As the title of the blog says, here we will be discussing all the major external factors that influence the shelf life of bakery products. So, let’s get started….

Bakery goods are made to store and this storage is being done in a range of temperatures, from -21°C to ambient (sometimes 10°C, other times 55°C).Since we will be concentrating on the microbiological aspect of this issue, the influence that this temperature has on consequences like staling is primarily a topic of concern.

Except for crèmes, fruits and jams, that are added after baking, most bakery goods are exposed to high temperatures during baking. Almost all microbes will be destroyed during baking. Only extremely heat-resistant toxins may be created in the initial stages of the production process.

Despite the fact that baking destroys almost all living bacteria, occasionally one comes across a product that has been tainted even if no man has ever touched it. When the correct conditions (temperature, moisture), together with the presence of spores on the product, are present, this can be a reason. Another factor might be cross-contamination brought on by microbes in the air.

Chilled storage denotes conditions between 0 and 5 degrees Celsius that are close to but above the freezing point. Both the type of deterioration and the rate at which it happens can be altered by chill storage. Low temperatures have a selective impact that stunts the growth of microbes.

Microbes are not always destroyed even though they cannot grow in cold temperatures. A phenomenon known as cold shock is brought on by cooling, and although it causes death and harm in some microbes, it is not as predictable as baking.

Water's availability to take part in reactions changes as ice crystals form inside the product during freezing. Less water is available to enable deteriorative reactions when the temperature drops and more water turns to a solid form. If the product is frozen, in most situations just 10% of the water is still liquid. In terms of microbial safety, the decrease in water activity during freezing only significantly affects shelf life above - 8°C, the freezing temperature at which microbial growth is possible. Less than -18°C is typically utilised for frozen bakery storage conditions. No microbes can sustain these temperatures, although lingering microbial or endogenic enzyme activity might linger and eventually ruin a product.

The product's internal relative humidity, often referred to as water activity, interacts with the relative humidity of the surrounding air. It is always possible for moisture in bread products and their surrounding environment to move from a high to a low relative humidity level, albeit this is not always moisture. Low water activity bakery products that are kept in environments with high relative humidity will absorb water from the gas phase.

Local areas will have higher water activity levels as a result of condensation of water on product surfaces. At the site of lower water activity, spores of, for example, fungus that were before unable to germinate, would thereafter proliferate and moulds will become apparent.

Therefore, relative humidity is a crucial factor that must be taken into account when storing food.In an atmosphere with a high relative humidity level, even products like biscuits that are microbiologically stable can get spoilt.

Packaging can be used to some extent to regulate relative humidity. Packaging materials act as a barrier, affecting the rate at which gases with varying compositions from the environment can reach the product. We alter the environment inside the packaging to influence how quickly the microbes grow. For bakery products with significant water activity, such as very perishable items, the Modified Atmosphere Packaging (MAP) or "gas flushing" approach is widely utilised. The process involves flushing oxygen out of the packing, which slows down the growth of aerobic microorganisms (like mould) and lowers the danger of lipid oxidation, particularly in high-fat foods.

Since the majority of germs and spores are airborne, contamination during cooling, buffering, and pre-packaging handling can easily happen, the design of the entire manufacturing process effects the shelf life of bakery products. Controlling the air flow is one method that can be used while working on a continuous line with little man handling between mixing and finished packing. The manufacturer can arrange the air flow such that it always moves toward places that are more polluted by establishing over- and under pressure rooms (such as warehouse, maintenance, etc).Risks are minimised by applying high filtering before allowing air to pass over cooling products.

Radiation techniques are used to sterilise the air and any exposed surfaces near the product. Specific energy portions of the electromagnetic spectrum are the focus of radiation methods. According to the research team of Anmol Industries, one of the leading chocolate biscuits brands in India, UV11 and infrared12 in particular have a beneficial impact on shelf life. UV is frequently utilised in high-perishable foods, such as dairy-based cakes and pies, and is mostly used in cleanroom technology (as are cheesecakes).

With this we come to an end of this series, hope you find this information interesting. If you have any doubts or need more information on this, do write to us in the comment section.