Module 5.2: Cereal and Cereal Flours

Cereal and Cereal Flours

Learning Outcomes

  • Understand the structure of cereal grains and the effects of processing on their nutrient quality.
  • Differentiate various types of flour and their products.

Structure of Cereal Grains

  • Cereal grains are vital food crops.
  • Each grain consists of:
    • Bran: Hard outer layer that protects the soft endosperm; high in fiber and minerals.
    • Endosperm: Largest part (83%), containing starch within a protein matrix; used primarily in white bread.
    • Germ: Smallest portion (2.5%); the embryo of the grain, high in fat, which can affect shelf life due to rancidity.
Key Concepts of Grain Structure
  • Grains can be consumed whole or processed into products like bread, cereal, oil, pasta, and starch.
  • Bran and aleurone layer are removed during processing, resulting in lower nutritional value in products like white flour.

Composition of Cereals

  1. Carbohydrates (79-83%): Mainly starch and fiber.
  2. Lipids (1-7%): Mostly unsaturated fatty acids; essential fats.
  3. Proteins (7-14%): Lower biological value; gluten proteins like gliadin and glutenin are key for bread-making.
  4. Vitamins: B-vitamins (e.g., B1, B2) are present; lost during milling, leading to conditions like beri-beri.
  5. Minerals: High in whole grains, particularly iron.
  6. Enzymes: Alpha-amylase aids in starch breakdown.
Nutritional Impact of Processing
  • Whole grains retain nutritional components (fiber, vitamins, minerals).
  • Processing (e.g., milling) depletes vital nutrients, making refined grains less nutritious.

Types of Cereal Grains

  • Major Grains: Rice, wheat, and corn are the primary grains consumed worldwide.
  • Wheat:
    • High protein content; ideal for bread-making (especially hard wheat).
    • Classifications:
    • Hard Wheat (12-18% protein): Ideal for bread.
    • Soft Wheat (8-11% protein): Ideal for cakes and pastries.
Variations of Wheat
  • Classified by season (winter vs. spring) and texture (hard vs. soft).
  • Corn and rice are also critical grains with various forms and processing impacts.

Types of Rice

  • Main varieties: Indica (tropical) and Japonica (subtropical/temperate).
  • Forms of rice include:
    • White Rice: Milled to remove bran and germ.
    • Brown Rice: Retains bran and germ; more nutritious.
    • Glutinous Rice: Sticky texture; used in desserts.
    • Converted/Parboiled Rice: Processed to retain nutrients.
  • Rice types vary by grain size, amylose content, and processing techniques affecting cooking quality.

Corn and Other Cereal Types

  • Corn: Products include grits, meal, and cornstarch; important to Native Americans.
  • Oats: High in fat; includes forms like oat groats, rolled oats, and oat bran.
  • Barley: Used for malt and beverages; significant in ancient cultures.
  • Sorghum and Millet: Gluten-free grains, often used in porridge and alcoholic beverages.

Recent Developments in Grains

  • Amaranth: High protein, gluten-free, traditional food of Aztecs.
  • Kamut: Ancient grain, high protein, often an alternative to wheat.
  • Quinoa: Known as "Inca rice," high in protein, gluten-free, quick cooking.

Cereal Products

  • Pasta and Noodles: Made from durum wheat; types include macaroni, spaghetti, and different shapes.
  • Typical ingredients include semolina, flour, and sometimes eggs.
  • Noodle Varieties: Include local types such as Miki, Sotanghon, and White Bihon.

Key Points for Review

  • The main structural components of cereal grains include bran, endosperm, and germ.
  • Nutritional quality decreases with processing.
  • Familiarity with types of cereal grains and their products is essential for food preparation courses.