Wellness Foods + Supplements 1/2022

Antioxidants in baked goods
three phases (initiation with formation of
free radicals, propagation and finally termination
with formation of non-radical products).
Whereas the Maillard reaction and
caramelisation need high activation energy
and thus mainly occur during thermal treatments,
lipid oxidation requires low energy
along with oxygen.
Fats impart taste and texture to the product
but because they susceptible to oxidation
leading to the development of rancidity and
off-flavour through the autooxidation or lipid
oxidation reactions, additives, such as antioxidants
are also added to the mixture.
Antioxidants have become an indispensable
group of food additives mainly because
of their unique properties of enhancing
the shelf life of food products without any
damage to sensory or nutritional qualities.
Concerns about the safety of synthetic antioxidants
have given rise to a large body of
research on natural sources of antioxidants.
Natural antioxidants allow food processors
to produce stable products with ‘‘clean’’
labels of all-natural ingredients. They bring
less rigorous burden-of-safety proof than
that required for synthetic products. In addition
to their antioxidant activity, some natural
antioxidants, such as vitamins, minerals,
and enzymes, are also regarded as nutrients
due to their bioactivity.
Tocopherols and tocotrienols, collectively
known as tocols, are monophenolic and lipophilic
compounds that are widely distributed in plant tissues. The
main commercial source of natural tocopherols is the soybean oil.
Tocotrienols, less common than tocopherols, are present in palm oil,
rice bran oil, as well ascereals and legumes. Tocopherols and tocotrienols
are classified into alpha, beta, gamma, delta, depending on
their chemical structures. These eight molecules are part of the group
known as vitamin E.
Tocopherols and tocotrienols are primary antioxidants, which act by
terminating the free-radical chain reaction by donating hydrogen or
electrons to free radicals and converting them to more stable products.
Secondary antioxidants, such as ascorbic acid, citric acid, lecithin
or flavonoids can be also added to the products. Secondary antioxidants
can be broadly classified as oxygen scavengers and chelators.
They have a synergic effect, together with tocopherols, as they
act as hydrogen donors to the tocopheryl radical, thereby regenerating
the primary antioxidant. Hence tocopherols can be used at
lower levels if a synergist is incorporated simultaneously in the food
product.
In order to protect the baked goods from oxidation, antioxidants can
be applied either to the final product, or directly to the oil previous
to the mixing of ingredients. To measure the efficacy of tocopherolbased
antioxidants, accelerated oxidation tests have been performed.
In the first experiment, the Rancimat test was used. It is a simple,
quick an efficient way to screen the effectiveness of antioxidants
used in fats and oils. The method is an accelerated oxidation test in
which the oil or fat to be tested is run at elevated temperatures whilst
exposing the sample to air, accelerating the oxidation process of the
oil. Soybean oil, one of the mayor oils in the baking industry, was
mixed with different tocopherol-based natural antioxidants.
Tocobiol ® is a natural antioxidant made from the distillation of a single
raw ingredient, whole non-GMO soybean oil. It naturally contains
mixed tocopherols, plant sterols, squalene and monoglycerides
which provide its unique antioxidant and dispersibility properties.