Food Chemistry

If you take 20 mL of a 0.1M NaOH salutation to titrate 40 mL of an HCL solution to the phenolphthalein end point. What is the molarity of the HCL solution?

0.05M HCL

What are 5 characteristics for selecting lipid antioxidants?

1. Non-toxic 2. No flavor or odor 3. Fat soluble 4. Anti-oxidant activity 5. Economic

List 3 reasons for controlling Maillard browning in foods.

1. Undesirable browning in foods causing strong colors and odors; 2. Prevent anti-nutritional effects; 3. Some products of the Maillard reaction are mutagenic 4. Undesirable flavor; 5. Nonuniform color consistency

Name five spices which contain essential oil eugenol.

1) Cloves, 2) cinnamon, 3) Jamaica allspice, 4) sage, 5) sweet basil, 6) bay leaves, 7) sweet marjoram

Name 5 foods or ingredients which contain the alkaloid stimulant caffeine.

1) Coffee, 2) tea, 3) chocolate, 4) chocolate milk, 5) cocoa, 6) kola nut extract

Common names of following fatty acids: C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, C20:0

4:0 (Butyric), 6:0 (Caproic), 8:0 (Caprylic), 10:0 (Capric), 12:0 (Lauric), 14:0 (Myristic), 16:0 (Palmitic), 18:0 (Stearic), 20:0 (Arachidic)

Describe the Maillard reaction and name two key factors that influence it.

A non-enzymatic browning reaction between reducing sugars and amino acids during heating. Key factors: temperature, pH, water activity, and sugar/amino acid type.

Describe the chemical basis of the Maillard reaction and name the initial reactants involved.

A reducing sugar reacts with a free amino group (amino acid or protein), forming a Schiff base and Amadori compounds, leading to flavor and color development.

What pigment is formed when chlorophyll loses its magnesium, phytol group, or both?

a. Pheophytin (loss of magnesium) b. Chlorophyllide (loss of phytol) c. Pheophorbide (loss of both magnesium and phytol).

Name 3 chemical agents capable of denaturing proteins.

Acids, Alkalis, Metals, Organic Solvents, and Aqueous Solutions of Organic Solvents

Rate the following materials from lowest to highest thermal conductivity: Water, Aluminum, Stainless Steel, Glass, Air, Copper

Air < Water < Glass < Stainless Steel < Aluminum < Copper

Put these amino acids in order from smallest to largest molecular size: arginine, alanine, and cysteine.

Alanine smallest, cysteine, arginine largest

Give the four main classifications of proteins and the solvents with which they can be extracted.

Albumins (water and dilute saline), Globulins (dilute saline), Prolamines (70% ethanol), Glutelins (dilute acid or alkali)

Give the 3 main polymorphic forms of crystalline fat and their general characteristics.

Alpha (α) – lowest melting point, least stable, least dense, forms quickly, used in foams Beta-prime (β′) – intermediate melting point and stability, desirable for smooth texture and creaming properties (e.g., margarine, shortening) Beta (β) – highest melting point, most stable, highest density, coarse crystals

Name 4 colorants that are exempt from FDA certification.

Annato extract, caramel, paprika, riboflavin, turmeric, carmine

Name three classes of flavonoids.

Anthocyanidins, isoflavones, flavonols, catechins, etc

Name 3 charged amino acids.

Arginine, lysine, aspartic acid, glutamic acid

Name three synthetic antioxidants commonly used in foodstuff.

BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), TBHQ (tert-butylhydroquinone), PG (propyl gallate)

Name 5 common chemical food additives for food preservation.

BHA, BHT, TBHQ (antioxidants), benzoates and calcium propionate (antimicrobials), sodium nitrite (curing agent with antimicrobial properties)

What are the compounds responsible for pungency in the black pepper, chilli peppers, mustard and ginger?

Black pepper: piperine, chili pepper: capsaicin, ginger: gingerol, mustard: allyl isothiocyanate