FAT RICH DAIRY PRODUCTS

Module 10. Special butter and related products

Lesson 33
MARGARINE PRODUCTION

33.1 Introduction

Margarine is an emulsion of edible oils and fats with water. Physical properties of margarine are similar to butter. It shall be free from mineral oil and animal body fats. It may contain common salt not exceeding 2.0 per cent, permitted emulsifying and stabilizing agents, BHA or TBHQ upto a maximum limit of 0.02 per cent.

33.2 Definition of Margarine

According to FSSR-2011, margarine is classified as Table margarine and Industrial margarine. Table margarine means an emulsion of edible oils and fats with water. It shall be free from rancidity, mineral oil and animal body fats. It may contain common salt not exceeding 2.5%, skimmed milk powder not exceeding 2%. It shall conform to the following specifications, give below in table.

Table 33.1 FSSR-2011 Requirement for table margarine

Another class of margarine according to FSSR-2011 Act – 2011 is bakery or industrial margarine. It shall be free from added colour and flavour, rancidity, mineral oil and animal body fats. It may contain common salt not exceeding 2.5%, further its standards are listed below.

Table 33.2 FSSR-2011 Requirement for industrial margarine

Table 33.3 Common permitted food additives for Margarine/Table Spread according to FSSR-2011

Natural food colours
Beta carotene	25 mg/kg (maximum)
Annatto extracts (as bixin/norbixin)	20 mg/kg(maximum)
Curcumin	05 mg/kg (maximum)
Antioxidant (Singly or in combination)
Lecithin	GMP
Ascorbic acid	GMP
Propyl gallate, ethyl gallate, Octyl gallate, Dodecyl gallate or a mixture thereof	200ppm (maximum)
Butylated Hydroxy Anisole (BHA)	200ppm (maximum)
Natural and synthetic tocopherols
Citric acid, Tartaric acid, Gallic acid	GMP
TBHQ	200ppm (maximum)
Antioxidant Synergist
Sodium citrate	GMP
Emulsifying agents
Mono and di glycerides of fatty acids	GMP
Mono and di glycerides of fatty acids esterified with acetic, acetyl tartric, citric, lactic, tartaric acids and their sodium and calcium salts	10g/kg (maximum)
Lecithin	GMP
Polyglycerol esters of fatty acids	5g/kg(maximum)
Preservatives
Sorbic acid	1000 mg/kg(maximum)
Sodium/ Potassium/ Calcium sorbate expressed as Sorbic acid	1000 mg/kg(maximum)
Benzoic acid	1000 mg/kg(maximum)
Sodium/ Potassium/ benzoate expressed as Benzoic acid	1000 mg/kg(maximum)
Acidity regulators
Citric acid	GMP
Lactic acid	GMP
Flavours
Natural flavours and natural flavouring substances/ Nature identical flavouring substances/ Artificial flavouring substances	GMP
Diacetyl	4 mg/kg (maximum)

It is also provided further that such coloured and flavoured margarine shall only be sold in sealed packages weighing not more than 500grams. Test for Argememe oil shall be negative. It shall also contain starch not less than 100 p.p.m. and not more than 150 ppm.

33.3 Margarine Process Line

It consists of two blocks one is “dairy block” wherein the cream concentration, pasteurization and cooling of cream takes place and other is “margarine block” wherein preparation of the mix and phase inversion accompanied by working and cooling takes place.

Fig. 33.1 Process line for the production of Spreads

(Source: Tetrapak Processing System, AB, Lund, Sweedan)

Fig. 33.2 Scrapped surface crystallizer

Fig. 33.3 Pin-rotor

Dairy block: Starts with pasteurized cream of 35 to 40 % fat content. Temperature is adjusted to 60 – 70°C before it enters the cream concentrator. Cream fat content is automatically controlled by the continuous standardization device and 82 – 84% fat level is reached in concentrator. Cream is then cooled to 18 – 20°C, before being routed to a holding/pre-crystallization tank (Fig 33.1).

Margarine block: In margarine black product mix is prepared and various ingredients are mixed together, according to the recipe. Concentrated cream is mixed with appropriate volumes of vegetable oil, salt and water phase. After thorough mixing, the mixture is pumped into a buffer tank. The process is continuous from the buffer tank, from which the product mix is taken to the high pressure pump.

It is then fed into the scraped surface coolers, where phase inversion takes place. Before final cooling, the spread is held and worked by pin rotors. The pin-rotors, besides further crystallizing the emulsion, also physically breaks up and works the crystals to improve the texture of the final product. Product enters final cooling stage and then to storage silo. From silo, it is pumped into the filling machine, often a tub-filling machine.

33.4 Factors Which Affects Rheological Quality of Margarine

Solid fat content (SFC): The solid attributes of a margarine fat through a temperature range is characterized by its 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. SFC is measured by nuclear magnetic resonance (NMR) spectroscopy as the number of protons in the solid state over the total number of protons in the fat, i.e. in both solid and liquid states. The consistency of margarine at any temperature can be predicted from its SFC1 or SFI at that temperature. The SFC and crystal components are responsible for the consistency of the margarine.

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. Polymorphs are the different forms of the solid state, this is due to existence of TAG molecules in a number of crystal forms. TAGs can crystallize in different polymorphs with the four major forms being sub-α, α, β’ and β. However, the fat crystals in margarine and shortening are only in β’ and β forms. A pure TAG would be most stable in the β form, but a mixture of TAGs will be most stable in the β’ form. Transformation from one polymorph to another can occur in the solid state without melting. The change is from the lowest to the highest melting point, that is, α to β’, β’ to β. Several factors that influence polymorphism, for example, purity of the fatty acids, temperature, rate of cooling, presence of crystal nuclei and the type of solvent used. The β’-crystal polymorph occurs as single needle-shaped crystals about 5–7 mm long, while the β-crystal polymorph is 20-30mm long. The smaller the crystal, the smoother is the product, while bigger crystals will impart a coarse, grainy and brittle texture.

33.5 Merits and Demerits of Margarine

Margarine has the following merits compare to butter

● Spreadability: It is one of the most highly regarded attributes and margarine shows good spreadability at refrigeration temperature as compare to butter. Products with a solid fat index (SFI) of 10–20 at serving temperature were found to be optimal on a consumer panel. SFI at 10°C have been recorded and that is in the range of 19-21.

● 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. It varies from smooth to mealy or floury, grassy, granular or sandy and, finally, coarse and lumpy. This attribute can be altered to the desired level by using different vegetable oil in the formulation where as butter has less scope to alter consistency and texture.

● Contains minimum or no cholesterol in the product

● Product is cheaper than butter

● Following are the demerits of Margarine

● Bland in flavor and taste: Flavour and mouthfeel of margarine is weak as compare to butter.

● Oil Separation: There is possibilities of oil separation when the crystal matrix is inadequate to entrap the liquid oil. This occurs because of transformation of the crystals to the β-form. The β -crystals continuously grow bigger (causing sandiness) until the network can no longer retain its lattice structure to entrap the liquid oil. The liquid oil then exudes from the product and the aqueous phase coalesces.

● Sandiness: β’ polymorph is the desired form in margarine. β’ has very small crystals so that it can incorporate a large volume of liquid oil in the crystal network giving a smooth, continuous and homogeneous product. However, the β -crystals have the tendency to grow bigger and bigger into needle-like agglomerates. The large crystals impart a sensation of sandiness in the mouth.

33.6 Packaging of Margarine

The wrapping material must be

• Grease proof

• Impervious to light,flavouring and aromatic substances.

• Impermeable to moisture

• Parchment paper

• Aluminum foil

• Outer paper cartons with PE layer inside

• Plastic tubs of PP / PS.

• Can withstand storage temperature of 5°C.

Margarine is first wrapped in parchment paper, after wrapping the pat or bar packets continue to a cartoning machine for packing in cardboard boxes, which are subsequently loaded on pallets and transported to the cold store. Tubs are also used for margarine packing.

33.7 Uses

* Table margarine is used for direct consumption in place of table butter

* Industrial margarine is used in confectionery and bakery industry as softener.