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Cereal Foods World, Vol. 64, No. 4
DOI: https://doi.org/10.1094/CFW-64-4-0040
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Wheat Preprocessing Methods to Improve Nutritional and Technological Functionality
Anne Vissers,1 Michael Adams, and Gary Tucker

Department of Baking and Cereal Processing, Campden BRI, Chipping Campden, Gloucestershire, U.K.

1Corresponding author. Tel: +44 1386 842153; E-mail: anne.vissers@campdenbri.co.uk; LinkedIn: https://www.linkedin.com/in/annemaria-vissers and https://www.linkedin.com/company/campden-bri.


© 2019 AACC International, Inc.

Abstract

All wheat-based products require preprocessing of the grain before they can be used as food ingredients. Preprocessing techniques, both physical and biochemical, affect the nutritional value and techno-functionality of wheat in different ways and are the subject of this review. Physical techniques, such as milling, dry heating, and extrusion, improve the nutritional properties of wheat by increasing the digestibility of starches and proteins. However, care needs to be taken to not induce extensive protein cross-linking or damage heat-sensitive vitamins when using these methods. Biochemical methods, such as enzyme treatments, sprouting, and fermentation, are less harsh. These methods also can increase the nutritional value of wheat: micronutrients (e.g., vitamin levels, mineral bioavailability) especially benefit from biochemical treatments. With regard to techno-functional properties, physical treatments increase functionality by improving the baking properties of flour (e.g., starch gelatinization). Sprouting and fermentation treatments can be less beneficial due to increased enzyme activity, which can be challenging to control. Enzyme activity that is too high results in poor bread quality. Most of the research on the techno-functionality of wheat has focused on bread applications, while other bakery products, such as cake, have not been investigated as thoroughly. These types of products, however, also could benefit from pretreatment to create products with higher nutritional values while maintaining desired eating qualities.





Cereals have long been staple carbohydrate-based food sources around the world. Wheat is one of the three major cereal crops cultivated globally, along with corn and rice. In 2018, global wheat production reached 725.1 million tonnes, which was 30% of total cereal production (13). Grains have an outer indigestible polysaccharide layer, the bran layer, which surrounds the energy-providing starches and proteins (57). To create access to these nutrients, whole grains need to be processed before consumption. Additionally, processing the grains into flour and its components can introduce valuable techno-functional properties that enable production of a large range of products.

Various methods for preprocessing cereals into flour and its components can be utilized to enable their application in the food industry. Due to the significance of wheat in the food supply chain, it is important to understand what effects these different preprocesses have in terms of nutritional and techno-functional properties to tailor their application in the food products. For example, it is widely known that wheat milling and fractionation techniques, as applied for thousands of years, improve nutritional and techno-functional properties. These properties have been researched extensively and recently reviewed (24). The focus of this article is alternative preprocessing techniques based on either physical methods, such as heating, or chemical and biochemical methods, such as sprouting.

Nutritional Properties of Wheat

Wheat can comprise as much as 50% of a person’s daily energy intake (65) and provides significant quantities of valuable nutrients in the form of starch, dietary fiber, protein, vitamins, and minerals and a low amount of fat (Table I). Most components are located predominantly in the endosperm (57), while dietary fiber is present predominantly in the bran (57,62). The majority of the fiber is absent from white (refined) wheat flour because the bran is removed during the milling and refining process. Wheat kernel content is about 8–18% high-quality proteins; the exact content depends on the specific variety (55). The nutritional quality of proteins is defined by protein digestibility and amino acid composition (65). For the latter, especially, the content of essential amino acids is important (65). It should be noted that even though wheat contains all of the essential amino acids it is limiting in lysine and methionine (16).

Wheat is also a good source of micronutrients such as vitamins and minerals. Wheat consumption can contribute significantly to the intake of A vitamins (carotenoids), B vitamins, and E vitamins (tocopherols). Intake levels depend, however, on the type of flour consumed. For example, white flour lacks some B vitamins, such as thiamine, which are present in the bran and lost during milling and refining (46).

Even though cereals contain fairly high amounts of minerals (Table I) and contribute significantly to daily intake, the minerals generally have low bioavailability (3), meaning they are not in a form the body can easily utilize during digestion. Wheat flour also contains antinutrients such as phytic acid that interact with multivalent ions such as iron to form phytates, which are insoluble complexes, resulting in reduced mineral absorption. To combat low vitamin and mineral bioavailability, countries around the world (14) fortify flour with niacin, thiamine, calcium, and iron. Even though wheat flour is fortified with iron, its bioavailability remains low when added in its elemental form (3).

Techno-functional Properties of Wheat

In addition to its high nutritional value, wheat has many techno-functional properties and is an ingredient used in a wide variety of bakery products. One of the unique properties of wheat is the presence of the gluten proteins that allow formation of highly viscoelastic doughs. These gluten networks enable retention of the gas formed in bread dough during yeast and sourdough fermentation (7,55). Cysteines, sulfur-containing amino acids predominant in gluten proteins, oxidize as a result of stretching and folding actions during mixing that incorporate oxygen into the dough. The highly elastic network formed by the gluten proteins gives bread its desired final texture. Important parameters for a good bread flour, therefore, are a high protein content, good ratio between high and low molecular weight glutens (55), moderate levels of damaged starch, and moderate levels of amylase activity. Elevated amylase activity results in profound starch breakdown and formation of sticky bread with poor texture (11).

For plain cakes and biscuits, on the other hand, the development of a strong gluten network is not desirable, because consumers prefer soft-eating products. Cake structure depends more on starch than on protein properties (26) and cake production requires a soft milling wheat with relatively low protein content. Flour water absorption is lower for soft wheat cake flour than for hard wheat bread flour because of the lower levels of starch damage during milling. The low protein and gluten content hinder gluten development during cake batter mixing (26). In biscuits, structure is mainly determined by solidified fat and sugar in the glassy state; plain flour from soft wheat with low water absorption and low gluten development is required.

Preprocessing wheat kernels modifies starch and protein properties by, for example, partial denaturation or cross-linking. Choosing the right preprocess provides opportunities to tailor the final flour product for optimal functionality and nutritional value in the final product.

Heat Treatments

One of the preprocesses often applied to wheat is heat treatment. Heating of wheat grains or flour is primarily performed to modify functional properties rather than nutritional properties. With regard to nutritional properties, the effects of dry heating on wheat digestibility have not been widely investigated, mainly because raw flour is not generally consumed. Instead, wheat flour is consumed in the form of baked products in which the starch has been gelatinized in the presence of water and made more accessible to digestive enzymes (42). The most widely used heat treatment methods, dry heating and extrusion, are discussed in the following sections.

Dry Heating. Wheat grains and flour can be heated at various moisture levels, which is correlated with changes in both nutritional and functional properties. For nutritional properties, preheating wheat flour at a low moisture level (15%) followed by drying and reboiling did not affect in vitro starch digestibility relative to untreated flour (9). Preheating wheat starch at 35% moisture decreased digestibility significantly, resulting in high levels of resistant starch. It was hypothesized that heating in the presence of moisture increased pregelatinization of the starch, followed by retrogradation during drying. Additionally, protein denaturation and subsequent complexation to starch might affect starch digestibility (9). Based on protein denaturation and aggregation, protein digestibility varied with heat treatment intensity. In vitro protein digestibility (IVPD) of untreated durum wheat flour was 90.8% and was not affected by wet cooking (1:10 [wt/wt] flour/water) at 100 or 140°C for 10 min. Heating the flour for an additional 30 min, however, led to an 8% decrease in protein digestibility (23). Pasini et al. (45), in contrast, determined that IVPD of bread crumb was lower than IVPD of raw bread dough. The lower IVPD was correlated with aggregation of proteins, which limited access by digestive enzymes (45). Most types of heat treatment improve nutritional quality if digestibility of macronutrients is considered. Care needs to be taken, however, when retention of heat-sensitive components, such as vitamins, is important.

With regard to techno-functional properties, dry heat treatment of wheat flour provides an alternative to chlorine treatment as a means of producing cake flour (59). The treatment of soft wheat flour with chlorine improves cake baking performance and enables production of high-ratio cakes (higher ratios of sugar to flour) with increased palatability and shelf life (17). In recent years, however, concerns about the food safety of chlorine treatment have resulted in discontinuation of the use of chlorinated flour in most countries. During the search for an alternative treatment, it was discovered that heat-treated flour has properties similar to chlorinated flour—both chlorine and heat treatment of flour improved the functional properties of flour used in cake formulations (19,25,59). Heat treating wheat flour improves starch swelling and creates stronger cakes that do not collapse upon baking compared with nontreated flour (26,59). During processing, flour is often heated on fluidized bed dryers using hot air (41,61), a form of scraped surface heat exchanger, or the recently investigated Revtech technology (25). As with a heat exchanger, the Revtech technology allows for continuous rather than batch heating of flour (25). Irrespective of the heating method used, a variety of target temperatures, ranging from 60 to 140°C (25,33,54), and times, ranging from 2 min to 5 hr (26,54), are used. Changes in functionality mainly depend on the flour moisture content during treatment (33).

Presumably, heat treatment affects all flour components. Guy et al. (19) used a Rapid Visco analyser to determined that dry heat treatment (moisture levels <8%) of soft wheat flour (120–130°C) increased starch gelatinization viscosity by 1.5 times. Water absorption and pasting viscosity were positively correlated with heating temperature (26,41). It was hypothesized that heat treatment modifies the hydrophobicity of starch granules (54), making them swell more easily, which contributes to viscosity. Higher cake batter viscosity stabilized batters and improved expansion during baking (41), resulting in softer cakes with finer crumb structures (25).

Heating flour at elevated moisture contents (>13%) decreased protein solubility in acetic acid, which was correlated with gluten cross-linking and aggregation (33). The cross-linked gluten proteins had less opportunity to form the strong gluten networks that are desirable for bread making. Bread made with heat-treated flour, therefore, had lower volumes than bread made with unheated flour (58). Heat-treated flour provides increased functionality in cakes due to the lack of strong gluten network formation, which is undesirable for these products. Both the protein denaturation and increase in starch swelling properties contribute to improvement in cake batter stability.

Extrusion. Dry heating treatment modifies wheat only through the application of high temperatures. Using extrusion, however, the raw material can be processed with simultaneous application of temperature and pressure, temperature and shear, or a combination of all three parameters. Application of various physical treatments simultaneously allows modification of both nutritional and techno-functional properties. Extrusion is a process widely applied in the food industry, mainly to produce aerated snacks, breakfast cereals, and pet foods, and can be grouped with other high-temperature, short-time processing methods (51). During the extrusion process, the raw material is fed into a rotating screw. The screw rotation exposes the product to high shear, leading to pressure build up that can cause product expansion when it passes through the die, resulting in aerated products.

Extrusion improves starch digestibility (56,63) by pregelatinizing (5) and partially degrading starch (6). Starch breaks down in the cooking zone of the extruder due to the high shear forces and temperatures and also is promoted at low moisture levels due to high friction levels (6). Elevated temperatures have two effects. Increased temperatures kinetically accelerate starch breakdown. The higher temperatures, however, also decrease product viscosity, decreasing shear forces and subsequently decreasing the starch breakdown rate. As starch digestibility increases, protein digestibility is also reported to increase due to partial denaturation and greater accessibility by digestive enzymes (56). It should be noted, however, that the bioavailability of essential amino acids, such as lysine, are reported to decrease due to the occurrence of Maillard reactions at elevated temperatures (56). Proteins denature and can ultimately cross-link to either starch or another protein, forming novel linkages and structures with altered digestibility. The retention of vitamins, especially heat-labile vitamins, depends on temperature, screw speed, specific energy input, moisture level, feed rate, and die diameter (56). These parameters can be adapted and set to increase vitamin retention. Minerals, on the other hand, are heat stable and unlikely to be lost in the steam distillate at the die (56). Additionally, extrusion hydrolyzes phytate, releasing phosphate molecules and minerals and, thereby, increasing mineral bioavailability.

On a functional level, smaller starch polymers provide lower cold and hot pasting viscosity (37) and increased water absorption due to starch pregelatinization (36). The increased water absorption of extruded flour softened the bread crumb and increased bread volume when added at a 5% level (36). Extruding wheat bran increased water absorption as well due to starch pregelatinization and enhanced fiber solubility. When increased levels of nonextruded bran were added to bread dough, its development time increased, and stability was reduced. Adding extruded bran diluted the strength of these negative effects and improved dough and bread properties. It is likely that there is competition for water between bran fibers and gluten proteins, which negatively affects gluten network formation (15). Effects of bran addition and extrusion on bread volume were complex and depended on bread type (15,38).

Whereas extrusion is a technique that applies temperature, pressure, and shear simultaneously, puffing is a technique that applies only pressure and heat. Puffing can also pregelatinize starch (34) but is expected to have a lesser effect on starch polymer size. Using gun-puffers, superheated steam is created inside the wheat kernel and subsequently released by a pressure drop. Puffing of wheat increased water absorption and the solubility of starch by 2.5 times (34). Neither the digestibility of puffed wheat nor its application in bakery products has been investigated.

Chemical Treatments

Heat treatment induces physical modifications in cereal grains and flours. Physical modification, however, is not the sole method available for wheat processing. As alternatives to heat treatment, biochemical and chemical methods can be used, including enzyme treatment, alkaline treatment, fermentation, and sprouting. All of these techniques are discussed in the following sections as they relate to nutritional and functional changes.

Enzyme Treatment. Both endogenous and added enzymes are a tool widely used in grain and flour processing to induce profound changes in both nutritional and techno-functional properties. Endogenous enzymes in wheat, such as amylases, are activated during pre- and postharvest sprouting or dough processing. Exogenous enzymes added to the product matrix, such as amylases, xylanases, and proteases, can be of fungal or bacterial origin and are often used as processing aids (48). Enzymes can act on the structural components of wheat, such as fibers, proteins, and starches, resulting in partial breakdown or cross-linking. The use of enzymes in the cereal and baking industry has been reviewed by Poutanen (48), and some aspects are highlighted in the discussions of sprouting and fermentation below. The use of enzymes as a preprocessing method to modify wheat properties is not discussed further here, as it would require a stand-alone review.

Alkaline Treatment. Alkaline treatment of cereals is an ancient process, used to improve both the nutritional value of animal feed (43) and corn (maize) products (38). Alkaline treatment of wheat and barley improves starch digestibility in ruminants (43). The improved digestibility is correlated with partial hydrolysis of cereal polysaccharides, which increases accessibility and breakdown by digestive enzymes. For food products, alkaline treatment is most commonly applied to corn kernels using a process called nixtamalization. Nixtamalization is the process of boiling corn kernels in calcium hydroxide (pH 9) to soften the hard shell around the kernel and, thereby, improve processability. In addition to improving processability, nixtamalization improves corn nutritional properties by increasing the bioavailability of the essential amino acid lysine (38). Nixtamalization also improves techno-functional properties, such as water absorption, for further processing into corn crisps (chips) (1) or tortillas. Improved techno-functional properties are correlated with alkaline modification of the starch and interactions with calcium ions.

There is limited research on nixtamalization of crops other than corn. One patent for wheat and other cereals was found (22). The inventors combined enzymatic protease treatment using alkaline-resistant proteases with the traditional nixtamalization process, aiming to reduce the amount of water and calcium hydroxide applied. The nixtamalization process has a high environmental burden due to its water requirements and the alkaline wastewater that must be treated before being returned to the environment (38). Agrahar-Murugkar et al. (1) created a mixed flour containing nixtamalized corn, wheat, rice, and sorghum to which sprouted legumes were added. The flour had improved water absorption but lower protein solubility compared with the untreated mixed control flour (1). Because the flour contained a mixture of both nixtamalized and sprouted ingredients, it is challenging to attribute the changes in physical behavior to either nixtamalization or sprouting. The effects of treating individual ingredients was not investigated but is worthwhile, considering the changes the authors observed.

Fermentation. The aim of both nixtamalization and fermentation is to improve the nutritional properties of cereals. Sourdough leavening of bread dough relies on fermentation by both bacteria and yeast rather than yeast alone. The bacteria and yeast degrade the starch, resulting in formation of leavening gases and organic acids. Sourdough breads require prolonged fermentation, which gives the breads their distinct flavors and reported changes in nutritional values compared with yeast-leavened breads (49). One of the nutritional benefits of fermentation relates to decreased glycemic index (GI) because starch is degraded to lower levels. The formation of organic acids during sourdough fermentation and subsequent decrease in pH is thought to cause the decrease in GI (29). When making bread, there are changes in the vitamin contents and composition. Yeast leavening increases riboflavin (B2) levels more than does sourdough leavening, suggesting synthesis of this vitamin by yeast. Thiamine levels, on the other hand, decreased in yeast-leavened bread and were unaffected in sourdough-leavened bread (4). When assessing vitamin levels in finished bread products and untreated flours, the heat stability of vitamins should be kept in mind because most vitamins are heat sensitive. Fermentation also increased mineral bioavailability, especially that of magnesium, iron, and zinc, and was related to phytate breakdown (31).

Because the main purpose of fermentation has been modification of nutritional and sensory properties, research on the effects of sourdough fermentation on techno-functional properties such as gelatinization and the potential to form protein structures is limited. Most commonly, the effects of fermentation on final bread properties have been investigated. Messia et al. (39) assessed prefermentation of wheat bran to improve whole wheat bread characteristics. Prefermentation by lactobacilli increased arabinoxylan solubility and maintained high bread volume when added to white flour to make whole wheat bread. Addition of untreated bran to white flour decreased bread volume (39,53) because the sharpness of untreated bran particles ruptured the foam structure. Fermentation decreased the size of bran polymers, rendering more water available for starch gelatinization in the resulting bread dough (53).

Sprouting. The application of sprouted cereals in processed food products is a fairly recent development. In recent years, the popularity of use of sprouted grains, either as whole grains or as flour, in bakery products has increased because of health benefits associated with their consumption, as reviewed by Lemmens et al. (28). Sprouting of wheat induces many biochemical changes associated with seed development and ultimately results in the formation of shoots and rootlets. Activation of endogenous enzymes such as amylases increases starch availability for the germinating seed, and proteases mobilize proteins. Consumption of sprouted cereals is associated with prebiotic effects (66), increased bioavailability of minerals due to phytase activation during germination (27), and higher vitamin levels. It should be kept in mind, however, that levels of bioactive compounds vary highly with sprouting conditions. For example, vitamin E contents in wheat were found to increase after 7 days at 16.5°C (64) but decreased after 4 days at a higher temperature of 28°C (47). Levels can vary due to transportation of vitamins from the kernel to the rootlets, contributing to seedling development (28). Generally, the B vitamins tend to increase but, due to their water solubility, can leach into the steeping water if care is not taken (47). Nongerminated wheat does not contain detectable amounts of vitamin C, but this vitamin is synthesized during sprouting at sufficient levels to provide a valuable source of vitamin C (28,64). However, this vitamin also is water soluble and can be lost during prolonged sprouting. Lemmens et al. (28) point out that there were limited numbers of clinical trials performed. All the health benefits associated with the consumption of sprouted cereals were observed from in vivo trials using rodents, in vitro studies, measurements of levels of antioxidative compounds, and subsequent extrapolation of the health benefits to humans. The small number of clinical trials performed challenges allocation of clear health benefits to the consumption of sprouted cereals. An additional challenge is the large number of factors that play a role in modulation of nutrients and antinutrients during sprouting and human metabolism.

On a functional level, increased amylase and protease activities induce significant changes in flour properties. Wheat flour with high amylase activities (low Hagberg falling numbers) generally result in poor bread quality due to high starch breakdown (11). This phenomenon often increases when wheat suffers preharvest sprouting. In dough systems containing low-amylase flours, the majority of added water is absorbed by large starch molecules and proteins (7). Degraded starch fractions from sprouted-wheat (high-amylase) flours increase water absorption and induce competition with proteins for available water. This reduces gluten network formation and has a negative effect on dough rheology. Bread made from sprouted-wheat flour tends to be soft, sticky, and dense (11). The lack of dough stability results in the collapse of the bubble network during proofing and the early stages of baking.

When using sprouted-wheat flour in bread dough systems, the enzyme activity levels need to be controlled carefully. For optimal functionality, some amylase activity is desirable when combined with limited modification of the gluten proteins by proteases to maintain their functionality. Addition of sprouted-wheat flour at low levels (0–2%) increased breadmaking performance and showed a potential for use of sprouted-wheat flours as bread improvers and could potentially enable bakers to not use fungal amylases during baking. Addition of sprouted flour at 1.5% increased bread specific volume and softened the crumb. Determination of gluten aggregation properties indicated that even though proteases were activated during sprouting, gluten formation properties were not affected (35). Amylases synthesized during sprouting were thermostable up to 70°C and still degraded starch during early baking (52). The gluten proteins, however, were less heat stable and tended to denature around 60°C (52). The differences in inactivation and denaturation temperature makes it challenging to inactivate amylase sufficiently without negatively impacting the gluten proteins. There is, however, a 2015 patent (10) disclosing a method to achieve amylase inactivation while retaining gluten functionality. The method involves heating the sprouted seeds at relatively low temperatures that are gradually increased during drying. The decrease in moisture content during drying increases the thermal stability of proteins (60) and allows inactivation of amylase with limited denaturation of gluten proteins. The inventors show improved functionality of the flour and the ability to produce good quality bread from 100% sprouted-wheat flour (52).

Alternative Techniques Not Widely Used

The most widely researched and applied methods for grain and flour processing have been discussed above. There are, however, a few less commonly used techniques that are worth mentioning.

Microwave Treatment. In addition to conventional heating methods that use contact heating or convection heating with air (as discussed earlier), microwave heating has been researched. Microwaves heat materials more quickly than conventional heating systems, which can be advantageous when heat-sensitive components such as vitamins are present. Dry heating (110–132°C) of wheat flour using microwaves has been patented (18) and researched for steamed bread and biscuit applications (50). Qu et al. (50) determined that microwave (700 W for up to 30 sec) treatment of flour (20% moisture) decreased water absorption measured with a farinograph and maintained dough stability. Heating times beyond 30 sec caused a significant increase in damaged starch and enzyme inactivation.

Microwave energy is dissipated better with elevated water levels due to the dielectric properties of water. The method, therefore, is less effective for products with low water contents and has not been investigated as widely for flour processing. Due to the shorter processing times required, it might be a technique that could be used to alter wheat functionality without causing major damage to heat-sensitive components.

Pulsed Electric Field. Because heat treatment can damage heat-sensitive components, methods that do not result in elevated temperatures would be advantageous. One such method is pulsed electric field (PEF), a technique most often applied as a tool to sterilize products while maintaining lower temperatures. High voltage pulses of short duration can perforate materials such as bacterial cells, resulting in their inactivation (40). Alternatively, PEF can be used to puncture plant cell walls, facilitating extraction of pigments and proteins (40). The technique is generally applied to high-moisture foods because water contributes to the transfer of the electric pulses through the medium. Wheat kernels and flour, however, do not contain high levels of moisture. Although PEF is not directly applied to wheat kernels or wheat flour, the technique does enable pregelatinization and partial breakdown of starch (20) and modification of protein secondary structures (30) when applied in slurries. PEF technology is only applicable to products that do not contain air bubbles and that have low electrical conductivity (40), thus successful treatment of bread dough using PEF is unlikely. In addition, applying PEF to bread dough increases the risk of yeast inactivation.

Ultrasound. As with PEF, ultrasound is a nonthermal technique use in food processing for microbial inactivation (8). Ultrasound waves, with frequencies that cannot be heard by humans, create cavities in microbial and plant cells. For this reason, the method is often used for extraction. In addition to extraction, ultrasound waves can modify the properties of native and cross-linked starches, cavitating and gradually decreasing the size of starch granules and potentially breaking down the starch (8). As a consequence, starch pasting viscosity decreases, while cold water solubility improves (32). Treating a gluten protein isolate with ultrasound decreased the protein aggregate size and intrinsic viscosity due to disruption of noncovalent interactions. Protein size, as such, was not affected. The decrease in intrinsic viscosity increased protein hydrophobicity related to exposure of hydrophobic amino acids (44).

As a technique to modify starch and protein techno-functional properties, ultrasound provides a valuable research tool to study dough properties in a nondestructive way (2). The speed at which the ultrasonic waves travel through a dough system depend on the composition of the dough. At a constant water level, functional dough properties can be studied and provide information on flour functionality (e.g., bread or biscuit flour) (2).

Prospects

The available literature highlights the ability of wheat preprocessing to modulate its nutritional and techno-functional properties in a variety of ways. All of the techniques reviewed in this article contribute to the wide applicability of wheat in staple food products. The nutritional effects of the most commonly used methods (dry heating, extrusion, sprouting, and fermentation) are illustrated in Figure 1. The effects of these techniques on techno-functional properties are illustrated in Figure 2. On the nutritional side, many aspects have been investigated, and most preprocessing methods improve nutritional properties by increasing overall flour digestibility and, therefore, the availability of energy. However, heat treatment that is too extensive can decrease overall nutritional value due to Maillard reactions, interaction between carbohydrates and proteins, and damage to heat-sensitive components.

In general, the fundamental effects of heat treatment, extrusion, sprouting, and fermentation on functional properties such as water uptake and starch gelatinization in flour have been fairly well researched. Application of these techniques to either bread or sweet bakery products has been not been widely investigated. Previously gained insights into the effects of preprocessing of wheat on nutritional and techno-functional properties provide an excellent starting point for further application of these processed raw ingredients in bakery products. Gaining further insights enables the development of bakery products that are optimized for nutritional quality while desired sensory characteristics are maintained.


 

Anne Vissers works as a senior bakery scientist within the Baking and Cereal Processing Department at Campden BRI and joined the organization in November 2017. Her work focuses on research directed toward ingredient functionality in bakery products. Prior to joining the organization, Anne studied for an M.S. degree in food process engineering at Wageningen University, Netherlands, graduating in 2012. In 2017 she obtained a Ph.D. degree in food chemistry from the same university.

 

 

 

Michael Adams is the bakery science section manager within the Baking and Cereal Processing Department at Campden BRI and joined the organization in April 2016. Mike studied for a B.S. degree (honors) in microbiology at the University of Manchester, graduating in 2005. Since graduating, Mike has worked primarily within R&D and technical roles for multinational fast-moving consumer goods (FMCG) organizations. Most recently, he led the development of own-label products for a major high street health and wellness retailer, specializing in spotting new trends in functional foods, sports nutrition, and free-from foods.

 

 

Gary Tucker is the head of the Baking and Cereal Processing Department at Campden BRI and has worked for the company since 1989. Prior to his present role, he managed the thermal processing work at Campden BRI for 18 years. Gary studied chemical engineering at Loughborough University and is a chartered chemical engineer. He holds an M.Phil. degree for work in the measurement of rheological properties of foods and a Ph.D. degree for work related to time-temperature integrators.

 

 

 

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