Shelf life evaluation of cakes

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• Shelf life evaluation of cakes

Hicran Koç Volkan Köseoglu Esra Çakir Dilek Saglam
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Definition and classification
Cake is a bakery product, which is mainly
composed of

• wheat flour,
• water,
• sugar,
• egg,
• fat,

• humectants,
• glucose syrup,
• modified starch,
• baking powder (sodium bicarbonate),
• antimicrobial agent (potassium sorbate).

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• Cakes are found in the group of intermediate
  moisture food products.
• moisture content of 20
• water activity in the range of 0,65-0,90
• Different types of cakes according to formulation
  
• or process type
• Sponge cake Low fat level
• Fruit cake Medium
  fat level and fruit
• Plain cake High fat
  level
• Chocolate-coated cake Moisture barrier
  present

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Factors Affecting Stability and Shelf Life

• Mould growth two main factors limit
• Stalling the shelf life of
  cakes
• rancidity
• off-flavors and odours other than rancidity
• crystallization of sugars
• moisture migration and loss
• chocolate bloom
• colour fade, change and transfer.

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Microbiological Factors

• The most common microorganisms that cause
  spoilage are moulds and yeasts !
• The growth of these microorganisms depends on
• water activity
• temperature
• pH of the system.
• Some spices of mould isolated from cakes are
  Eurotium, Aspergillus and Penicillium

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• Some ingredients of cakes are potential sources
  of harmful organisms such as eggs, cocoa powder
  and desiccated coconut. However, by pasteurizing
  and dehydrating of these components make them
  safe for human consumption.
• We can reduce the risk of microbial spoilage by
  optimizing pH, water activity and making suitable
  formulation for optimum ERH. Also addition of
  mould inhibitors such as organic acids (sorbic,
  propionic and benzoic acid) retards mould growth

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• Moulds are aerobic organisms, so levels of O2
  must be kept below 1 for longer shelf life.
  Beside this, CO2 has an inhibitory effect on
  moulds. As a combination of inhibitory effects of
  low O2 level and elevated CO2 levels, modified
  atmosphere packaging is effective way of
  prevention of moulds growth
• As a result, several hurdles can be combined such
  as MAP, aw and pH to make additive effects on the
  inhibition of mould growth. However, the use of
  MAP on the control of fungal spoilage of cakes is
  not common

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Physical Factors

• Staling
• Staling occurs when cooked starch molecules start
  to crystallize. Staling of cake is much slower
  then breads, since cake includes less flour and
  more fat.
• Ingredients have relative effects on cake
  staling, prevention of staling can be achieved by
  type and concentration of sugar, fat, or egg
  product, cocoa type and sodium bicarbonate
  concentration.
• For example, butter and sucrose were shown the
  best ingredients to slow cake staling compared
  with shortenings and glucose

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Moisture Migration

• When there is a moisture difference between cake
  and environment, moisture in cake migrates until
  equilibrium reaches. Moreover, between components
  in cakes, migration of the water can be seen.
• Moisture migration can be controlled by suitable
  formulation with balancing ERHs of components in
  cake. Also moisture barriers can be used for
  preventing migration.

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Chemical Factors

• Rancidity
• Fat component of cake can be oxidized and this
  cause rancidity, off-flavor and odor.
• By using high quality ingredients and storing
  fats correctly, rancidity can not be a major
  problem. However, using butter oil in the
  production, can cause hydrolytic rancidity. Also,
  in some cakes with a shelf life of 3 to 6 months,
  oxidative rancidity is observed more

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EXTENDING SHELF LIFE OF CAKES
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• Addition of natural antioxidants
• Salami (2002),
• Effects of natural plant antioxidants (thyme,
  ginger or mushroom powder) on oxidative and
  microbiological stability of cakes
• Storing at room temperature for 8 wk.
• Result All antioxidants
• retard rancidity,
• extend shelf life from 3 week ? 6 week

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MAP (Modified Atmosphere Packaging)

• (Rodriguez et al., 2002)
• Effect of modified atmosphere packaging on the
  shelf life of sponge cakes
• 3 packaging atmospheres (50 CO250 N2 100
  CO2 standard air (control)),
• Samples were examined for
• visible fungal growth throughout storage,
• gaseous composition of the atmosphere
• microbial populations
• Result 50CO250N2 atmosphere extended shelf
  life of the sponge cakes by 2-3 days with respect
  to packaging in standard air

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Ingredients and Formulation

• (Gelinas et al., 1999).
• Relative effects of ingredients on staling
• An accelerated shelf-life test was used for 21
  days at 21C. Effects of 28 ingredient
  combinations on incidence of cake staling was
  determinated.
• Result Staling was greatly reduced by partly
  replacing shortening with butter and glucose with
  sucrose. The composition of solid fat and sugars
  can be optimized for extending shelf life

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• Shelf Life Extenders
• IFEGs Shelf Life Extenders (SLETM)
• A series of liquids which offer an ideal and
  effective combination of
• water binding (aW control),
• mold inhibitor
• moisturizer.

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Irradiation

• Gamma rays were used to kill all the microbes
  present and fatty lipids will oxidize, creating a
  rancid taste.
• Applying low doses of the chemical preservative
  (0.2 percent by weight) and of irradiation (1
  kilogray or less) protected cakes amazingly,
• Result increase the shelf life of a cake from
  just 7 days to almost 4 months.

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• Cake CoatingsCEBAO Cake Coatings the icing
  on the cake contributing to a good shelf life by
  resisting fat migration from the cake
• Vakum Packaging and Cold Storage
• Tortuga Gold Rum.
• Each cake is vacuum packed and has a shelf
  life of six months. If they are frozen or
  refrigerated, these cakes have a much longer
  shelf life.

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• Preservatives
• FreshCake Cake Preservative improve cake stable
  in shelf life
• Newly developed SprayEncap technology make some
  ingredient microencapsuled and can bring more
  stable effect. Product ingredients are Sorbic
  acid , Potassium Sorbate, GMS, GDL. Usage is
  0.3-0.5 base on cake mix.
• Utilization Of Equilibrium RH TechnologyFormulati
  on
• ERH CALC, is a computer program which is
  produced by FMBRA. By this, formulations can be
  determined, and ERH is calculated and MFSL is
  estimated.

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RESULTS

• Cakes are semi-perishable food products. The main
  factors that effect shelf life of cake are mold
  growth, staling, and moisture migration. There
  are several methods for extending shelf life of
  cakes by controlling quality index reactions,
  such as MAP, preservatives, coatings, regulation
  of formulation, vacuum packaging and additives