Nutrition and Fermentation

Question 1

What does ANF stand for?

Answer 1

Anti-nutritional factors. These are substances which can be present or formed as metabolic product and reduce the availability of one or more nutrients

Question 2

How can proteases inhibitors be inhibited?

Answer 2

1. By heat
2. By micro-organism like lactobacillus or by fermentation

Question 3

What does protease inhibitor affect in GI tract? Which enzymes?

Answer 3

Trypsin and Chymotrypsin are affected

Question 4

How can one reduce GOS and what are the effects of GOS?

Answer 4

GOS stands for galacto-oligosaccharides and cannot be easily digested and thus can make us produce more gas. This can be reduce by pre-digestion by fermentation with LAB

Question 5

Cyanogenic glycosides are another ANF, how do they act?

Answer 5

Enzymatic release of HCN (hydrogen cyanide) upon eating of plants which targets mitochondria and inhibits aerobic respiration.

Question 6

How can one reduce cyanogenic glycosidase?

Answer 6

By fermentation and the enzyme responsible is B-glucosidase.

Question 7

What is special of phytic acid (another ANF) and what anti-nutrional aspects does it have?

Answer 7

It has 6 phosphate groups which make it highly negatively charged. For this reason it tends to bind to essential metal ions. This can also affect other enzyme which are dependent, for e.g. on calcium.

Question 8

Which microorganism can braked down phytic acid?

Answer 8

Moulds, yeast and LAB

Question 9

Are phenolic substance postive or negativein foods? Or both?

Answer 9

Positive: antioxidant activity
Negative: bitter taste

Question 10

How can vitamin B12 increased in fresh tempeh if plant cannot produce this vitamin?

Answer 10

Because some contamination can lead to the presence of microbes producing vitamin b12 which through fermentation can increase the quantity of this vitamin a lot.

Question 11

How does S. thermophilus and L. bulgaricus interact?

Answer 11

Exchange of folate and amino acid to increase folic acid which is beneficial to health.

Question 12

Why is vitamin K important?

Answer 12

1. blood clotting
2. bone strength
3. insulin metabolism

Question 13

How does vitamin K act?

Answer 13

Vitamin K acts by changing the glutamic acid residue to a gammacarboxy-glutamic residue. So now we have two negative charges instead of 1 and therefore can bound calcium.

Question 14

Where is vitamin k found and how is vitamin k2 made?

Answer 14

Vitamin k is found in plants and vitamin k2 is produced by bacteria.