Food Additives

Food Additives
Additives are used to:
• improve the keeping quality of a food by making it last longer on the shelf or in the fridge, for example a preservative to prevent the growth of bacteria or a humectants to stop food from drying out
• Improve the taste or appearance of a food, for example by the use of flavours, thickeners and colours.

Another benefit of food additives is that consumers can be offered a wider choice of foods. Many processed foods contain additives. Some common examples are bacon, margarine, ice cream and bread.
Some people believe that because food additives are chemicals they should be banned. However, everything in the world, including us and the food we eat, is made of chemicals. Air, water, glucose and salt are chemicals in the same way that food additives are.
Many food additives occur naturally, such as red colour from beetroot (Beet red), and purple colour from grape skins (anthocyanins). These colours can be extracted and added to other foods.
Some food additives found in nature can be manufactured, for example, ascorbic acid. Other additives are manufactured but not found in nature, such as aspartame, which is used to replace sugar.

Preservative food
Preservative food additives can be used alone or in conjunction with other methods of food preservation. Preservatives may be antimicrobial preservatives, which inhibit the growth of bacteria or fungi, including mold, or antioxidants such as oxygen absorbers, which inhibit the oxidation of food constituents. Common antimicrobial preservatives include calcium propionate, sodium nitrate, sodium nitrite, sulfites (sulfur dioxide, sodium bisulfate, potassium hydrogen sulfite, etc.) and disodium EDTA. Antioxidants include BHA and BHT.
Other preservatives include formaldehyde (usually in solution), glutaraldehyde (kills insects), ethanol and methylchloroisothiazolinone. FDA standards do not currently require fruit and vegetable product labels to reflect the type of chemical preservative(s) used on the produce. The benefits and safety of many artificial food additives (including preservatives) are the subject of debate among academics and regulators specializing in food science, toxicology, and biology.

Natural food preservation
Natural substances such as salt, sugar, vinegar, alcohol, and diatomaceous earth are also used as traditional preservatives. Certain processes such as freezing, pickling, smoking and salting can also be used to preserve food. Another group of preservatives targets enzymes in fruits and vegetables that continue to metabolize after they are cut. For instance, citric and ascorbic acids from lemon or other citrus juice can inhibit the action of the enzyme phenolase which turns surfaces of cut apples and potatoes brown.

Emulsifier in Food
An emulsifier (also known as an emulgent) is a substance which stabilizes an emulsion by increasing its kinetic stability. Oil-in-water emulsions are common in food. Notable examples include:
 Vinaigrette – vegetable oil in vinegar; if prepared with only oil and vinegar (without an emulsifier), yields an unstable emulsion
 Mayonnaise – vegetable oil in lemon juice or vinegar, with egg yolk lecithin as emulsifier
 Hollandaise sauce – similar to mayonnaise
 Cream in espresso – coffee oil in water (brewed coffee), unstable

Humectants in food
Humectants Substances such as glycerol, sorbitol, invert sugars, honey which prevent loss of moisture from foods, especially flour confectionery; they also prevent sugar crystallizing and the growth of ice crystals in frozen foods.Humectant is a substance used primarily in foods and cosmetic products to help retain moisture. These substances are called hygroscopic, which means that they are able to absorb ambient water. Some humectants additives are beneficial when consumed or used. Others, particularly in some foods, are less helpful, may cause abdominal distress, and should probably be avoided.
Common humectant in food products is sorbitol. This humectants is a sugar alcohol derived from sugar. It is used in dietetic or sugarless foods and is lower in calories than sugar, so it is a popular choice among those who are dieting. In doses larger than 1.76 ounces (50 g), it has a laxative effect and can cause diarrhea. In the 1990s, consumer advocates successfully lobbied to have product warnings placed on foods containing sorbitol, so people could keep their consumption below harmful levels.

Stabilizer in Food
“Stabilizers are substances which make it possible to maintain the physico-chemical state of a foodstuff; stabilizers include substances which enable the maintenance of a homogenous dispersion of two or more immiscible substances in a foodstuff and include also substances which stabilize, retain or intensify an existing colour of a foodstuff.”
Food stabilizers are confused with preservatives. But there is a difference between the two. Stabilizers is used to retain the physical characteristics of the food whereas as preservatives prevent the spoilage of the food. Food stabilizers increase the stability and thickness of the food by binding its large molecules.

Purpose of Stabilizers
• They maintain the consistency of the food
• Food stabilisers do not allow the separation of ingredients that are bound together by emulsifiers.

Common Food Stabilizers
• Alginic acid is a popular food stabilizer that is derived from brown algae is used in ice-cream and syrups that we use on desserts.
• Agar agar is also used as food stabilizers in the food products like canned meat and pudding.
• Carrageenan is like agar agar that is also obtained from red algae. It is used in shampoos.
• Then there is gelatin, another food stabilizer.
• Pectin or calcium chloride is used as food stabilizers in dairy products.
• Lecithin and mono- and digycerides.

Applications of Stabilizers for Food
Stabilizers for food are used in many kinds of products. The most common ones that use the food stabilizers are
• Ice Cream
• Margarine
• Low-fat spreads
• Dairy products
• Salad dressings
• Mayonnaise

Specific additives used in food
Use the links below to find out about some of the specific additives used in food.
• Aspartame – a sweetener for foods and drinks
• Intense food sweeteners - can replace sugar to sweeten food and drinks
• Mono-sodium glutamate (MSG) – brings out the flavour in food
• Benzoate, sorbate and sulphite – used to preserve food
• Nitrates and Nitrates – used to preserve food
• Synthetic colours – used in highly coloured foods

Earthquake

An earthquake (also known as a quake, tremor, temblor or seismic activity) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.
An earthquake (also known as a quake, tremor, temblor or seismic activity) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.
In its most generic sense, the word earthquake is used to describe any seismic event — whether a natural phenomenon or an event caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus or hypo-center. The term epicenter refers to the point at ground level directly above the hypo-center.
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.
In its most generic sense, the word earthquake is used to describe any seismic event — whether a natural phenomenon or an event caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus or hypo-center. The term epicenter refers to the point at ground level directly above the hypo-center.

Vibration and Waves

A. Vibration
Vibration is an oscillating motion of an object through the equilibrium point periodically.

1 vibration from 2 – 1 – 2 – 3 – 2
a half vibration from 2 - 1 - 2

B. Deviation and Amplitude
Deviation is a particle vibrated positions toward the equilibrium point.
Amplitude is maximum deviation of a vibration from an equilibrium point of an oscillating object.

C. Period and Frequency
Period ( T )is the time needed to complete one oscillation
Frequency ( f ) is the number of oscillation occurred in one second



Hence, we can say that frequency is inversely proportional to period.


WAVE
Wave is preparative vibration. In its propagation, wave transfers energy from a place to other place, while the passed medium does not propagate.

Wave and Its Kinds
Based on the wave medium, there are two kinds of wave, i.e:
a. Mechanic wave
A wave in which the propagation needs an intermediate medium, for examples: sound wave,string wave

b. Electromagnetic wave
A wave in which it can propagate in vacuum or without medium, for example: light, sonar wave, radio wave

Based on the direction of propagation, there are two kinds of wave, i.e transverse wave and longitudinal wave.

A. Transverse Wave
Transverse wave is a wave that the direction or vibration is perpendicular toward direction of propagation. For examples: string wave, light,wave on water surface



B. Longitudinal Wave
Longitudinal wave is a wave that the direction of vibration is parallel with direction of propagation. For example: wave on spring and sound wave.



Speed of Wave
The speed of wave is a required distance to pass the wave per time unit

Making Sound Wave

How do vibrating objects make sound waves?
When you hit the drumhead it starts vibrating up and down. As the drumhead moves upward, the molecules next to it are pushed closer together. This group of molecules that are closer together is a compression.

When the drumhead moves downward, the molecules near it
have more room and can spread farther apart. This group of molecules
that are farther apart is a rarefaction. The rarefaction also
moves away from the drumhead.As the drumhead vibrates up and
down, it forms a series of compressions and rarefactions that move
away and spread out in all directions. This series of compressions
and rarefactions is a sound wave.

Wave

What is a wave?
• Waves transfer energy, but do not transfer
matter.

Mechanical Waves
• Mechanical waves require a medium in which
to travel.
• When a transverse wave travels, particles of
the medium move at right angles to the direction
the wave is traveling.
• When a compressional wave travels, particles
of the medium move back and forth along the
same direction the wave is traveling.
• Sound is a compressional wave.

Electromagnetic Waves
• Electromagnetic waves can travel through
empty space.
• The Sun emits different types of electromagnetic
waves, including infrared, visible light,
and ultraviolet waves.