FAT RICH DAIRY PRODUCTS

Module 10. Special butter and related products

Lesson 32
FAT SPREADS

32.1 Introduction

Spreads have a similar composition to margarine but are usually lower in fat. Low fat spreads have a fat content of 40g/100g. Spreads may be fortified with vitamins A and D. The production of margarine and spreads is very different to that of butter. Butter is pure and natural and has undergone minimal processing, whereas margarines and spreads are heavily processed and contain a number of additives, preservatives and colour compounds.

32.2 Classification of Spreads

Fat Spreads are classified as,

1. Dairy Spreads: Wherein only milk fat is used as a source of fat

2. Non-Dairy Spreads: Wherein Vegetable fat with or without milk fat used as a source of fat

In Indian contest fat spreads can further classified as follows.

1. Low fat spreads: Fat percent will be between 40 to 60%

2. Reduced fat spread: Fat percent will be between 60 – 70%fat

Eg: Amul lite: 10% Milk fat and 49% vegetable fat.

Based on fat content spread and margarine products are as classified as follows.

Table 32.1 FSSR-2011 classification of Fat Spreads

(a) Milk fat spread.............made of exclusively milk fat.

(b) Mixed fat spread.....made of a mixture of milk fat with any one or more of hydrogentated, un-hydrogenated, refined edible vegetable oils or interesterified fat.

(c) Vegetable fat spread……made of a mixture of any two or more of hydrogenated, unhydrogenated, refined vegetable oils or interesterified fat.

32.3 FSSR-2011 Definition For Fat Spread

According to FSSR-2011, fat spread is a product in the form of water in oil emulsion,

· Product may contain not more than 80%Fat and not less than 40%Fat by weight,

· Moisture should not be more than 56% and not less than 16% by weight,

· It may contain edible salt not exceeding 2% by weight in aqueous phase,

· Starch not less than 100ppm and not more than 150ppm,

· Diacetyl may be used as flavouring agent not exceeding 4.0ppm

· Permitted class II preservatives namely sorbic acid, and its sodium, potassium and calcium salts (calculated as sorbic acid), benzoic acid and its sodium its sodium and potassium salts (calculated as benzoic acid) singly or in combination not exceeding 1000 parts per million by weight,

· It may contain sequestering agent,

· Permitted emulsifier and stabilizer, permitted antioxidants (BHA or TBHQ) not exceeding 0.02% of the fat content of the spread,

· It may contain annatto and/or carotene as colouring agents,

· It shall be free from animal body fat, mineral oil and wax,

· Vegetable fat spread shall contain raw or refined Sesame oil (Til oil) in sufficient quantity, (so that when separated fat is mixed with refined groundnut oil in the proportion of 20:80 the red colour produced by Baudouin test shall not be lighter than 2.5 red units in 1 cm cell on a Lovibond scale.)

· The vegetable fat spread shall contain not less than 25 IU synthetic vitamin 'A' per gram at the time of packing

· Acid value of extracted fat should not be more than 0.5.

· Melting point of Extracted fat should not be more than 370C, in case of vegetable fat spread using capillary method.

· Unsaponifiable matter of extracted fat

(a) In case of milk fat and mixed fat spread Not more than 1 per cent by weight

(b) In case of vegetable fat spread Not more than 1.5 per cent

(c) Acid value of extracted fat Not more than 0.5

32.4 Labeling of Fat Spread

The word 'butter' will not be associated while labeling the product. The fat content shall be declared on the label. In mixed fat spread, the milk fat content shall also be declared on the label along with the total fat content.It shall be compulsorily sold in sealed packages weighing not more than 500gram under Agmark certification mark.

32.5 Manufacturing Process of Fat Spread

In general, production of spreads can be divided into the following parts:

· Preparation of the water phase and fat phase

· Emulsion preparation

· Pasteurisation

· Crystallisation

· Filling

The emulsion consists of a fat phase and a water phase. Minor ingredients such as emulsifiers, salt, preservatives or additives, colour, flavour and vitamins are dispersed in the respective phases according to their solubility. Consequently, the raw materials used in the emulsion preparation prior to processing of spreads can be divided into a fat phase and a water phase. The major ingredients in the fat phase are:

· Fat blend, normally consist of a blend of different fats and oils in order to achieve a defined solid fat content. In regard to reduced fat products, the fat phase constitutes less than 60% of the total emulsion.

· Minor ingredients such as emulsifier, lecithin, flavour and colour are dissolved in the fat phase before emulsification. Fat-soluble flavour and colour, butter flavour and β-carotene are added to achieve products which taste and look like butter. In addition, β-carotene has pro-vitamin A activity.

The major ingredients in the water phase are

·Water in which the minor ingredients are dissolved.

·Salt and preservative, whey powder, skimmed milk powder or other types of milk can be added.

· Since high water content is available n spreads, stabiliser(s) system is needed in order to have the necessary stability in the final crystallised product. Water-soluble flavour and colour can also be added, but are primarily used in low fat spreads. Alginates, pectin and carrageenans have a good water binding effect and gives stable emulsions.

Fig. 32.1 Schematic diagram of manufacture of vegetable fat spread.

In the case of low fat spreads, the water phase and the oil should have similar temperature and should be combined slowly when forming the emulsion. Additionally, it is very important that the emulsion is properly agitated to ensure homogeneity. However, care should be taken not to incorporate air during emulsification.

Prior to entering the crystallisation equipment, the emulsion is pasteurised, preferably in a scraped surface heat exchanger. A typical pasteurization process include a heating and holding sequence of the emulsion at 75-85°C for 16 sec. and subsequently a cooling process to a temperature of 45-55°C. The end temperature depends on the melting point of the fat phase: the higher the melting point, the higher the temperature.

The emulsion is pumped to the crystallisation line by means of a high pressure plunger pump (HPP). The crystallisation line for the production of margarine and related products typically consists of a high pressure SSHE which is cooled by ammonia or Freon type cooling media. The heart of the crystallisation line is the high pressure SSHE, in which the warm emulsion is super-cooled and crystallised on the inner surface of the chilling tube. The emulsion is efficiently scraped off by the rotating scrapers, thus the emulsion is chilled and kneaded simultaneously. When the fat in the emulsion crystallises, the fat crystals form a three-dimensional network entrapping the water droplets and the liquid oil, resulting in products with properties of plastic semi-solid nature. The crystallisation process, the processing conditions and the processing parameters have a great influence on the characteristics of the final spread product.

Limitations of conventional process: Using conventional mixers and agitators several difficulties can arise

i. Additives designed to thicken the product tend to form agglomerates which agitators cannot easily break down

ii. Long processing times are often required to complete hydration.

iii. Poor hydration may lead to unsatisfactory “mouthfeel”, and an unstable product

iv. Leading to storage problems once the product has been opened.

So, to overcome these limitations venturi assembly is introduced which is shown below schematically.

Fig. 32.2 Schematic diagram of manufacture of vegetable fat spread with venturi system

Selection of ingredients for Fat Spread: Major ingredients are commonly used in preparation of spreads are milk fat, milk proteins, vegetable fat, emulsifiers, stabilizers, acidulants, salt, colouring & flavouring agents, vitamins, and antioxidants.

Source and role of fat: Milk fat - cream, butter, butter oil, vegetable fat - sunflower, corn, soyabean & groundnut oil are preferred, milk fat fractions / vegetable oil fractions can also be used. Fat provides structure, energy, and taste including creaminess. It is acarrier of flavour and vitamins. It is good source of essential fatty acids. It improves spreadibility, firmness, plasticity depending on amount of fat used in the spread.

Source and role of Protein: Milk Protein - SMP, Whey Powder, WPC; Vegetable protein - Soy protein isolate Improve organoleptic, functional and nutritional properties Proteins play a role in viscosity, water holding capacity as well. Protein helps in enhancing emulsion stability of the spreads.

Emulsifiers: Fat soluble emulsifiers are preferred because of fat is the major portion in the product also fat present in continuous phase. Monoglycerides of saturated fatty acids, unsaturated fatty acids, lecithin, egg yolk solids are used at a level of 0.1 to 0.6%. These emulsifiers help in reducing the size of aqueous droplets and create stabilizing films at the water/oil interface, so product will be more softer and spreadable.

Stabilizers: Especially important in reduced/low fat spreads wherein high water holding ability of stabilizer improves body & texture of the spread. They help in increasing the viscosity and also to inhibit the coalescence of aqueous phase droplets during processing. Carboxy methy cellulose(CMC), Modified starch, Sodium alginate, starch can be used as stabilizers at a level of 0.1 to 0.5%.

Following are the two typical recipes of mixed fat spreads

32.6 Packaging

Moisture and air proof containers are required to pack this fat rich product. Suitable packaging materials for this purpose are polystyrene based / polypropylene based cups or tubs, polyethylene coated paper packs along with parchment paper.

32.7 Shelf Life and Storage

Various factors influences the shelf life of the fat spreads, they are

i. Moisture content

ii. Process treatment

iii. Type of ingredients

iv. Salt content

v. pH of the product

vi. Temperature of storage

vii. Preservative level

Refrigerated Storage is preferred for long life at 5°C, shelf life varies from 90days to 180days. Processing conditions & formulations also have influence on the shelf life of the product.

32.8 Uses

* Direct consumption along with sandwiches, salads etc.,

* Confectionery industry

* Bakery Industry