Lesson 9. NON-DAIRY INGREDIENTS IN ICE CREAM
NON-DAIRY INGREDIENTS IN ICE CREAM
Ice cream is made utilizing both dairy as well as non-dairy food ingredients. In this section, the role played by Non-dairy ingredients namely sweeteners, flavourings and colourings will be discussed.
While a sweet ice cream is generally desired by the public, sweeteners should be used in moderation, not only for optimum palatability, but also for handling properties.
9.2.1 Role of sweeteners in Ice cream
- To increase the acceptance of the product, not only by making it sweeter but also by enhancing the pleasing creamy flavour and the delicate fruit flavour.
- It increases the viscosity and TS content of mix; this improves the body and texture.
- It depresses the Freezing point of mix, resulting in slower freezing and thus requiring a lower temperature for proper hardening.
- It is usually the cheapest source of TS in the mix.
Lack of sweetness produces a flat taste, while too much tends to overshadow desirable flavours. Sugar may slow up the whipping of the mix.
For plain ice cream, level of sugar of 14-16% is found desirable. In case of fruit and chocolate ice cream, a higher sugar content of 17-18% is desirable.
9.2.2 Types of sweetening ingredients used in ice cream and frozen desserts
- Sugar (Sucrose) or sugar syrup
- Invert sugar (in paste or syrup form)
- Corn syrup, Dried corn sugar, Glucose syrup, Dried glucose syrup
- Maple syrup, Maple sugar
- Brown sugar
It is the percentage weight of dextrose present in the hydrolysed starch referred to as dextrose equivalent: higher the DE, higher will be the sweetness of the corn sugar.
It is a disaccharide composed of glucose and fructose. It is obtained from cane sugar and sugar beets. It may be used in dry or liquid form (67% sucrose). It provides a sweet taste without secondary or after flavours. However, sucrose is a contributor to dental caries. Invert sugar can be prepared by hydrolysis of sucrose with attendant increase in sweetness over that of sucrose.
It is a white crystalline powder. It contains as many calories as sucrose. It is available under trade name ‘Xyrofin’ by Xyrofin Ltd. It seems to have potential as a sweetener in dietetic ice cream because of the high relative sweetness value. It produces a softer, more easily scoopable product when held at -18°C.In fruit ice cream it brings out the flavour of fruit and berries. However,products containing fructose are susceptible to browning reactions.
9.2.6 Corn sweeteners
These are available in three major types viz., (i)Refined corn sugar (Dextrose), (ii) Dried corn syrup (referred to as corn syrup solids), and (iii) liquid corn syrup.
The advantages of incorporating corn syrup solids or corn syrup as part replacement of sucrose is as follows:
2. It serves as an economical source of solids.
3. It improves the shelf life of the finished product.
4. High fructose corn syrups (i.e. 42, 55 and 90%) also play an important role as sweetener in ice cream.
9.2.7 Dried corn syrup solids
It is produced by dehydration of corn syrup. It contains sugars like dextrose and maltose, together with dextrin, but usually contains no starch. It is economical than use of cane sugar but due to its lower sweetening effect, it is required to be used in greater amount. The effect on F.P. (raised) and smoothness (stabilizing effect due to higher TS contribution) gives Corn Syrup Solids (CSS) an advantage over that of dextrose. Recommended usage is 25-35% of the total sweetener that is to be supplied by CSS.
It is a white crystalline or granular sugar obtained by hydrolysis of corn starch. It is economical than sucrose. It is recommended for use in high-fat mixes for more desirable body, texture and melting properties. It is necessary in Sherbets and Ices to inhibit the crystallization of sucrose on the surface. Its effect of lowering the Freezing point limits the amount of dextrose that can be used to less than 25.0% of the total desired sugar.
It is a hexahydric alcohol, obtained by catalytic hydrogenation of D-glucose or invert sugar at high temperature and pressure, followed by ion-exchange treatment. It is easily water soluble and possess a ‘sweet cool’ and pleasant taste. This sweetener is useful in formulation of ‘soft ice creams’ and ‘diabetic mix’.
It is a pentahydric alcohol naturally occurring in fruits and vegetables. Commercially it is obtained by acid hydrolysis of xylan. However it has an excellent taste and has a cooling effect greater than sorbitol. It can be used as an excellent sugar substitute for diabetics.
c) Intense sweeteners
It is the first non-nutritive sweetener used commercially– a product derived from coal tar. It has sweetening effect up to 550 times that of sucrose. However, its use is drastically reduced due to its implication to occurrence of cancer in laboratory animals.
It is a dipeptide consisting of phenylalanine and L-aspartic acid. It is available under trade names ‘Nutra Sweet’ or ‘Saneeta’. Absence of bitter character and sucrose-like flavour makes it a source of sweetener superior to other high-intensity sweeteners like saccharin. It is non-cariogenic.
It is produced from sucrose by chlorination of 3-hydroxyl groups. It has been developed jointly by Mc Neil Specialty Products and Tate and Lyle Specialty Sweeteners. It is a non-caloric sweetener and offers unique combination of a sweet, sugar-like taste, free of any unpleasant aftertaste.
Stevia rebaudiana known as sweet leaf is widely grown is widely grown for its sweet leaves. As a sweetener and sugar substitute, stevia's taste has a slower onset and longer duration than that of sugar, although some of its extracts may have a bitter or licorice-like aftertaste at high concentrations.
With its steviolglyco side extracts having up to 300 times the sweetness of sugar, stevia has garnered attention with the rise in demand for low-carbohydrate, low-sugar food alternatives. Because stevia has a negligible effect on blood glucose, it is attractive as a natural sweetener to people on carbohydrate-controlled diets.It is available commercially as stevioside
Frozen desserts are valued mainly for their pleasing flavor and their cooling and refreshing effects. Among the flavouring substances, the important ones are vanilla, chocolate and cocoa, fruit and fruit extracts, nuts, spices, etc.
Vanilla and Chocolate are the dominant flavours, but there has been some shift in the ranking of other flavourings.
The type of flavourings utilized in ice cream and frozen desserts include:
(a) Natural flvourings: Non-citrus fruit, citrus fruit,tropical fruit, natural flavours from botanicals, spices, cocoa and chocolate,coffee, natural flavourings from vanilla beans and nuts.
(b) Synthetic flavourings: These include aromatic chemicals and imitation flavours.
(c) Liqueur flavourings: Alcohol, whiskey and other distilled beverages, fruit brandy distillate and brandy flavour essence and fruit liqueurs.
The last category (c) is prevalent in countries abroad.
It is obtained from beans of an orchid Vanilla fragrans. The natural compound which produces vanilla flavour is vanillin. It is available in liquid or powder forms as pure vanilla, reinforced vanilla with vanillin and imitation vanilla. Cured vanilla beans contain 1.5-2.0% vanillin on dry basis.
9.3.2 Fruit flavourings
Fruit may be crushed and used as such, but often it is necessary to add further flavours,either natural concentrated extracts or even synthetic to bring out the full flavour. The popular fruit flavourings used in ice cream include mango, strawberry,pineapple, orange, apple, papaya, jamun, etc.
9.3.3 Chocolate and cocoa
These are derived from beans of tree Theobroma cacao.When used as an ingredient in ice cream, about 2-3% cocoa is used. To overcome the bitter flavour of cocoa, additional sugar is necessary (17-18% sugar). The chocolate is also used as couverture(coating of other flavoured ice cream) to enrobe a small individual portion of ice cream.
Several kinds of nutmeats are popular including almonds,raisins, hazelnuts, pistachio, walnuts, pecans, etc. It must be ensured that the nutmeats are clean, free from shells or other extraneous matter and free from rancidity. The nutmeats may preferably be roasted or even fried in oil prior to its use.
9.4 Colourings in Ice Cream
Ice cream should have a delicate, attractive color that suggests or is readily associated with its flavour. Fruit ice cream needs to be colored because about 15% fruit commonly added, produces only slight effect on color. Chocolate ice cream is one of the exceptions, wherein the required amount of cocoa furnishes the desired color.
Most of the colors are synthetic origin. A weak alkaline solution of Annatto color is about the only vegetable color used in ice cream.
The list of permitted colorings for use in ice cream is furnished in Table 9.2.
Table 9.2 Clourants permitted by FSSA (2006) in ice cream
Several natural colourings have emerged due to negative health impact of the permitted synthetic colorants in ice cream. However, these have not got wide acceptance due to problems in stability of the colourants.