Transcript document
Day 4 • Wheat • Flour milling • Grains Words, Phrases, and Concepts • • • • • Endosperm Germ Bran Whole grain Gluten, glutenin, gliadin • Dietary fiber • Whole wheat flour and wheat flour • Hard and soft wheats • Soaker • Bleaching and maturing agents • Amylase and falling number • Malting • Patent, clear, straight flours • Aleurone • Absorption value Introduction Wheat: – Is a cereal grain. – Most widely grown grain in world. • Thousands of varieties available, adapted to different climates. – Most popular grain in baking. • Forms gluten. • Mild, nutty flavor. Wheat Kernel • Also called: – Wheat grain – Wheat berry • Three main parts: – Endosperm – Germ – Bran Wheat Kernel Whole wheat flour: – Is ground from entire wheat kernel. – Is a whole grain. White flour: – Is ground from white endosperm. – Also called “wheat flour” Wheat Kernel • Whether cracked, crushed, rolled, or ground, whole grains have the same amount of bran, germ, and endosperm as the original grain. • Whole grains can reduce risk of certain diseases. Wheat Kernel Endosperm • Contains mostly starch. – Starch is tightly packed inside granules. – Embedded in chunks of protein. • Two important proteins: glutenin and gliadin. – Form gluten when flour is mixed with water. – Gluten network is important in structure of baked goods. Wheat Kernel Wheat germ: • Is the embryo of the wheat plant. • Sprouts, or germinates, into new plant. • High in nutrients. • Can be purchased toasted. – Nutty flavor. – Less likely to oxidize and turn rancid. Wheat Kernel Bran • Protective outer layer of kernel. • High in dietary fiber. – Mostly insoluble fiber. – Good for health. • Softens and swells when wet. • Can be purchased as flakes. – Adds appealing rustic appearance to baked goods. – Valuable source of dietary fiber. Makeup of Flour White flour: • Ground endosperm. • Also called wheat flour. – Do not confuse wheat flour with whole wheat flour. • Key components: – starch – gluten-forming proteins Makeup of Flour White flour (cont.): • Also contains: – – – – – – Enzymes (proteins) Moisture Pentosan gums Lipids Ash Carotenoid pigments Classifying Wheat • Wheat kernels: classified as hard or soft. • Additional ways of classifying: color of kernel, planting time, botanical species. • Six major classes of wheat in U.S.: – Hard red winter – Soft red winter – Hard red spring – Hard white – Soft white – Durum Classifying Wheat Hard kernels are hard to mill. • Starch granules are damaged during milling. – Absorb water more easily. • Flours are coarse and gritty. – Do not pack well when squeezed in fist. – Good for dusting bench. Classifying Wheat Flours Hard Wheat Flours Soft Wheat Flours Bread and high gluten flour Form strong gluten Cake and pastry flour Gritty to touch Soft and silky Do not pack well Pack when squeezed Yeast-raised breads Cakes, cookies Form weak gluten Particle Size From largest to smallest in size: • • • • Wheat berries Cracked wheat and rolled wheat flakes Farina and durum semolina Flours, coarse and fine Particle Size Large grain particles: – Absorb water slowly. – Require gentle heating or overnight soaking • Soaked, softened grains called “soakers” • Can be good source of enzyme activity Additives and Treatments • Vitamins and minerals – Added to enriched flour- by law! – Removing the bran and germ removes nutrients – Iron, thiamin, riboflavin, niacin, folic acid added • Natural aging (Maturing proteins) – Air (oxygen) is the “additive” • Bleaching and maturing agents (Chemical) – Potassium bromate – Ascorbic acid and other bromate replacers – Benzoyl peroxide – Chlorine Additives and Treatments Additive Carotenoids Gluten Starch Use Air (oxygen) Whitens Strengthens --------- All flours Potassium bromate --------- Strengthens --------- High-gluten flour Ascorbic acid --------- Strengthens --------- High-gluten and some bread flours Benzoyl peroxide Whitens --------- --------- All flours Chlorine Whitens Weakens Increases ability to absorb water Cake flour Additives and Treatments • Amylase – Enzyme; breaks down starch into sugars • Most active on damaged starch granules (from milling) • Activity increases during early stages of baking – Has multiple functions • Provides food for yeast fermentation • Increases brown color and flavor from baking • Softens crumb and slows staling – Falling number: measure of amylase activity in flour Additives and Treatments • Amylase – Good sources: • • • • • • • Sprouted wheat berries Soakers Diastatic malt syrup Rye flour Untoasted soy flour Malted flour Dough conditioners Additives and Treatments • Amylase activity decreases when: – Amount of salt in dough is increased. – Baking temperature is increased. – Dough is retarded (refrigerated during fermentation). Additives and Treatments • Malted flour – Grains of barley are malted, or sprouted, before drying and pulverizing. – Used for its enzyme activity. • Amylase and protease – Also called dry malt, or simply malt. – Commonly added: • By miller to bread and high gluten flour. • By baker to yeast doughs. Additives and Treatments • Dough conditioners – Also called dough improvers – Added to yeast doughs – Multi-functional; most common benefit: • Strong gluten; for high volume and fine crumb. – Uses • Large-scale bread bakeries • Frozen yeast doughs • To eliminate bulk fermentation of yeast dough – Saves time, but flavor is sacrificed Additives and Treatments • Vital wheat gluten – Mostly gluten (up to 75 percent) – Creamy yellow powder – Added to yeast-raised doughs • Improves flour quality • Increases water absorption – Starting point: add 2-5 percent of flour weight Commercial Grades of Flour Patent flour: from heart of endosperm • Whitest in color, lowest in ash. • Most expensive. • Most white flours are patent flours. Commercial Grades of Flour Clear flour: from outer part of endosperm • Contains aleurone layer – Nutrient rich – High in enzyme activity • Used in rye and multi-grain breads Commercial Grades of Flour Straight flour: from entire endosperm • Not commonly used in U.S. Milling • In U.S. flours are milled based on separation of endosperm from bran and germ • For whole wheat flour- recombined • Distinct difference between milling of whole grain Patent Wheat Flours Bread flour • • • • • From hard red spring or hard red winter wheat High in gluten-forming proteins Unbleached or bleached Often contains malted barley flour Uses: breads, rolls, croissants, sweet yeast doughs Patent Wheat Flours Artisan bread flour • From hard red winter wheat • Compared with regular bread flour: – Lower in gluten-forming proteins (for irregular crumb) – Less water absorption (for crisper crusts) – Usually no added bleaching or maturing agents • Uses: crusty lean baguettes, flat breads (tortillas, pita) Patent Wheat Flours High-gluten flour • Generally from hard red spring wheat • Highest in gluten-forming proteins • Compared with bread flour: – Higher water absorption – Requires more mixing to fully develop – Sometimes bromated • Like bread flour: – Unbleached or bleached – Often contains malted barley flour • Uses: bagels, thin crust pizzas, hard rolls Patent Wheat Flours Pastry flour • • • • From soft wheat Low in gluten-forming proteins Usually unbleached Low water absorption – High spread in cookie dough • Uses: cookies, pie pastry dough, muffins, cakes Patent Wheat Flours Cake flour • • • • From soft wheat Also called chlorinated or high-ratio flour Stark white – highly bleached Chlorine treatment: – Increases water absorption, for thicker batters and stiffer doughs – Weakens gluten • Uses: high-ratio cakes, cookies Patent Wheat Flours All-purpose flour • • • • From hard wheat, soft wheat, or blend Also called H&R (hotel and restaurant) flour Unbleached or bleached Substitute with 60/40 or 50/50 blend of bread flour and cake flour • Uses: breads, cakes, cookies, muffins, pastries Other Wheat Flours Whole wheat flour • From hard red wheat – Whole wheat pastry flour is milled from soft wheat • • • • Also called graham or entire wheat flour A whole grain Many granulations available, from fine to coarse Compared with white flour: – Has higher absorption value; is a better drier – Forms less gluten – Baked goods are: denser, darker, stronger in flavor Other Wheat Flours Whole white wheat flour • • • • From white wheat; hard or soft Golden (not white) in color A whole grain Compared with regular (red) whole wheat flour: – Lighter in color – Milder in taste – Same amount of dietary fiber Other Wheat Flours Durum flour and durum semolina • From endosperm of durum wheat – Not whole grain • Durum flour is fine; also called semolina flour. • Durum semolina is coarse; looks like cornmeal. • Compared with white flour: – Yellow in color (high in carotenoids) – Very high in protein – Very hard kernel; hard to mill • Uses: pasta, semolina bread Functions of Flour 1. Providing structure – Essential in many baked goods and pastries • Holds size and shape of leavened baked goods; prevents collapse. • Provides thickening in pastry creams, pie fillings. – From gluten, starches, and pentosan gums • Gluten is important in pie crusts and crisp, dry cookies. • Starch is important in high-ratio cakes, muffins, and cake-like brownies and cookies. • Both important in yeast-raised breads. Functions of Flour 2. Absorbing liquids – Is a drier • Absorption value of flour: amount of water absorbed by flour when forming bread dough. – From gluten, starches, and pentosan gums • High-protein flours have higher absorption value than low-protein flours. – From protein, damaged starch granules, and pentosan gums. • Chlorinated cake flours have high absorption value because of chlorine’s effects on starch granules. Functions of Flour 3. Contributing flavor – Wheat: mild, nutty flavor • Flours differ in flavor. • Whole wheat flour: strongest flavor. Functions of Flour 4. Contributing color – From three sources • Pigments in bran layer – Red wheat bran is brown in color; white wheat is gold. • Carotenoids in endosperm – Durum wheat is highest in carotenoids; yellow in color. – Carotenoids whiten when bleached. • Maillard browning during baking – High-protein flours typically brown more when baked than low-protein flours. Functions of Flour 5. Adding nutritional value – Contribute starch, vitamins, minerals, and protein. • Protein in flour is low in lysine, an essential amino acid. – Whole wheat flour is better nutritionally than white flour. • Contains dietary fiber and many unidentified health-promoting substances. • Offers protection against certain diseases. Storage of Flours Flour has limited shelf life. – Six months maximum. – Oils oxidize when exposed to air. • Develops rancid, cardboard-like off flavors, – Whole wheat flour most susceptible. • Bran and germ contain most of the oils in flour. Storage of Flours When storing flour: – Rotate stock: practice FIFO (first in, first out). – Do not add new flour to old. – Cover bins and store in cool, dry area. • Ideally, store wheat germ and bran under refrigeration. – Watch for infestation from insects and rodents. • Silky cobwebs are a sign of flour moths. – Be especially vigilant with whole grains. Words, Phrases, and Concepts • • • • Triticum grains Cereal-free grains Pumpernickel Fermentation tolerance • Phytonutrients • Degerminated • Limewater • • • • • • Masa harina Groats Hull or husk Lignan Phytoestrogen ALA omega-3 fatty acid • Mucilage Introduction Many variety grains are available to bakers. – They vary in protein content. – Most cannot form gluten. • Exception: triticum grains Introduction Classification of variety grains and flours: – Cereal grains and flours • High in starch. • Rye, corn, oats, rice, pearl millet, and teff – Alternative wheat (triticum) grains and flours • Spelt, Kamut, triticale, einkorn, emmer – Cereal-free grains and flours • Amaranth, buckwheat, flaxseed, potato, quinoa, soy Cereal Grains Rye – Traditionally grown in cold climates • Russia, Eastern Europe, Scandinavia. • Rye bread consumption high in these regions. – Characteristically strong flavor. – Oils oxidize easily, shortening flour’s shelf life. – High in pentosan gums. • Increases absorption value of flour. • Important source of structure in rye dough. – Rye bread formulas: • Traditionally are sourdoughs. • In North America, often include white (wheat) flour. Cereal Grains Rye – Limited ability to form gluten. – Bread doughs are easily overmixed and have poor fermentation tolerance. • Breads tend to be dense and gummy. Cereal Grains Rye – Commercial grades: • • • • Light (white) rye: patent flour Medium rye: clear flour Dark rye: straight flour Pumpernickel: whole rye flour Cereal Grains Corn – Also called maize. – Sold as flour, meal, or grits. • The coarser the grain, the denser and crumblier the baked good. – White, yellow, or blue in color. – Degerminated corn has oil-rich germ removed. • Milder flavor. • Longer shelf life; less likely to oxidize. • Enriched, to replace valuable vitamins and minerals lost in germ removal. Cereal Grains Corn – Forms no gluten. – White (wheat) flour added to baked goods, to provide structure and fermentation tolerance. Cereal Grains Corn – Masa harina: • Used in making corn tortillas. • Dried corn is soaked in limewater (alkali). – – – – Softens corn kernels; easier to grind. Removes bran layer. Yellows the color and changes the flavor. Increases availability of nutrients. Cereal Grains Oats – Several products available: all are whole grain. • Made from dehulled whole oat kernels (groats). – Quick-cooking rolled oats are cut thin; regular rolled oats are coarser and chewier. Cereal Grains Oats – Rolled oats are steamed, then flattened between rollers. • Softens and precooks oats. • Prevents rancid oil off-flavors from developing. – Inactivates lipase enzymes. – Contain the gum beta-glucan. • Gluey, gummy consistency. • Source of soluble dietary fiber. – Commonly used in cookies, streusel toppings, muffins, breads. Cereal Grains Rice – Different varieties and types • Long-grain rice – Holds its shape well, especially if par-boiled. • Medium or short grain rice – Cooks into creamy, clingy texture. • Brown rice is a whole grain – Takes longer to cook; has a chewy texture. – Use: rice puddings, custards, pies Cereal Grains Rice flour – Uses: gluten-free baked goods; Middle Eastern and Asian cakes and cookies. – Medium and short-grain white or brown: • Best for gluten-free baked goods. – Long grain: • Best for dry, sandy cookies, like shortbread. – Also available: rice starch flour. • Purified rice starch (protein, etc. removed), pulverized into flour. Cereal Grains Pearl millet – Grown in Africa and India. – Tiny tear-shaped grains that pop like popcorn. – Must be cooked in water to soften. – Millet flour used in India in roti (flatbread). Teff – Grown in Ethiopia (in Eastern Africa) – Tiniest of cereal grains. – Teff flour used in a sour, spongy pancake called injera . Alternative Wheat Grains Spelt – Like all triticum (wheat) grains, not appropriate for wheat-free or gluten-free diets. – Ancestor of modern wheat. – Has close-fitting protective inedible husk (hull). • Difficult to harvest: kernels do not fall out easily. • Easier to grow organically: kernels are protected from insects and microorganisms. – Grown as specialty or health food. – Forms weak gluten that is easily overworked. – Use in place of soft wheat flour. Alternative Wheat Grains Kamut – Ancestor of modern durum wheat; high in protein. – Name is trademarked; licensed to those growing the grain organically. – Large kernels. • Two-three times size of regular wheat kernels. • Mild-tasting. – Uses: whole grain pasta, bread, bulgur, couscous. Alternative Wheat Grains Triticale – Cross between wheat and rye – Superior nutritional quality compared to wheat. – Use instead of soft wheat. Einkorn and Emmer (Farro) – Ancient; over 10,000 years old. – Close-fitting inedible husk; easy to grow organically. – Einkorn: soft, sticky dough; Emmer: heavytextured bread. Cereal-Free Grains and Flours Amaranth – Small, light-brown seeds from herb grown in Central and South America. – Unlike wheat and most cereal grains, high in lysine, an essential amino acid. – Uses: multi-grain breads; pops like popcorn. Cereal-Free Grains and Flours Buckwheat – Not wheat; forms no gluten. – Has strong flavor and dark color; often blended with white (wheat) flour. – Sold as: • Coarse grits. • Finely ground flour, whole grain or not. • Whole kernels, roasted; called kasha. – Uses: Russian pancakes (blini), Breton crêpes from north of France, Japanese soba noodles. Cereal-Free Grains and Flours Flaxseed – Small, hard, dark oval oily seeds. – Prized for its nutritional benefits: • Soluble dietary fiber from gummy mucilage. • Lignan, an antioxidant phytoestrogen. • ALA omega-3 fatty acid – Grind in blender or food processor before use. • Nutritional benefits available only when ground. • Refrigerate ground seeds, to minimize rancidity. – Uses: add to batters and doughs for health benefits. Cereal-Free Grains and Flours Potato – Tuber (root), not grain. – Cooked and dried, then cut into flakes or milled into flour. • Cooked (gelatinized) starch is easily broken down into sugars by amylase. • Increases water absorption of doughs; improves fermentation. – Uses: soft, moist yeast breads. – Also available: potato starch flour. • Highly purified; protein, etc. removed. Cereal-Free Grains and Flours Quinoa – Small, round seeds. – High in healthful unsaturated fatty acids. • Oxidizes easily; refrigerate ground quinoa. – Like amaranth, • Grows in South America. • High in lysine, an essential amino acid. – Uses: multi-grain breads. Cereal-Free Grains and Flours Soy – Oily legume; not a cereal grain or seed. – Very high in protein and fat, low in starch. – Defatted (fat removed) for use in baking. – Two types: • Untoasted; acts as a bleaching and maturing agent from active enzymes. • Toasted; excellent source of nutritionally highquality protein and other nutrients. – Uses: yeast doughs; milk and egg substitutes in various products Lab • Exercise 1 and 2 • Identify various grains/flours by sight and touch- answer questions- pg. 102 and 127 • Hydration comparison Lab • Each Group- Follow directions on pg. 104 for Flours as driers • Gr 1: Bread/ Semolina • Gr 2: Whole wheat/ Soy • Gr 3: Cake/ Rye • Gr 4: High gluten/White whole wheat • Pg. 104- use 6 qt. mixer- ½ formula- 250 g flour etc.