Food Chemistry major part of the discipline of study Food Science To assure the quality of foods and develop new food products the Food Scientist must understand Food Chemistry and the primary compounds
in foods which are carbohydrates, lipids and proteins CARBOHYDRATES Sugars Starches Dietary fiber Cellulose Gums Pectin
CARBOHYDRATES Sugars Monosaccharides Glucose Fructose Galactose Disaccharides Sucrose - - - - Table sugar Glucose and Fructose
Lactose - - - - Milk sugar Glucose and Galactose Maltose - - - - Corn sugar Glucose and Glucose CARBOHYDRATES Sugars Sweetness
Fructose Sucrose Glucose Galactose Maltose Lactose
1.3 1.0 0.56 0.4-0.6 0.3-0.5 0.2-0.3 CHO - Sweetness Carbonated beverage High fructose
corn syrup Sucrose Lactaid Lactose or Galactose and glucose CHO - Solubility Candy Invert sugar
Caramel Hard candy Ice Cream Lactose Sucrose HFCS CHO Corn Syrup Contains both Corn syrup
and HFCS acid pH Changes Flavor Solubility CHO - Starch Amylose
straight chain of glucose Amylopectin branched chains of glucose CHO - Hydrocolloids Hydrocolloids include gums and pectin Trap water and form gels or make
products viscous Used at low concentrations CHO - Bread Starch in bread helps produce the texture Sugars form brown crust Fiber in whole
grains LIPIDS or FAT Glycerol (3 carbon) alcohol Fatty acids attach to alcohol with ester bonds Triglyceride Diglyceride Monoglyceride Fat
Water insoluble (Non-polar) Smaller molecules Mix between CHO and/or Proteins Produce creamy or soft texture Fat Fatty acids
Chains of Carbon atoms with Hydrogens attached If every C has 2 H attached the fatty acid is saturated H H H H H H H H H C C C C C C C C - OH H H H H H H H H Fat Fatty acids If two C have a double bond so only 1 H attached the fatty acid is
monounsaturated H H H H H H H C C C C = C C C C OH H H H H H H H H Fat Fatty acids If there are more than one double bond the fatty acid is polyunsaturated H
H H H H H H
H H C C C C = C C C = C C C C C OH H H H H H H H H H H H H FAT - Oxidation Double bond is less stable and Oxygen molecules can attach to unsaturated fatty acids
FAT - Oxidation Prevent or slow oxidation by Hydrogenating unsaturated fatty acids (add hydrogens to double bonds) Vacuum package foods Packages that block or absorb light Keep products cool Add antioxidants FAT Melting point
The type of fatty acids will affect the melting point of the fat REDUCED FAT Ice Cream Remove some or all fat in food products Add other ingredients to give acceptable
texture Gums are added to this ice cream PROTEIN Made of varying amino acids Amino acids contain Nitrogen PROTEIN Bakery Items The amount of protein will affect the texture of bakery products
Protein is tougher than starch Flour to make pasta has highest amount of protein Flour to produce bagels in higher than flour used to produce bread PROTEIN - Denaturation Peptide bonds can be broken apart if the temperature is higher Peptide bonds can also be
broken apart by acid PROTEIN - Denaturation Diet beverages contain aspartame Aspartame is two amino acids The shelf-life is therefore shorter than for sugar sweetened drinks
PROTEIN - Cheese Proteins are charged molecules If the charge is neutral the protein will precipitate or coagulate The isoelectric point for Casein (milk protein) is approximately 4.5. At this pH curd forms and
is used to make cheese PROTEIN - SALT Some proteins are salt soluble Increased salt content extracts proteins from meats and these proteins can act like a glue
MOISTURE - Popcorn Water content is an important factor in many foods Amount and size of pop corn depends on proper moisture content COLOR - PIGMENTS
Different foods contain various pigments Broccoli chlorophyll Red Cabbage anthocyanins Carrots Beta carotene
Vitamins Fat soluble Vitamins A, D, E, K Water soluble Vitamin C B vitamins Minerals
Calcium Iron Sodium Trace minerals
