ONION
Onion (
Allium cepa)
is characterized by an exceptional concentration of rubidium (476.0% of the Daily Value [DV] per 100 g). Its
mineral profile is notably rich in:
boron (286.0% DV per 100 g),
cobalt (50.0%), and
silicon (17.0%). It is further distinguished by its
phytosterol content, specifically
beta-sitosterol (27.0% DV). The carbohydrate fraction includes
mono- and disaccharides (16.2%), with
glucose (13.0% DV) as a significant component, alongside
dietary fiber (15.0%). It contains a
substantial quantity of sucrose (6.5 g per 100 g) and
trace amounts of starch (0.1 g per 100 g). The
total purine base content per 100 g constitutes
3.0% of the daily allowance.
The concentration of
oxalic acid per 100 g is negligible (3 mg), representing
0.8% of the maximum tolerable daily intake (for further details, see
Rhubarb).
Thus, onion is low in vitamins, but it is rich in trace elements, especially – rubidium and boron, and contains phytosterols in sufficient quantities.
The occasional greening of the outer scales of onion bulbs is due to the light-dependent transformation of leucoplasts in the bulbs into chloroplasts and the corresponding accumulation of chlorophyll, which accumulates under the influence of sunlight. The green parts of the bulbs have a bitter taste, but they are not toxic and can be used in cooking.
Caloric content per 100 g: 38-41 kcal
Water per 100 g: 86 g
Ash per 100 g: 1 g
MINERAL ELEMENTS
Macroelements
| Name |
Content, mass fraction per 100 g of product |
% of daily norm |
| in numbers |
visually |
| Potassium |
148.0-214.0 mg |
7% |
 |
| Calcium |
26.6-31.0 mg |
3% |
 |
| Silicon |
5 mg |
17% |
 |
| Magnesium |
12.2-14.0 mg |
4% |
|
| Sodium |
2.0-4.3 mg |
0% |
 |
| Sulfur |
65-95 mg |
8% |
|
| Phosphorus |
32-58 mg |
7% |
|
| Chlorine |
25 mg |
1% |
|
Trace Elements
| Name |
Content, mass fraction per 100 g of product |
% of daily norm |
| in numbers |
visually |
| Aluminum |
400 mcg |
1% |
|
| Boron |
200 mcg |
286% |
  |
| Vanadium |
No data |
|
|
| Iron |
0.8 mg |
4% |
|
| Iodine |
2.2-3.1 mcg |
2% |
|
| Cobalt |
5 mcg |
50% |
 |
| Manganese |
110.0-380.0 mcg |
12% |
|
| Copper |
85.0-90.0 mcg |
9% |
|
| Molybdenum |
No data |
|
|
| Nickel |
0.800-13.5 mcg |
3.3% |
|
| Rubidium |
476 mcg |
476% |
 |
| Selenium |
0.500 mcg |
0.8% |
|
| Fluorine |
31 mcg |
1% |
|
| Chromium |
0.7-2 mcg |
4% |
|
| Zinc |
120.0-850.0 µg |
4.6% |
|
PROTEINS AND AMINO ACIDS
| Name |
Content, mass fraction per 100 g of product |
% of daily norm |
| in numbers |
visually |
| Total protein content |
1.1-1.4 g |
2% |
|
| Content of essential amino acids |
0.257-0.321 |
1.2% |
|
| Content of non-essential amino acids |
0.569-0.810 |
1.1% |
|
Essential Amino Acids
| Name of acid |
Content, g per 100 g of product |
% of daily norm |
| in numbers |
visually |
| Valine |
0.021-0.038 |
2% |
|
| Histidine |
0.014-0.018 |
2% |
|
| Isoleucine |
0.03-0.04 |
3% |
|
| Leucine |
0.050-0.053 |
2% |
|
| Lysine |
0.05-0.06 |
2% |
|
| Methionine |
0.010-0.012 |
0.6% |
|
| Threonine |
0.028-0.040 |
3% |
|
| Tryptophan |
0.019-0.020 |
5% |
|
| Phenylalanine |
0.035-0.040 |
2.7% |
|
Non-Essential Amino Acids
| Name of acid |
Content, g per 100 g of product |
% of daily norm |
| in numbers |
visually |
| Alanine |
0.035-0.060 |
0.8% |
|
| Arginine |
0.160-0.210 |
3% |
|
| Aspartic acid |
0.070-0.093 |
0.7% |
|
| Glycine |
0.033-0.040 |
1.1% |
|
| Glutamic acid |
0.220-0.330 |
2.1% |
|
| Proline |
0.012-0.021 |
0.4% |
|
| Serine |
0.021-0.028 |
0.3% |
|
| Tyrosine |
0.014-0.018 |
0.9% |
|
| Cystine |
0.004-0.010 |
0.9% |
|
FATS AND FATTY ACIDS
| Name |
Content, mass fraction per 100 g of product |
% of daily norm |
| in figures |
visually |
| Total fat content |
0.2 g |
0.2% |
|
| Content of unsaturated fatty acids |
0.142 |
0.3% |
|
| Content of omega-3 unsaturated fatty acids |
0.014 g |
1.4% |
|
| Content of omega-6 unsaturated fatty acids |
0.100 g |
1% |
|
| Content of saturated fatty acids |
0.071 g |
0.3% |
|
Unsaturated Fatty Acids
| Acid Name |
Content, g per 100 g of product |
| Palmitoleic C 16:1 (omega-7) |
0.0 g |
| Oleic C 18:1 (omega-9) |
0.028 g |
| Linoleic C 18:2 (omega-6) |
0.100 g |
| Linolenic C 18:3 (omega-3) |
0.014 g |
| Stearidonic C 18:4 (omega-3) |
0.0 g |
| Gadoleic C 20:1 (omega-11) |
0.0 g |
| Arachidonic C 20:4 (omega-6) |
0.0 g |
| Eicosapentaenoic C 20:5 (omega-3) |
0.0 g |
| Erucic C 22:1 (omega-9) |
0.0 g |
| Clupanodonic C 22:5 (omega-3) |
0.0 g |
| Docosahexaenoic C 22:6 (omega-3) |
0.0 g |
| Nervonic C 24:1 (omega-9) |
0.0 g |
Saturated Fatty Acids
| Acid Name |
Content, g per 100 g of product |
| Myristic C 14:0 |
0.0 g |
| Palmitic C 16:0 |
0.071 g |
| Stearic C 18:0 |
0.0 g |
| Arachidic C 20:0 |
No data |
| Behenic C 22:0 |
No data |
| Lignoceric C 24:0 |
No data |
Sterols
| Name |
Content, mass fraction per 100 g of product |
% of daily norm |
| in figures |
visually |
| β-Sitosterol |
15 mg |
27% |
 |
| Cholesterol |
0.0 mg |
0% |
– |
CARBOHYDRATES
| Name |
Content, mass fraction per 100 g of product |
% of daily norm |
| in figures |
visually |
| Total carbohydrate content |
8.2-11.2 g |
3.5% |
|
| Mono- and disaccharides |
8.1 g |
16.2% |
|
| Glucose |
1.3 g |
13% |
|
| Fructose |
1.2 g |
3.4% |
|
| Galactose |
0.0 g |
0% |
|
| Sucrose |
6.5 g |
– |
– |
| Lactose |
0.0 g |
0% |
|
| Starch |
0.1 g |
– |
– |
| Maltose |
0.0 g |
– |
– |
| Fiber |
3 g |
15% |
|
PURINE BASES