Eggs, Fruits, Vegetables, and Food Preparation Techniques

Shell

Composed of calcium carbonate; it protects the egg's contents and is porous, allowing gas exchange.

Shell Membranes

Two membranes (inner and outer) located just inside the shell; they act as barriers against bacterial invasion.

Air Cell

Forms between the two shell membranes at the larger end of the egg as it cools after laying; its size increases with age.

Albumen (Egg White)

Contains layers (thick and thin) rich in protein; provides protection and nutrition to the developing embryo.

Chalazae

Rope-like structures that anchor the yolk in the center of the egg white.

Vitelline Membrane

Encloses the yolk, maintaining its shape and integrity.

Yolk

Contains fats, proteins, vitamins, and minerals; serves as the primary source of nutrition for the embryo.

Air Cell Enlargement

As moisture and carbon dioxide escape, the air cell grows.

pH Increase

The egg white becomes more alkaline, affecting its functional properties.

Thinning of Albumen

The thick albumen becomes thinner, leading to a flatter appearance when cracked.

Yolk Membrane Weakening

The yolk becomes more prone to breaking.

Inspection

Mandatory for safety; ensures eggs are free from contaminants.

Grading

Voluntary; assesses quality based on interior and exterior factors.

Grade AA

Firm yolk, thick white, clean shell.

Grade A

Reasonably firm yolk, reasonably thick white.

Grade B

Flattened yolk, thin white, possibly stained shell.

Candling

A method where eggs are held up to a light source to inspect internal quality, such as air cell size and yolk position.

Haugh Units

A measure of egg quality based on the height of the egg white (albumen) relative to the egg's weight; higher values indicate fresher eggs.

Egg Substitutes

Often made from egg whites with added vitamins and minerals; suitable for those reducing cholesterol intake.

Value-Added Eggs

Eggs enhanced through the hen's diet, such as omega-3 enriched or organic eggs, offering additional health benefits.

Calories

Approximately 78 kcal per large egg.

Protein

About 6 grams of high-quality protein.

Fat

Approximately 5 grams, including saturated and unsaturated fats.

Vitamins and Minerals

Rich in vitamins A, D, E, B12, riboflavin, and folate; minerals include iron, phosphorus, and selenium.

Emulsifying

Lecithin in yolks helps blend ingredients like oil and water.

Binding

Proteins coagulate upon heating, helping to hold ingredients together.

Foaming

Whipped egg whites incorporate air, providing volume and lightness.

Thickening

Egg proteins thicken mixtures when heated, as in custards.

Leavening

Beaten eggs can help leaven baked goods.

Color and Flavor

Contribute to the appearance and taste of dishes.

Use Fresh Eggs

They provide better structure.

Separate Carefully

Ensure no yolk contaminates the whites.

Use Clean Equipment

Avoid any fat residue.

Add Acid

A small amount of cream of tartar stabilizes the foam.

Beat at Moderate Speed

To build a stable foam without overbeating.

Interfering

Eggs can prevent the formation of large ice crystals in frozen desserts.

Clarifying

Egg whites can trap particles in liquids, aiding in clarification.

Emulsifying (Terminology)

Egg yolks help combine ingredients that typically don't mix, like oil and water.

Protein Denaturation

Heat causes proteins to unfold and coagulate.

Overcooking

Can lead to rubbery textures and greenish yolks due to iron-sulfur reactions.

Nutrient Loss

Excessive heat can degrade some vitamins.

Boiled

Cooked in the shell; varying times yield soft to hard yolks.

Poached

Cracked into simmering water; results in tender whites and runny yolks.

Fried

Cooked in a pan with fat; includes sunny-side-up, over-easy, etc.

Scrambled

Beaten eggs cooked while stirring.

Baked

Eggs cooked in a dish in the oven.

Soft-Boiled

Boil for about 4-6 minutes; yolk remains runny.

Medium-Boiled

Boil for about 7-9 minutes; yolk is slightly set.

Hard-Boiled

Boil for about 10-12 minutes; yolk is fully set.

Proper Storage of Eggs

Store at 40°F (4°C) or below in their original carton to prevent moisture loss and odor absorption.

Placement of Eggs

Keep eggs on an inside shelf rather than the door to maintain a consistent temperature.

Duration for Fresh Eggs

Fresh eggs can be stored for 3-5 weeks.

Fruit (Botanical Definition)

The mature ovary of a flower, typically containing seeds. Examples include tomatoes, cucumbers, and peppers.

Vegetable (Botanical Definition)

Edible parts of plants such as roots, stems, and leaves. Examples include carrots (root), celery (stem), and lettuce (leaf).

Culinary Perspective on Fruits

Fruits are generally sweet or tart and used in desserts or snacks.

Culinary Perspective on Vegetables

Vegetables are more savory and used in main dishes or sides.

Cell Wall

Provides structural support; composed mainly of cellulose.

Pectins

Polysaccharides that act as a glue between cells; important in gelling processes.

Cellulose

A structural carbohydrate that provides rigidity.

Lignin

A complex polymer that adds hardness; increases with plant age.

Chlorophyll

Green pigment; sensitive to heat and pH changes.

Carotenoids

Yellow, orange, and red pigments; relatively stable during cooking.

Anthocyanins

Red, purple, and blue pigments; color varies with pH.

Betalains

Red and yellow pigments found in beets; sensitive to heat and pH.

Blanching

A process where fruits or vegetables are briefly boiled and then plunged into ice water.

Acids in Fruits and Vegetables

Contribute to tartness; include citric, malic, and oxalic acids.

Phenolic Compounds

Responsible for browning reactions.

Tannins

Provide astringency; found in unripe fruits.

Phytochemicals

Non-nutritive compounds with health benefits, such as flavonoids and carotenoids.

Acidity and Sweetness of Fruit

As fruits ripen, acidity decreases and sugar content increases, enhancing sweetness and flavor.

Functional Foods

Provide health benefits beyond basic nutrition.

USDA Grading of Fruits and Vegetables

Voluntary grading standards based on factors like appearance, size, and absence of defects.

Fruit Juices Labeling

Labels must include name and address of the manufacturer, ingredient list in descending order by weight, and nutrition facts, unless exempted for small businesses.

Changes During Heating

Heating can soften cell walls, alter pigments, and reduce nutrient content, especially water-soluble vitamins.

Dry Heat Methods

Roasting, baking, grilling; enhance flavor through caramelization.

Moist Heat Methods

Boiling, steaming, blanching; preserve nutrients and color.

Goals When Preparing Fruits and Vegetables

Preserve nutrients, enhance flavor and texture, ensure safety, and maintain visual appeal.

Storage of Fruits and Vegetables

Refrigerate most vegetables and some fruits like berries; room temperature for bananas, tomatoes, and onions.

Enzymatic Browning

Occurs when enzymes react with oxygen, causing browning in cut fruits; prevention methods include acidic treatments, blanching, and reducing oxygen exposure.

Ethylene Gas

A natural plant hormone that accelerates ripening.

Acidic treatments

Treatments such as lemon juice used to prevent spoilage.

Blanching

A cooking process that involves briefly boiling food and then plunging it into ice water.

Reducing oxygen exposure

A method to prevent spoilage by limiting the amount of oxygen that comes into contact with food.

Ethylene

A natural plant hormone that accelerates ripening.

Danger Zone

The temperature range between 40°F (4°C) and 140°F (60°C) where bacteria grow rapidly.

Proper Thawing

Methods include refrigerator (safest), cold water (submerge in sealed bag; change water every 30 minutes), and microwave (cook immediately after thawing).

Cross Contamination

Transfer of harmful bacteria from one surface or food to another.

Natural

No artificial ingredients or preservatives; minimally processed.

Organic

Produced without synthetic pesticides or fertilizers.

Fortification

Adding nutrients not originally present in the food.

Enrichment

Adding back nutrients lost during processing.

Food Allergy

Immune response to a food protein.

Food Intolerance

Difficulty digesting certain foods.

Food Sensitivity

Non-allergic reaction causing symptoms.

Water Activity (aw)

Measure of free water in a product; affects shelf life.

Subjective Evaluation

Based on personal opinions (e.g., taste tests).

Objective Evaluation

Measurable data (e.g., pH levels, texture analysis).

Using Senses to Evaluate Food

Assessing food quality through appearance, aroma, taste, texture, and sound.

Monosaccharides

Simple sugars like glucose, fructose, and galactose.

Disaccharides

Sugars formed from two monosaccharides, such as sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).