Milling Baking Nutrition What types of wheat are there? How can flour allergies be prevented?/What causes flour allergies? What is a flour specification? What types of flour are available and what are they used for? What is a premix? What is Celiac disease?/What is wheat/gluten intolerance? Q) What type of Wheat has the shortest growth cycle? Q) What are the Wheat seasons? Q) How does Wheat grow? Q) What is the aerial pest control? Q) What are the divisions of the plant protection? Q) What is the plant quarantine? Q) What are the organizations of the Wheat plant in World? Q) Are there development projects? Q) How do you start Wheat mill? Q) Where can you buy Wheat mill machines here in the _______? Q) Wheat mill and Wheat plantation-What's the difference? Q) Where do we go from here? Q) How many grain foods are needed daily? Q) What's the difference between whole wheat and white bread? Q) Is bleached white flour harmful? Q) What's the difference between all-purpose flour and bread flour? Q) What nutrients have been removed to make white bread? Q) What is the difference between whole wheat, graham, and stone ground flours? Q) Where is wheat produced? Q) How is wheat traded? Q) Where is wheat milled? Q) Which regions consume wheat based products? Q) Will fortification be a benefit where wheat is not the main staple food? Q) Which flour should be enriched or fortified? Q) What do we mean by enrichment or fortification? Q) How are the minerals and vitamins added? Q) Is flour fortification safe? Q) How much does it cost? Wheat Q) What type of Wheat has the shortest growth cycle? Q) What are the Wheat seasons? Q) How does Wheat grow? Q) What is the aerial pest control? Q) What are the divisions of the plant protection? Q) What is the plant quarantine? Q) What are the organizations of the Wheat plant in World? Q) Are there development projects? Q) How do you start Wheat mill? Q) Where can you buy Wheat mill machines here in the _______? Q) Wheat mill and Wheat plantation-What's the difference? Q) Where do we go from here? Q) How many grain foods are needed daily? Q) How much is an ounce? Q) Are bread and other grain foods fattening? Q) What's the difference between whole wheat and white bread? Q) What's considered a "whole grain"? Q) Are all brown breads whole grain? Q) Is bleached white flour harmful? Q) What's the difference between all-purpose flour and bread flour? Q) What is semolina and how does it differ from durum flour? Q) Will a high-carbohydrate diet make me insulin resistant and, therefore, fat? Q) Are crackers high in fat? Q) What's the difference between flour and corn tortillas? Q) Do I have to eliminate my favorite desserts to have a healthy diet? Q) Can white and wheat flour be substituted for each other in most recipes? Q) What is the benefit of grinding whole grain at home vs. the whole wheat bread purchased in the store Q) Can cake flour be substituted for in a recipe? Q) Does whole wheat pastry flour have the same nutrients as whole wheat flour? Are they interchangeable Q) What is couscous? Q) Which bread molds first - wheat or white? Q) What nutrients have been removed to make white bread? Q) What is the difference between whole wheat, graham, and stone ground flours? Q) What is durum wheat, and what is it used for? Q) What is gluten? Q) What is spelt?
Wheat: The Raw Material The Wheat Kernel Wheat Grading Wheat Quality Parameters The Flour Mill Laboratory Determination of Wheat Quality Parameters Wheat Preparation for Milling Milling Units Laboratory Mills Experimental Mills Experimental Milling Example Special Adaptations to Experimental Milling Milling Evaluation Assessing Quality in the Mill Laboratory Wheat Storage and Blending Facilities and Equipment Preliminary Cleaning Preconditioning of Wheat Storage Facilities and Equipment Preserving Grain Quality Blending of Mill Mixes in Storage Procedures and Control Wheat Cleaning and Conditioning Unmillable Material Methods of Separating Wheat Impurities Theory of Conditioning Wheat for Milling Heat Conditioning of Wheat Wheat Conditioning Equipment Tempering Bins Different Approaches to Wheat Conditioning Cleaning of Preconditioned Wheat Cleaning-House Flow Sheet Future Trends The Grinding Process Grinding Machines Prebreak The Roll Surface Operation of the Roller Mill Grinding The Sieving Process Principles of Sieving Sifters Sieve Surface and the Flow Granulation Control Future Sieving Developments The Purification Process Principles of Purification The Purifier Surface The Purifier and the Flow Balance The Future of Purifiers Mill Design Planning Land Requirements Mill Building Equipment Allocation The Mill Flow Sheet Special-Purpose Mills Future Trends in Mill Construction Flour Handling and Blending Flour Storage and Blending Quality Control and Analysis Infestation and Pest Control Air Classification and Fine Grinding Whole Wheat, Meals, Blends, and Reconstituted Enrichment and Ingredients Flour Stabilization Flour Drying Packaging Loading and Shipping Milling of Durum Wheat Durum Wheat Quality Cleaning House Wheat Conditioning Milling Product Quality Milling of Soft Wheat Wheat Quality Wheat Preparation for Milling Milling Procedure Soft Wheat Sprout Damage Control Cake Flours Cookie Flour 11. Air in the Flour Milling Industry Principles Equipment Environment in the Flour Mill Grain Aeration Air in Purification and Cleaning Machines Pneumatic Conveying Mill Process Control Automation Raw Materials Testing of Intermediate Stocks The Future of Mill Process Control Mill Maintenance Types of Maintenance The Mill Maintenance Program Planning of Maintenance Food Safety and Hygiene in the Flour Mill Flour Mill Hygiene, Infestation and Pest Control World Flour Milling Industry Good Manufacturing Practices (GMP) Flour Milling Industry Dust Emission & Risk Management Program Mill Management Staffing and Organization of a Flour Mill *Mill Management Models Why Universal Flour Fortification? What is the extent of iron deficiency? Why is iron deficiency a serious health problem? Why is folic acid important? Where is wheat produced? How is wheat traded? Where is wheat milled? Which regions consume wheat based products? Consumption in Eastern Europe is high at 262 kg/person/year. In developing countries less at 74 kg/person/year and in Western Europe and other high income countries at 155 kg/person/year. There are only a half dozen countries in the world where wheat flour consumption per capita is less than 10 kg/year. Will fortification be a benefit where wheat is not the main staple food? Sometimes people question the value of flour fortification when wheat consumption is not the main staple food. However, where wheat consumption is as low as 20 kg/year, as in the case of Indonesia, fortification of iron for instance at a level of 50 mg/kg equals an additional intake of 1000 mg of iron annually. This is equivalent to more than two months of daily iron supplementation at 30 mg/day- a dose that has been shown effective in correcting iron deficiency anemia for women and children. In Venezuela, iron fortification at half that level reduced IDA from 37% to 16% in two years 14 . Clearly wheat flour fortification will not provide enough iron, folic acid and other essential vitamins and minerals to everyone who is deficient. This is but one of the approaches in combating micronutrient deficiency on a national scale. If flour was fortified, however the public health benefit to those who consume it and to most nations would be would be enormous. Which flour should be enriched or fortified? The fortification of wheat flour with micronutrients, or enrichment as it is called in some countries, has been used for many decades as a cost-effective public health program to improve nutritional health. Currently about 30 countries are fortifying most of their wheat flour with iron and folic acid. The Americas are advanced on this and include Canada, US, Caribbean and most of Latin America. In the Middle East the many of Gulf States fortify and in Asia, Indonesia is leading the way. It is now time to introduce the concept of Universal Flour Fortification, meaning that all wheat flour of a certain type, whether produced domestically or imported, will be fortified in order to reduce and help eliminate micronutrient deficiencies around the world. In practical terms there are many types of flour produced and some are more amenable to fortification than others. Iron fortificant bio-availability is still a subject of research and development. Commercially available forms of iron fortificant as iron sulphate and elemental iron is largely inhibited in absorption in high extraction milling (whole meal flours). The level of phytic acid in flour closely follows its ash content; making ash a good way to specify what flours should be fortified. It is proposed that flours with ash contents below 0.6% are suitable for fortification with all nutrients, while flours with higher ash contents should be considered for folic acid and vitamin A fortification only. The reason for that is these two nutrients represent true fortification, since vitamin A is not naturally present in wheat while the levels of folic acid being added are much higher than those in wheat. The levels of the other B vitamins and the minerals being added are typically to restore the levels in white flour to those found naturally in whole wheat. If more bioavailable iron compounds such as iron EDTA or iron chelates become commercially available at a cost affordable to the industry or society they could also be included. This still means that the bulk of flour milled throughout the world is suitable for fortification with folic acid, iron plus other essential nutrients including vitamin A, other B vitamins, niacin and zinc. In moving forward it is practical to target high capacity mills that supply large amounts of flour to the market, have more sophisticated milling process with quality assurance and dosing feeders available or easily installed at relative low cost to the mill. If these flour mills have fortification as a norm then this is likely to have a trickle down effect within the industry to smaller mills. This will allow more time to address the issues of bio-availability of iron fortificants, costs of implementing in smaller mills and the associated quality assurance and monitoring issues. What do we mean by enrichment or fortification? In its natural state, wheat is a good source of vitamin B1 (thiamin), vitamin B2 (riboflavin), niacin, vitamin B6 (pyridoxine), vitamin E, as well as iron and zinc. However, since most of these nutrients are concentrated in the outer layers of the wheat grain, a significant proportion is lost during the milling process. The more highly refined the flour the greater the loss of these vitamins and minerals. Enrichment is considered as replacing the losses of these essential vitamins and minerals to close to the original levels. Fortification is where the amount added is set not only to replace the losses but also provide deficient populations with significant amounts of these nutrients. In the case of universal flour fortification we are talking about both enrichment and fortification. How are the minerals and vitamins added? The technology of flour fortification is simple. A premix of the micronutrients to be added is prepared or procured. The premix is then added to the flour at a uniform rate through a volumetric screw feeder located towards the end of the milling process. The premix can be fed directly on to the flour by gravity or by air convection using a pneumatic system. Which vitamins and minerals should be added to flour? In Canada where the average per capita wheat consumption is 270 kg/yr wheat flour enrichment standards are: Nutrient Ppm Nutrient ppm Thiamin 6.4 Vitamin B6 3.1 Riboflavin 4.0 Calcium 1500* Folic Acid 1.5 Magnesium 1900 Niacin 53 Pantothenic Acid 13 Iron 44 * Equivalent amount in flour but to be added at bakery In Indonesia where the average per capita wheat consumption is 20 kg/yr flour enrichment standards are: Nutrient Standard (ppm) Source Thiamin 2.5 Mononitrate Riboflavin 4.0 Riboflavin Zinc 30 Zinc Oxide Folic Acid 2.0 Folic acid Iron 50 Reduced iron Each country will have its own standard depending upon the consumption of wheat flour and pattern of micronutrient deficiency. In the Philippines the current law and implementing regulation will include vitamin A fortification to come into effect in 2006. There is a good rationale to have uniformity of standards in regions where flour is traded. In general virtually all countries that do not enrich flour with iron and folic acid have nation wide deficiencies in these micronutrients. Thus it makes sense for flour to be fortified with these plus other micronutrients as determined beneficial and cost effective on a national basis. Will iron be absorbed from flour? For the past 60 years iron and vitamins have been added to flour in the US and other countries to reduce the prevalence of anemia and deficiencies. Although the strictly scientifically controlled blinded trials were not done when this was introduced it is clear that countries where this has been done have a lower prevalence of iron deficiency anemia. This can be seen in USA, UK, Canada, Sweden and Chili following flour fortification. In Venezuela, for example, fortification of wheat flour led to the reduction of anemia from 39% to 16% in children age 16 during the period 1992 to 1994 15 Phytic acid which is located mainly in the bran and its biodegradation products are well established chelators of iron in particular, and other divalent irons in general (i.e. Ca, Zn and Mn). The amount of iron absorption is inversely related to the phytic acid content of flour. An international group led by Sharing United States Technology to Aid in the Improvement of Nutrition (SUSTAIN) have produced guidelines for iron fortification of cereal food staples 16 . The fortificant selected needs to match the milling process and storage conditions. Further research is underway to further document and improve iron bioavailability from flour. In the mean time this guideline is most useful to ensure the best results from iron fortified flour. Is flour fortification safe? Among those with some medical knowledge, there may be concern about too much iron. In fact, it is difficult to absorb too much iron. While deficient individuals may absorb up to 10-15% of iron intake, those in a no deficient state will usually absorb only about 1% or less. It is true that specific diseases do cause iron overload, but these are not due to higher iron intake. The experience of countries with iron fortification for 50 years shows no evidence of harm to those with iron overload diseases 14 . There are no documented ill effects of flour fortification with folic acid and the theoretical interaction with vitamin B 12 that some were predicting have not happened in the US or other places where folic acid has been mandatory added to flour. So it seems so far that only good things come with flour fortification. Micronutrients Grains of truth about WHEAT FLOUR Definition Flour is the product obtained by grinding wheat kernels or “berries.” The kernel consists of three distinct parts: bran, the outer covering of the grain; germ, the embryo contained inside the kernel; and endosperm, the part of the kernel that makes white flour. During milling, the three parts are separated and recombined accordingly to achieve different types of flours. There are six different classes of wheat: Hard Red Winter, Hard Red Spring, Soft Red Winter, Hard White, Soft White and Durum. The end products are determined by the wheat’s characteristics, especially protein and gluten content. The harder the wheat, the higher the protein content in the flour. Soft, low protein wheats are used in cakes, pastries, cookies, crackers and Oriental noodles. Hard, high protein wheats are used in breads and quick breads. Durum is used in pasta and egg noodles. History Ground grain was one of civilized man’s first foods. Ancient methods of grinding can be traced to the Far East, Egypt and Rome. As early as 6,700 B.C., man ground grains with rocks. Water mills did not appear until 85 B.C. in Asia Minor. Windmills appeared between 1180 and 1190 A.D. in Syria, France and England. Storage Flour should be stored in airtight containers in a cool, dry place (less than 60 percent humidity). All-purpose, bread and cake flour will keep for 6 months to a year at 70°F and 2 years at 40°F; store away from foods with strong odors. Whole-wheat flour should be refrigerated or frozen, if possible. Before using refrigerated or frozen flour, allow it to warm to room temperature and inspect for rancidity and taste. Nutritional value Wheat flour is an excellent source of complex carbohydrates. Other than gluten flour, all types of wheat flour derive at least 80 percent of their calories from carbohydrates. Depending on the flour type, the percent of calories from protein ranges from 9 to 15 percent, except from gluten, which has 45 percent protein content. Calories from fat are never more than 5 percent. In addition, wheat flour provides from 3 g (cake flour) to 15 g (whole-wheat flour) of dietary fiber per 1-cup serving. Wheat flour contains B-vitamins, calcium, folacin, iron, magnesium, phosphorus, potassium, zinc, minimal amounts of sodium and other trace elements. Types of flour White flour is the finely ground endosperm of the wheat kernel. All-purpose flour is white flour milled from hard wheats or a blend of hard and soft wheats. It gives the best results for many kinds of products, including some yeast breads, quick breads, cakes, cookies, pastries and noodles. All-purpose flour is usually enriched and may be bleached or unbleached. Bleaching will not affect nutrient value. Different brands will vary in performance. Protein varies from 8 to 11 percent. Bread flour is white flour that is a blend of hard, high-protein wheats and has greater gluten strength and protein content than all-purpose flour. Unbleached and in some cases conditioned with ascorbic acid, bread flour is milled primarily for commercial bakers, but is available at most grocery stores. Protein varies from 12 to 14 percent. Cake flour is fine-textured, silky flour milled from soft wheats with low protein content. It is used to make cakes, cookies, crackers, quick breads and some types of pastry. Cake flour has a greater percentage of starch and less protein, which keeps cakes and pastries tender and delicate. Protein varies from 7 to 9 percent. Self-rising flour, also referred to as phosphated flour, is a convenience product made be adding salt and leavening to all-purpose flour. It is commonly used in biscuits and quick breads, but is not recommended for yeast breads. One cup of self-rising flour contains 1 ½ teaspoons baking powder and ½ teaspoon salt. Self-rising can be substituted for all-purpose flour by reducing salt and baking powder according to these proportions. Pastry flour has properties intermediate between those of all-purpose and cake flours. It is usually milled from soft wheat for pastry-making, but can be used for cookies, cakes, crackers and similar products. It differs from hard wheat flour in that it has a finer texture and lighter consistency. Protein varies from 8 to 9 percent. Semolina is the coarsely ground endosperm of durum, a hard spring wheat with a high-gluten content and golden color. It is hard, granular and resembles sugar. Semolina is usually enriched and is used to make couscous and pasta products such as spaghetti, vermicelli, macaroni and lasagna noodles. Except for some specialty products, breads are seldom made with semolina. Durum flour is finely ground semolina. It is usually enriched and used to make noodles. Whole wheat, stone-ground and graham flour can be used interchangeably; nutrient values differ minimally. Either grinding the whole-wheat kernel or recombining the white flour, germ and bran that have been separated during milling produces them. Their only differences may be in coarseness and protein content. Insoluble fiber content is higher than in white flours. Gluten flour is usually milled from spring wheat and has a high protein (40-45 percent), low-starch content. It is used primarily for diabetic breads, or mixed with other non-wheat or low-protein wheat flours to produce a stronger dough structure. Gluten flour improves baking quality and produces high-protein gluten bread. Substituting Any recipe calling for all-purpose flour may use ½ whole-wheat flour and ½ all-purpose flour. If wanting the product to be 100% whole wheat, substitute 1-cup whole-wheat flour minus 1-tablespoon for every cup of all-purpose or bread flour the recipe calls for. To create a lighter whole-wheat loaf, add 1-tablespoon gluten flour and 1-tablespoon liquid for each cup of whole-wheat flour. Revised 2005 Wheat Flour Terms The Food and Drug Administration inspects and approves the use of flour treatments and additives that are used to improve the storage, appearance and baking performance of flour. The treatment additives are in no way harmful. “Enriched” flour supplemented with iron and four B-vitamins (thiamine, niacin, riboflavin and folic acid) and may be with calcium. Reconstituting the nutritional status of a processed food ingredient to match that of the original raw materials. “Fortified” implies that something is added to a product that makes its nutritional status higher than the product made from “unprocessed” raw materials. i.e. Cereals. “Pre-sifted” flour is sifted at the mill, making it unnecessary to sift before measuring. “Bromated” flour is largely discontinued in the United States. Ascorbic acid is now being added to strengthen the flour for bread dough’s. “Bleached” refers to flour that has been bleached chemically to whiten or improve the baking qualities. No change occurs in the nutritional value of the flour and no harmful chemical residues remain. It is a process which speeds up the natural lightening and maturing of flour. “Unbleached” flour is aged and bleached naturally by oxygen in the air. It is more golden in color, generally more expensive and may not have the consistency in baking qualities that bleached flour does. Unbleached is preferred for yeast breads because bleaching affects gluten strength. “Patent” flour, bleached or unbleached, is the highest grade of flour. It is lower in ash and protein with good color. Market-wise, it is considered the highest in value and mostly used by bakers. “Organic” or chemical-free flour is not standardized, so its definition varies from state to state. It may be grown and stored without the use of synthetic herbicides or insecticides. It may also mean no toxic fumigants were used to kill pests in the grain and no preservatives were added to the flour, packaging, or food product. “Gluten” is a protein formed when water and wheat flour is mixed. Gluten gives bread dough elasticity, strength and gas-retaining properties. Wheat is the only grain with sufficient gluten content to make raised or leavened loaf of bread. |