2.1 Wheat flour
Wheat flour is a product that is obtained from the
grinding of wheat and being used widely as staple food for human. The
production of wheat flour is more than any other flour. Wheat were being called
“soft” when the gluten content is low, and are called
“hard” if the gluten content is high. Hard flour, or bread flour, is
high in gluten, with 12% to 14% gluten content. Its dough has elastic toughness
that holds its shape well during baking process and it is suit for bread baking.
Compared to hard flour, soft flour was low in gluten content and thus results
in a finer and crumbly texture of the bread loaf.
Wheat flour rich in carbohydrate which help to provide
energy that we need to get through the day. Besides, it contains protein in the
form of gluten. People with celiac disease or gluten intolerance must avoid
consuming wheat flour as it can cause indigestion and inflammation due to
exposure to gluten. Moreover, consuming wheat flour will provide us with
vitamin B which help in support our metabolism to and help to derived energy
from our food.
2.2 Cassava flour
With the rise in popularity of gluten-free baking in
recent years, cassava flour is the one type of flour being choose as a wheat
flour substitute in bread making. Not only gluten-free flour, but also grain,
and nut free. Cassava flour is made from the whole root of the cassava or yuca
plant. The root is peeled and being dried. The roots being shredded into a fine
mash, by using a machine processor machine or hand-held grater. Then the roots
being press and dry, was spread onto a drying rack. The substance left is the
Although cassava and tapioca flour are from the same
source, but they actually are not same. Tapioca flour is the extracted starch
from the cassava roots and usually used as thickening agent. Cassava flour
mostly used for the regular baking and as a cooking flour. Moreover, its starch
concentration is less compared to other flour. Therefore, it was believed that
this flour is easier to digest by most people. Cassava flour is a good choice
for people that suffered from health conditions like high blood pressure or
cholesterol, diabetes, since it is extremely low in salt, sugar and fat content.
As mention before, since it is grain and nut-free, people that have allergies
towards nuts also can consume product that made from cassava flour.
2.3 What is gluten?
Gluten is a protein that found in grains such as wheat,
rye and barley and barley. The
proteins are secretory proteins, being synthesized on the rough endoplasmic
reticulum and co-translationally transported into the lumen of the ER (Kumamaru et
al., 2007). Among
the gluten containing grains, wheat is the most commonly used in industry
especially in bread making. It contributes to the ability of dough to rise and
maintain its shape and leavened the bread. Gluten
component proteins are found in the endosperm of mature wheat grain, where they
form a continuous framework around the starch granules.
There are two main proteins found in gluten which are
glutenin and gliadin and they contribute to the structure of the bread. Most
negative health effect were come from gliadin. Gliadin contains peptide
sequences that are highly resistant to gastric, pancreatic, and intestinal
proteolytic digestion in the gastrointestinal tract (R.B. Jessica, 2017).
Glutenin contributes to the elastic character of gluten while gliadin
contributes to extensibility. A balance between elasticity and extensibility is
necessary for baking performance specifically in bread making.
2.4 Gluten role in baking
Gluten proteins are the most important protein group in
bread making. Gluten forms when water is added to flour and is mixed. During
mixing, addition of water cause a continuous network of protein forms, giving
the dough its strength and elasticity. This process were called as kneading. By
holding gas produced during fermentation, the protein network allows bread to
rise. It also allows the dough to maintain its shape. These two functions of
the protein network are what give bread its chewy texture.
2.5 What happen when we substitute wheat flour with other type of
flour in bread making?
In bread making, we cannot simply substitute the bread
flour or wheat flour with other gluten-free flour. As mention before, gluten
protein that consist of glutenin and gliadin give the bread’s elasticity and
extensibility. Therefore, using non-gluten flour will give effect to the
firmness of the bread after baking.
Xanthan gum or other gum that similar to it were being
used as an important ingredients that must be added to gluten-free flour. The
absence of gluten will make it necessary to have something that can act as
gluten substitutes. Xanthan gum was a fermented corn sugar product by using a
microbe called “Xanthomonas caempestris”. This gum is used widely as an
additive in many food products and mostly act as stabilizer and thickener
agent. But nowadays, our market already have gluten-free flour that being added
with Xanthan gum to make the preparation for baking any product become easier.
However, some people do have allergies towards corn
product and they were advised to avoid this type of gum. Therefore, there were
other alternatives that can be used to substitutes Xanthan gum. Some products
that can replace the Xanthan gum are gelatin and agar. Gelatin will gives
sticky and moist texture inside the bread. It will form gel-like structure when
being mixed with water and cause the dough become stretchy. Gelatin was not
suitable for vegetarians because mostly were being derived from animals.
Agar-agar is another choice for vegan to substitute Xanthan gum as it is
derived from seaweed. Similar to gelatin, agar-agar was being used as
stabilizer and thickener agent as well as the formation of gel-like structure
when being mixed with water. It will help to stretch the dough and give the
firmness towards the bread. But, excessive number of agar-agar content will
cause the bread becomes very soft and wet.