IV. Hydrolysis / Denaturation

Question 1

2 methods of starch hydrolysis

Answer 1

chemical (temp and HCl) and enzymatic (amylase)

Question 2

proteins can be denatured by (5)

Answer 2

pH, temp, bleach, detergent, alcohol

Question 3

what happens when you add salt to protein? (low/high)

Answer 3

low: salting in (proteins become more soluble)
high: salting out (proteins precipitate)

Question 4

principle of titration to find FFA?

Answer 4

lipid + ethanol (solvent) + NaOH (base neutraliser)
PP (phenolphthalein) as pH indicator
NaOH neutralises FFA, measure NaOH used

Question 5

pH at endpoint?

Answer 5

8.3
all FFA has been neutralised
PP turns pink

Question 6

formula to find %FFA

Answer 6

% FFA = (v × N × 28.2) / w

where
v = Volume of NaOH used (in mL)
N = Normality of NaOH
28.2 = Conversion factor (specific to oleic acid)
w = Weight of fat/oil sample (in grams)

Question 7

formula for Normality

Answer 7

n / L

or

M * n

Question 8

formula for specific gravity

Answer 8

Specific gravity = (W2 – W0) / (W1 – W0)

where
W0 = weight of empty microtube
W1 = weight of microtube + 1 mL of water
W2 = weight of microtube + 1 mL of sample