Food Science and Nutrition
Food Science and Nutrition
This domain tests nutrient functions, digestion, dietary planning, food safety, and the science behind preparation. Questions often ask you to select a meal, diagnose a food-safety error, or explain why a recipe technique works.
Core rules and concepts
- Macronutrients: carbohydrates (4 kcal/g), proteins (4 kcal/g), fats (9 kcal/g). Micronutrients do not supply energy but support regulation and metabolism.
- MyPlate emphasizes half the plate fruits and vegetables, lean protein, whole grains, and low-fat dairy or alternatives.
- Dietary Reference Intakes include RDA, AI, UL, and AMDR; the UL is a ceiling, not a target.
- Food safety: keep cold foods at 40°F or below and hot foods at 140°F or above; the danger zone is 40–140°F. Cook poultry to 165°F, ground meat to 160°F, and whole cuts to 145°F with rest time.
- HACCP prevents hazards through analysis, critical control points, monitoring, correction, verification, and record keeping.
- Preparation science: Maillard browning needs heat and low moisture; gluten develops with kneading; emulsions need an emulsifier; overcooking vegetables degrades heat-sensitive vitamins.
Worked example
A student packs a chicken salad sandwich, yogurt, and cut melon for a field trip and leaves the cooler in a hot car. Which is the strongest correction? The issue is time-temperature abuse: perishable foods are in the danger zone. The fix is not “add ice later”; it is to use an insulated cooler with sufficient ice packs, keep it closed, and discard perishables that exceeded 2 hours (1 hour if above 90°F). The melon and yogurt are also risky because cut fruit and dairy support pathogen growth.
Traps
Do not confuse the danger zone with freezing; freezing stops growth but does not sterilize. Do not treat all fats as unhealthy; type and amount matter. Do not assume “natural” means safe. Do not use the UL as a recommended intake. Watch serving-size math: labels often list multiple servings per package.