Post on 03-Dec-2014
By: Cheong Kai Liang
CHOCOLATE
2.1 Definition
Chocolate is a confection produced from the fruit of the tropical tree, Theobroma cacao.
The fruit, known as cacao beans, are fermented, dried, roasted, and ground, and the resulting
product is called cocoa liquor. Cocoa liquor can be separated into cocoa butter which is a
smooth, solid fat used in both food and cosmetics, and cocoa powder. Cocoa butter and cocoa
powder are later combined in various proportions with other ingredients to produce chocolate. 1
Chocolate is defined by the concentration of cocoa liquor or cocoa butter that it contains.
According to Food and Drug Administration (FDA), the definition of a typical chocolate must
contain:
The Standard Identity Formula for a Typical Chocolate
Item Percentage (%)
Sugar 52.38
Milk
- Whole milk powder 12.00
- Milk protein concentrate 0.00
Chocolate liquor 10.00
Added fat:
- Cocoa butter 25.27
- Vegetable fat 0.00
Soya Lecithin 0.33
Vanillin 0.02
Total 100.00
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2.2 Physical Properties of Chocolate
i) Melting Point
The temperature that chocolate begins to melt at is a very important property because it
helps define the textural properties that you experience when eating a piece of chocolate. This
melting point is determined mostly by the fat composition in the chocolate, which come from
cocoa butter or milk fat depending on the type of chocolate. The process used to crystallize the
fat when making chocolate, called tempering, is also an important factor for the melting point.
Cocoa butters from different parts of the world will have different melting points
depending on their fatty acid composition – thus the terms hard and soft cocoa butters.
Chocolate manufacturers can select and/or blend different types of cocoa butters to achieve the
melt they want for their chocolate product. Milk fats also have their own characteristic melting
points and will affect the melting characteristics of milk chocolates.
ii) Water Activity
Chocolate is a very low moisture food. Moisture contents of chocolate range from 0.5-
1.0%. As the moisture content in chocolate increases, the viscosity will also increase. The low
moisture levels in chocolate make it a very stable food product at room temperature.
iii) Viscosity
Viscosity or the flow characteristics of chocolate are measured in various. High viscosity
chocolate is difficult to pump from one part of the factory to another. However, if the viscosity
is too thin, certain molding and depositing machines will not work right. Therefore chocolate
viscosity is a physical property that is carefully monitored and tightly controlled within defined
limits. There are several factors that affect viscosity of chocolate. Increasing moisture and/or the
particle size of the mixture will create higher viscosity. Conversely, increasing temperature and
adding emulsifiers will tend to reduce viscosity.
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2.3 Type of chocolate
There are three main types of chocolate: dark chocolate, milk chocolate, and white
chocolate. The ingredients that make up each of these types of chocolate are different and there
are specific regulations that define the composition of these products. The Food and Drug
Administration (FDA) has established standards of identity for many chocolate and cocoa
products in the United States. The standards define the percentages of key ingredients that must
be present in each type of chocolate.
i) Dark Chocolate
Picture 2.1: Dark Chocolate
Dark chocolate is rich, full-bodied chocolate with less sweetness and no milk flavor. At
the moment there is no standard of identity to define a dark chocolate for regulatory purposes in
the United States. However, this term is often used by consumers to describe both semisweet
(bittersweet) and sweet chocolate due to the levels of chocolate liquor. Below is the standard of
identity by FDA to define chocolate liquor, bittersweet and sweet chocolate:
a) Chocolate liquor
Produced by the grinding of the cocoa bean nib (center) to a smooth liquid state.
Chocolate liquor does not contain vegetable fat and may also be referred to as chocolate,
unsweetened chocolate, baking chocolate, or bitter chocolate. Despite its name “liquor”,
there is no alcohol in chocolate liquor.
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b) Semisweet (bittersweet) chocolate
Chocolate liquor with added cocoa butter and sugar. The FDA standards require
at least 35% chocolate liquor. Fat content may vary but averages between 30-35%.
Semisweet chocolate is also referred to as dark chocolate.
c) Sweet chocolate
Chocolate that contains more sweeteners and cocoa butter than semisweet
chocolate. The level of chocolate liquor must be at least 15% to meet the standard. Sweet
chocolate can also be referred to as dark chocolate by consumers.
ii) Milk Chocolate
Picture 2.2: Milk Chocolate
The most common kind of chocolate. Milk chocolate contains nutritive carbohydrate
sweeteners, chocolate liquor, cocoa butter, milk (or cream), and flavors. Milk chocolate must
contain at least 10 percent chocolate liquor and 12 percent milk solids to meet the US standard of
identity. The only fats allowed in milk chocolate are cocoa butter and milk fat.
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iii) White Chocolate
Picture 2.3: White Chocolate
White chocolate contains the same ingredients as milk chocolate with the exception that
white chocolate does not contain any of the nonfat portion of chocolate. White chocolate must
contain at least 20 percent cocoa butter, 14 percent total milk solids, and less that 55 percent
sweetener (sugar).
2.4 Chocolate’s composition
The nutritional content of chocolate varies according to the recipe. Most of the contents
in chocolates are metabolized to different forms of elements. Generally, chocolate contains:
1) Protein – needed for cell maintenance and repair.
2) Fat – varies, but chocolate contains approximately 30–45 per cent fat, of which about half is
saturated fat
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3) Vitamin E – a fat-soluble vitamin essential for cell membranes.
4) Calcium, phosphorus and magnesium – minerals essential for strong bones and teeth.
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5) Iron – needed to form haemoglobin, the oxygen-carrying compound in blood.
6) Caffeine and theobromine – nervous system stimulants.
7) Copper – assists iron metabolism, formation of melanin (in hair and skin) and functioning of
the central nervous system.
8) Sugars – varies, but often make up about 50 per cent.
9) Antioxidant phytochemicals (such as flavonoids) – cocoa beans, the main ingredient of
chocolate (particularly dark chocolate), contain more than 600 plant chemicals, including
antioxidants, that may protect against heart disease and cancer.
2.5 Health effect of chocolate
2.5.1 Benefits of chocolate
Chocolate's beneficial levels of magnesium is 56 mg in a 50g (~2oz) bar of dark
chocolate may help to explain some of chocolate's sedative effect on stressed-out people. Stress
causes the body to deplete its supplies of magnesium, ultimately leading to an out-of-balance
biochemistry. It may be that the magnesium in chocolate helps restore the body's magnesium
balance
Chocolate also has a more direct stress-reducing effect. It contains a compound called
anandamide also known as the "bliss chemical" that binds to certain receptors in the brain to
promote relaxation. This happens in a manner similar to the effect of some components of
marijuana though the effect is much more subtle. Further, chocolate contains enzyme inhibitors
that decrease the body's ability to metabolize anandamide, thus "prolonging the high." Another
mood-altering compound found in chocolate is phenylethylamine, a chemical supposedly
released by the brain when we are in love. Many researchers, however, discount this as a mood-
altering factor, noting that phenylethylamine levels are higher in cheese and sausage which are
not associated with stress reduction and that the phenylethylamine in chocolate is too rapidly
metabolized by the body to have the purported effect.
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The high fat content of chocolate does trigger the brain's production of natural opiates.
Similarly, the sensory pleasures taste, smell and mouth feel associated with chocolate can
undoubtedly have a calming effect on the eater.
Antioxidants are important soldiers in the war our body constantly wages against free
radicals, which can cause all sorts of cellular damage. More generally, antioxidants are essential
to how the body detoxifies itself. Dark chocolate is packed with antioxidants called
bioflavonoids. They reduce loss of long-term memory and learning ability, maintain the ability
of brain cells to respond to a chemical stimulus; a function that normally decreases with age and
protect capillaries against oxidative damage.
While dark chocolate is clearly a superstar when it comes to antioxidants, experts
recommend to consume food with antioxidants from a variety of sources, not just chocolate.
Different phytochemicals are present in different amounts in various foods, and getting a nice
mix of these nutrients from a variety of fresh fruits and vegetables is the best way.
Research is ongoing, but two primary reasons have emerged as to why chocolate is good
for coronary health:
1. Cocoa appears to help the body modulate nitric oxide, a compound critical for healthy
blood flow and blood pressure; and
2. The flavonols in cocoa reduce the chance of blood clots and prevent fatty substances in
the bloodstream from clogging arteries.
Antioxidants, such as catechins, are substances found in some foods like tea, fruits and
vegetables and are thought to protect the body against degenerative illnesses like heart disease
and cancer. The antioxidant content of chocolate has been found to be significantly higher than
tea. Chocolate, particularly dark chocolate, is a good source of catechins and may help prevent
the oxidation of blood cholesterol and decrease the tendency for blood clotting. However, more
evidence is needed on how these findings translate to heart health. If you want to boost your
intake of catechins, while keeping your fat intake low, try drinking cocoa instead of eating
chocolate, since it generally has a much lower fat content.
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2.5.2 Disadvantages of chocolate
Obesity
Chocolate is high calories, and its calories content are higher than an equal size of fruits
or vegetables. Excess caloric intake leads to weights gain. Being overweight can result in a
number of health problems, including heart disease, diabetes and high blood pressure. Hershey's
standard 43g milk chocolate bar contains 210 calories, 13g of fat and 24g of sugar. Having only
one or two small pieces of the chocolate bar, rather than the entire thing is harmless. However, If
a person regularly eats more food than their body needs, they will store the excess energy as
body fat. Chocolate is energy dense, which means it contains comparatively high levels of
kilojoules for its weight, approximately 2,200kJ per 100gm. The density of energy in chocolate
is mainly because it is loaded with refined sugar and fats. The added fats are usually in the form
of hydrogenated vegetable oils which is tasty, yet extremely unhealthy for people. The body
treats these converted oils the same way as saturated fats in the body so they may be stored
easily. Regularly eating energy dense foods is perhaps the fastest way to gain excess weight, but
it would be wrong to say that regularly eating chocolate will lead to obesity.
Picture 2.4: Obesity
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Below are the calories content of common chocolate bars that found in the supermarket:
Chocolate Bar Calories per average bar
Cadbury's Creme Eggs 170 (1 egg 39gr.)
Cadbury's Crunchie 185 (40gr.)
Cadbury's Whirls 118 (50gr.)
Cadbury's Wholenut 270 (50gr.)
Dairy Crunch 49 (1 piece)
Drifter 260 (52gr.)
Fry's Choc Cream 210 (50gr.)
Kit Kat 228 (45gr.)
Lion Bar 313 (65gr.)
Maltesers 187 (37gr.)
Mars Bar 175 (32gr.)
Milky Bar 165 (30gr.)
Milky Way 97 (23gr.)
Revels 168 (35gr.)
Rolo 220 (each)
Snickers 266 (57gr.)
Toffee Crisp 93 (18gr.)
Topic Bar 234 (47gr.)
Turkish Delight 185 (51gr.)
Twix 286 (57gr.)
Table 2.1: Common chocolate bars and the calorie content per chocolate bar
Consumption of chocolate calories could monitored by selecting the smaller portions.
However, consideration should be taken that chocolates contain variety of substances, some of
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which have addictive properties such as theobromine and caffeine which could stimulate and
mood elevation. They also contain phenethylamine which can cause endorphin releases in the
brain.
Sugar Complications
Chocolate contains large amount of sugar. Without sugar it would taste too bitter for most
people to eat. The refined sugar in processed chocolate can lead to dental problems like gum
disease and caries when eaten often without regular and proper teeth brushing. Caries is caused
by the dissolution of the teeth by acid produced by the metabolism of dietary carbohydrates by
oral bacteria. The two primary bacteria involved in caries formation are mutans streptococci and
lactobacilli. Diet and nutrition may interfere with the balance of tooth demineralization and
remineralization in several ways. The diet provides sugars and other fermentable carbohydrates,
which are metabolized to acids by plaque bacteria. The resultant low pH favors the growth of the
acidogenic and aciduric bacteria (mutans streptococci). Bacteria can also use sugar as a type of
glue to cling to your teeth, making it difficult to get rid of with just a toothbrush.
Picture 2.5: Caries
Plaque that is not removed can harden and form "tartar". The longer the plaque and tartar
remain on teeth, the more harmful they become. The bacteria causes inflammation of the gums
that is called "gingivitis." In gingivitis, the gums become red, swollen and can bleed easily. 10
Gingivitis is a mild form of gum disease that can usually be reversed with daily brushing and
flossing
Another concern of eating large amounts of sugar each day is the increased risk for
diabetics. If you are a diabetic, chocolate can cause your blood sugar to elevate by supplying you
with more than a meal's worth of sugar.
Gastrointestinal Discomfort
Stomach upset caused by chocolate can be related to various disorders, such as irritable
bowel syndrome (IBS), food allergy or lactose intolerance. The primary type of food allergy that
most IBS patients have, is dairy allergies. Many people often have to frequent the washroom
immediately or shortly afterwards when indulging in any type of dairy product such as cheese,
milk, or in this case, the milk chocolate. The milk content in the chocolate irritates the gut and
the high sugar content in chocolates also affect the yeast count in your gut hence affect the
digestion system. Chocolate also contains caffeine which is acidic. Acidic foods can cause
increase of stomach’s acidity, which can result in heartburn, acid reflux or inflammation of an
existing stomach ulcer. Other than that, caffeine is a bowel stimulant which can worsen
symptoms of irritable bowel disease or diarrhea.
High Potassium
Chocolate is high in potassium and hence should be avoided by those suffering with
adrenal disease or kidney disease in order to avoid elevated levels of the mineral in their blood.
A 2 oz. piece of chocolate contains more than 200 mg of potassium. Therefore, if you have a
condition that requires you to restrict the potassium in your diet, chocolate is not the treat for
you.
Migraines
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Migraine headaches are a common neurological disorder, and studies show that their
prevalence has increased in the last two decade. The exact cause of the increased prevalence is
not clearly known, however there are evidence that it is due to dietary factors. In a survey
conducted on 429 people with migraine in Northwestern University Medical Center, Chicago, it
is found that 16.5% of the respondents reported migraines triggered by cheese or chocolate,
28.4% reported sensitivity to all alcoholic drinks, 11.8% were sensitive to red but not white
wine, and 28% were sensitive to beer.
Phenylethylamine, theobromine, and caffeine, the chemical triggers in chocolate that may
affect migraine by influencing the release of serotonin, causing constriction and dilation of blood
vessels, or by directly stimulating areas of the brain such as the trigeminal ganglia, brainstem,
and neuronal pathways. It may also cause headache by altering the cerebral blood flow and
releasing norepinephrine. Some people experience headache if they eat chocolate but not when
they drink caffeinated beverages. That is because there are some people who are sensitive only to
either phenylethylamine or caffeine, while others may be sensitive to both.
Acne and pimples
A recent study has shown that most people, around 70 per cent, believe that certain foods
can cause or exacerbate acne. Chocolate was indicated as one of the main culprits. However,
there is no evidence to back up this long held belief. According to scientific research to date,
there are no compounds, ingredients or naturally occurring chemicals in chocolate that can either
trigger acne or make it worse.
Picture 2.6: Acne
Heart disease and cancer 12
Chocolate’s flavonoids have shown good dose-response bioavailability in humans. There
exists several mechanisms of how flavonoids may be protective against cardiovascular disease
and these include: antioxidant, anti-platelet, anti-inflammatory effects, as well as possibly
increasing HDL, lowering blood pressure, and improving endothelial function. Additionally,
aggregation of platelets at the site of plaque rupture and endothelial dysfunction has been
implicated in the pathogenesis of atherosclerosis. Current research has shown that a number of
components of chocolate, particularly catechin and epicatechin, have significant antiplatelet
effects, quantitatively similar to that of aspirin. Antioxidants, such as catechins, are substances
found in some food like chocolate, tea, fruits and vegetables and are thought to protect the body
against degenerative illnesses like heart disease and cancer. Chocolate, particularly dark
chocolate, is a good source of catechins and may help prevent the oxidation of blood cholesterol
and decrease the tendency for blood clotting.
But, cocoa also happens to be very high in Copper, which unfortunately inhibits the
action of certain flavonoids, particularly Hesperidin, which is an essential flavanone. This can
lead to a greater incidence of vascular degeneration such as varicose veins, haemorrhoids,
aneurysms, bruising, heart disease, and stroke in those with elevated copper levels. High copper
sources such as chocolate and cocoa products, cola drinks, and coffee, not only aggravates many
high copper-related medical conditions, but it is responsible for creating new ones. At the same
time, copper is an important co-factor for angiogenesis (new blood vessel formation with
cancers), so with the exception of colon cancer, for which copper and calcium are somewhat
protective for, most other types of malignant or benign tumors, hemangiomas, and fibroids, are
associated with high copper levels. Dark, bitter chocolate has the highest catechin content, but at
the same time has also the highest copperlevel. Light or milk chocolate has the lowest copper
level, but also the lowest catechin content.
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Graph 2.1: Risk factor for cancer associated with flavonoid and copper level in the body
However, more evidence is needed on how these findings translate to heart health. If you
want to boost your intake of catechins, while keeping your fat intake low, try drinking cocoa
instead of eating chocolate, since it generally has a much lower fat content.
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