12 Technology of Ice Cream and Frozen Desserts – I: Ingredients and formulation

Atanu Jana

Ice cream is a delicately flavoured dairy based product consumed in frozen condition and liked by one and all. Ice cream contains a sizeable amount of dairy ingredients because of which it is highly nutritious as well as highly palatable. Even the functional properties of protein and natural emulsifiers present in dairy ingredients enable the product to be adequately aerated to obtain a quality (smooth, soft) product. The non-dairy ingredients used in formulation of ice cream mix also plays an important role; sweeteners for sweetening and flavor enhancement, stabilizers for viscosity building, emulsifier for smoothness and melt resistance, flavor for flavouring and colour for eye appeal.

FSSAI definition and specifications for Ice cream

Ice Cream, Kulfi, Chocolate Ice Cream or Softy Ice Cream means the product obtained by freezing a pasteurized mix prepared from milk and /or other products derived from milk with or without the addition of nutritive sweetening agents (sucrose, dextrose, fructose, liquid glucose, dried liquid glucose, maltodextrin, high maltose corn syrup, honey), fruit and fruit products, eggs and egg products, coffee, cocoa, chocolate, condiments, spices, ginger and nuts. Such product may also contain bakery products such as cake or cookies as a separate layer and/or coating. The product may be frozen hard or frozen to a soft consistency; it shall have pleasant taste and smell free from off flavour and rancidity. The said permitted food additives are stabilizers, emulsifiers, flavourings and colouring agents. The specifications for three types of ice cream are collated in Table 1.

Note: In case where chocolate, cake or similar food coating, base or layer forms a separate part of the product, only the ice cream portion shall conform to the requirements for ice cream. The type of ice-cream shall be clearly indicated on the label, otherwise standard for ‘Ice-cream’ (full fat) shall apply.

Frozen Dessert/Frozen Confection

FSSAI definition: Frozen dessert/frozen confection means the product obtained by freezing a pasteurized mix prepared with milk fat and/or edible vegetable oils and fat having a melting point not exceeding 37oC in combination with milk protein alone or in combination with vegetable protein products, singly or in combination. The nutritive sweetening agents permitted is sugar, dextrose, fructose, liquid glucose, dried liquid glucose, maltodextrin, high maltose corn syrup and honey. The flavourings permitted include fruit and fruit products, eggs and egg products, coffee, cocoa, chocolate, condiments, spices, ginger and nuts. Egg and egg products can also be used. The product may contain bakery products such as cake or cookies as a separate layer/or coating. The product may be frozen hard or frozen to a soft consistency. The product shall have pleasant taste and flavor, free from off-flavour and rancidity. The specifications of three types of frozen dessert/confection are collated in Table 2.

Note: In case where chocolate, cake or similar food coating, base or layer forms a separate part of the product, only the frozen dessert/confection portion shall conform to the requirements. The type of frozen confection shall be clearly indicated on the label otherwise, standards of frozen dessert/confection shall apply.

Types of ice cream and frozen desserts

Ice cream is manufactured as regular, custard/French, reduced fat, light, low, and no-fat versions. Other frozen desserts include sherbet, water ice, mellorine, frozen yoghurt, frozen dairy dessert, frozen confection, frozen dairy confection, milk shake, smoothies, shake and slush. The nomenclature varies from country to country depending on the prevailing legislation. The freezing technique may involve stirring (agitation) during freezing, or without stirring (quiescent), or a combination of the two. Similarly the degree of freezing results in products that are hard frozen, or designed for dipping or scooping, or used as soft serve or a milkshake.

Ingredients for Ice cream and frozen desserts

The ingredients used in formulation of ice cream mix include (i) Dairy and (ii) Non-dairy ingredients. The role played by dairy ingredients in Ice cream and frozen desserts is discussed first.

A. Dairy ingredients

I.     Milk fat: The fat component of ice cream mix increases the richness of flavor, produces a characteristic smooth texture by lubricating the palate, helps to impart body, and aids in producing desirable melting properties. Fat contributes 9 kcal of energy/g to the diet. Premium ice creams generally have fat content ranging from 14 to 18%. It has now become desirable, however, to create light ice creams, < 10% fat, with the same perceived quality.

The best source of milk fat in ice cream for high quality flavor is fresh sweet cream, from fresh sweet milk. Other sources of milk fat include sweet (unsalted) butter, frozen cream. Whey creams have also been used, but may lead to flavor or texture problems.

1. Milk solids not fat: The milk solids-not-fat (MSNF) improves the texture of ice cream, aids in imparting body and chew resistance to the finished product, are capable of allowing a higher overrun without being snowy or flaky, and may be a cheaper source of total solids (TS). The content of MSNF used in a mix can vary from 10 to 13%. The traditional sources of such solids are fresh concentrated skimmed milk, or spray dried low-heat skim milk powder (SMP). However, most ice cream formulations now use other sources of MSNF (buttermilk powder/whey powder) or milk protein (Na-caseinate, Total milk proteinate, Ultrafiltered retentate, etc.) to replace all or a portion of skim milk solids, for both functional and economical reasons.

Lactose can be reduced in milk ingredients through use of ultrafiltration, or modified by limited hydrolysis to its constituent monosaccharides. Buttermilk solids have often been cited as a useful substitute for skim milk solids. Buttermilk powder contains higher concentration of phospholipids than SMP, which exert emulsification property and can reduce the need for emulsifiers. Whey protein concentrates with similar protein to SMP can be produced. Protein content can vary from 25% to ≥ 75%.

1. Non-dairy ingredients

The non-dairy ingredients utilized in ice cream mix making include sweeteners, stabilizers, emulsifiers, colourings and flavourings. These are individually discussed herein.

1. Sweeteners

   Sweet ice cream is usually desired by the consumer. The sweetening agents are added to ice cream mix at a rate of usually 12–17% by weight; higher quantity is advocated for preparing Chocolate and Fruit ice creams. Sweeteners improve the texture and palatability of ice cream, enhance flavors and are usually the most economical source of TS. Sugar helps in balancing the ‘fattiness’ in ice cream. Their ability to lower the freezing point of a solution enables control over the temperature-hardness relationship. The most common sweetening agent used is sucrose, alone or in combination with other sugars (i.e. corn syrup solids, sorbitol, etc.).

A typical sweetener blend for an ice cream mix usually includes 10–12% sucrose and 4–5% corn syrup solids (corn starch hydrolysate syrup, commonly referred to as glucose solids). The properties of few sweeteners utilized in ice cream mix formulation are shown in Table 3.

Ice cream prepared commercially invariably contains added stabilizers and emulsifiers. The stabilizers are compounds that have ability to hydrate water, increase the viscosity of ice cream mix and contribute to smooth body and texture and impart melting resistance. The significant role played by them is to prevent coarseness in ice cream during ‘heat shock’ encountered by ice cream during its cold storage. Examples of stabilizers include guar gum, carrageenan, locust bean gum, sodium alginate, modified starches, etc.

Emulsifier helps in preparing good emulsion of fat during ice cream mix preparation and inducing controlled de-emulsification of milk fat, imparting drier appearance and melting resistance of ice cream. It improves whippability of ice cream mix and favours formation of numerous small sized air cells leading to ‘smoothness’ of product. Few examples of emulsifiers include mono- and di-glyceride of fatty acids, lecithin, polysorbates, etc.

Guar gum is often used in combination with carrageenan and LBG to impart excellent properties to ice cream.

Colourings and flavourings

Addition of colour improves the eye appeal and also helps in identifying the flavor (green colour with mint flavor, orange with mango flavor) that has been used in ice cream. Uniform shade of colour is important throughout the mass of ice cream. Few examples of permitted colourings include Erythrosine supra, Ponceau 4R, Fast green FCF, Tartrazine, etc.

Ice cream is enjoyed because of its delicate flavor. Several manufacturers of ice cream compete with other manufacturers with regard to the total number of flavours that they cater to in the market. People have varied preference of a specific flavor or flavourings and they like to enjoy the same too. Examples of flavourings include malt, caramel, honey, fruits, nuts, cocoa, alcohol, etc.

Balancing ingredients in ice cream mix

It is important that small producers understand how to develop new ice cream mixes to meet the changing customer demands. ‘Balancing’ the mix involves maintaining the correct balance between:

•  Fat and sugar which controls the ‘fattiness’ of the product in the mouth.

•  Water and solids, which controls the texture or hardness/softness.

The formulation of an ice cream mix should also take into account the cost and availability of ingredients.

In order to balance a formula and make a mix, ingredients such as milk, skim milk, or water may be necessary. This is because a concentrated source of milk fat such as cream will contribute serum solids along with the fat. Similarly concentrated sources of MSNF may also contribute fat to the mix, for example, condensed whole milk. In instances where liquid sugar is used, water in the ingredient may dilute the solids. Therefore balancing of ingredients is necessary.

Some of the factors affecting the choice of composition include legal requirements, which must be met, the quality desired in the finished product (increasing fat and total solids (TS) are usually associated with increasing quality), and the cost to be borne by the consumer. Premium products usually command a higher price.

There is usually an inverse relationship between fat and TS. The lactose component of MSNF is less soluble and is above its saturation level in ice cream. Hence, increasing lactose content in a decreasing quantity of water, increases the risk of lactose crystallization. There is also generally an inverse relationship between corn syrup solids (CSS) levels and TS. The CSS will contribute to a firmer, chewier texture, which is more desirable when there are low solids present. Likewise, as TS increases, there is lower requirement for stabilizer. Additionally, as fat levels in a mix increase, there is generally less need for emulsifier in order to optimize the extent of coalescence of the fat.

Composition of ice cream and frozen desserts

    Based on the type of ice cream being produced, its composition is bound to change. Low-fat ice cream contains lower fat compared to its richer counterparts. Chocolate ice cream is associated with lower SNF compared to plain ice cream. The sugar content of ‘Fruit ice cream’ and ‘Chocolate ice cream’ is usually greater than that kept for plain ice cream. The stabilizer quantity used is greater in Sherbets and Ices compared to that used in ice cream. The pH of Sherbets, Ices and Frozen yoghurt is much lower than normally associated with plain ice cream. The composition of few variants of ice cream and frozen desserts is depicted in Table 4.

Web links

• www.pdf.capitalism5.com/download/1408