Chemical composition and nutritional value of beer

We all know that the taste of beer is smooth and glycolic, delicate and light, hoppy and malt.Unforgettable, do you know what ingredients in the beer combine to create such a taste?

The main chemical components of beer, with the exception of moisture, can be summarized as follows:

1. Alcohol

Alcohol content is a method of expressing the strength of beer, and its content is determined by the concentration of the original wort and the degree of fermentation of the beer. According to the known alcohol content and residual extract content, the raw wort concentration of beer can be roughly calculated by the following formula:

ω=(2.0665ω alcohol +ω1)×100/100+1.0665ω alcohol

In the formula: ω—the original wort concentration (%)

ω1 - true concentration of beer (%)

ω alcohol-alcohol content (%)

Alcohol is the main source of beer heat, and it is also a necessary ingredient to increase beer viscosity and foam viscosity and make beer foam fine.

2. Carbohydrates

After fermentation, most of the monosaccharides, disaccharides and maltotriose in wort are fermented and assimilated by yeast, and only a small amount remains in the beer. The residual amounts of dextrin and fermentable sugars are determined by the nature of the yeast used and the fermentation process. Generally speaking, the content of fermentable sugars in normally fermented beer is very small. Too high residual fermentable sugar is detrimental to the biological stability of beer.

The sweetness of beer is determined by the sugars and individual other substances contained, and dextrin itself has no taste. The relative sweetness of the relevant components in beer, based on sucrose, can be expressed as follows:

Sucrose 100 Glycerin 130

Fructose 173 Glycine 64

Glucose 74 Alanine 92

Maltose 32

Carbohydrates and alcohol are both the main sources of the calorific value of beer, and the caloric value of beer can be roughly calculated as follows:

Calorific value (J/100ml)=[4×solid matter (g/100ml)+7×alcohol (g/100ml)]×4.186

3. Nitrogenous substances

Nitrogen-containing substances in wort, after fermentation, part of low-molecular-weight nitrogen-containing substances are assimilated by yeast, and part of high-molecular protein is precipitated with the decrease of temperature and pH value. At the same time, yeast also secretes some nitrogen-containing substances during the metabolic process. The residual nitrogen content in beer accounts for 8% to 10% of its residual extract, which is equivalent to 50% of the nitrogen content of wort. Bacteria and fermentation process conditions vary greatly. Beer with high nitrogen content in malt or high concentration of original wort has higher residual nitrogen content; otherwise, it is lower.

4. Carbon dioxide

The carbon dioxide content in beer depends on the wine storage temperature and wine storage pressure. Generally, the carbon dioxide content in beer is 0.35% to 0.55%, and the carbon dioxide content in artificially aerated beer can be as high as 0.70%.

5. Minerals

The extract of beer usually contains 3% to 4% ash. The composition of ash is related to the composition of raw materials, especially the composition of water.

6. Other volatile components

Beer also contains trace amounts of lipids, hop resins, polyphenols, pigments, and organic acids such as lactic acid, succinic acid, oxalic acid and tartaric acid.

7. Volatile Components

A few of the volatile components in beer come from raw materials, and the vast majority come from fermentation products, mainly including the following components:

(1) Higher alcohols, mainly isoamyl alcohol, dimethyl butanol, dimethyl propanol, trimethyl propanol, propanol, etc.;

(2) Aldehydes, mainly acetaldehyde;

(3) Fatty acids and other organic acids, mainly acetic acid, butyric acid, caproic acid, caprylic acid, isovaleric acid and lactic acid;

(4) Esters, mainly ethyl acetate, isoamyl acetate, phenethyl acetate and ethyl caproate, etc.;

(5) Sulfides, mainly hydrogen sulfide, dimethyl sulfide, mercaptan, sulfur dioxide, etc.;

(6) Diacetyl.

Nutritional value of beer

01 Beer and Calories

1. Calculation of beer calorific value

The calorific value of beer can also be roughly calculated by the following formula:

Calories (J/L) = original wort concentration × 36.4 × 4.186

2. Comparison of heat produced by beer and other foods (J/kg)

Beer (12% original wort concentration) 1800

Apple Juice 1968

Tomato Juice 837

Orange Juice 1968

Grape Juice 3098

White wine 2931

Red wine 3224

The calories of 1L beer are equivalent to: 500g potatoes, 0.75L milk, 6~7 eggs, 65g cream; 250g brown bread.

3. Calorie conversion

The heat released by the decomposition of:

1g carbohydrate 17.17J 1g fat 38.94J

1g protein 17.17J 1g alcohol 29.73J

4. Calories needed by the human body

Basal metabolism of 70kg body 7.95kJ/d

Light physical labor (10.05～10.89)kJ/d

Heavy physical labor (14.65～18.84)kJ/d

02Beer and vitamins

The vitamins contained in beer vary from wine to wine, and examples are shown in the table.

Vitamins in beer Unit: mg/L

Vitamin name Content in beer

Thiamine (vitamin B1) 0.005~0.15

Riboflavin (vitamin B2) 0.3~1.3

Pyridoxine (vitamin B6) 0.4~1.5

Niacinamide 5~20

Pantothenic acid 0.4~1.2

Folic acid 0.1~0.13

Biotin (vitamin H) 0.002~0.015

Inositol ~60

Choline 100~300