Food Chemistry

Rank the following foods by their corresponding water activities from highest to lowest: syrups, jams, potato chips, and bread

Bread (0.96), syrups (0.88), jams (0.77), potato chips (0.30)

Name 3 chemical properties of food phosphates that governs their usefulness as food additives.

Buffering Capacity, Water Retention, Chelation of Metal Ions, Emulsifying Properties, Phosphorylation and Gelation, Saltiness Control, Antimicrobial Activity, Stabilizing Proteins

What kinds of food emulsions are? (1) Butter (2) Mayonnaise (3) Milk

Butter = water in oil, Mayonnaise = oil in water, Milk = oil in water

Name three anticaking agents.

Calcium aluminium silicate, Tricalcium Phosphate, Calcium Silicate, Cellulose, Silicon Dioxide (SiO₂), magnesium silicate, Magnesium Carbonate, Calcium Carbonate, Sodium Aluminosilicate,Stearic Acid, Rice Flour

Name 6 fatty acids in chocolate.

Capric, caprylic, lauric, myristic, palmitic, oleic, stearic, linoleic

Categorize the following pigments in water or fat soluble and plant or animal source based: Carotenoid, myoglobin, anthocyanin, chlorophyll, melanin

Carotenoid: Fat, plant Myoglobin: Water, Animal Anthocyanin: water, Plant Chlorophyll: Fat, Plant Melanin: Insoluble, plant & animal

Put these nuts in order from least fat content to greatest based on a 1 ounce serving. Pine nuts, cashews, macadamia, chestnuts, almonds

Chestnuts, cashews, almonds, pine nuts, macadamia

Name 6 major pigment groups found in food sources.

Chlorophylls, Carotenoids, Anthocyanins, Flavonoids, Betalaines, Anthoxanthins, Lutein, Zeaxanthin, Hemoglobin, Myoglobin, xanthophylls

Name the enzyme found in onions responsible for irritating the eyes once an onion is cut; also, name the compound formed by this enzyme and describe the mechanism in the eye this compound stimulates.

Chrymatory-factor synthase. Chrymatory-factor synthase forms sulfenic acid which rearranges into syn-propanethial-S-oxide. This stimulates the lachrymal glands within the eyes which causes the irritation.

Name 5 antimicrobial spices.

Cinnamon, cloves, mustard, allspice, horseradish, onion, garlic, oregano, thyme, cumin, rosemary, ginger, basil, fennel, coriander, black pepper

What are the flavor/antimicrobial compounds associated w/the following spices: Cloves, Cinnamon, Oregano, Thyme, Vanilla Beans, Garlic, and Onion?

Cloves: Eugenol; cinnamon: cinnamic aldehyde; Oregano: carvacrol; Thyme: thymol; Vanilla Beans: Vanillin ; Garlic: allicin; onion: allicin

Arrange them according to saturated fat percentage: butter, coconut, pork fat, olive oil

Coconut (90), Butter (63), pork fat (37.5), olive oil (14)

List 5 types of bonds that important for the structure of proteins.

Covalent, hydrogen, van der waals, disulfide, electrostatic

Classify these candies as crystalline or non-crystalline: caramel, toffee, rock candy

Crystalline: Rock candy Non-crystalline: Caramel, toffee

Name 5 hydrophobic surfactants.

DATEM, Soy lecithin, Calcium stearoyl lactylate, Glycerol monoleate, Sorbitan trioleate, Oleic acid

What are four ways to inhibit enzymatic browning?

Decrease pH, HPP, addition of sulfites, addition of antioxidants, chelation of minerals, prevent exposure to oxygen, MAP, freezing, dehydration

How is the boiling point of water affected by boiling on the moon, adding gelatin, boiling on Mount Everest, and adding table sugar?

Decrease, no effect, decrease, increase.

Name three effects of protein denaturation.

Decreased solubility, altered water-binding capacity, loss of biological activity, increased susceptibility to attack by proteases, increased intrinsic viscosity, inability to crystallize.

Name 5 ways to lower the water activity of a food.

Dehydrate, add sugar, add salt, freeze drying, freezing, combination of any of these methods

Name 3 practiced chemical modifications of maize starch in the US.

Derivitization (monostarch substitution and cross linking), acid thinning, dextrinization, oxidation, hydrolysis