How Flour Affects Bread Quality

VOLUME 3 /NUMBER 11 Flour Quality

Practical technology from Lallemand Inc.

LOUR PERFORMANCE depends on its bushel weight, heat damage, foreign mat - fungal alpha- amylase. Enriching replaces a composition, which in turn depends ter, broken kernels, and presence of wheat portion of the nutri ents lost during milling Fon wheat characteristics and milling. from other classes. and in the United States includes thia- The quality of bread flour is determined by Milling separates the bran and germ mine, riboflavin, niacin, iron, and (op- its ability to produce a consistent finished fractions from the endosperm, which is tionally) calcium. product with these characteristics: used to make flour, and reduces endosperm Flour age and storage are important • High loaf volume particles to the correct size. A series of sepa- because fresh flour without chemical • Symmetrical loaf shape ration and sizing steps converts one hun - maturing lacks the strength and tolerance • Attractive and even crust color dred pounds of wheat into about seventy- for breadmaking. Flour with chemical • Fine and uniform crumb structure five pounds of various flour types. Patent maturing may perform well when very • Smooth texture flour is made from the purest endosperm fresh, but not for the five to twenty-one • Light crumb color fraction with the lowest bran content. days after milling while it is respiring or • High absorption (moisture content) Clear flour is made from less pure fractions “sweating.” Flour is normally stable over a • Tolerance to processing variations and has higher protein and bran content. long period of time when stored properly • Tolerance to ingredient variations Straight flour contains all the flour frac - but can deteriorate when exposed to tions and has a protein and bran content extremes of temperature and humidity. WHEAT AND MILLING that falls in between the other two. CHARACTERISTICS Flour treatment includes bleaching, FLOUR COMPOSITION Wheat classes are based on the hardness, maturing, malting, and enriching. Bleach- Ash is the mineral residue remaining after color, and growing season of the wheat vari- ing removes yellow endosperm pigments organic matter has been incinerated. eties. Hard wheats have a higher protein using oxidizing agents like benzoyl perox - Wheat bran contains more minerals than content than soft wheats and are used most - ide. Chemical maturing improves flour does endosperm, so ash content roughly cor - ly for yeast-raised products. Soft wheats are strength and tolerance using oxidizing relates with flour type. Typical ash levels used mostly for chemically leavened prod - agents like potassium bromate, ascorbic are 0.4 to 0.45 percent for patent flours, ucts. Durum wheats are a type of hard wheat acid, or azodicarbonamide. Standardizing 0.45 to 0.5 percent for straight flours, and used mostly for pasta products. Color refers amylase activity in flour is accomplished approximately 0.6 percent for clear flours. to the red, white, or amber appearance of by adding malted wheat or barley flour or Continued the bran on the outside of the kernel. Winter wheat is planted in the fall and harvested in early summer. Spring wheat is COMMON TYPES OF WHEAT AND FLOUR planted in the spring and harvested in late summer. WHEAT CLASS FLOUR TYPE PROTEIN RANGE APPLICATIONS Growing conditions interact with the Hard red spring Clear 13. 0–15.0% Specialty breads wheat variety to affect its quality. High soil High gluten 13. 5–14.5% Specialty breads fertility and low moisture during the grow - Whole wheat 14. 0–16.0% Specialty breads ing season give higher wheat protein. Low Hard red winter Patent 11. 0–13.0% White pan bread soil fertility and high moisture give lower Straight 10. 0–11.0% All purpose wheat protein. High moisture during har - HRS/HRW blends Patent 11. 0–13.0% White pan bread vest negatively affects quality, as sprouting Whole wheat 13. 5–15.0% Specialty breads may occur thereby increasing the amylase Hard white (winter) Patent 11. 0–13.0% White pan bread enzyme level. Soft red winter Patent 7. 0–9.0% Cakes Wheat grades are based on government Clear 8. 0–10.0% Cookies, crackers, standards. The grade standards include muffins, pastries HRW/SRW blends Straight 10. 0–11.0% All purpose This issue was produced in consultation with Soft white Patent 7. 0–9.0% Sponge cakes B. L. D’Appolonia, Professor Emeritus, Clear 8. 0–10.0% Flat breads, noodles, pastries Department of Cereal Science, North Dakota Durum Semolina 12. 0–14.0% Pasta State University, Fargo, ND 58105. How Flour Affects Bread Quality (Continued)

Color can be evaluated visually or with Kjeldahl method or NIR instrument. It is Farinograph. It is affected primarily by instruments. It is influenced by the yellow affected primarily by wheat growing condi- wheat variety, which determines the char- endosperm pigments, bran particles, and tions. The protein content of flour is usually acteristics of the glutenin and gliadin frac- foreign material. Flour color has a direct about 1 percent less than the wheat from tions of gluten, which make up about 85 effect on crumb color and combines with which it was milled and is about 1 percent percent of the flour protein. Typical crumb structure to influence crumb lower for patent flour than it is for clear. Farinograph stability times for bread flours “brightness.” Bleached bread flour is char - Typical flour protein levels for bread pro- are 8 to 12 minutes. acterized by a typical white creamy color. ducts range from 11 to 15 per cent. Damaged starch is created during Protein quantity is calculated from Protein quality is measured indirectly milling. Higher damaged starch levels the nitrogen content determined by the by dough-testing devices such as the increase absorption and the amount of yeast fermentation. Percentage of damaged starch in flour is determined as grams of starch susceptible to hydrolysis by alpha- Farinograph amylase per 100 grams of flour on a 14 per - cent moisture base. Typical damaged starch FARINOGRAPH CURVE provides as the flour becomes developed and eventu - levels in bread flours are 5 to 10 percent. useful information for bakers ally breaks down. The shape of the curve Absorption is measured by the Farino- Astriving to produce consistent indicates the strength of the flour. A narrow graph as an indication of the flour’s ability products with flour of variable quality. The curve that drops off rapidly indicates a weak to hold water while maintaining its consis - Farinograph is used to determine flour flour, whereas a wider, more level curve indi - tency. High protein and damaged starch strength and to predict processing charac- cates a stronger flour. The relative strengths levels give high absorption, which is good teristics like water absorption and mixing of successive lots of flour can be judged by for baking performance because it increases time. simply examining the shape of the Farino- the finished product yield and improves The instrument works by measuring the graph curves or by comparing the measure - shelf life. Typical absorption levels for bread resistance to mixing of a flour and water ments labeled on the example below. flours are 58 to 66 percent. dough. The resistance is recorded as a curve Amylase enzyme activity is measured by viscosity tests like the Brabender Amy- lograph. It is influenced by wheat growing conditions and malting at the mill and is Arri val Time Peak Time Departu re Time most important in straight lean doughs, 1.5 minutes Sta bility Time 7.5 minutes 12.5 minutes where it affects the amount of yeast fer - 11.0 minutes mentation. Typical Amylograph values for

0 malted bread ﬂour are 450 to 550 0

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D Absorp tion: 60. 7% N

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B MTI: 30 BU 2 A Valorimeter: 66 R

0 1 Lallemand Baking Update is produced by

0 Lallemand Inc. to provide bakers with a 0 5 7 1 2 3 4 6 7 8 9 0 9 2 3 4 5 6 8 9 1 8 source of practical technology for solving MINUTES problems. You can find the latest issues online at www.lallemandbaking.com. If you have questions or comments, Arrival Time The time required for the curve to Absorption The percentage of water required to please contact us at: reach the 500 Brabender Unit (BU) line . Indi- center the curve on the 500 BU line at the maxi- cates the rate of hydration of the flour. mum consistency of the dough (peak). Due to LALLEMAND Inc. Peak Time The time required for the flour to formula and processing differences, this may 1620 Préfontaine Montréal, QC H1W 2 N8 Canada reach full development. Gives an indication of not be true absorption in the bakery. tel: (800) 840-4047 ( 514) 522- 2133 optimum mixing time in the bakery. MTI (mixing tolerance index) The difference email: solution s@ lallemand.com Departure Time The time at which the curve in BU from the top of the curve at peak time to www.lallemand.com leaves the 500 BU line. the top of the curve five minutes after the peak Stability Time The interval between the arrival is reached. A higher value means the flour breaks To the best of our knowledge, the information in Lallemand Baking Update is true and accurate. How- time and the departure time. A lso referred to as down faster after reaching full development. ever, any recommendations or suggestions are made “tolerance” of the flour to over- and under- Valorimeter An empirical quality score derived without warranty or guarantee. mixing. A higher value means the flour is more from a template. Higher values indicate a © 2018 Lallemand Inc. tolerant. stronger flour.