CHAPTER CEREALS.pdf

# Wheat classification and composition Wheat classification and composition provides a detailed overview of the different types of wheat, their protein content, primary culinary applications, and the distinct nutritional contributions of the three main components of a wheat kernel: the endosperm, bran, and germ. ## 1. Wheat classification and composition ### 1.1 Classification of wheat Wheat can be classified into three main groups based on its characteristics and uses [4](#page=4). #### 1.1.1 Hard wheat Hard wheat is primarily used for bread making. It typically contains 10-12% protein and its flour is used for bread and macaroni products [4](#page=4) [5](#page=5). #### 1.1.2 Durum wheat Durum wheat is specifically used for pasta making. It has a higher protein content, around 13-14%, and is ground into semolina for macaroni products [4](#page=4) [5](#page=5). #### 1.1.3 Soft wheat Soft wheat, containing 8-9% protein, is utilized for making biscuits, cakes, cookies, crackers, and breakfast cereals [5](#page=5). #### 1.1.4 Semolina Semolina is a coarse flour prepared from both hard and durum wheat and is a key ingredient for pasta products [21](#page=21) [4](#page=4). ### 1.2 Composition of the wheat kernel The wheat kernel, also known as the wheat berry, is the seed from which the wheat plant grows. During milling, this kernel is separated into three distinct parts, each contributing differently to the final flour and nutritional profile [6](#page=6). #### 1.2.1 Endosperm * **Proportion:** Constitutes approximately 83% of the kernel's weight [7](#page=7). * **Primary Use:** It is the main source of white flour which is used for bakery products like bread, biscuits, and cakes [20](#page=20) [7](#page=7). * **Nutritional Content:** Contains protein, carbohydrates, and iron. It is also a source of major B vitamins (riboflavin, niacin, thiamine) and soluble fiber [7](#page=7). * **Semolina:** Coarsely ground endosperm, with a chemical composition similar to white flour, is used for macaroni and pasta products [21](#page=21). #### 1.2.2 Bran * **Proportion:** Accounts for about 14.5% of the kernel's weight [8](#page=8). * **Inclusion:** Bran is included in whole wheat flour [8](#page=8). * **Nutritional Content:** Contains small amounts of protein, but is rich in the three major B vitamins, trace minerals, and dietary fiber. This fiber is insoluble [8](#page=8). * **Primary Use:** Mainly used as poultry and cattle feed [22](#page=22). #### 1.2.3 Germ * **Proportion:** Makes up approximately 2.5% of the kernel's weight [9](#page=9). * **Description:** The germ is the embryo or sprouting section of the wheat seed [9](#page=9). * **Processing Consideration:** It is often separated during flour milling due to its 10% fat content, which can limit the shelf life of flour [9](#page=9). * **Nutritional Content:** Contains minimal quantities of high-quality protein but a greater share of B-complex vitamins and trace minerals [9](#page=9). * **Uses:** The germ can be purchased separately and is a component of whole wheat flour. Wheat germ is used for producing wheat germ oil, and the residual solvent-extracted germ, rich in proteins and B vitamins, can be used in weaning foods [22](#page=22) [9](#page=9). ### 1.3 Milled wheat products The important milled products derived from wheat include white flour, semolina, resultant wheat flour, germ, and bran [20](#page=20). #### 1.3.1 White flour This is the primary product of wheat milling and is extensively used in the manufacture of various bakery products [20](#page=20). #### 1.3.2 Resultant wheat flour * **Yield:** Constitutes about 10% of the milled wheat basis [21](#page=21). * **Composition:** It is a mixture of fine bran, shorts, clears, and tail fines [21](#page=21). * **Application:** Used for preparing unleavened bread such as chapatis and nans [21](#page=21). #### 1.3.3 Mill feed Mill feed is a mixture comprising bran, germ, and shorts [21](#page=21). #### 1.3.4 Wheat shorts * **Origin:** Another fraction obtained during roller milling of wheat, typically mixed with bran and germ in the mill feed [22](#page=22). * **Composition:** Consists of fine bran particles, germ, and a small proportion of floury endosperm particles [22](#page=22). * **Quality:** Contains less than 9.5 percent crude fiber [22](#page=22). * **Nutritional Superiority:** Exceeds whole grain in protein, fat, phosphorus, niacin, thiamine, and riboflavin content [22](#page=22). --- # Grain processing and nutritional value Processing, particularly milling, significantly impacts the nutritional value of grains, primarily through the removal of outer layers and the subsequent alteration of nutrient content [12](#page=12). ### 2.1 The impact of processing on grain nutrition Grains undergo processing before consumption, and methods like milling can reduce their nutritional value. The extent of nutrient loss is generally dependent on how much of the outer layers are removed during processing. This removal leads to a loss of fiber, vitamins, and minerals. Consequently, highly milled grains such as white maize flour, polished rice, and white wheat flour are less nutritious because they have lost most of the germ and outer layers, along with most B vitamins and some protein and minerals [12](#page=12). > **Tip:** Processing can not only make nutrients easier to digest but also facilitates the addition of nutrients through fortification [11](#page=11). #### 2.1.1 The extraction rate The extraction rate is a key factor determining the nutrient content of flour. It is defined as the number of parts by weight of flour produced from 100 parts of the grain [18](#page=18). * **Definition:** Extraction rate = (Weight of flour produced / Weight of grain) * 100 [18](#page=18). Flours can be produced with varying extraction rates, depending on how much bran, germ, and pericarp are removed [18](#page=18). * **High extraction rate flours:** These flours include more bran, resulting in a higher content of dietary fiber, vitamins, and minerals. They retain significantly more micronutrients compared to low-extraction flours [18](#page=18). * **Low extraction rate flours:** These flours contain less B vitamins, minerals, protein, and fiber for the consumer [18](#page=18). > **Example:** A flour with an extraction rate of 80% means that 80 kilograms of flour were produced from 100 kilograms of wheat. This flour would retain more of the wheat's original bran, germ, and nutrients than a flour with a lower extraction rate, such as 70%. #### 2.1.2 Grinding and particle size Beyond the removal of outer layers, grinding itself reduces the particle size of grains. This reduction in particle size has implications for the glycaemic index and resistant starch content of the grain [19](#page=19). #### 2.1.3 Enrichment of cereals Due to the nutrient losses incurred during processing, grains used as breakfast cereals are often enriched. Enrichment involves adding back essential nutrients that were lost during processing or adding nutrients not originally present in significant amounts [18](#page=18). --- # Quality control tests for flour This section details essential quality control tests performed on flour, linking their results directly to the quality and performance of finished bakery products [26](#page=26). ### 3.1 Moisture content * **Method:** Low temperature heating, typically oven-dried following AOAC or AACC standards [27](#page=27). * **Importance:** * Indicates grain storability [27](#page=27). * Moisture content exceeding 14.5% can lead to mold, bacteria, and insect infestation, causing deterioration during storage [27](#page=27). * Affects profitability as wheat grains and flour are often sold by weight; higher moisture content means higher weight and thus more revenue [27](#page=27). ### 3.2 Ash content * **Method:** High temperature incineration [28](#page=28). * **Importance:** * Provides an indication of the yield expected during milling [28](#page=28). * Indirectly reveals the amount of bran contamination in the flour, impacting milling performance [28](#page=28). * Can affect the color of the finished product, potentially leading to a darker hue [28](#page=28). * Specific ash content requirements vary; specialty products may need low ash, while whole wheat flour naturally has high ash content [28](#page=28). ### 3.3 Protein content * **Method:** High temperature combustion [29](#page=29). * **Importance:** * Related to many processing properties, including water absorption and gluten strength [29](#page=29). * Affects the texture and appearance of the finished product [29](#page=29). * Low protein content typically results in a crisp or tender product, suitable for snacks and cakes [29](#page=29). * High protein content leads to a chewy texture, desirable for pan bread [29](#page=29). * Higher protein content necessitates more water and longer mixing times to achieve maximum dough consistency [29](#page=29). ### 3.4 Falling number * **Method:** Viscosity analysis using a falling number instrument, which measures the resistance of a flour and water paste to a falling stirrer [30](#page=30). * **Results:** Expressed in seconds, serving as an index of enzyme activity in the wheat or flour sample [30](#page=30). * **High Falling Number (FN) (>300 seconds):** Indicates minimal enzyme activity, suggesting good quality wheat or flour [30](#page=30). * **Low Falling Number (FN) (<250 seconds):** Signifies substantial enzyme activity and potential sprout damage in the wheat or flour [30](#page=30). * **Importance:** * Measures the level of enzyme activity [31](#page=31). * Adequate enzyme activity is crucial as yeast require sugars for proper development, which are produced by enzymes [31](#page=31). * High enzyme activity can lead to excessive sugar production, insufficient starch, resulting in sticky dough and poor finished product texture [31](#page=31). * If the FN is too high, enzymes can be added to the flour [31](#page=31). * If the FN is too low, the enzymes cannot be removed, rendering the flour unusable [31](#page=31). > **Tip:** The Falling Number test is a critical indicator of sprout damage and its impact on enzyme activity, which directly affects dough properties and end-product quality. ### 3.5 Flour color * **Method:** Color measurement of the flour [33](#page=33). * **Importance:** * Affects the quality of finished products [33](#page=33). * Generally, a bright white color is preferred for many flour applications [33](#page=33). ### 3.6 Gluten strength properties Gluten is the protein network that provides elasticity and extensibility to dough, influencing its behavior during processing and the texture of the final product. Several tests assess gluten strength. #### 3.6.1 Gluten washing and Gluten Index * **Method:** Gluten washing measures wet gluten content. The Gluten Index is derived from this measurement as an indication of gluten strength [34](#page=34). * **Importance:** * A High Gluten Index indicates strong gluten [34](#page=34). * Gluten is responsible for the elasticity and extensibility of flour dough [34](#page=34). * Wet gluten content reflects protein content and is a common specification requested by end-users [34](#page=34). #### 3.6.2 Farinograph * **Method:** Measures flour water absorption and dough strength by assessing the dough's resistance to the mixing action of paddles [36](#page=36). * **Results:** Includes absorption, arrival time, stability time, peak time, departure time, and mixing tolerance index [36](#page=36). * **Importance:** * Estimates the amount of water needed for dough preparation [36](#page=36). * Evaluates flour blending requirements [36](#page=36). * Determines mixing requirements for dough development and tolerance to over-mixing [36](#page=36). * Predicts finished product properties; strong dough mixing properties often correlate with a firm product texture [36](#page=36). * **Characteristics:** Weak gluten flour exhibits lower water absorption and a shorter stability time compared to strong gluten flour [37](#page=37). > **Example:** A baker uses the Farinograph to determine the exact water percentage for a bread dough to achieve optimal consistency and workability. #### 3.6.3 Extensigraph * **Method:** Measures dough extensibility and resistance to extension. It assesses the force required to stretch a dough sample with a hook until it breaks, evaluating its visco-elastic properties [40](#page=40). * **Importance:** * Extensibility indicates the dough's elasticity and its ability to stretch without breaking [40](#page=40). * Measures gluten strength and bread-making characteristics [40](#page=40). * Can also evaluate the effects of fermentation time and additives on dough performance [40](#page=40). * **Characteristics:** Weak gluten flour shows lower resistance to extension (R value) than strong gluten flour [41](#page=41). #### 3.6.4 Alveograph * **Method:** A visco-elastic recorder that determines gluten strength by measuring the force needed to inflate and break a bubble of dough [44](#page=44). * **Importance:** * Useful for characterizing the dough properties of weak gluten wheats [44](#page=44). * Weak gluten flour, identified by a low P value (gluten strength) and a long L value (extensibility), is preferred for cakes and confectioneries [44](#page=44). * Strong gluten flour, with high P values, is preferred for breads [44](#page=44). * **Characteristics:** * Strong dough requires more force to blow and break the bubble (high P value) [45](#page=45). * A bigger bubble indicates the dough can stretch to a very thin membrane before breaking, signifying higher dough extensibility (L value) [45](#page=45). * Strong dough results in a larger area under the curve (W value) and requires more force [45](#page=45). * **Comparison:** Weak gluten flour has lower P values than strong gluten flour [46](#page=46). #### 3.6.5 Mixograph * **Method:** A recording dough mixer that measures flour water absorption and dough mixing characteristics by assessing the dough's resistance to the mixing action of pins [49](#page=49). * **Importance:** * Quickly determines dough and gluten properties, particularly useful for small flour quantities [49](#page=49). * Used to screen early generation lines for dough gluten strength [49](#page=49). * Flour water absorption measured by the mixograph often serves as the bake absorption in bread baking tests [49](#page=49). * **Characteristics:** Weak gluten flour exhibits a shorter peak time and less mixing tolerance compared to strong gluten flour [51](#page=51). ### 3.7 Starch properties #### 3.7.1 Amylograph * **Method:** Viscosity analysis measuring the resistance of a flour and water slurry to the stirring action of pins or paddles as the slurry is heated, causing starch granules to swell and form a paste [53](#page=53). * **Importance:** * Measures flour starch properties and enzyme activity, particularly that resulting from sprout damage (alpha-amylase enzyme activity) [53](#page=53). * High enzyme activity leads to a thicker slurry [53](#page=53). * High enzyme activity can cause sticky dough and result in poor color and weak texture in the finished product [53](#page=53). * **Comparison:** Sprouted wheat flour demonstrates a lower peak viscosity than sound flour [56](#page=56). > **Tip:** The Amylograph is essential for understanding how starch and enzyme activity influence dough hydration and final product characteristics, especially when dealing with potentially sprouted grains. --- # Factors affecting baking quality and bread making process This section details the key components influencing flour's baking quality and outlines the critical stages of the bread-making process. ### 4.1 Factors affecting baking quality of flour The baking quality of flour is influenced by several factors, with gluten content and quality being the most significant. Other contributing elements include flour fineness, amylase and protease activity, starch quality, lipids, and flour aging [60](#page=60). #### 4.1.1 Gluten content and quality Gluten is crucial for providing elasticity to dough and retaining gas during fermentation, which contributes to loaf volume. Gluten derived from hard wheat yields high-quality bread characterized by thin cell walls and a porous structure. Conversely, gluten from soft wheat does not produce good bread quality. Higher protein content in dough leads to a greater retention of carbon dioxide (CO2), resulting in a higher loaf volume [61](#page=61). Gluten is formed from glutenin and gliadin proteins, which constitute approximately 85% of flour proteins; the remaining proteins include globulin, albumin, and protease. When flour interacts with water, it forms gluten, a cohesive and extensible substance. This gluten network is vital for trapping CO2 produced by yeast during fermentation [62](#page=62). #### 4.1.2 Flour fineness The particle size of flour significantly impacts loaf volume; both overly coarse and overly fine flour particles can reduce it. Over-grinding can damage starch granules, leading to swelling in the injured areas [63](#page=63). #### 4.1.3 Starch quality Different starches contribute to varying loaf volumes, with starches from hard wheat generally yielding higher volumes than those from soft wheat. This variation is related to the amylose and amylopectin content within the starches [64](#page=64). #### 4.1.4 Lipids Lipids play a crucial role in baking by aiding gluten-forming proteins in retaining CO2 produced during fermentation. The thin lipid layers formed contribute to dough plasticity and enhance ovenspring. Lipids appear to seal gas cells that burst during baking, thereby preserving the loaf's volume. They also contribute to the freshness of baked bread. During mixing, some free unsaturated fatty acids undergo enzymatic oxidation, which can affect the crumb's brightness [69](#page=69). #### 4.1.5 Amylase and protease activity Wheat flour naturally contains sufficient alpha-amylase; however, malt is often added at levels of 0.2-0.4% to increase its concentration. Amylase acts on starch to produce fermentable sugars. Protease, in small quantities, has a mellowing effect on dough. However, an excess of protease can degrade gluten, leading to dough softening [70](#page=70). #### 4.1.6 Flour aging When flour ages, lipase hydrolyzes fat into free fatty acids (FFAs). This process can deteriorate flour quality, resulting in gluten that lacks elasticity and breaks easily. Aging flour for several months generally improves its baking quality. Similar improvements are observed when flour is treated with bleaching agents and improvers, such as nitrogen peroxide, chlorine dioxide, benzoyl peroxide, ascorbic acid, potassium bromate, or ammonium or potassium persulfate [68](#page=68) [71](#page=71). The beneficial effects of these aging and improver agents stem from: * Inhibition of proteases, which are often in a dormant state [74](#page=74). * Oxidation of sulfhydryl (SH) groups to disulfide (SS) bonds [74](#page=74). * Oxidation of reducing substances present in the flour [74](#page=74). ### 4.2 Ingredients in bread making Essential ingredients for bread making include: * Flour [77](#page=77). * Fat/shortening [77](#page=77). * Water [77](#page=77). * Sugar [77](#page=77). * Salt [77](#page=77). * Surfactant [77](#page=77). * Milk solids [77](#page=77). * Yeast [77](#page=77). #### 4.2.1 Flour Flour provides the fundamental structure for the dough mixture. Its proteins form the skeleton of the dough structure. Gliadin contributes viscosity to the gluten, while glutenin provides elasticity. When hydrated together, these proteins form a viscoelastic three-dimensional gluten network [78](#page=78). #### 4.2.2 Fat/shortening The quantity of added fat or shortening, typically ranging from 2% to 6%, influences the bread quality. Shortening improves loaf volume and crumb grain. It acts as a lubricant within the gluten matrix, potentially reducing dough resistance to the diffusion and expansion of leavening gases, leading to increased volume and improved grain [79](#page=79). #### 4.2.3 Water Water is essential for hydrating gluten proteins during mixing and gelatinizing starch during baking. It also acts as a solvent for other solutes and serves as the dispersion medium for various ingredients. The greater the quantity and the stronger the quality of gluten protein, the higher the water absorption capacity [80](#page=80). #### 4.2.4 Sugar Sugar serves as a substrate for yeast fermentation. However, large amounts can retard fermentation by increasing osmotic pressure, leading to cell dehydration and interfering with cell metabolism. Sugar is typically used in quantities of 2% to 6%. It also affects gluten protein hydration by competing with wheat proteins for available water. The inversion of sucrose, due to the hygroscopicity of fructose, contributes to moisture retention in baked bread. Furthermore, inversion facilitates crust browning through Maillard reactions between glucose and fructose and carbonyl amines [81](#page=81). #### 4.2.5 Salt Salt (NaCl) is a common ingredient in batters and doughs, usually added at 1.5% to 2%. Its functions include improving taste and flavor, stabilizing fermentation, and strengthening the gluten structure [82](#page=82). #### 4.2.6 Surfactants Surfactants are often used as partial replacements for shortening. They form complexes with proteins, which strengthens the dough and enhances volume. By complexing with amylose and amylopectin, surfactants can soften the crumb and retard staling. Examples include monoglycerides and their esters, and sucrose fatty acid esters [83](#page=83). #### 4.2.7 Milk solids Fluid milk is commonly used in home baking and small bakeries, while non-fat milk solids (like skim milk powder) are preferred in larger commercial operations. The typical inclusion rate is 3% to 8%. For bread to be labeled as "milk bread" commercially, it must contain 8.2 parts of milk solids per 100 parts of flour [84](#page=84). #### 4.2.8 Yeast Yeast, typically *Saccharomyces cerevisiae*, is used at about 2% to 3%. It contributes to flavor, influences the rheological properties of dough, and produces gas for leavening. The fermentation process can be represented by the equation: $C_6H_{12}O_6 \rightarrow 2CO_2 + 2C_2H_5OH$. Compressed yeast (30% solid) is widely used in commercial bread production, while active dry yeast (92% solid) is popular for home baking due to its longer shelf life [85](#page=85). ### 4.3 Bread making process The bread-making process involves several distinct stages: preparation of dough, fermentation of dough, and baking [88](#page=88). #### 4.3.1 Dough preparation methods Several methods are employed for dough preparation: ##### 4.3.1.1 Straight dough method This is a single-step process where all ingredients are combined in one batch. Mixing continues until the dough achieves the desired smoothness and elasticity [89](#page=89). * **Advantages:** Requires minimal labor, has a shorter fermentation time compared to the sponge and dough method, and yields better flavor [89](#page=89). * **Disadvantages:** It is inflexible, requiring a fixed fermentation time, and ripe dough must be baked immediately [89](#page=89). ##### 4.3.1.2 Sponge and dough method This method consists of two steps: forming a sponge and then developing the dough. The sponge typically includes 50% to 60% of the total flour, all the yeast, yeast food (malt), and enough water to create a stiff dough. The remaining flour, salt, and water are then mixed with the sponge to form the final dough. This dough is briefly fermented before scaling, shaping, and proofing [90](#page=90). A simplified diagram of the sponge and dough method is: * Initial Sponge: Flour, yeast, water [90](#page=90). * Dough Development: Add remaining flour, yeast, water [91](#page=91). ##### 4.3.1.3 Mechanical dough method (Continuous mixing) This method is increasingly popular due to its advantages: * **Advantages:** Eliminates bulk fermentation, thus preventing losses; allows for the incorporation of extra water; and produces better bread from weaker flours [93](#page=93). * **Process:** It utilizes equipment like continuous mixers, developers, and extruders. This process requires more fermenting agents and higher mixing temperatures. Ingredients are mixed under pressure, then conditioned in a developer under pressure before being extruded directly into bread pans. Bread produced by this method exhibits uniform quality and texture [93](#page=93). #### 4.3.2 Fermentation of dough Optimal fermentation occurs at temperatures not exceeding 30 degrees Celsius. While yeast grows rapidly at higher temperatures, so do undesirable microorganisms. Temperatures around 60 degrees Celsius lead to yeast inactivation because the inactivation rate outpaces the reaction rate. The optimal pH range for yeast activity is 4.8 to 5.5. Yeast food is commonly added to accelerate gas production. The duration of fermentation is influenced by the concentrations of yeast, sugar, and salt, as well as the gluten structure strength and fermentation temperature. A stronger gluten structure necessitates a longer fermentation time [95](#page=95). #### 4.3.3 Baking Baking involves significant changes, including a substantial increase in volume and the development of rigidity [96](#page=96). * **Too low a baking temperature:** Delays protein coagulation and starch gelatinization, leading to an impaired crumb structure [96](#page=96). * **Too high a baking temperature:** Results in a reduced increase in volume due to rapid crust formation [96](#page=96). The recommended baking temperature range is 204 to 232 degrees Celsius. During baking, moisture content in the crumb decreases from approximately 45% to 35% due to evaporation. Bread is typically baked for about 30 minutes within the temperature range of 204 to 232 degrees Celsius [96](#page=96) [97](#page=97). > **Tip:** Understanding the interplay between ingredient properties (like gluten and starch) and processing conditions (like temperature and time) is crucial for achieving desired bread characteristics. > **Example:** A baker might choose a harder wheat flour for a bread requiring a strong, elastic dough structure capable of holding a significant amount of gas, leading to a higher loaf volume with an open crumb. Conversely, a softer wheat flour might be preferred for a cake where tenderness is the primary goal. --- ## Common mistakes to avoid - Review all topics thoroughly before exams - Pay attention to formulas and key definitions - Practice with examples provided in each section - Don't memorize without understanding the underlying concepts

| Term | Definition | |------|------------| | Hard Wheat | A type of wheat typically used for bread making due to its higher protein content which contributes to dough strength. | | Durum Wheat | A hard, vitreous grain of a wheat species used primarily in the manufacture of pasta and semolina products. | | Soft Wheat | A type of wheat with lower protein content, making it ideal for producing tender baked goods such as cakes, cookies, and biscuits. | | Semolina | A coarse meal made from durum wheat or hard wheat, used in making pasta, couscous, and puddings. | | Wheat Berry | The entire intact kernel of wheat, comprising the bran, germ, and endosperm, often referred to as the wheat kernel itself. | | Endosperm | The starchy part of the wheat kernel, which constitutes the largest portion and is the primary source of white flour used in baking. | | Bran | The outer protective layer of the wheat kernel, rich in dietary fiber, B vitamins, and minerals; it is often separated during milling. | | Germ | The embryo of the wheat seed, which contains the plant's potential to grow; it is rich in fats, vitamins, and minerals. | | Whole Wheat Flour | Flour that includes all three parts of the wheat kernel – the endosperm, bran, and germ – providing a higher nutritional content. | | Extraction Rate | The percentage of flour obtained from a given weight of grain during the milling process; a higher rate means more of the outer layers are included. | | Milling | The process of grinding grain into flour; it involves separating the different components of the kernel, such as the endosperm, bran, and germ. | | Fortification | The process of adding essential nutrients to food products, such as grains and cereals, to improve their nutritional value. | | Glycemic Index (GI) | A measure of how quickly a food causes blood sugar levels to rise after consumption. Finely ground grains tend to have a higher GI. | | Resistant Starch | A type of starch that is not completely digested in the small intestine, behaving similarly to dietary fiber and offering potential health benefits. | | Gluten | A protein complex formed when flour is mixed with water, providing elasticity and cohesiveness to dough, which is crucial for bread structure and gas retention. | | Glutenin | A component of gluten that contributes to the elasticity and extensibility of the dough, providing strength to the gluten network. | | Gliadin | A component of gluten that contributes to the viscosity and extensibility of the dough, affecting its ability to stretch. | | Falling Number (FN) | A test that measures the enzyme activity in flour by assessing the viscosity of a flour-water paste when stirred and heated; it indicates sprout damage. | | Alpha-amylase | An enzyme that breaks down starch into smaller sugars, providing food for yeast during fermentation. Its activity is critical for dough development and bread texture. | | Protease | Enzymes that break down proteins; in small amounts, they can mellow dough, but in excess, they can weaken the gluten structure. | | Farinograph | An instrument used to measure flour water absorption and dough mixing characteristics, providing information on dough stability and mixing tolerance. | | Extensigraph | A tool used to measure dough extensibility and resistance to extension, assessing the visco-elastic properties of the dough. | | Alveograph | A device that measures dough strength by assessing the force required to blow and break a bubble of dough, indicating gluten strength and extensibility. | | Mixograph | An instrument that measures flour water absorption and dough mixing characteristics by assessing the resistance of dough to mixing pins, useful for screening early generation lines. | | Amylograph | A device that measures the viscosity of a flour-water slurry as it heats, indicating starch properties and enzyme activity, particularly alpha-amylase. | | Lipids | Fats found in wheat, which can affect dough plasticity, oven spring, and help preserve freshness in baked bread. | | Surfactants | Compounds used in baking that can strengthen dough, enhance volume, and retard staling by forming complexes with proteins and starches. | | Saccharomyces cerevisiae | The scientific name for baker's yeast, a microorganism essential for leavening bread by producing carbon dioxide and ethanol. | | Fermentation | The process by which yeast consumes sugars in dough and produces carbon dioxide and alcohol, causing the dough to rise and develop flavor. | | Straight Dough Method | A method of bread making where all ingredients are mixed in a single batch, followed by a single fermentation period. | | Sponge and Dough Method | A two-step bread making process involving the initial formation of a sponge (a pre-ferment) followed by the addition of remaining ingredients to form the dough. | | Mechanical Dough Method | A continuous bread making process that uses specialized equipment to mix and condition dough under pressure, often producing uniform quality. | | Oven Spring | The rapid expansion of dough during the initial stages of baking due to the release of gases and heat. | | Crumb | The soft, porous interior of a baked bread product, which is influenced by flour properties, dough development, and baking conditions. | | Crust | The outer hard layer of a baked bread product, formed during baking due to moisture evaporation and Maillard reactions. | | Gluten Index | A measurement indicating the strength of gluten, derived from wet gluten content, reflecting elasticity and extensibility. | | Dough Strength | Refers to the resistance of dough to deformation and stretching, influenced by gluten quality and quantity, and measured by instruments like the Farinograph and Extensigraph. | | Dough Extensibility | The ability of dough to stretch without breaking, a key characteristic related to gluten quality and important for bread volume. | | Dough Elasticity | The ability of dough to return to its original shape after being stretched, also related to gluten quality. | | Staling | The process by which baked bread becomes firm and dry over time, involving changes in starch and gluten structure. | | Viscosity | A measure of a fluid's resistance to flow; in baking, it's used to assess dough and paste consistency. | | Sprout Damage | Damage to wheat kernels caused by premature germination, leading to increased alpha-amylase activity which can negatively affect baking quality. | | Ash Content | The mineral content of flour, determined by burning a sample and weighing the inorganic residue; it indirectly indicates the amount of bran present. | | Moisture Content | The amount of water present in flour or grain, critical for storage stability and dough hydration. | | Sulfhydryl Group (SH) | A chemical group involved in protein structure; oxidation to disulfide bonds (SS) is important for gluten strengthening during flour aging or chemical treatment. | | Disulfide Bond (SS) | A chemical bond formed between two sulfur atoms, contributing to the strength and stability of the gluten network. |