Step 1: Understanding the Concept:
Cereal storage proteins are classified into different groups based on their solubility in various solvents.
This system of classification is known as the Osborne classification system, developed by Thomas Burr Osborne in 1907.
Step 2: Detailed Explanation:
According to the Osborne classification system, plant and cereal proteins are categorized into four distinct groups based on their solubility:
1. Albumins: Soluble in water and dilute salt solutions. These are metabolic proteins and enzymes.
2. Globulins: Insoluble in pure water but soluble in dilute salt solutions (such as saline).
3. Prolamins: Insoluble in water or absolute alcohol, but soluble in aqueous alcohol solutions (typically 70--80% ethanol). These are the primary storage proteins in most cereals (e.g., gliadin in wheat, zein in maize).
4. Glutelins: Insoluble in water, salt solutions, or alcohol, but soluble in dilute acids or bases (dilute acid and alkali).
Glutelins are high-molecular-weight storage proteins, such as glutenin in wheat and oryzenin in rice, which provide structural strength and elasticity to dough.
Therefore, cereal proteins soluble in dilute acid and alkali are glutelins.
Step 3: Final Answer:
Cereal proteins soluble in dilute acids and alkalis are classified as glutelins, which corresponds to Option (B).