Understanding Food Chapter 17: Vegetables PDF

Understanding Food Amy Brown Chapter 17: Vegetables Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Composition of Vegetables Plant pigments fall into three major groups: – Carotenoids – Chlorophyll...

Understanding Food Amy Brown Chapter 17: Vegetables Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Composition of Vegetables Plant pigments fall into three major groups: – Carotenoids – Chlorophylls – Flavonoids Carotenoids and chlorophylls are found in plastids and are fat soluble. Flavonoid pigments are water soluble, and have a tendency to be lost in cooking water. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Composition of Vegetables Legumes: Members of the plant family Leguminosae that are characterized by growing in pods. Vegetable legumes include beans, peas, and lentils. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Composition of Vegetables Fruits and vegetables may carry a vast array of phytochemicals—nonnutritive compounds in plants that possess health-protective benefits. Cruciferous: A group of indole-containing vegetables named for their cross-shaped blossoms; they are reported to have a protective effect against cancer in laboratory animals. – Examples include broccoli, brussels sprouts, cabbage, cauliflower, kale, mustard greens, rutabaga, kohlrabi, and turnips. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Purchasing Vegetables Grading Vegetables Most fresh produce deteriorates too quickly to grade, so most grading is presently voluntary; it is based on: – Ripeness – Color – Shape – Size – Uniformity – Freedom from bruises and signs of decay. Slide Development: Lonnie M. Lowery, Ph.D. The only fresh vegetables currently subject to USDA grading are: – Potatoes – Carrots – Onions Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Purchasing Vegetables Selecting Vegetables Vegetables are from living plants that grow in cycles with the passing seasons. The season of the year is the most important consideration when selecting vegetables. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Purchasing Vegetables Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Purchasing Vegetables Legumes B e a n s , peas, and lentils serve as excellent sources of fiber, protein, iron, and complex carbohydrates. The single common identifying factor among all legumes is that they grow as seeds within a pod. Dried beans have served as a dietary staple since the Bronze Age. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Purchasing Vegetables Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Shiitaki Cremini Oyster Portabella Button Slide Development: Lonnie M. Lowery, Ph.D. Enoki Copyright 2004 Thomson Learning Preparation of Vegetables Vegetables can be prepared by: Dry-heat methods – Baking – Roasting – Sautéing – Deep-fat frying Slide Development: Lonnie M. Lowery, Ph.D. Moist-heat methods – Simmering – Steaming – Microwaving Copyright 2004 Thomson Learning Preparation of Vegetables Serving styles also vary and include: – Plain – Buttered – Creamed – Au gratin: Food prepared with a browned or crusted top. A common technique is to cover the food with a bread crumb/sauce mixture and pass it under a broiler. Slide Development: Lonnie M. Lowery, Ph.D. – Glazed – Scalloped: Baked with milk sauce and bread crumbs. – Stuffed …or in: – Soufflés – Omelets – Cream soups Copyright 2004 Thomson Learning Preparation of Vegetables Regardless of the cooking method or serving style selected, some general principles governing the handling and preparation of vegetables should be followed: – Buying – Storage – Washing – Cooking liquid – Timing Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Preparation of Vegetables When heated, vegetables undergo several changes in: – Texture – Flavor – Odor – Color – Nutrient retention Understanding these phenomena can help to retain as much of their quality as possible during preparation. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Preparation of Vegetables Degorge: To peel and slice vegetables, sprinkle them with salt, and allow them to stand at room temperature until droplets containing bitter substances form on the surface; the moisture is then removed. Specific gravity: The density of a substance compared to another substance (usually water). Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Preparation of Vegetables Legumes are best prepared by simmering rather than boiling. There are three methods for preparing dried beans: – Overnight soak – Short soak – No soak Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Preparation of Vegetables Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Storage of Vegetables Refrigerated A cooler temperature is the most important factor in reducing respiration rates, and most fresh vegetables will last at least three days if refrigerated. Storage times for various vegetables are ultimately based on their water content. Slide Development: Lonnie M. Lowery, Ph.D. Some vegetables require special storage treatment. For example: – Bean sprouts are best stored in a bowl of cold water in the refrigerator, and the water should be changed frequently. – Ginger root should be frozen or stored in an airtight container to trap its moisture. Copyright 2004 Thomson Learning Storage of Vegetables Dry Storage Proper storage does not automatically imply refrigeration. For instance: – Tomatoes (unripe) – Eggplant – Winter squash – Tubers (potatoes) – Dried legumes – Most bulbs (onions) …should never be stored in a refrigerator. Slide Development: Lonnie M. Lowery, Ph.D. Copyright 2004 Thomson Learning Storage of Vegetables Controlled-Atmosphere Storage This special method slows down the natural respiration of fresh vegetables by: – Reducing the amount of oxygen (below 21%) – Increasing the amount of carbon dioxide (above 0.03%) …available to them while in storage. Slide Development: Lonnie M. Lowery, Ph.D. Other advanced storage methods include: – Modified-atmosphere packaging (MAP) – Edible coatings – Plastic shrink- or stretchwraps Copyright 2004 Thomson Learning