Properties of margarine

Margarine was invented in France by Hippolyte Mèges-Mouries. It was patented and first manufactured in 1869. The product was developed to meet butter shortages caused by the increasing urban population during the Industrial Revolution, as well as the need for a table spread with satisfactory keeping quality for the armed forces.

Margarine is a butter substitute that is made from vegetable oils that have been solidified by a process called hydrogenation. Depending on the type of margarine, the process can be fully hydrogenated, causing the oils to solidify, or partially hydrogenated, causing the semisolid oils to be lighter and more spreadable with more water, carbohydrate and protein stabilizers.

The aqueous phase consists of water, salt and preservatives. The fatty phase, which contributes to the polymorphic behaviour of margarine, is a blend of oils and fats. Margarine is recognized as a healthy table spread and a cheaper alternative to butter for use in cooking and in food preparation.

A good margarine should not suffer oil separation, discolouration, hardening, sandiness, graininess and water separation. The oils and fats, process conditions and handling methods used should be selected so as not to produce a strong crystal network, crystal migration and transformation of β’- to β-crystals.

Spreadability is one of the most highly regarded attributes of margarine, perhaps

second only to flavour. Products with a solid fat index (SFI) of 10–20 at serving temperature were found to be optimal on a consumer panel.

Consistency and texture
Consistency is the measure of smoothness, evenness and plastic state in margarine. It can range from very soft, like petroleum jelly, to soft, medium, firm, tough, hard and brittle. Texture is a measure of the structure.

Oil Separation Oil-off occurs in margarine when the matrix of fine fat crystals is no longer of sufficient size or character to be able to enmesh all of the liquid oil. The problem is most serious for stick products as the outside of the inner wrappers may become oil soaked, and if severe, oil will leak out of the package.

An important physical attribute of margarines is that they are spreadable even when first lifted out of a refrigerator. A harder margarine is used in the bakery industry and a still harder margarine with a high melting point is used in puff pastry to facilitate rolling into the dough.

Melting A high-quality table margarine melts quickly with a cooling sensation on the palate. Flavour and salt components of the aqueous phase are immediately perceptible by the taste buds, and there is no lingering greasiness or waxiness. The melting performance of margarines is normally expressed by the solid phase line. This gives the concentration of solids (determined by Nuclear Magnetic Resonance) as a function of temperature. For margarines, the temperature range from around 10ºC (leaving the refrigerator) to around 40ºC (melting in the mouth) is of importance.

Solid fat content
The solid attributes of a margarine fat through a temperature range is characterized by its solid fat content SFC or solid fat index (SFI) profile. SFC is an important property of an oil or fat, and is the ratio of the solid to the total phase at a particular temperature.

Polymorphic form
Polymorphic forms are the solid phases of the same chemical composition with different crystalline structures, but which yields identical liquid phases on melting.
Properties of margarine