Prevention Dr.Jihan Abdulhussein
Lec.14 Non- sugar sweetener
Sweeteners are added sugars that are used as ingredients to both satisfy our taste and
in some cases provide added energy. Taste sensation is initiated by the arrival of a
stimulus at the taste buds. Taste recognition occurs when the receptor sites of the
cells of the taste buds carry, by cranial nerves, a qualitative and quantitative
message to the brain. The messages are processed, and the stimulus is recognized as
either sweet, sour, salty, or bitter, or some combination of these four.
The sweetness of sugars all sugar contributes sweetness to food, but the relative
sweetening power varies among sugars. In general, the more easily the sugar
dissolves in water, the greater its sweetening power. For example, fructose is 75%
sweeter than any other sugar. It is soluble in water; difficult to crystallize, as a result
it is expensive, and useful in syrup. At the other extreme, the least sweet, least
soluble sugar is lactose. Lactose is seldom if ever used as sweeteners because it is
almost impossible to dissolve in the food to be sweetened.
It's difficult to determine whether taste is genetically linked, acquired in utero,
neonatal, or influenced by visual, auditory, or taste stimuli during infancy, early
childhood or even adulthood. Theoretically an individual can initially acquire and
refine taste desire in any of the following stages: (1) in uteri, (2) during breast or
bottle feeding, (3) while passively being fed solid (4) while more actively seeking
different nonspecific foods, (5)and while purposely seeking specific food .
Taste buds are present and functioning before birth, a fact demonstrating by
injecting sweetening agents into the amniotic fluid results in an increased rate of
swallowing by the fetus. At birth, infants show a taste preference for sucrose, and
their taste cells are more responsive to sucrose than other sugar and the newborn
baby respond unfavorably to a bitter substance.
Non- sugar sweeteners sometimes referred to as sugar substitutes, sugar replacers
or alternative sweeteners. There is increasing interest in the use of sweetening
agents which confer sweetness but are safer for teeth. The usefulness of these
compounds has to be judged from a nutritional, dental, toxicological, economic and
technical point of view.
Sugars substitutes can be divided into bulk sweeteners (nutritive, caloric) and
intense sweeteners (non-nutritive, non-caloric), some of these are naturally
occurring compounds. Grouping sweeteners as "nutritive" or "non-nutritive"
acknowledges a difference in the amount of energy provided by the sweetener.
Bulk sweeteners (caloric)
Many of the bulk sweeteners are sugar alcohols, and being chemically similar to
sugars, they have a similar caloric content to sucrose, the most commonly known
include sorbitol, mannitol, and xylitol. Because sorbitol and mannitol are only half
as sweet as sucrose, there may be a tendency to increase caloric intake with the use
of these two compounds. Xylitol is the most popular sugar alcohol due to its
similarity to sucrose in visual appearance and sweetness.
One of the disadvantages of the bulk sweeteners is that they are only partially
absorbed in the small intestine and pass the colon where they may induce osmotic
diarrhea. Bulk sweeteners are therefore not recommended for children under three
years of age and care must be taken with sugar-free medicines containing bulk-
sweeteners, since high intakes cause gastrointestinal disturbance.
1-Sorbitol: It is used extensively as a non- sugar sweeteners in confectionery,
chewing gum, liquid oral medicine, and toothpastes. The negative heat of
dissolution is used advantageously in mints, which have pleasant cool taste.
It is a derivative of glucose, occurs naturally in such fruits as apples, pears and
peaches and in several vegetables.
It is not actively absorbed from the gastrointestinal tract and is absorbed at about
one third of the rate of glucose absorption. This means that eating food rich in
sorbitol allow blood glucose level to remain above the fasting level for a longer time
than dose eating food correspondingly rich in glucose. Thus eating sorbitol may
delay the onset of hunger. For this reason, sorbitol is an ingredient in some foods
designed for use in weight – reducing diets.
Sorbitol is less cariogenic than sucrose, as it fermented slowly by plaque organisms,
and the rate is very much slower than that for glucose and sucrose. Sorbitol and
sorbitol- containing products are considered safe for teeth.
The oral microflora may adapt to sorbitol so that it loses its safe for teeth prop erty
2-Mannitol less popular than sorbitol, partly because of its higher price, and they
have a similar dental properties. It is used in toothpaste, mouth rinses and as a
dusting agent for chewing gum.
3-Xylitol
It is the best nutritive sucrose substitute with respect to caries prevention.
Xylitol can be considered as non-cariogenic and anti-cariogenic that prevent dental
caries. It's non- fermentability in plaque and its saliva stimulating effect may support
this statement.
Xylitol may have an anti-microbial effect since the plaque accumulation after
xylitol consumption is reduced and there is a good evidence that the ability of
plaque to produce acids by metabolism of sugar reduced by xylitol. This seems to be
explained adequately by the decrease in S. mutans in plaque exposed to xylitol and
possibly a decreased in plaque quantity, xylitol have ability to inhibit growth and
metabolism of S. mutans to the same degree as some antimicrobial
Microbiological studies have shown clearly that plaque organism did not adapt to
metabolize xylitol.
It was proved that foods or beverages containing xylitol cause lower blood glucose
and lower insulin responses compared to sugar-containing foods or drinks. So used
in diabetes management.
Intense sweeteners (non-caloric) called intense sweeteners because they have
sweetness hundreds to thousands of time than sucrose.
These substances impart sweetness but furnish no calories (have a negligible energy
value, or too little to have any clinical importance).
They are chemically not related to sugar. An intense sweetener should permit caloric
reduction without sacrificing palatability.
The need for intense sweeteners is acute for primary preventive dentistry practices, a
non-carious product that could be used in oral medication, mouth rinses, toothpaste
and all form of candy is highly desirable.
They are safe for teeth because they cannot act as an energy source for dental plaque
microorganisms so they are not metabolized to acids by the oral microorganisms
and they cannot cause dental caries. Thus, they are a perfect as far as dental caries is
concerned. However they have disadvantages in taste, stability, lack of volume,
although a sweeteners with a low physical weight is also highly desirable for
reducing the size of product packages. The most popular intense sweeteners are:
1-Saccharin: is a considered approximately 300 times sweeter than sucrose. Due to
its intense sweetness, the use of saccharin is only about 4% as costly as an
equivalent sweetness derived from sucrose; it is compatible with most food and drug
ingredients.
It has a bitter taste in concentration over 0.1%, although the perception of this
varies between individual.
Saccharin has been reported to inhibit bacterial growth and metabolism but its caries
inhibiting effect are small.
2-Aspartame: It is a dipeptide consisting of aspartic acid and phenylalanine. It is
approximately 200 times sweeter than sucrose with a similar taste to sucrose.
Individuals with phenylketonuria should avoid ingestion of aspartame.
3-Acesulfame K: It is approximately 200 times sweeter than sucrose. It has a
pleasant sweet taste, so have a good potential as a sweetener in most classes of food
and drinks and useful sweetener in boiled sweet and preserves.
Protective factors in food
Food and food component (dietary factors) that counteract the damaging effects of
carbohydrates and have anti-cariogenic (caries inhibiting) properties are sometime
referred to as cariostatic (protective) factors, fluoride are undoubtedly the most
effective of these factors, other factors in food are :
Phosphate: The most promising of the organic phosphates was phytate, identified
as the most active substances in unrefined cereals. The effectiveness of phytate
appears to be due to its ability to adsorb readily and firmly to enamel surfaces and
so prevent the dissolution of enamel by acids.
However, the problem was that it was present naturally inside the bran particles and
so was not readily available in its natural form, in the mouth. Therefore, to be
effective, phytate would need to be extracted from grain and then used as food
additive. However, this would not be desirable since phytate binds minerals
calcium, magnesium, iron and zinc reduced their absorption from the gut, it
probable that this side effect will make it unwise to recommend the use of phytate as
a food additive.
Fats: Fats seems to reduce the cariogenicity of food, they may act merely by
replacing carbohydrate in the diet. Fat may also form a protective barrier on the
enamel, or surround the carbohydrates, making these less available and speeding up
their removal from the mouth. Bacterial surface properties involved in plaque
formation could also be altered by fats. Certain fatty acids have antimicrobial effect
and have been shown to inhibit glycolysis in human dental plaque.
Milk and cheese: Despite being one of the main sources of sugar in the diet of
small children, normal milk consumption dose not cause dental caries, and an
inverse relationship between the consumption of milk and caries increment has been
reported. Milk is considered non- cariogenic or even anti-cariogenic in spite of the
fact that lactose is fermented by dental plaque but its less acidogenic than other
mono and disaccharides. On the other hand, milk has a combination cariostatic
component in the readily available form: protein (casein), calcium and phosphate,
calcium and phosphate that present in high concentration are able to prevent enamel
demineralization.
Human breast milk is higher in lactose and lower in phosphorus and calcium;
however, the epidemiological studies have associated breast-feeding with low level
of dental caries. Breast feeding provide no opportunity to added additional sugar to
milk feeds and breast-fed infant are perhaps less likely to use baby bottles
containing sugary liquids, however prolonged, and nocturnal suckling have been
associated with increased caries risk .
The evidence from many studies shows that cow’s milk a non-cariogenic drink
suitable for use as an artificial saliva in caries prone xerostomic patients, since it
appear to have caries protective properties.
Consuming cheese following a sugary snack virtually abolish the usual fall on pH
that is associated with sugars consumption. Cheese stimulates salivary secretion due
to its sharp testing, the high protein (casein) calcium and phosphorus content
seem to be another factor in the cariostatic mechanism of cheese as it increase their
concentration in dental plaque, the calcium concentration within dental plaque
strongly influences the balance between de- and remineralization of enamel.
There is also increased evidence that chewing cheese may reduce the levels of
cariogenic bacteria.
Fruit and dental caries
Health report through out the world encourage increased consumption of fruit and
vegetables, also they reported that in order to reduce the risk of dental caries,
consumption of non- milk extrinsic sugars should be decreased and that sugars
should be replaced by fresh fruit vegetables, and starchy food. It is also preferable to
consume whole fresh fruit as opposed to juices, because their mastication provides a
good stimulus to salivary flow, in addition fresh fruit juices contain non-milk
extrinsic sugars, since liquidation release the fruit sugars from cellular structure of
the fruit.
Testing food cariogenicity
Dental caries is a result of demineralization brought about by frequent pH drops in
the plaque. However, numerous studies have focused on methods to evaluate food
cariogenicity, most often by the use of pH assessment of dental plaque exposed to
the food items in question.
There is no doubt that its easy to rank the relative cariogrenic potential of a variety
of foodstuffs by evaluating and comparing the Stephan curve derived when each
foods are eaten under controlled condition.
Ranking of food, according to their capacity to induce a pH drop in dental plaque
under known condition in a few individual, should therefore only be considered as
gross estimates of their relative cariogenicity.