FTEC 447 EXAM 1

Four components of an analytical approach to food chemistry

1.Determining those properties that are important characteristics of safe, high-quality foods 2.Determining those chemical and biochemical reactions that have important influences on loss of quality and/or wholesomeness of foods 3.Integrating the first two points to better understand how key chemical and biochemical reactions influence quality and safety 4.Applying this understanding to various situations encountered during formulation, processing, and storage of food

Temperatures some simple sugars begin to caramelize:

Fructose 110° C Galactose 160° C Glucose 160° C Sucrose 160° C Maltose 180° C

Give an example of a mild and a severe acidic condition for Tryptophan

mild) forms Β-oxyindolylalanine severe) forms N-formylkynurenine and kynurenines.

What gives starches their ability to thicken or create pastes?

partially crystallized soluble granules

What is the kind of bond that forms between amino acids?

peptide bond (carboxyl group to amino group)

When using the Bradford Assay what would a color change from brown to dark blue say about the overall protein concentration of the sample?

protein concentration is denser

What are the two types of dietary fiber?

soluble and insoluble

Which part of an amino acid contributes the most to how a protein will form?

The unique side chain differentiates amino acids and is what alters the shape of the protein. The structure of a protein defines it's function. It also provides a charge to the amino acid.

Despite not being digested by the body, what is one benefit that dietary fiber provides?

Bacteria help break down the fibers through fermentation. They produce short chain fatty acids and help increase microflora of the gut. They do this by stimulating the growth and/or bioactivity of the microorganisms in your large intestine and colon.

Why is it important to know how fast enzymatic reaction occur? And what factors affect the rate at which they happen?

Because enzymes are used to drive reactions to improve/add value to foods, it's important to know the speed of which it's done and if/when an enzymatic process should be used.

What is carmelization?

Caramelization in a non-enzymatic browning reaction involving the oxidation of sugar. When sugar undergoes caramelization, volatile chemicals are produced, resulting in the characteristic caramel flavor.

What's a simple sugar?

Carbohydrates are composed of carbon, hydrogen, and oxygen, in a chemical formula which can be expressed as Cx(H2O)y. The simplest carbohydrates are the "simple sugars," monosaccharides and disaccharides. Disaccharides are composed of two monosaccharides.

What are the principle criteria for a substance to be classified as a dietary fiber?

Dietary Fibers are not digested by the stomach or broken down in the small intestines.

Three Important Common Disaccharides

Disaccharides are anhydrides of 2 monosaccharides Sucrose—Glucose+fructose, also known as table sugar, or just plain sugar. Americans consume about 43 pounds a year! Lactose—galactose+glucose, occurs mainly in milk. Lactose intolerance syndrome is when a person can't produce enough lactase to digest lactose. Maltose—glucose+glucose. Produced during the malting of grains, meaning maltose gives us beer, the greatest of gi

How do Endogenous and Exogenous enzymes differ in relation to food and food safety?

Endogenous affect color quality (maillard reactions) Exogenous affect nutrient availability

Where are amino acids produced in cells?

Endoplasmic reticulum

What is one thing that happens to excess glucose in the body?

Excess glucose is stored in the liver and muscles as glycogen.

Three Important Common Monosaccharides

Glucose—the most common and most important simple sugar. Fructose—"fruit sugar," lowest glycemic index of all the natural sugars. Galactose—"milk sugar," not as sweet as either glucose or fructose.

What chemical bond hold sugar atoms together?

Glycosidic

List three food additives that can lead to the oxidation of amino acids.

Hydrogen peroxide benzoyl peroxide sodium hypochlorite

Where do amylases used in different beverage productions come from?

Malting Aspergillus oryzae

Water activity vs moisture

Moisture refers to the absolute amount of water present in a food, while water activity has to do with the form in which the water exists in the food, such as free or chemically bound water.

Can you describe two reasons why someone would want to use artificial sugars?

More intense sweetness flavor with less less calories

What do yeast and other microorganisms consume to produce ethanol and CO2? What kind or kinds specifically?

Starches Glucose

What are two key factors that affect the ability of an enzyme

Temperature and pH

What contributes to color formation in the BCA method that differentiates it from other assays?

The universal peptide backbone also contributes to the color formation unlike in other assays

How do amylases assist in fermentation?

amylase is an enzyme that hydrolyses bonds between glucose molecules of a starch chain, making sugars for the yeast to ferment.

which part of a starch granule is crystalline?

amylopectin

how would I be able to tell amylopectin apart from amylose?

amylopectin has branched chains

In the case of Cystine and Cysteine, oxidative derivatives are considered____________ if they can be reduced within the body back to their original form.

bioavailable

What fundamental principle does the Biuret Test and Lowry Assay rely on?

by binding the protein molecules to Coomassie dye under acidic conditions results in a color change from brown to blue