09-05-2013, 04:09 PM
Food Chemistry(Preservatives)
[attachment=53668]
Preservatives
Definition of Preservative: - "Preservative" means a substance which when added to food, is capable of inhibiting, retarding or arresting the process of fermentation, acidification or other decomposition of food.
Preservatives or antimicrobial agents play an important role in today’s supply of safe and stable foods
Increasing demand for convenience foods and reasonably long shelf life of processed foods make the use of chemical food preservatives imperative
Some of the commonly used preservatives – such as sulfites, nitrate, and salt – have been used for centuries in processed meats and wine
Classification of Preservative: - Preservatives shall be divided into following classes:
1) Class I Preservatives
2) Class II Preservatives
Class I Preservative shall be:-
Common salt.
(b) Sugar
© Dextrose.
(d) Glucose 1[Syrup].
(e) Spices.
(f) Vinegar or acetic acid.
(g) Honey.
[(h) edible vegetable oils
1[Addition of Class I preservatives in any food is not restricted unless otherwise provided in the rules.]
Sodium Chloride
Sodium chloride has been used for centuries to prevent spoilage of foods
Fish, meats and vegetables has been preserved with salt
Today, salt is used mainly in combination with other processing methods
The antimicrobial activity of salt is related to its ability to reduce the water activity (aw) thereby influencing microbial growth
Glucose
Most abundant sugar in nature
Fruits
“grape sugar”
“Dextrose” b/c it is dextrorotatory
Carbohydrates converted to glucose
Produces energy for our cells
Circulating carbohydrate
Blood sugar
LIQUID GLUCOSE
LIQUID GLUCOSE or Corn Syrups are purified concentrated aqueous solution of polysaccharides obtained from partial (controlled) hydrolysis of maize starch.
The solids are composed of various carbo-hydrates; dextrose, maltose and higher polysaccharides.
The different carbohydrate profiles combined with various available solid levels give Liquid Glucose its unique application functions
Benzoic Acid
Benzoic acid occurs naturally in many types of berries, plums, prunes, and some spices
As an additive, it is used as benzoic acid or as benzoate
The latter is used more often because benzoic acid is sparsely soluble in water, and sodium benzoate is more soluble
The undissociated form on benzoic acid is the most effective antimicrobial agent
pKa of 4.2; optimum pH range is from 2.5 to 4.0
Parabens
They differ form benzoic acid in that they have antimicrobial activity in both acid and alkaline pH regions
The antimicrobial activity in parabens is proportional to the chain length of the alkyl group
Parabens are more active against molds and yeast than against bacteria, and more active against gram-positive than gram-negative bacteria
They are used in fruitcakes, pastries, and fruit fillings
Sorbic Acid
Sorbic acid is a straight-chain, trans-trans unsaturated fatty acid, 2,4-hexadienoic acid
As an acid, it has a low solubility in water at room temp
The salts, sodium, or potassium are more soluble in water
Sorbates are stable in the dry form; the are unstable in aqueous solutions because they decompose through oxidation
The rate of oxidation is increased at low pH, by increased temp, and by light exposure
Sulfites
Sulfur dioxide and sulfites have long been used as preservatives
Serving both as antimicrobial substance and as antioxidant
Sulfur dioxide is a gas that can be used in compressed form in cylinders
It is liquid under pressure of 3.4 atm and can be injected directly in liquids
It can also be used to prepare solutions in ice cold water
It dissolves to form sulfurous acid
[attachment=53668]
Preservatives
Definition of Preservative: - "Preservative" means a substance which when added to food, is capable of inhibiting, retarding or arresting the process of fermentation, acidification or other decomposition of food.
Preservatives or antimicrobial agents play an important role in today’s supply of safe and stable foods
Increasing demand for convenience foods and reasonably long shelf life of processed foods make the use of chemical food preservatives imperative
Some of the commonly used preservatives – such as sulfites, nitrate, and salt – have been used for centuries in processed meats and wine
Classification of Preservative: - Preservatives shall be divided into following classes:
1) Class I Preservatives
2) Class II Preservatives
Class I Preservative shall be:-
Common salt.
(b) Sugar
© Dextrose.
(d) Glucose 1[Syrup].
(e) Spices.
(f) Vinegar or acetic acid.
(g) Honey.
[(h) edible vegetable oils
1[Addition of Class I preservatives in any food is not restricted unless otherwise provided in the rules.]
Sodium Chloride
Sodium chloride has been used for centuries to prevent spoilage of foods
Fish, meats and vegetables has been preserved with salt
Today, salt is used mainly in combination with other processing methods
The antimicrobial activity of salt is related to its ability to reduce the water activity (aw) thereby influencing microbial growth
Glucose
Most abundant sugar in nature
Fruits
“grape sugar”
“Dextrose” b/c it is dextrorotatory
Carbohydrates converted to glucose
Produces energy for our cells
Circulating carbohydrate
Blood sugar
LIQUID GLUCOSE
LIQUID GLUCOSE or Corn Syrups are purified concentrated aqueous solution of polysaccharides obtained from partial (controlled) hydrolysis of maize starch.
The solids are composed of various carbo-hydrates; dextrose, maltose and higher polysaccharides.
The different carbohydrate profiles combined with various available solid levels give Liquid Glucose its unique application functions
Benzoic Acid
Benzoic acid occurs naturally in many types of berries, plums, prunes, and some spices
As an additive, it is used as benzoic acid or as benzoate
The latter is used more often because benzoic acid is sparsely soluble in water, and sodium benzoate is more soluble
The undissociated form on benzoic acid is the most effective antimicrobial agent
pKa of 4.2; optimum pH range is from 2.5 to 4.0
Parabens
They differ form benzoic acid in that they have antimicrobial activity in both acid and alkaline pH regions
The antimicrobial activity in parabens is proportional to the chain length of the alkyl group
Parabens are more active against molds and yeast than against bacteria, and more active against gram-positive than gram-negative bacteria
They are used in fruitcakes, pastries, and fruit fillings
Sorbic Acid
Sorbic acid is a straight-chain, trans-trans unsaturated fatty acid, 2,4-hexadienoic acid
As an acid, it has a low solubility in water at room temp
The salts, sodium, or potassium are more soluble in water
Sorbates are stable in the dry form; the are unstable in aqueous solutions because they decompose through oxidation
The rate of oxidation is increased at low pH, by increased temp, and by light exposure
Sulfites
Sulfur dioxide and sulfites have long been used as preservatives
Serving both as antimicrobial substance and as antioxidant
Sulfur dioxide is a gas that can be used in compressed form in cylinders
It is liquid under pressure of 3.4 atm and can be injected directly in liquids
It can also be used to prepare solutions in ice cold water
It dissolves to form sulfurous acid