Studying the composition of bran is important for determining their nutritional value and suitability for various purposes, including use as animal feed or functional food ingredients. The composition of bran can vary depending on the type of grain (wheat, grain, oats, barley, rice etc), variety, grinding technology and other factors.
Main components, which are investigated as part of bran:
- Cellulose (dietary fiber): This is the main value of bran. The total fiber content is investigated, as well as its factional composition (soluble and insoluble fiber). Methods include enzymatic gravimetry and other chemical methods.
- Squirrels: The total protein content is determined (by the Kjeldahl method) and amino acid composition, which is important for evaluating the nutritional value for animals.
- Jury: Total fat content is measured (extraction methods) and the fatty acid composition is determined (gas chromatography).
- Carbohydrates: The content of total carbohydrates is studied, as well as individual factions, such as starch, sugars, hemicelluloses.
- Vitamins: The content of group B vitamins is determined (thiamine, riboflavin, niacin, pyridoxine, etc.), vitamin E and other fat-soluble vitamins (HPLC methods, spectrophotometry).
- Mineral substances (ash): The total content of mineral substances is determined (weighing after burning), as well as the contents of individual macros- (calcium, phosphorus, potassium, magnesium) and trace elements (iron, zinc, copper, selenium etc) using atomic absorption spectrometry, ICP-MS.
- Humidity: It is determined by drying to a constant mass.
- Enzyme activity: The activity of certain enzymes can be studied, such as phytase.
- Antioxidants: The content of phenolic compounds is determined, tocopherols and other antioxidants (spectrophotometric methods, TOP).
- The presence of harmful substances: The content of mycotoxins is controlled, pesticides, heavy metals and radionuclides (HPLC methods, gas chromatography, atomic absorption spectrometry, radiometry).
Research methods:
A wide range of laboratory methods is used to study the composition of bran, including:
- Chemical methods of analysis: Titrimetry, extraction, sedimentation, spectrophotometry.
- Chromatographic methods: Gas chromatography (GH), high pressure liquid chromatography (TOP).
- Spectroscopic methods: Atomic absorption spectrometry (AAS), inductively coupled plasma – mass spectrometry (ICP-MS).
- Physical methods: Drying, weighing, screening.
- Microscopic methods: To determine the structure and presence of foreign impurities.
The results of bran composition research are important for:
- Estimates of fodder value: Preparation of balanced rations for animals.
- Use in the food industry: Development of products with enriched content of food fibers and other useful substances.
- Quality control: Ensuring compliance of bran with established standards.
The nutritional value of bran of different species can differ significantly. Наприклад, oat bran is known for its high content of soluble fiber (beta-glucans), while wheat bran is rich in insoluble fiber. Rye bran also has its own peculiarities in composition. Therefore, compositional research is key to optimal use of this valuable by-product.