Cottam
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- 2
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