Shelf-life enhancement of baked goods

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SHELF-LIFE
ENHANCEMENT OF BAKED GOODS
An Academic presentation by Dr. Nancy Agnes,
Head, Technical Operations, FoodResearchLab
Group www.foodresearchlab.com Email
info_at_foodresearchlab.com
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Today's Discussion
OUTLINE
Introduction Staling Emulsifier Catalysts or
Enzymes Hydrocolloids Water Activity (Aw)
Reduction of Microbial Load Novel Shelf-Life
Solutions
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Introduction
Extending the shelf-life of Baked product
development relies on the manufacturers, product
developers, process and packaging technologists
to produce attractive and delicious products that
stay fresh for a long time without any
microorganisms. Shelf-life of baked goods
depends on a complex set of conditions. Contd...
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Understanding how each of these factors is
involved in the physical and chemical
translation will aid in determining the loss of
shelf-life with time during New Food product
development. Having said that, certain chemical
reactions and physical changes are unavoidable,
but a few methods could be employed to delay them
and obtain a high-quality product life. Contd...
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Staling
At ambient temperatures, most baked goods such as
bread and rolls become moist and spongy,
undergoing deterioration in quality, which is
commonly known as staling. Generally, the higher
the moisture content found in the fresh product
will increase the changes resulting from
staling. For instance, bread, sweet goods and
cakes stale faster than do cookies and crackers
due to their higher moisture content. Contd...
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If we look closely at bread, the crumb and the
crust are undergoing staling at different rates
due to the same reason. Crumb staling is evident
from many physiochemical changes such as changes
in taste, aroma, hardness and starch
crystallization and retrogradation, leading to
insoluble starch content. To address these
problems of staling, packaging solutions can be
deployed to prevent moisture loss and to keep the
crumb soft and flavourful. Staling can be
slowed by handling the storing and shipping
temperatures below 32 ? during a bakery product
development.
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Emulsifier
Emulsifiers slow down the enhancing moisture
retention. Surfactants provide many
staling process by
functions in shelf-life

• improvements, such as increasing the bread loaf
  volume and obtaining an optimal and functional
  gluten structure.
• This process leads to a softer crumb with
  improved crumb resilience and moisture
  retention.
• Contd...

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Gluten proteins hinder the protein molecules
interaction due to ionic repulsion. Salt
increases the dough strength by suppressing the
ionic repulsion. Fatty acid present in
surfactants (DATEM, SMG) bind to the hydrophobic
areas of gluten proteins. Saturated fatty acids
of monoglycerides are better than unsaturated
versions in obtaining the desired outcome, such
as better air incorporation. Contd...
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Using oil in cake enhances shelf-life.
mixes produce a tender cake with
However, this affects the foaming ability.
Incorporation of emulsifiers such as acetylated
or lactylated monoglycerides will improve the
oil's functionality in cakes.
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Catalysts or Enzymes
Enzymes can be classified based on the reactions,
substrates, end products, thermal stability,
and source. In baking, amylases (starch-degrading
enzymes) are often used to break down
gelatinizing starches during baking. Heat
stability and their mode of action are the main
parameters for their performance and heavy
usage. Contd...
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This is crucial as the amylases need to modify
the gelatinization of starch during baking at
temperatures above 150 ?, improving crumb
softness. Commonly used amylases are obtained
from Aspergillus oryzae glucoamylase,
Aspergillus niger malted wheat/barley Bacillus
subtilis Bacillus megaterium and Bacillus
stearothermophilus.
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Hydrocolloids
Hydrocolloids are used to improve water solubility
, increase viscosity and ability to form
gels. Hydrocolloids also improve and stabilize
the texture and inhibit the ice crystallization
with stable emulsions. Gums are high-molecular-we
ight polysaccharides with fiber and
proteins. Contd...
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Commonly used gums in baked products are agar,
carrageenan, cellulose gum, methylcellulose,
alginates, guar, locust bean gum, xanthan gum,
and psyllium husk. In products such as icings
and meringues, gums bind water to prevent
syneresis and provide freeze/thaw stability with
a gloss.
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Water Activity (Aw)
Aw is defined as a measure available moisture in
a food system.
of the
Aw should not be confused with the total amount
of water present in the food. Humectants can be
used to control microbial and chemical
activities to relative vapour pressure. Contd...
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Water binds to sugars, starches, and salt with
hydrophilic binding sites. Sugars and sugar
alcohols, such as mannitol, maltose, sucrose,
sorbitol and fructose are the commonly used
effective humectants. Honey is a
multifunctional humectant that helps in
improving the stability of frozen dough
products. Honey has also found to enhance
flavour qualities with antioxidant
properties. Contd...
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Reduction of Microbial Load
Good health and safety standards in plants can
prevent contamination problems. Apart from contro
lling Aw, manufacturers can add ingredients to
aid in controlling microorganisms. Natural inhibi
tors such as vinegar and raisin juice
concentrate reduce pH to inhibit microbial
growth. Food additives such as sorbate and propio
nate are effective against yeasts, mould and
bacterial growth.
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Novel Shelf- Life Solutions
Protein Ingredients from soy, whey, and milk
provide improvements in the shelf-life stability
of foods due to their water-binding capacity.
During the baking process, proteins unfold,
exposing additional water-binding sites
unavailable in the native protein
form. Therefore when these ingredients are
incorporated into bakery filling formulations,
water will be tightly bound to the protein
resulting in a moist end product with reduced
starch retrogradation. Contd...
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Sometimes, the management of moisture content
can lead to flavour changes. It is advisable to
use oil-based flavours that bake-off less easily
and at a lower temperature for a longer
time. Edible films and coatings have been
developed in response to consumer demands for
foods with high quality and long shelf-life. For
environmental reasons, there is a necessity for
reducing disposable packaging and improving
recycling options. Contd...
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Edible films improve the mechanical properties
in food and control the loss of volatile
flavours. Edible mass transfer barriers have
proven to be effective with protein, lipids and
polysaccharides. Freezing has been proven to
preserve food and naturally extend the
shelf-life. Freezing will lower the negative
impact of staling on taste, texture. Contd...
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If the baked goods are spoiling sooner than
consumed, then consider freezing your products
in an air-tight container. Better packaging
Baked goods with shelf-life
between two weeks and achieved largely based
six months are on packaging
technology. High-quality barrier films are
widely available at a reasonable cost. Contd...
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Contd...
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A few of the latest technology includes adding
gases to control the atmosphere (Modified-
atmosphere packaging (MAP)), have added weeks of
shelf-life from a shelf-life study. However,
faulty seals, package integrity and the residual
oxygen in the pack may result in less safe baked
goods. Even upon appropriate sealing, the risk
of anaerobic bacterial growth is
present. Manufacturers should be conscious of Aw
and pH conditions to avoid such microbial growth.
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