RD Exam Prep: Domain 1 Topic A Questions and Answers 100% Pass

RD Exam Prep: Domain 1 Topic A Questions and Answers 100% Pass Water - Answer- Boiling point: 212 degrees F at sea level. Drops 1 degree F for every 500 foot increase in altitude. Freezing point: 32 degrees F. The addition of salt or sugar lowers the freezing point of water. Salt lowers the freezing point 2x as much as sugar. Water Activity (WA): Foods with higher WA levels are more likely to spoil. Fresh foods like milk, meats, and veggies have a WA level of 0.95-1.0 Water makes these chemical reactions possible: ionization, hydrolysis, pH changes, salt formation, and the release of CO2 Carotenoids - Answer- Carotene (yellow-orange): sweet potatoes, carrots, winter squash, cantaloupe, apricots Lycopene (red-orange): tomatoes, watermelon, pink grapefruit, papaya Xantophyll (yellow): pineapple, pumpkins, peppers, summer squash Chlorophyll - Answer- A (blue-green), B (yellow-green). Broccoli, green cabbage, lettuces, spinach, bok choy, green beans Chlorophyll breakdown occurs as veggies ripen or during processing to form chlorophyll derivatives that differ in color and texture: -Chlorophyllin: bright green color and mushy texture in alkaline environment; ex: baking soda added to cooking water -Chlorophyllide: phytyl group detaches form chlorophyll in vegetable, turning water green -Pheophorbide: chlorophyll loses magnesium (replaced by hydrogen) and phytyl group in presence of acid and heat. Drab olive color. -Pheophytin: chlorophyll loses magnesium (replaced by hydrogen) in presence of acid and heat. Breakdown starts within 5 minutes of heating vegetable. Drab olive color. Flavonoids - Answer- Anthocyanin (red-purple): red cabbage, eggplant, radish, red potato, pomegranate, berries Anthoxanthin (cream white): onions, cauliflower, white potato, turnip, mushroom, ginger Betalanins (purple-red/yellow): beets Chemical and Physical Changes to Plant Pigments - Answer- Flashcards 6-11 Carotenoids - Answer- Color: Orange, red, yellow Heat: light orange Acid: lighter color Alkaline: brown Cooking Metal: no effect in color Chlorophyll A - Answer- Color: blue-green Heat: bright green at first, drab olive green Acid: grayish green Alkaline: bright green, chlorophyllin Cooking Metal: copper and zinc retain color but not used d/t toxicity Chlorophyll B - Answer- Color: green Heat: bright green at first, drab olive green Acid: olive brown, pheophytin Alkaline: bright green, chlorophyllin, mushy texture Cooking Metal: copper and zinc retain color but not used d/t toxicity Anthocyanins - Answer- Color: red-purple Heat: drab reddish-brown Acid: red Alkaline: purple, green, blue Cooking Metal: iron, aluminum, tin change red purples to blue Anthoxanthins - Answer- Color: white/cream Heat: little change, slight yellowing Acid: bright white Alkaline: yellow-white Cooking Metal: iron darkens pigments, aluminum causes loss of yellows and whites Betalains - Answer- Color: purple-red/yellow Heat: dark purple-red Acid: red Alkaline: yellow Cooking Metal: aluminum turns bright yellow, iron darkens Structure of Plant Cells - Answer- The plant's cellular walls are held together by several fibrous compounds including: -Gum: viscous structures used as thickeners and gems. Ex: xanthan gum, guar gum -Pectin: found in cell walls and tissues of plants. Apples, citrus, and plums do not need additional pectin in preparations. All other fruits need added pectin. -Cellulose: main structural component of cell walls used for thickening and anticaking properties. Tough. Ex: whole grains, legumes. -Hemicellulose: surrounds tough cellulose to provide structure cell walls. Ex: cereal grains, beans.