327
common glycosidic sugars are glucose, galactose, xylose, arabinose, and rhamnose
(Fig. 11.8).
According to the type of sugar, glycosides can be called glucosides, rhamnosides, arabinosides, etc. If the glycoside contains several sugar molecules, they are
interconnected into an oligosaccharide molecule. According to the number of sugar
molecules, monoglycosides, diglycosides, triglycosides, etc. differ. Aglycones or
genes are chemically very heterogeneous compounds. They can be alcohols
(coniferyl), acids (benzoic), aldehydes (salicylic aldehyde), coumarins, xanthones,
flavonoids,
anthocyanin
derivatives,
anthraquinone
derivatives,
and
cyclopentanoperhydrophenanthrene derivatives. Sugar is most often bound via O,
but it can also be bound via C (thioglycosides), via N (nitrogen glycosides), etc.
Glycosides are very common in plants. Many plant pigments are glycosides. Some
plant families are especially rich in glycosides. Glycosides are important in pharmacy, as pharmacologically active substances, while in food they are found only in
traces. Glycosides are found in smaller amounts in the meat of fruits and vegetables.
They are present in the seeds as amygdalin and limetin, as well as in the epidermis
(auranciamarin).
Fatty acids Depending on the number of hydrogen atoms attached to the free
valences of carbon in the acid molecule, there are three types of fatty acids:
saturated, monounsaturated, and polyunsaturated. Depending on the length of the
fatty acid chain, they are divided into short chain, medium chain, and long chain.
The maximum number of hydrogen atoms is attached to all carbon atoms in saturated fatty acids, i.e., all carbon atoms are “saturated” with hydrogen. This type of
fatty acids dominates in fats that are solid at room temperature (fats of animal origin). Monounsaturated fatty acids (MUFAs) have such a chemical composition that
allows them to bind two more hydrogen atoms in the fatty acid molecule. Fats containing such fatty acids are in a liquid state at room temperature. These foods are
most often of plant origin and we call them vegetable oils. However, some fats are
often called oil even though they are in a solid state at room temperature as is the
case with palm oil. The most common fatty acid that belongs to the family of monounsaturated fatty acids is oleic acid (Fig. 11.9), the main ingredient in olive oil. The
longer the acid residues, the higher the melting point. If the acids are unsaturated,
the melting point with the number of double bonds decreases. Animal fats contain a
significant amount of saturated fatty acids, especially stearic and palmitic. Animal
fats are mostly solid at room temperature except for North Sea fish oil. If there are
a lot of unsaturated acids in the molecule, then these are oils, which are liquid at
room temperature (olive oil, soybean, sunflower, rapeseed oil).
The human body needs a full range of unsaturated fatty acids for its normal functioning, because they are an integral part of the body (cell membranes, various hormones, and enzymes). Most of the unsaturated fatty acids are created by the body
itself, but it needs raw materials. These raw materials are actually essential fatty
acids, which are necessary to enter the body from the outside through food and
without which life is not possible. The human body needs only two essential fatty
acids: linoleic (LA) from the group of omega-6 fatty acids and alpha linolenic
11 Chemical Composition and Nutritional Properties of Functional Food
common glycosidic sugars are glucose, galactose, xylose, arabinose, and rhamnose
(Fig. 11.8).
According to the type of sugar, glycosides can be called glucosides, rhamnosides, arabinosides, etc. If the glycoside contains several sugar molecules, they are
interconnected into an oligosaccharide molecule. According to the number of sugar
molecules, monoglycosides, diglycosides, triglycosides, etc. differ. Aglycones or
genes are chemically very heterogeneous compounds. They can be alcohols
(coniferyl), acids (benzoic), aldehydes (salicylic aldehyde), coumarins, xanthones,
flavonoids,
anthocyanin
derivatives,
anthraquinone
derivatives,
and
cyclopentanoperhydrophenanthrene derivatives. Sugar is most often bound via O,
but it can also be bound via C (thioglycosides), via N (nitrogen glycosides), etc.
Glycosides are very common in plants. Many plant pigments are glycosides. Some
plant families are especially rich in glycosides. Glycosides are important in pharmacy, as pharmacologically active substances, while in food they are found only in
traces. Glycosides are found in smaller amounts in the meat of fruits and vegetables.
They are present in the seeds as amygdalin and limetin, as well as in the epidermis
(auranciamarin).
Fatty acids Depending on the number of hydrogen atoms attached to the free
valences of carbon in the acid molecule, there are three types of fatty acids:
saturated, monounsaturated, and polyunsaturated. Depending on the length of the
fatty acid chain, they are divided into short chain, medium chain, and long chain.
The maximum number of hydrogen atoms is attached to all carbon atoms in saturated fatty acids, i.e., all carbon atoms are “saturated” with hydrogen. This type of
fatty acids dominates in fats that are solid at room temperature (fats of animal origin). Monounsaturated fatty acids (MUFAs) have such a chemical composition that
allows them to bind two more hydrogen atoms in the fatty acid molecule. Fats containing such fatty acids are in a liquid state at room temperature. These foods are
most often of plant origin and we call them vegetable oils. However, some fats are
often called oil even though they are in a solid state at room temperature as is the
case with palm oil. The most common fatty acid that belongs to the family of monounsaturated fatty acids is oleic acid (Fig. 11.9), the main ingredient in olive oil. The
longer the acid residues, the higher the melting point. If the acids are unsaturated,
the melting point with the number of double bonds decreases. Animal fats contain a
significant amount of saturated fatty acids, especially stearic and palmitic. Animal
fats are mostly solid at room temperature except for North Sea fish oil. If there are
a lot of unsaturated acids in the molecule, then these are oils, which are liquid at
room temperature (olive oil, soybean, sunflower, rapeseed oil).
The human body needs a full range of unsaturated fatty acids for its normal functioning, because they are an integral part of the body (cell membranes, various hormones, and enzymes). Most of the unsaturated fatty acids are created by the body
itself, but it needs raw materials. These raw materials are actually essential fatty
acids, which are necessary to enter the body from the outside through food and
without which life is not possible. The human body needs only two essential fatty
acids: linoleic (LA) from the group of omega-6 fatty acids and alpha linolenic
11 Chemical Composition and Nutritional Properties of Functional Food