FAT RICH DAIRY PRODUCTS

Module 4. Consumer cream products

Lesson 12
OTHER CONSUMER CREAM PRODUCTS

12.1 Introduction

Cream products are classified according to their method of production and their fat content. Cream is defined as that part of milk rich in fat which has been separated by skimming or otherwise and compulsory descriptions exist for clotted cream, double cream, whipping cream, whipped cream, sterilized cream, cream or single cream, sterilized half cream and half cream. Pasteurized cream accounts for most of the cream produced for retail consumption and industrial use. Other pasteurized creams include extra thick creams, the texture of which is modified by homogenization and sequential cooling, and frozen versions of single, whipping and double creams. UHT creams conforming to the standards for half, single, whipping and double creams are made for the convenience of extended life storage at ambient temperatures. UHT cream packed in aerosol containers with a nitrous oxide propellant and containing, for example, sugar, carrageenan and mono- and di-glycerides of fatty acids to enhance foam stability, are available for dessert and beverage applications example for topping hot chocolate.

12.2 Half and Single Creams (10-18 Percent Fat)

These creams would normally be used as pouring creams for use in desserts and beverages. Homogenization is essential for half and single creams both to produce an acceptable viscosity and to prevent separation of the fat and serum phases. Single cream is commonly subject to single-stage homogenization at pressures up to 25 MPa, but higher pressures of up to 30 MPa, are required to produce an acceptable viscosity in half cream. In each case a homogenization temperature of 55°C is used. In the US a product described as 'half and half is retailed and consists of a mixture of milk and cream with a fat content between 10.5 and 18%. 'Light' cream has a fat content of 18-30%.

12.3 Double Cream (> 48% Fat)

Double cream is marketed predominantly in Europe and represents an extra rich product for addition to desserts. Homogenization is not usually necessary for double cream with the exception of UHT sterilized product. Homogenization, controlled cooling, or a combination of these processes may, however, be used to produce 'extra-thick' pasteurized creams of much higher viscosity than is normal. Single-stage homogenization is used at a pressure of 3.5 MPa, or less, at. 55°C.

12.3.1 High-fat spreadable creams

These are produced in other countries including Yugoslavia and Iran. Manufacture of some types involve passage of cream through a second, specially designed separator, but in other cases a heating process similar to that of scald cream is used.

12.3.2 High fat creams

Several high fat spredable creams are found as indigenous products around the world. Examples are Gammer cream (Iraq) and Kajmac (Yugoslavia). High fat creams can be simply produced by passing normal cream through a second separation. Such a separator should have relatively wide disc spacing, and the distribution channels should be approximately half way down the disc faces. As the fat content in the cream rises and the globules pack together more tightly, the stability of the emulsion is reduced and phase inversion takes place very easily. A very high fat cream (70-80 percent fat) is known as plastic cream.

12.3.3 Confectionary, butter or mock creams

Such products are low moisture products containing high concentrations of sugar or other sweeteners and are used as cake and bun fillings. They are in fact, phase inverted creams with the aqueous phase emulsified in the fat. The fat base is aerated by mechanical beating. Sweetener is usually added later.

12.3.4 Dried cream

Dried cream may be considered to be a dried milk product with a higher fat content than dry whole milk. Depending on the initial cream the fat content is 40-70% and the moisture content is less than 2% (cf. anhydrous milk fat). Spray drying is used, problems arising not from the drying stage, but from handling the warm powder. The fat is in the liquid state on leaving the drying chamber and prone to membrane rupture and subsequent caking. Non-fat solids, usually sodium caseinate, and a carbohydrate carrier (lactose, sucrose or glucose) must be present to encapsulate and protect the fat globules and cyclone separation is not suitable due to caking on the cyclone walls and blocking of filters. A satisfactory solution is to remove the powder from the dryer on a moving belt and cool to solidify the fat in a fluidized bed. Alternatively, the Filtermat dryer may be used.

Dried cream powder is susceptible to oxidation and manufacture requires a high heat treatment, prior to drying, to inactivate lipases and the addition of an anti-oxidant before storage. A 'free-flow' agent such as calcium silicate should also be added and the storage temperature should be sufficiently low to maintain the fat in solid form and prevent caking. Dried cream has only limited functionality and does not reform as the natural product unless special emulsification and homogenization procedures are used. The product does, however, have an ingredient role as a free-flowing milk fat concentrate.

12.4 Cream Substitutes

The demand for substitutes arises primarily for economic reasons rather than the dietary concern which has stimulated the development of other dairy product substitutes. Indeed the high sugar content of many substitute creams precludes their acceptance as truly 'healthful' foods, although low calorie and reduced-fat substitutes are now increasingly popular.

Imitation cream

It is available in a number of consistencies corresponding to different types of natural cream. The product resembles natural cream in being a fat-in-water emulsion. A fat content of 15% is common and such a formulation also containing 7% sugar, 3% milk solids-non-fat and 0.4% emulsifier. When vegetable fats are used, the selection of fats depends on the properties required in the end product. Fat modification permits close matching with desirable organoleptic properties, but in all cases homogenization, usually two-stage, is an essential part of processing. The physical properties of imitation creams closely resemble those of their natural counterparts, but the physico-chemical relations of the fat globules are entirely different.

12.4.1 Imitation soured cream

It is made using acidulants such as glucono-δ- lactone and has recently found popularity as a 'party-dip'. Some types of imitation creams are suitable for whipping, but various types of 'whipped topping' are produced. These include aerosolized products containing 24-35% fat, 6-15% sugar and 1-6% vegetable protein which, in combination with stabilizers and emulsifiers, produce a very stable whip. Frozen, ready whipped toppings and powders, formulated for easy reconstitution, are also widely available and utilize the same basic ingredients. Flavouring and colouring may be added to produce a mousse.

12.4.2 Coffee whitener

It is prepared either as a liquid product, frozen for retail distribution or as a powder blend. The fats in such products are usually of non-dairy origin.

12.4.3 Low calorie cream substitutes

These are made in which a sweetener, usually aspartame, replaces sugar and there is an increasing demand for products in which the fat is partly or wholly replaced. Bulking agents such as carboxy methyl cellulose, pectin or poly dextrins may be used as the base or the fat may be replaced directly by fat-replacers such as Stellar, prepared from modified corn starch, or Simplesse, prepared from whey protein concentrate. Dried cream extract may be added to improve flavour. A product with many of the properties of cream, 'cell cream', has also been developed which consists of ultrafine cellulose particles dispersed in water.