Do Gluten Substitutions in Baking
Effect the Quality of the Product?
Shawna Jenkins
March 13, 2014
1
Gluten can be defined as proteins that occur naturally in wheat, rye, barley and any
crossing of these grains. Currently there are up to three million Americans suffering from celiac
disease, which occurs when the body’s defense system negatively interacts with gluten by
attacking the lining of the small intestine. This results in a less than healthy intestinal lining
lacking the ability to absorb vital functional nutrients. Celiac disease has also been linked to
other prevalent diseases including anemia, osteoporosis, diabetes, intestinal cancers and
autoimmune disorders. 1
Wheat gluten proteins are divided into two subcategories, gliadins and glutenins. These
proteins, when combined, have unique properties of dough formation and are ideal for bread
making. Although distinctive characteristics are established, their exclusivity is being mimicked
by gluten-free substituted flours in baking.2 Studies are being conducted with the addition of
concentrates or isolates of proteins to enhance gluten-free baking mixes to provide similar
texture and structure of classic baking methods.3 However this proves difficult because of the
complicated rheological characteristics of the gluten proteins. Not only are the rheological
properties trying to be replicated in a similar fashion, improved nutrition is also of importance.
These characteristics can be indicative of the quality of the finished product.4 This leads to the
question, do gluten substitutions in baking effect the quality of the product?
Gluten Properties
Gluten proteins, gliadins and glutenins, are separated by the basis of their functional
properties. Gliadins are monomeric proteins formed by both high and low molecular weight
subunits that are linked together by covalent disulfide bonds. People who suffer from celiac
disease are most affected by the gliadin proteins. Glutenins are multimeric proteins responsible
for the strength and elasticity of dough.5
2
There is much controversy between those who are actually diagnosed with celiac disease
and those who are self-diagnosed non-celiac gluten sensitive. Both conditions are generated by
the intake of the gliadin protein and the negative side effects in association with intestinal
malfunction. Symptoms are similar in people who are affected by celiac disease and those with
non-celiac gluten sensitivity, but a gluten-free diet is not necessarily recommended for those who
are not diagnosed with the disease. With this recommendation, many people distressed by the
non-celiac gluten sensitivity are suffering.6
Individuals with celiac disease and non-celiac gluten sensitivity have conveyed struggle
when following a gluten-free diet. This is due to the discrepancies of food labels and gluten-free
claims made by the food industry.7 To reduce some of the stress of finding pure, gluten-free
foods, the Food and Drug Administration implemented a final rule on August 2, 2013 defining
“gluten-free” for food labeling. Before this statute was enforced there were no federal standards
in regard to the purity of labeling for the food industry. The ruling states to be deemed “glutenfree”, an item must contain less than 20 ppm presence of gluten or not include any trace of
wheat, rye, or barley.1 With the expansion of the gluten-free market, labeling is becoming more
standardized. Conventionalization of the gluten-free market is proving to enhance the product
literacy for the consumer. 8
Gluten contamination is of much concern to the Food and Drug Administration. Not only
were limits set for labeling of foods that contained gluten, but also products that are essentially
gluten-free. Items such as millet grain, which is inherently gluten-free, is not required to depict a
“gluten-free” label. But with potential contamination, a study was conducted to ensure that these
items were completely gluten-free. 22 samples were taken and tested for presence of gluten.
3
Seven samples contained more than the 20 ppm of gluten presence tolerated by the Food and
Drug Administration standards.9
Gluten-Free Substitutions
An alternative to baking with traditional flours containing gluten, people diagnosed with
celiac disease or non-celiac gluten sensitivity have the option of using gluten-free substitutions.
The ability to mimic traditional flour has been a challenge for food scientists, but the additions of
proteins such as collagen, albumin and pea have attested significant positive effects. The adding
of collagen reduced volume of standard bread loaves, whereas the addition of albumin increased
the volume of the tested loaves. Pea protein had the most significant effect on the bread loaves,
imitating a classic bread recipe most closely.3
Not all gluten-free flours are suitable for all baking recipes. The term flour can be defined
as a finely-ground, meal of grains, nuts, seeds, and legumes. Each type of flour listed is
comprised of unique nutritional profiles as well as specific baking qualities. Most gluten-free
bread mixes are blends of flours, like almond meal/flour, flaxseed meal/flour, and soy flour.10
Almond meal/flour is made from blanched almonds. Almonds have a positive nutritional
profile including a low amount of carbohydrates and a rather high amount of protein. Almond
flour adds moisture, and provides nutty flavors to pastries and baked goods. It is not ideal for the
replacement of flour in quick breads. Flaxseed meal/flour is produced by the milling of whole
flaxseeds, manufacturing the availability of heart healthy, omega-3 fatty acids. Flaxseed
meal/flour can also be used in replacement of eggs or fats in baked goods. Soy flour is produced
by the milling of soybeans. Similarly to almond meal/flour, soy flour is relatively low in
carbohydrates and high in protein per serving. Soy flour is also a worthy source of calcium, iron,
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and magnesium. It can be used to thicken sauces, provide nutty flavors and aromas, and reduce
fat absorption in frying.11
Legume flours are also making a statement in gluten-free substitution in relation to
baking. When studied, chickpea flour gained the highest volume value as well as the softest
crumb texture amongst other substitution tests. Legume flours provide healthful benefits such as
positive sources of protein and fiber. They are best used in blend with other gluten-free flours to
ensure balance of taste and texture. These types of studies are promising in finding substantial
substitutes for gluten rich flours. 12
Using oats as a gluten flour substitute is also becoming more recognized. Oats, which are
the second most important cereal crop throughout the world, have not been utilized for human
consumption nearly as much as they should until recently. Full of healthful dietary benefits, oats
are known to reduce blood glucose levels, lower blood lipids, and lessen the risk of coronary
heart disease. Oats provide essential amino acids, unsaturated fatty acids, vitamins, minerals and
antioxidants. In the past, oats were omitted from the typical gluten-free diet although tolerable by
most who are diagnosed with celiac disease and non-celiac gluten sensitivity.13 More research is
being conducted to clarify the use of oats as a suitable gluten exchange for baking.
Characteristics and Quality of Baking with Gluten-Free Products
The basis of gluten-free substitution in baking is involved with providing those suffering
with celiac disease and non-celiac gluten sensitivity with the same opportunities as those having
neither food allergies nor sensitivities.
The increasing demand for gluten-free products in recent years has given rise to the study
of chemical composition and structural characteristics in gluten-free substitutions for baking
methods. Improvements of shelf life, mouthfeel, and moisture properties are all being
5
examined.14 The addition of gums, also known as hydrocolloids, are being added to gluten-free
baking mixes to enhance the structure of final baked products to similarly resemble traditional
flours in baking. They resemble comparable dough properties and increase moisture content and
texture. Sensory properties are determined by the structure of ranging levels. The level of crumb
structure is examined while developing products with desired qualities. These examinations are
performed by X-ray microtomography. Size of pores, amount seen, and roundness were all
included when determining structural characteristics.15
Creating a similar texture in gluten-free breads proves to be one of the most difficult
concepts in flour substitutions. Most gluten-free breads are characterized by inadequate quality
and high cost compared to that of traditional bread recipes. Texture quality is reduced due to the
staling effects caused by retrogradation of starch molecules. Implementation of rice flours as
well as potato and corn starches have been found to reduce this problem as well as generate a
more crumbly bread.16 To enhance dough properties, the effects of emulsifying agents and
enzymes added to the dough was researched. Parameters such as volume, firmness and crumb
structure were tested. Modification of dough properties was noted, but not a significant favorable
product was created.17 Another suggestion in gluten-free substitution in baking is the influence of
mixing. Mixing time influenced the volume, increasing peak height in regards to a longer mixing
time. Not only did mixing time have significant results, the type of mixer used created diversity
in final products. This area of study is little researched and is in need of more revision.18
The overall goal is to produce products that are high quality, nutritious, and appealing to
all individuals. To improve quality in production of breads, the addition of enzymatic
components, types of flour, dough treatment and method of baking and mixing are all being
studied.19
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Conclusion
Gluten proteins, naturally occurring in wheat, rye, and barley are divided into two groups:
gliadins and glutenins. The gliadin-glutenin complexity has a major effect on the quality of
baked good products.2 Those who are diagnosed with celiac disease are not the only individuals
who deal with the negative side effects pertaining to gluten intolerance within the intestine.
There is also a group termed non-celiac gluten sensitive that endures the struggle of finding
healthy, gluten-free food options as well.6 Purity labeling has been enforced by the Food and
Drug Administration since 2013 and set parameters to ease the difficulty of finding and
following a gluten-free diet.1
Substitutions to traditional gluten-rich flours are being discovered daily. To produce the
best tasting, textured, and similar product mixing of flours such as almond meal/flour, flaxseed
meal/flour and soy flours are being tested.11 The use of legume flours are also being utilized
because of their healthful benefits and ideal baking qualities. Oats, which are widely studied, are
being employed as a recent substitution as well. Similar to legume flours, they are full of
beneficial qualities to assist in better overall health.13
Although the perfect and most comparable replacement has not been identified thus far,
research is coming close to perfecting baking with gluten-free substitutions. Unfortunately,
gluten substitutions do affect the overall product when baking.
Future research is crucial to better understand the group of individuals with non-celiac
gluten sensitivity. The rise in celiac disease and gluten intolerance is widely recognized and will
be continually studied.20
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Application to Dietetic Practice
It has been noted that celiac disease has a direct correlation with other prevalent
diseases.1 Obesity is more than a problem in the United States currently, it is an epidemic. In
2010 alone, 62.8% of the adult population had a body mass index between the ranges of 25-29,
which is considered as “obese”. There is evidence that patients diagnosed with celiac disease
have a higher rate of obesity due to the following of a gluten-free diet, although most patients
with celiac disease are already obese at diagnosis. Dietitians need to be educated in advising
patients how to manage the potential health risk.21
Gluten sensitivities are being diagnosed at very young ages. Gluten-free diets followed
by children need to be closely monitored by dietitians to ensure adequate nutrition for growth
requirements, development and optimal activity. Some adverse health effects are plausible such
as hormone imbalances and early induced deficiencies. Removal of wheat from diet also means
removal of dietary iron, folate and B vitamins. Studies show that 20%-38% of children
diagnosed with celiac disease have nutritional complications like caloric imbalance of proteins,
dietary fiber, and vitamin deficiencies. Daily calorie intake does not change in children with
celiac disease, however dietary counseling is advised. 22
Availability of gluten-free products is becoming more accessible, but with the rise in
demand, the increase in price is also being seen. Still limited in many stores, gluten-free products
almost double their wheat-based counterpart when found. Since a gluten-free diet is the only
treatment for those suffering from celiac disease, the high expense and limited availability is
almost as much of a nuisance.23
The gluten-free trend has become widely popular in the recent years. The gluten-free
product market had expected sales of $2.6 billion in 2012 alone. The mass increase in sales is
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directly due to the positive health connotation that a gluten-free diet will provide. Dietary advice
for those choosing to follow a gluten-free diet proves that there is little study of the complete
removal of gluten proteins. Gluten proteins do have potential health benefits including
improvement of blood lipid levels, blood pressure control, enhancement of the immune system
and triglyceride reduction.24
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