WHAT IS SUGAR?
Sugar is a sweet natural ingredient obtained from various plants, especially sugar cane and sugar beet, it is used as a sweetener in food and drink.
The most common kinds of sugar
- Sucrose is often called table sugar – made up from glucose and fructose, extracted from sugar cane or sugar beet and also naturally in most fruits and vegetables.
- Fructose and glucose – found in fruits, vegetables and honey.
- Lactose is commonly called milk sugar – found in milk and dairy products.
- Maltose is also known as malt sugar – found in malted drinks and beer.
Making Sense of Sugar (2016)
WHAT IS THE MELTING POINT OF SUGAR?
Chest of Books (2016) states when sugar is heated without the addition of water a point is reached at which they change from a crystalline to a liquid state. This is called the melting point.The melting point of sucrose is 160° to 161°C.
Impure solutions of sucrose will give variable melting points. After sugar is melted and cooled slowly it forms hard shapeless sugar sometimes called “barley sugar.” If sucrose is heated above the melting point brownish-colored substances called caramel are formed.
When there is moisture, caramelisation may begin at temperatures below 100°C. Maltose melts at about 100°C. Having a lower melting point than sucrose it decomposes more easily by heat. The melting point of Fructose is 95°C.
WHAT IS THE MELTING POINT OF MARSHMALLOWS?Marshmallows have a very low melting point. The melting point of marshmallows is 45°c. However, due to marshmallows being mostly sugars, they are likely to burn rather quickly.
When marshmallows are toasted, a chemical change occurs. The sugar molecules in the marshmallow are being changed into carbon. Sugar can be changed into water molecules. When you toast marshmallows, the heat causes a chemical reaction producing water molecules which then evaporate, leaving the carbon behind.
- The swelling – as you heat the marshmallow, the moisture inside expands, which causes the marshmallow to swell.
- The escape – as the moisture expands, it creates tiny holes in the marshmallow, which allow the moisture to escape as steam.
- The sugar rush – as the marshmallow does not now have moisture, it is a sucrose char. Oxygen in the air rushes to the surface of the marshmallow.
- The flame on stage – oxygen diffuses to the surface of the marshmallow from the surrounding air. At the surface of the marshmallow, carbon reacts with oxygen, which produces a blue flame.
- The oxidation stage – carbon atoms combine with oxygen atoms to produce carbon monoxide, and then carbon dioxide.
- The oxyinterruptus stage – as you remove the marshmallow from the fire and blow the marshmallow out, the oxidation process is interrupted, creating soot which is evidence of incomplete combustion: hydrocarbon + oxygen → carbon monoxide + carbon + water.