Maharashtra Board Class 11 Food Science and Technology Chapter 13 Sugar and Its Product PDF Download

Sugar And It's Products

Sugars are simple carbohydrates which are classified as monosaccharides namely glucose, fructose, galactose and disaccharides namely sucrose, maltose and lactose. Sugar plays a very important role in any cuisine. Additionally it provides energy to the body as it is form of carbohydrate.

13.1 Sources And Properties Of Sugars

The main source of sucrose are sugar cane (10-12%), beetroot (12-18%), honey and some fruits and vegetable. Natural sources of monosaccharides and disaccharides are indicated in table 13.1.

13.1 Table: Natural Sources Of Sugar

Properties Of Sugar

1. Hygroscopic Nature: Sugars have the ability to absorb moisture from surroundings. So sugar should be stored in dry place, in airtight containers, thats why sugar based products become sticky if not properly stored. Fructose has the highest hygroscopic power.

2. Solubility: Sugars are soluble carbohydrates. Based on solubility the sugars can be arranged in descending order as- fructose, sucrose, glucose, maltose and lactose.

3. Sweetness Index: All sugars differ in their sweetness from each other. Generally sucrose is considered as standard with value 1.0. All other sugars are compared with this standard and their sweetness index is considered as shown in figure Table 13.2.

Table 13.2 Sweetness Index

Teacher's Note

Sugar is found in many foods we eat every day. For example, when you eat a ripe mango or drink milk, you are eating different types of sugar that come from nature.

Exam Trick

Remember: Sucrose = table sugar (the one we use at home). Fructose = fruit sugar (the sweetest one). Glucose = body sugar (what your body uses for energy).

Points To Remember

Monosaccharides have one sugar unit. Disaccharides have two sugar units joined together.
Sucrose is the sugar we use most in our kitchens.
Fructose is the sweetest type of sugar.
Sugar must be stored in dry, airtight containers because it absorbs water from air.

4. Fermentation

Sugar (Sucrose) undergoes fermentation easily by the biological process in which enzymes from yeast are involved to convert into glucose, fructose, or maltose, and last products carbon dioxide and alcohol. This property is very much important in bakery industry, alcoholic beverages, other fermented products like idli, dosa, etc.

5. Hydrolysis Reactions

These reaction are categorized in two types

A. Acid Hydrolysis

Sugar on reaction with acids hydrolyses to a new product.

Sucrose + Acid → Fructose + Glucose (invert sugar)

Heat is accelerator in the hydrolysis by acid

B. Enzyme Hydrolysis

Sucrase enzyme hydrolyses sucrose to yield a liquid invert sugar.

Sucrose + H₂O \(\xrightarrow{\text{Sucrase Enzyme}}\) Fructose + Glucose (invert sugar)

Teacher's Note

Hydrolysis means breaking sugar into smaller pieces using acid or enzymes. This is like breaking a big chocolate bar into smaller pieces so your body can use it better.

Exam Trick

Remember: Acid hydrolysis = needs acid + heat. Enzyme hydrolysis = needs enzyme + water. Both break sucrose into glucose and fructose.

Points To Remember

Hydrolysis means breaking down sugar into smaller sugar units.
Acid hydrolysis uses acid and heat to break sugar.
Enzyme hydrolysis uses special enzymes and water to break sugar.
Both types produce invert sugar (glucose + fructose mixture).

6. Heat Treatment

Sugar can be treated with heat in two ways either by dry heat (caramelisation) or wet heat treatment (Crystallization)

Definition

When dry heat is applied to sugar crystals and it reaches a temperature above its melting point, the sugar melts and decomposes to form a colourless liquid which on continuous heating changes its colour to yellow, light brown and finally dark brown. This decomposed sugar is known as caramel and this process is known as Caramelisation.

Characteristics

Caramel sugar is brown in colour.

It has pungent and strong flavor and slightly bitter taste.

It is less sweet than original sugar.

It is in a crystalline state, which is soluble in water.

On cooling, caramel turns solid and brittle and has transparent shiny appearance.

Temperature of caramelisation depends on type of sugar. Fructose caramelizes at 110°C, sucrose at 170°C and maltose at 180°C.

It can be used as a flavouring in puddings and desserts, as a filling in bonbons, or as a topping for ice cream and custard.

13.2 Effect Of Dry Heat On Sugar-Caramelization

Caramelisation is the complex process in which when sugar is heated without any water or liquid where various physical and chemical changes take place.

Teacher's Note

When you heat sugar in a pan without water, it turns brown and becomes caramel. This is like cooking jaggery at home - it becomes dark and hard when it cools down.

Exam Trick

Remember the color order: No color → Light yellow → Medium brown → Dark brown → Black → Burnt. The darker it is, the more bitter it tastes and less sweet it becomes.

Points To Remember

Caramelisation is heating sugar without water until it turns brown.
Different sugars caramelize at different temperatures.
Caramel changes color from yellow to dark brown as heat increases.
Caramel becomes hard and brittle when it cools down.
Caramel tastes bitter and less sweet than sugar.

Uses Of Caramel In Cookery

i. Decoration: Caramel is used to decorate desserts like custard and puddings. It's also used on cakes as a decorative agent.

ii. Binding Agents: Since caramel solidifies on cooling, it can be used as a binding agent. When the hot liquid caramel is mixed with other food ingredients and allowed to cool it turns solid, thereby holding the ingredients together. This is seen in sugar brittles such as til or groundnut chikki where caramel acts as binding agent.

iii. Flavour and Taste: Addition of caramel to fruit cake and christmas cake imparts a desirable flavour and taste to the preparation.

iv. Colour: Since the caramel is brown in colour, it gives a brown natural colour to preparations like fruit cake, and christmas cake.

v. Variations in Texture: Solid pieces of caramel in chocolates and ice creams brings variation in the texture of the products.

vi. Coating Agents: In preparations like caramel popcorn, caramel acts as a coating agent and improves the appearance, colour and flavour.

Teacher's Note

Caramel is used in many Indian sweets like til chikki and groundnut brittle. It helps stick all the ingredients together and makes them taste better.

Exam Trick

Remember: Caramel = decoration + binding + flavour + color. It does many jobs in cooking! Like how ghee works in many Indian dishes - it's not just for taste, but also for texture and look.

Points To Remember

Caramel is used to decorate cakes and puddings.
Caramel sticks ingredients together when it cools (like in chikki).
Caramel gives brown color to cakes and sweets.
Caramel adds bitter and strong flavor to sweets.
Caramel makes texture rough or smooth depending on size of pieces.

Activity 1

Aim: To find out the effect of dry heat on sugar-caramelisation

Materials Needed: Sugar, pan, burner

Method:

1. Take a pan, add sugar to it.

2. Heat on a slow flame.

3. Sugar will start melting into a colourless liquid.

4. Slowly the colour will start becoming yellow and then darken.

5. Take out from flame and let it cool.

6. Crush the caramel into small chunks and use it for garnishing ice-creams, etc.

Conclusion: Caramel helps to improve texture

13.3 Effect Of Moist Heat On Sugar-Crystallization

Sugars are soluble in water due to which they impart various degrees of sweetness to different products like tea, coffee, syrups, etc. Solubility increases with increase in temperature. This property is extremely useful in preparation of sweets like rawa laddu, burfi, balushahi and sugar coated groundnuts.

In order to understand how and why crystals are formed in a sugar solution, let us first understand the types of solution.

Solution

Solution is made up of solute and solvent.

Solute + Solvent → Solution
Sugar + Water → Sugar water solution

Types Of Solution

1. Unsaturated Solution: When a solution has the capacity to dissolve more solute at the ambient temperature, then this type of solution is called as unsaturated solution.

2. Saturated Solution: When a solution does not has the capacity to dissolve any more solute at the ambient temperature, then this type of solution is called as saturated solution.

3. Supersaturated Solution: At a given temperature, if more sugar is added to a saturated solution, it will become supersaturated.

Teacher's Note

When you mix sugar with water, it dissolves. If you keep adding more sugar, one day no more sugar will dissolve - that's a saturated solution. This is like how much salt you can mix in a cup of water.

Exam Trick

Remember: Unsaturated = can add more sugar. Saturated = no more sugar can dissolve. Supersaturated = extra sugar added (unstable, will form crystals).

Points To Remember

A solution has two parts: solute (sugar) and solvent (water).
Unsaturated solution can dissolve more sugar.
Saturated solution cannot dissolve any more sugar.
Supersaturated solution has extra sugar that will form crystals.
More heat helps sugar dissolve better in water.

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