Significance and sources of riboflavin in foods

1. Significance and sources of riboflavin
Domina Petric, MD

2. Riboflavin is essential for the
intermediary metabolism of
carbohydrates, amino acids and lipids.
Riboflavin also supports cellular
antioxidant protection.
The vitamin discharges these functions as
coenzymes that undergo reduction through two
sequential single-electron transfer steps.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
2
Significance of riboflavin

3. This allows the reactions catalyzed by
flavoproteins (flavoenzymes) to involve
single- as well as dual-electron transfers.
Flavoproteins serve as switching sites
between obligate two-electron donors,
such as the pyridine nucleotides, and
various obligate one-electron acceptors.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
3
Significance of riboflavin

4. Deficiency of the vitamin B2
first manifests itself in
tissues with rapid cellular
turnover: skin and
epithelium.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
4
Significance of riboflavin

5. Riboflavin is widely distributed in
foods, where it is present almost
exclusively bound to proteins,
mainly in the form of flavin
mononucleotide (FMN) and flavin
adenine dinucleotide (FAD).
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
5
Distribution in foods

6. Rapidly growing, green, leafy vegetables
are rich in the vitamin.
Meats and dairy products are the most important
contributors of riboflavin in diets, with milk
products providing about one-half of the total
intake of the vitamin.
Animal tissues have been found to contain small
amounts of riboflavin-5′α-D-glucoside, which
appears to be as well utilized as free riboflavin.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
6
Distribution in foods

7. April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
7

8. Diary product Riboflavin mg/100 g
Milk 0,17
Yogurt 0,16
American cheese 0,43
Cheddar cheese 0,46
Cottage cheese 0,28
Ice cream 0,21
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
8
Diary products

9. Meat Riboflavin mg/100 g
Liver, beef 3,50
Beef 0,24
Chicken 0,19
Lamb 0,22
Pork 0,27
Ham, cured 0,19
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
9
Meats

10. Cereals Riboflavin mg/100 g
Wheat, whole 0,11
Rye 0,08
Oat meal 0,02
Rice 0,01
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
10
Cereals

11. Vegetables Riboflavin mg/100 g
Asparagus 0,18
Broccoli 0,20
Cabbage 0,06
Carrots 0,06
Cauliflower 0,08
Corn 0,06
Lima beans 0,10
Potatoes 0,04
Spinach 0,14
Tomatoes 0,04
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
11
Vegetables

12. Fruits Riboflavin mg/100 g
Apples 0,01
Bananas 0,04
Oranges 0,03
Peaches 0,04
Strawberries 0,07
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
12
Fruits

13. Eggs: 0,30.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
13
Other

14. • Riboflavin is stable to heat.
• Most means of heat sterilization, canning
and cooking do not affect the riboflavin
contents of foods.
• Exposure to light (sun drying, sunlight
exposure of milk in glass bottles, cooking in
an open pot) can result in substantial losses,
for the vitamin is very sensitive to
destruction by light.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
14
Stability

15. • Riboflavin photodegradation can be
exacerbated by sodium bicarbonate, which
is used to preserve vegetable colors.
• As riboflavin in cereal grains is located
primarily in the germ and bran, the milling
of such materials, which removes those
tissues, results in considerable losses in
their contents of the vitamin.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
15
Stability

16. The non covalently bound forms of
riboflavin in foods (FMN, FAD) and free
riboflavin appear to be well absorbed.
Covalently bound flavin complexes, such
as are found in plant tissues, are stable to
digestion and thus unavailable.
In general, riboflavin in animal products
tends to have a greater bioavailability
than that in plant products.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
16
Bioavailability

17. Riboflavin is
synthesized by the
bacteria populating
the hindgut.
Microfloral riboflavin can
be absorbed across the
colon to contribute to
nutritional riboflavin
status of the host.
April 15, 2018
Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
17
Hindgut microflora

18. • Combs GF. The Vitamins. Fundamental Aspects
in Nutrition and Health. Elsevier Inc. 2008.
Literature
April 15, 2018 18