Although most people still use the term margarine to refer to any type of table spread, the Food Standards Code defines margarine to contain at least 80% fat. Spreads require about 60% fat to suit baking purposes. You can use lower-fat spreads for ‘spreading’ on bread during toasting.
Brief history of margarine
Hyppolyte Mege Mouries, a French chemist, developed and patented the formula for making margarines.
He came up with the formula at the height of industrial revolution in the late 1860s when the swelling number of urban dwellers outstripped the available butter supply.
He made it as an imitation of the real butter to meet the demand. Fortunately for him, margarine became very popular due to its lower cost and close imitation of butter.
The real butter was so expensive that only the wealthy could afford it. The low-cost of margarine gave the poor people an opportunity to use spreads on their breads.
Types of margarine
There are two types of margarine in the market, namely:
a) Table margarine
This is the type of margarine that people regularly use as a table spread. It should have a wide melting point range, easy spread, and quick melting in the mouth.
b) Confectionery/bakery margarine
This type of margarine is common in the confectionery/baking industry. Just as the name suggest, it is useful for making cakes, biscuits, and other pastries. To make it more plastic, the manufacturer adds about 4-8% of hard fat.
To achieve a higher Solid Fat Index (SFI), it is advisable to keep this type of margarine at temperatures of between 33.3°C and 37.8°C. bakery margarine has a rapid creaming rate, wide plastic range, and a small proportion of fully hydrogenated fat (melting point 54°C).
Fat separation is critical to obtaining the right proportions of the fat blends. Different fats have different melting points, hence the applicability of the fractionation method.
Melting characteristics of fats:
Ingredients for making margarine:
- Refined vegetable oil/fat
- Milk/whey/cream/reconstituted skimmed milk/skimmed milk/milk powder (optional)
- Salt and other flavors
- Emulsifiers and antioxidants
- Color e.g. annato
- Vitamins e.g. vitamins A,D, and E
- Plant sterols (optional) - they can reduce low density lipoproteins (LDL)/bad cholesterol
- Other additives of your choice, e.g. spices
Procedure for making margarine
Step one: Fat Blend formulation
Here, you blend different refined oils and fats to meet the requirements of a given type of margarine. Some blends have one, others two or more fat/oil blends. Whatever the case, the aim of blending is to have a high-quality blend that will produce the highest quality product.
The final blend should exhibit high level of stability, suitable consistency, and wide range of plasticity at varying temperatures.
Plasticity and spread ability are key features of a high-quality margarine, which depend on the ration of solid to liquid phases.
The crystalline character of the solid phase will determine the consistency and firmness of the margarine.
While blending, be careful to ensure that you obtain the same physical properties of the butterfat regardless of the climatic conditions and temperatures. You should obtain refined fats and oils from the factory ready for blending.
Fat blend refining process
Involves removal of phospholipids and other water-soluble materials from the crude oil. Heat the oil and 1-3 percent water to a temperature of 70°C for half an hour to one hour. After heating, separate the mixture by centrifugation into degummed oil, gums, and water.
b) Neutralization/ saponification
Saponification is the removal of the free fatty acids from the oil. Neutralize the acids by sodium hydroxide (NaOH) to get neutralized oil and soap. Heat the oil and NaOH to 90°C for 60 minutes then wash with water and separate by centrifugation. You further hydrolyse the soap by adding an acid to get fatty acids and sodium acid and water. You centrifuge this mixture once again to separate the fatty acids from the soap stock.
Bleaching involves the removal of pigmentation, metals, soap, hydroxides, and base residues from the neutralized oil. The preferred bleach is bleaching earth (fine ground earth mineral material).
After adding the bleach, heat the mixture to 105°C for 30 to 60 minutes. After this, separate the mixture by a filtration process.
This step is necessary to expel all the off-flavors in the oil. Carbonyls and hydroperoxides are the major culprits for the volatile flavors.
To achieve deodorization, heat the oil to temperature of between 205°C and 275°C under vacuum (1 – 5 mmHg) for between 3 – 8 hours.
The vacuum will remove oxygen and promote vaporization. The volatile flavors will escape with the vapor.
After vaporization, cool the oil blend to temperatures of between 140°C - 150°C and add 50 ppm of citric acid to scavenge for copper and iron metals by chelation.
Hydrogenation is the addition of hydrogen to saturate the double bonds of the fatty acids. Saturation will make the product firmer and more stable to prevent oxidation. Hydrogenation is effective in the presence of a catalyst such as nickel.
Hydrogenation increases the melting point of the oil/fat and improves its resistance to oxidation and flavor deterioration.
Add hydrogen gas into the oil and heat to 200°C at 90 psi for between 6 and 16 hours in the presence of nickel. After this holding period, cool and filter the mixture to remove the nickel.
Step two: Blending the fats
The fat blends constitute the fatty phase of the margarine. The objective of making the fat blend is to obtain a mixture with a steep SFI curve.
This will ensure that the product remains firm under refrigeration but fairly spreadable and easily melts in the mouth.
Storage of fat blends
For easy handling and transportation, it is advisable to keep the refined oils/fats in liquid state.
If you have to store them for more than three days, it is better to convert them to solid and later remelt shortly before use. This will help you avoid the unnecessary oxidation.
Store solid fats in melting tanks fitted with agitators to keep the fats liquefied and homogeneous before transferring them to the composition tanks where you will weigh them into various proportions.
The composition tanks should be warm to avoid recrystallization of the high meting constituents. Store the individual fats slightly above their individual melting points.
Add fat soluble ingredients such as coloring matter and vitamin concentrates at this point.
The three typical mixtures of the margarine
- Hydrogenated groundnut oil melting point 45°C (25%) + Cotton seed oil liquid (25%) + Coconut oil melting point 24°C (50%)
- Hydrogenated groundnut oil melting point 45°C (18%) + Hydrogenated groundnut oil melting point 32°C (40%) + Groundnut oil liquid (22%) + Palm kernel oil melting point 28°C (20%)
- Coconut oil (40%) + Palm kernel oil melting point 28°C (20%) + Soya bean oil liquid (20%) + Hydrogenated whale oil melting point 45°C (20%).
Step three: Tempering of the fat blends
Tempering tanks consist of hot water jacket or coils for heating and a stirrer. These will be instrumental in adjusting the temperatures of the fat blends for the subsequent steps, emulsification or churning since different fats have different temperatures.
The temperatures depend on the blend and emulsification techniques. The temperatures may vary from 26°C to 40°C or even higher if you are making confectionery margarine.
Step four: Preparation of the aqueous phase
You can use skim milk or water or even a mixture of skim milk and water for the aqueous phase. You may also add some water-soluble ingredients.
Emulsify the milk containing part with fat blends to produce a product that tastes and feels like butter. The amount of milk varies from country to country and from product to product; however, the best brands of margarine contain at least 12% milk.
Reasons for using milk for aqueous phase are four-fold
- Imparts desirable flavor and aroma and eliminates any too marked sensation of fat on the palate.
- Aids in emulsion production and stabilization
- It retards by its denatured serum proteins development of undesirable taste by oxidation of the fat during storage
- Provides some of the solid, non-fatty ingredients, which give the uncharacteristic brown, granular, aromatic sediment as does butter when you subject it to frying.
You can use milk in the form of cream, whole milk, skimmed milk, reconstituted milk, whey, and/or buttermilk for the constitution.
Some countries prohibit the use of milk and milk derivatives in margarine. In such cases, you only have the option of using water for the aqueous phase.
However, in most instances, milk, skimmed milk or reconstituted skimmed milk forms the basis of the aqueous phase.
Preparing the aqueous mix
After mixing the aqueous phase, pasteurize it to produce the desired diacetyl aroma just as the one obtained from cultured butter.
Inoculate 1% acid and aroma producing starter culture into the pasteurized serum milk phase to ripen it and produce the aroma.
Some manufacturers prefer to introduce the flavor concentrated into the aqueous phase rather than culture it.
Permitted food grade chemical preservatives, e.g. benzoic and sorbic acid, prevent deterioration of the product. Antioxidants prevent oxidation defects that might arise.
Step five: Emulsion blending and mixing
Churning and emulsification
Here, you mix the fat blends and the aqueous phase with their ingredients to produce an emulsion. Churn the emulsion vigorously at temperatures of between 32°C - 35°C to produce a homogenous product.
Ensure the churn has strong baffles to facilitate mixing and shearing of the mixture. It should also have a jacket to facilitate efficient heating and cooling.
Cooling and crystallization of the emulsion
After mixing, subject the mixture to shock cooling to -4°C - 10°C and rapid solidification to fix the emulsion and ensure desired crystal formation for better consistency and smooth texture.
Introduce the emulsion onto a cooling surface, usually a rotating drum that brings the temperature to below the freezing point. The product should come out as dry flakes or a soft sheet; the latter is preferable.
Some systems use brine as the coolant while majority of systems use direct expansion ammonia.
Step six: Tempering
The flaky substance or sheet that results from shock cooling has a high solid to liquid ration, hence reduced plasticity.
Tempering in rollers of various designs aims to increase the product plasticity by reducing the solid to liquid ratio by slowly increasing the temperature to 10°C - 15°C from -4°C - 10°C as it matures. This process is called resting period and it may last for between 12 – 18 hours depending on the type of margarine you are making.
The favorable solid to liquid ratio that result from the maturing period facilitates kneading and plasticizing. However, when you are manufacturing the margarine by a continuous process, you may completely omit this step.
Step seven: Kneading and plasticizing
Here, you work the margarine mixture to impart the qualities of consistency and firmness.
Subject the margarine to deformation by exerting pressure and shearing forces by using roller bats, kneading tables and/or mixers/blenders.
You can add salt and other ingredients at this stage die to the thoroughness of the mixing process.
Step eight: Blending
Blending is applicable to the batch method where you can use high-speed blenders to knead the margarine and give it the final working and plasticizing.
This step facilitates proper quality control to ensure consistent quality of different batches. You can also use this step to adjust standardization of the water and other ingredients such as salt.
Step nine: Packaging
After blending, allow the margarine to rest in the cold store at 10°C - 12°C to harden it some more before you mold and package it.
These nine simple steps will guide you through the process and show you how simply you can make margarine even at home.