9

Bio & Food Chemistry (Fach) / FC (Lektion)

Diese Lektion wurde von DrOetti erstellt.

Lektion lernen

zurück  |  weiter 1 / 1

• Give the definition of foods. Foods are matrials which, in their naturally occuring, processed or cooked form are consumed by humans as nutrition and for enjoyment.
• Give the definition of food chemistry. The research of processes and interactions of biologial and non-biologcal components in foods.
• Which three factor determine shelf-life? 1) Sensory: Does it taste good enough to be eaten? 2) Nutirional: Does it provide nutrition? 3) Safety: Is it non-toxic?
• Which are the five quality defining attribues of food and how can they be altered? give at least two examples, with food. 1) Texture:  softening (peach), toughening (bread) 2) Flavour: deve (pig meat), caramelization (onions) 3) Color: darkening (avocado), bleaching (salad) 4) Nutritive value: loss, or altered bioavailability of vitamins (cooked veggies) or proteins (cooked meat) 5) Safety: Removal of toxins (soaked nuts), generation of toxins (spoiled milk)
• Which are the four main factors negatively affecting shelf-life? Humidity Air (Oxigen) Light Temperature
• Name three types alterations that can occur in foods and which foods/compounds are effected. 1) Non-enzymatic browning -> baked goods 2) enzymatic browning -> cut fruits 3) Oxidation -> Lipids, Vitamins
• How is the energy stored in food measured? what does it depend on? The energy stored in food is measured by the ammount of head generated by comustion at 500°C. It is generally measured in kcal, which is the ammount of head needed to heat 1g of Water by 1°K. Chemically speaking the  energy stored in food depends on the ammount of C-O and C-H bonds, with C-O bonds having a greater ammount of energy stored.
• Name three special properties of water. -high melting and boiling point compared to similar compunds -froms strong OH bonds -increases in volume when frozen
• Which water availability (aw) do... ...intermdiate moisture foods show? ...classifies a food as "preserved"? ...is the threshhold for microbial proliferation? aw(IMF): 0.9-0.6 preseved: 0.85 no microbial proliferation < 0.6

zurück  |  weiter 1 / 1