Food Biotechnology VU
Lecture 1
INTRODUCTION TO FOOD, DEFINITIONS AND BASIC CONCEPTS
Module 1: Introduction to Food, Definition and basic concepts
Food Science The study of food science involves understanding the nature, composition
and behavior of food materials under varying conditions of growth, harvest, transportation,
processing, storage, handling and use.
Food Technology: is the application of food science & engineering principles to the
selection, preservation, processing, packaging, distribution, and use of safe, nutritious, and
wholesome food.
Food Biotechnology:
Application of technology to modify genes of animals, plants, and microorganisms to
create new species which have desired production, marketing, or nutrition related
properties. Called genetically engineered (GE) or genetically modified (GM) foods.
Food Security: Food security is achieved when all people, at all times, have physical,
social and economic access to sufficient, safe and nutritious food to meet their dietary
needs and food preferences for an active and healthy life. (800 million people suffer from
hunger).
Nutrition:
“The science of food, the nutrients and substances therein, their action, interaction, and
balance in relation to health and dis-ease, and the process by which the organisms ingest,
digest, absorb, transport, utilize, and excrete food substances” (The Council on Food and
Nutrition of the American Medical Association).
Food is required for four main reasons:
• as a source of energy;
• as a source of raw materials for growth and development;
• to supply minute chemicals that serve to regulate vital metabolic processes;
• to supply food components (phytochemicals) that retard the development and
progression of degenerative diseases.
,Food Biotechnology VU
Module 2: Food composition
Carbohydrates
Carbohydrate is the collective name for polyhydroxyaldehydes and polyhydroxyketones,
and these compounds form a major class of biomolecules that perform several functions in
vivo, including the storage and transport of energy. Indeed, carbohydrates are the major
source of energy in our diet. The name carbohydrate derives from their general empirical
formula, which is (CH2O)n; however, the car-bohydrate group contains several derivatives
and closely related compounds that do not fit this general empirical formula but are still
considered to be carbohydrates. There are three distinct classes of carbohydrates:
monosaccharides (1 structural unit), oligosaccha-rides (2–10 structural units) and
polysaccharides (more than 10 structural units).
Module 3: Water Contents in foods
It exists in three forms in foods
1. Free Water: This is form of water that retains its physical properties and hence acts
as dispersing agent for colloids and solvents of choice.
2. Chemically adsorbed water: This water is held tightly and it is componenet of cell
walls or protoplast and is held tightly with proteins.
3. Chemically bound water: This is form of water that is bound chemically, i.e.
lactose monohydrate or also in form of some salts Na2So4.10H2O etc.
Module 4: Carbohydrates Contents of food
Monosaccharides
The monosaccharides are also termed simple sugars, are given the suffix -ose and classified
as aldoses or ketoses depending on whether they contain an aldehyde or ketone group. The
most common monosac-charides are either pentoses (containing a chain of five carbon
atoms) or hexoses (containing a chain of six carbon atoms). Each carbon atom carries a
hydroxyl group, with the exception of the atom that forms the carbonyl group, which is also
known as the reducing group.
,Food Biotechnology VU
Monosaccharides are assigned optical configurations with respect to comaparison of their
highest numbered asymmetric car-bon atom to the configuration of D-glyceraldehyde or L-
glyceraldehyde. By convention, the carbon atoms in the monosaccharide molecule are
numbered such that the reducing group carries the lowest possible number; therefore, in
aldoses the reducing group carbon is always numbered 1 and in ketoses the numbering is
started from the end of the carbon chain closest to the reducing group. Most naturally
occurring monosaccharaides belong to the D-series, i.e. their highest numbered carbon has
a similar optical configuration to D-glyceraldehyde.
Oligosaccharides
Oligosaccharides contain 2–10 sugar units and are water soluble. The most significant
types of oligosac-charide occurring in foods are disaccharides, which are formed by the
condensation (i.e. water is eliminated) of two monosaccharide units to form a glycosidic
bond. A glycosidic bond is that between the hemiacetal group of a saccharide and the
hydroxyl group of another compound, which may or may not be itself a saccharide.
Disaccharides can be homoge-neous or heterogeneous and fall into two types:
Non-reducing sugars in which the monosaccharide units are joined by a glycosidic bond
formed be-tween their reducing groups (e.g. sucrose and tre-halose). This inhibits further
bonding to other sac-charide units
Reducing sugars in which the glycosidic bond links the reducing group of one
monosaccharide unit to the non-reducing alcoholic hydroxyl of the second monosaccharide
unit (e.g. lactose and maltose). A reducing sugar is any sugar that, in basic solu-tion, forms
an aldehyde or ketone allowing it to act as a reducing agent, and therefore includes all
monosaccharides.
Of the disaccharides, sucrose, trehalose and lactose are found free in nature, whereas others
are found as glycosides (in which a sugar group is bonded through its anomeric carbon to
another group, e.g. a pheno-lic group, via an O-glycosidic bond) or as building blocks for
polysaccharides (such as maltose in starch), which can be released by hydrolysis. Probably
the three most significant disaccharides in food are su-crose, lactose and maltose.
Sucrose is the substance known commonly in households as sugar and is found in many
plant fruits and saps. It is isolated commercially from sugar cane or the roots of sugar beet.
Sucrose is composed of a-D-glucose residue linked to a b-D-fructose residue and is a non-
, Food Biotechnology VU
reducing sugar. Its systematic name is a-D-glucopyranosyl-(1↔2)-b-D-fructofuranoside
(hav-ing the suffix -oside, because it is a non-reducing sugar). It is the sweetest tasting of
the disaccharides and is an important source of energy.
Lactose is found in mammalian milk and its sys-tematic name is b-D-galactopyranosyl-
(1↔4)-b-D-glucopyranose. To aid the digestion of lactose, the intestinal villi of infant
mammals secrete an enzyme called lactase (b-D-galactosidase), which cleaves the molecule
into its two subunits b-D-glucose and b-D-galactose. In most mammals the production of
lac-tase gradually reduces with maturity into adulthood, leading to the inability to digest
lactose and so-called lactose intolerance. However, in cultures where cattle, goats and
sheep are milked for food there has evolved a gene for lifelong lactase production.
Maltose is formed by the enzymatic hydrolysis of starch and is an important component of
the barley malt used to brew beer. It is a homogeneous disaccha-ride consisting of two
units of glucose joined with an a(1→4) linkage, and is systematically named 4-O-a- D-
glucopyranosyl-D-glucose. Maltose is a reducing sugar and the addition of further glucose
unit yields a series of oligosaccharides known as maltodextrins or simply dextrins.
Polysaccharides
Polysaccharides are built of repeat units of monosaccharides and are systematically named
with the suf-fix -an. The generic name for polysaccharides is glycan and these can be
homoglycans consisting of the one type of monosaccharide or heteroglycans consisting of
two or more types of monosaccharide.
Polysaccharides have three main functions in both animals and plants: as sources of energy,
as structural components of cells, and as water-binders. Plant and animal cells store energy
in the form of glucans, which are polymers of glucose such as starch (in plants) and
glycogen (in animals). The most abundant structural polysaccharide is cellulose, which is
also a glucan and is found in plants. Water-binding substances in plants include agar, pectin
and alginate.
Polysaccharides occur as several structural types: linear (e.g. amylose, cellulose), branched
(e.g. amy-lopectin, glycogen), interrupted (e.g. pectin), block (e.g. alginate) or alternate
repeat (e.g. agar, carrageenan). According to the geometry of the glycosidic link-ages,
polysaccharide chains can form various con-formations, such as disordered random coil,
extended ribbons, buckled ribbons or helices. One of the most im-portant properties of a
Lecture 1
INTRODUCTION TO FOOD, DEFINITIONS AND BASIC CONCEPTS
Module 1: Introduction to Food, Definition and basic concepts
Food Science The study of food science involves understanding the nature, composition
and behavior of food materials under varying conditions of growth, harvest, transportation,
processing, storage, handling and use.
Food Technology: is the application of food science & engineering principles to the
selection, preservation, processing, packaging, distribution, and use of safe, nutritious, and
wholesome food.
Food Biotechnology:
Application of technology to modify genes of animals, plants, and microorganisms to
create new species which have desired production, marketing, or nutrition related
properties. Called genetically engineered (GE) or genetically modified (GM) foods.
Food Security: Food security is achieved when all people, at all times, have physical,
social and economic access to sufficient, safe and nutritious food to meet their dietary
needs and food preferences for an active and healthy life. (800 million people suffer from
hunger).
Nutrition:
“The science of food, the nutrients and substances therein, their action, interaction, and
balance in relation to health and dis-ease, and the process by which the organisms ingest,
digest, absorb, transport, utilize, and excrete food substances” (The Council on Food and
Nutrition of the American Medical Association).
Food is required for four main reasons:
• as a source of energy;
• as a source of raw materials for growth and development;
• to supply minute chemicals that serve to regulate vital metabolic processes;
• to supply food components (phytochemicals) that retard the development and
progression of degenerative diseases.
,Food Biotechnology VU
Module 2: Food composition
Carbohydrates
Carbohydrate is the collective name for polyhydroxyaldehydes and polyhydroxyketones,
and these compounds form a major class of biomolecules that perform several functions in
vivo, including the storage and transport of energy. Indeed, carbohydrates are the major
source of energy in our diet. The name carbohydrate derives from their general empirical
formula, which is (CH2O)n; however, the car-bohydrate group contains several derivatives
and closely related compounds that do not fit this general empirical formula but are still
considered to be carbohydrates. There are three distinct classes of carbohydrates:
monosaccharides (1 structural unit), oligosaccha-rides (2–10 structural units) and
polysaccharides (more than 10 structural units).
Module 3: Water Contents in foods
It exists in three forms in foods
1. Free Water: This is form of water that retains its physical properties and hence acts
as dispersing agent for colloids and solvents of choice.
2. Chemically adsorbed water: This water is held tightly and it is componenet of cell
walls or protoplast and is held tightly with proteins.
3. Chemically bound water: This is form of water that is bound chemically, i.e.
lactose monohydrate or also in form of some salts Na2So4.10H2O etc.
Module 4: Carbohydrates Contents of food
Monosaccharides
The monosaccharides are also termed simple sugars, are given the suffix -ose and classified
as aldoses or ketoses depending on whether they contain an aldehyde or ketone group. The
most common monosac-charides are either pentoses (containing a chain of five carbon
atoms) or hexoses (containing a chain of six carbon atoms). Each carbon atom carries a
hydroxyl group, with the exception of the atom that forms the carbonyl group, which is also
known as the reducing group.
,Food Biotechnology VU
Monosaccharides are assigned optical configurations with respect to comaparison of their
highest numbered asymmetric car-bon atom to the configuration of D-glyceraldehyde or L-
glyceraldehyde. By convention, the carbon atoms in the monosaccharide molecule are
numbered such that the reducing group carries the lowest possible number; therefore, in
aldoses the reducing group carbon is always numbered 1 and in ketoses the numbering is
started from the end of the carbon chain closest to the reducing group. Most naturally
occurring monosaccharaides belong to the D-series, i.e. their highest numbered carbon has
a similar optical configuration to D-glyceraldehyde.
Oligosaccharides
Oligosaccharides contain 2–10 sugar units and are water soluble. The most significant
types of oligosac-charide occurring in foods are disaccharides, which are formed by the
condensation (i.e. water is eliminated) of two monosaccharide units to form a glycosidic
bond. A glycosidic bond is that between the hemiacetal group of a saccharide and the
hydroxyl group of another compound, which may or may not be itself a saccharide.
Disaccharides can be homoge-neous or heterogeneous and fall into two types:
Non-reducing sugars in which the monosaccharide units are joined by a glycosidic bond
formed be-tween their reducing groups (e.g. sucrose and tre-halose). This inhibits further
bonding to other sac-charide units
Reducing sugars in which the glycosidic bond links the reducing group of one
monosaccharide unit to the non-reducing alcoholic hydroxyl of the second monosaccharide
unit (e.g. lactose and maltose). A reducing sugar is any sugar that, in basic solu-tion, forms
an aldehyde or ketone allowing it to act as a reducing agent, and therefore includes all
monosaccharides.
Of the disaccharides, sucrose, trehalose and lactose are found free in nature, whereas others
are found as glycosides (in which a sugar group is bonded through its anomeric carbon to
another group, e.g. a pheno-lic group, via an O-glycosidic bond) or as building blocks for
polysaccharides (such as maltose in starch), which can be released by hydrolysis. Probably
the three most significant disaccharides in food are su-crose, lactose and maltose.
Sucrose is the substance known commonly in households as sugar and is found in many
plant fruits and saps. It is isolated commercially from sugar cane or the roots of sugar beet.
Sucrose is composed of a-D-glucose residue linked to a b-D-fructose residue and is a non-
, Food Biotechnology VU
reducing sugar. Its systematic name is a-D-glucopyranosyl-(1↔2)-b-D-fructofuranoside
(hav-ing the suffix -oside, because it is a non-reducing sugar). It is the sweetest tasting of
the disaccharides and is an important source of energy.
Lactose is found in mammalian milk and its sys-tematic name is b-D-galactopyranosyl-
(1↔4)-b-D-glucopyranose. To aid the digestion of lactose, the intestinal villi of infant
mammals secrete an enzyme called lactase (b-D-galactosidase), which cleaves the molecule
into its two subunits b-D-glucose and b-D-galactose. In most mammals the production of
lac-tase gradually reduces with maturity into adulthood, leading to the inability to digest
lactose and so-called lactose intolerance. However, in cultures where cattle, goats and
sheep are milked for food there has evolved a gene for lifelong lactase production.
Maltose is formed by the enzymatic hydrolysis of starch and is an important component of
the barley malt used to brew beer. It is a homogeneous disaccha-ride consisting of two
units of glucose joined with an a(1→4) linkage, and is systematically named 4-O-a- D-
glucopyranosyl-D-glucose. Maltose is a reducing sugar and the addition of further glucose
unit yields a series of oligosaccharides known as maltodextrins or simply dextrins.
Polysaccharides
Polysaccharides are built of repeat units of monosaccharides and are systematically named
with the suf-fix -an. The generic name for polysaccharides is glycan and these can be
homoglycans consisting of the one type of monosaccharide or heteroglycans consisting of
two or more types of monosaccharide.
Polysaccharides have three main functions in both animals and plants: as sources of energy,
as structural components of cells, and as water-binders. Plant and animal cells store energy
in the form of glucans, which are polymers of glucose such as starch (in plants) and
glycogen (in animals). The most abundant structural polysaccharide is cellulose, which is
also a glucan and is found in plants. Water-binding substances in plants include agar, pectin
and alginate.
Polysaccharides occur as several structural types: linear (e.g. amylose, cellulose), branched
(e.g. amy-lopectin, glycogen), interrupted (e.g. pectin), block (e.g. alginate) or alternate
repeat (e.g. agar, carrageenan). According to the geometry of the glycosidic link-ages,
polysaccharide chains can form various con-formations, such as disordered random coil,
extended ribbons, buckled ribbons or helices. One of the most im-portant properties of a
