Food science current

Why is food science called an integrated course?

It involves related topics from various disciplines.

How did the food supply affect the development of early civilizations?

Civilizations formed where water, game, and land provided abundant food supplies.

What tool helped food scientists begin to understand food spoilage?

The microscope.

What are the three major periods in the development of food?

1. Food discoveries of early peoples. 2. Invention of modern machines and development of food. 3. Government regulation to keep the food supply safe.

What two laws are the basis for FDA rules and regulations?

Pure Food and Drug Act (1906) and Food, Drug, and Cosmetic Act (1938).

What guide is used for safe food handling in restaurants, grocery stores, and institutions?

FDA Food Code.

What does the USDA Organic seal indicate?

The product is certified organic and contains 95% or more organic content.

Give examples of hydroponic crops and explain how they are grown.

Tomatoes, cucumbers, and lettuce are grown with their roots suspended in a liquid nutrient solution.

Why do consumers use food analogs?

They look and taste the same but may have benefits like a longer shelf life or no refrigeration requirement.

Name 10 food processing techniques.

Blanching, canning, chopping, dehydrating, freezing, vacuum packaging, salting, liquefying, pasteurizing, and smoking.

What is the advantage of using cryogenic liquids in food production?

They help maintain much of the color, texture, and nutritive value of fresh foods.

How does food defense differ from food security?

Food defense protects food from intentional adulteration, while food security is access to nutritionally adequate and safe food.

Name three benefits of studying food science.

1. Over half of all jobs are linked to food. 2. Helps people enjoy today's food supply while avoiding hazards. 3. Helps people become better cooks.

What food analogs are regular parts of your diet?

Salt substitutes and sugar substitutes.

How can this course help evaluate future food developments?

By understanding the safety and history of food.

Why is food science an applied science?

It applies chemistry, physics, biology, and nutrition to food production, processing, and packaging.

What are the metric base units for mass, length, volume, time, and temperature?

Mass: gram (g); Length: meter (m); Volume: liter (L); Time: second (s); Temperature: Celsius (°C).

How does mass differ from weight?

Mass measures the amount of matter and does not change by location; weight measures gravitational force and changes by location.

Why shouldn't you measure from the end of a ruler?

The end may be chipped, worn, or uneven.

How many cubic centimeters are in 55 milliliters?

55 cm³.

What is the Celsius temperature scale based on?

The freezing point (0°C) and boiling point (100°C) of pure water.

What are the steps of the scientific method?

Ask a question, define the problem, conduct research, state a hypothesis, design the experiment, conduct the experiment, evaluate results, and report results.

What is the difference between a hypothesis, theory, and law?

A hypothesis is an educated guess, a theory explains known facts, and a law is a widely accepted explanation that consistently predicts phenomena.

What is the function of the control in an experiment?

It serves as the standard for comparison.

What are the two types of observations?

Quantitative (numerical) and qualitative (descriptive).

What are nine food science lab safety procedures?

Follow procedures exactly; be serious; tie back long hair; be cautious around heated glass; remember hot glass looks like cold glass; protect eyes, skin, and clothing from acids and bases; mix chemicals only as instructed; dispose of chemicals properly; clean up after the lab.

What are the four main factors that influence taste preferences?

Physical (taste buds), psychological (taste bias), cultural (foods like grits), and environmental (food availability).

What factors affect a person's ability to detect flavors?

Texture, aroma, sound, feel, appearance, and taste.

What is taste bias?

A dislike for a food caused by a negative experience.

What are the three main categories of sensory characteristics?

Appearance, flavor, and texture.

What three aspects of color are measured by a colorimeter?

Hue, value, and chroma.

What are the two components of flavor?

Taste and aroma.

What five basic tastes can the human tongue sense?

Salty, bitter, sour, sweet, and savory.

What five qualities are used to evaluate food texture?

Chewiness, graininess, brittleness, firmness, and consistency.

When are trained and untrained taste panelists used?

Trained panelists are used during product development, and untrained panelists are used after products reach the marketplace.

What factors must researchers control in a taste test?

Influence from other testers, psychological bias, evaluation form design, and environmental factors.

Name the three subatomic particles and their properties.

Protons: positive, in the nucleus, about the same mass as neutrons. Neutrons: neutral, in the nucleus, about the same mass as protons. Electrons: negative, orbit the nucleus, much less mass.

How are chemical symbols used to represent elements?

The first letter is capitalized, a second lowercase letter may be added, and some symbols come from Latin names.

What is the difference between atomic number and atomic mass?

Atomic number is the number of protons; atomic mass is approximately the sum of protons and neutrons.

How are chemical formulas used in food science?

They show which elements make up a compound and how many atoms of each are present.

What is the most stable arrangement for electrons?

A full outer electron shell.

How does an element's location on the periodic table predict its reactions?

Elements in the same group have the same number of outer electrons and react similarly.

How do ionic and covalent bonds differ?

Ionic bonds involve electron transfer, while covalent bonds involve sharing electrons.

What are the categories of pure substances?

Elements (iron, calcium, potassium) and compounds (salt, baking soda).

Give two examples of homogeneous mixtures and two examples of heterogeneous mixtures.

Homogeneous: tea and soft drinks. Heterogeneous: vegetable soup and hot cocoa.

What is the difference between physical and chemical changes?

Physical changes alter form without changing identity; chemical changes create new substances with different properties.

Compare the three states of matter.

Solids have a definite shape and volume, liquids have a definite volume but no definite shape, and gases have neither a definite shape nor volume.

How do you know a chemical equation follows the law of conservation of matter?

The same number of each type of atom appears on both sides of the equation.

How does the body use kilocalories for energy?

The body obtains energy from carbohydrates, fats, and proteins measured in kilocalories, which cells use for movement, growth, repair, and body functions.

What is basal metabolism?

Basal metabolism is the energy the body needs at rest to maintain essential functions.

What factors affect basal metabolism?

Age, sex, body size, muscle mass, and genetics.

What is the difference between conduction and convection in heat transfer?

Conduction transfers heat through direct contact, while convection transfers heat through the movement of a liquid or gas.

How does radiation differ from conduction and convection in heat transfer?

Radiation transfers energy through electromagnetic waves and does not require direct contact or movement of a fluid.

What phase changes require the addition of energy?

Melting (e.g., melting butter), vaporization (e.g., boiling water), sublimation (e.g., dry ice changing directly to gas).

What phase changes require the removal of energy?

Freezing (e.g., water becoming ice), condensation (e.g., steam forming water droplets), deposition (e.g., water vapor forming frost).

What factors can affect the rate of reaction in cooking?

Temperature (higher heat speeds reactions), concentration (more reactants increase reaction rate), surface area (cut food cooks faster).

What atoms or groups of atoms are found in pure water?

Hydrogen atoms, oxygen atoms, and hydroxyl groups (OH⁻).

What is the difference between Bronsted-Lowry and Lewis theories of acids and bases?

Bronsted-Lowry acids donate protons and bases accept protons; Lewis acids accept electron pairs and Lewis bases donate electron pairs.

How can acids and bases be identified?

By their pH and by indicators that change color depending on acidity or alkalinity.

What does pH stand for?

pH means the potential, or power, of hydrogen and indicates the acidity or alkalinity of a solution.

How can pH be measured?

With indicator paper, a color-changing indicator solution, or a pH meter.

How many grams of acetic acid equal 1 mole?

Approximately 60.05 g.

How do you make 0.6 M CH3COOH solution?

For 1 L of solution, use 36.03 g acetic acid and add enough distilled water to make the final volume 1 L.

Why is pH important in digestion?

Different digestive enzymes work best at specific pH levels.

What is the pH of stomach acid and the small intestine?

Stomach acid has a pH of about 1-3, while the small intestine is around pH 7-8.

How do acids and salt help preserve food?

Acids lower pH and inhibit microorganisms; salt removes water and makes conditions less favorable for microbial growth.

How do chemical leavening agents work?

They produce carbon dioxide gas during a chemical reaction, causing the food mixture to rise.

What ingredients can be added when using baking soda as a leavening agent?

Buttermilk, lemon juice, and vinegar.

How does double-acting baking powder work?

It releases some carbon dioxide when mixed with liquid and additional gas when heated.

How does pH affect angel food cake quality?

Proper pH helps egg-white proteins form a stable foam; too much acidity or alkalinity can weaken the foam.

How does the age of an egg affect its pH level?

As an egg ages, carbon dioxide escapes, causing the pH to increase and become more alkaline.

How do acids affect fruit quality?

Acids help maintain fruit color, flavor, and firmness, and can slow browning reactions.

What are three functions of water in the body?

Regulates temperature, transports nutrients and wastes, supports chemical reactions.

What are three functions of water in the food supply?

Acts as a solvent, provides moisture and texture, allows chemical and enzymatic reactions.

How does the water molecule differ from other compounds of similar size?

Water is polar and forms hydrogen bonds, giving it high boiling and melting points.

What is the structure of a water molecule?

It contains two hydrogen atoms covalently bonded to one oxygen atom, with a bent shape making it polar.

How do covalent bonds differ from hydrogen bonds?

Covalent bonds share electrons within a molecule; hydrogen bonds are weaker attractions between molecules.

Why does water form hydrogen bonds with other molecules?

Water is polar, with partially positive hydrogen atoms attracted to partially negative atoms on nearby molecules.

Why does ice float in water?

Hydrogen bonds hold ice in an open structure that is less dense than liquid water.

How are atmospheric pressure, temperature, and boiling point related?

A liquid boils when its vapor pressure equals atmospheric pressure; higher pressure raises boiling point.

What are two ways water can be used as a heat medium in cooking?

Boiling and steaming.

What are the advantages of steaming vegetables over boiling?

Steaming causes less loss of water-soluble vitamins, minerals, color, and flavor.

What are three types of water-based solutions?

Solid-in-liquid (e.g., salt water), liquid-in-liquid (e.g., vinegar in water), gas-in-liquid (e.g., carbonated water).

What are the three ways water becomes part of the structure of food?

Bound water (chemically or physically associated), immobilized water (trapped), free water (available for reactions).

What does water activity measure?

It measures how much water is available for microorganisms and chemical reactions, affecting spoilage.

Why should you drink water before feeling thirsty?

Thirst can occur after the body has begun losing water; drinking regularly helps maintain hydration.

What are two examples of biological contaminants in water?

Bacteria and viruses.

What are two examples of chemical contaminants in water?

Pesticides and heavy metals.

What are two examples of physical contaminants in water?

Sediment and debris.

What is the difference between hard and soft water?

Hard water contains higher levels of calcium and magnesium ions; soft water contains fewer.

What happens during photosynthesis?

Plants use sunlight to convert carbon dioxide and water into glucose and oxygen.

What are the three categories of carbohydrates in food?

Sugars, starches, and dietary fiber.

What elements make up all carbohydrates?

Carbon, hydrogen, and oxygen.

Name three monosaccharides and a source of each.

Glucose (grapes), fructose (honey), galactose (milk).

Name three monosaccharides and give a source of each.

Glucose—grapes; fructose—fruit; galactose—milk products.

What monosaccharides make up sucrose and what is a common food source?

Sucrose = glucose + fructose; table sugar.

What monosaccharides make up lactose and what is a common food source?

Lactose = glucose + galactose; milk.

What monosaccharides make up maltose and what is a common food source?

Maltose = glucose + glucose; malted grains.

What is hydrolysis?

Hydrolysis is the splitting of a compound by adding water.

What conditions can trigger hydrolysis?

Acids, bases, heat, or enzymes.