Dairies from Tokyo to Toronto, Beijing to Berlin are examining the
opportunities created by Extended Shelf Life (ESL) technology, while new processing, filling and
packaging systems are being developed and launched. Behind this technological drive are strong commercial
arguments. Even a few extra days of
shelf life can be a significant benefit to the producer, the retailer, and the
consumer. Further days beyond that - up into the spectrum of an extra 30 or
even 90 days - opens up new and unique horizons for the marketing of milk and
other dairy products.
The definition of ESL differs
depending on geography and which products are being processed. In the USA, the objective is to use ESL technology to
maximize the shelf life of ‘white’ and value added chilled milk products to
between six and nine weeks, under storage below 6°C. The ESL processing
treatment used to achieve this longer shelf life is a high heat treatment, and
benefits include larger marketing and distribution areas and more efficient
production and distribution.
The key to ESL technology is hygiene. The shelf life of a
chilled dairy product cannot be extended without first raising the levels of
hygiene across the whole dairy. New processing and filling/packaging offers
good opportunities for lifting the hygiene level in most dairies. However no
single piece of equipment will do the trick. ESL is not just about technology and equipment, it is about a system, the success of which is dependent on the hygienic strength of the
entire production and distribution chain.
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Starting off with the same quality
of raw milk, it can be seen that ESL
processing technology reduces the microbial load by a much greater degree than
regular pasteurisation. Then, due to the superior hygienic
design, ESL filling technology provides a much greater degree of protection
against re-contamination from the filling environment. Thus in effect, the quality of the
product fed to the filler is largely maintained without re-contamination. The combined effect of the
processing and filling, results in the ESL product having a reduced microbial
load compared with a regular pasteurised product - which will be spoiled in
shorter time, due to this load. Broadly, this means that an ESL
product will tend to be safer and of superior quality than a pasteurised product, as
a result of having been produced in a more hygienic and tightly controlled
environment.
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ESL technology offers advantages in terms of both product
safety and product quality. The basis for this is improved hygiene and the
reduction of the risk of re-contamination by pathogenic and spoilage organisms
during production and distribution.
Globally, consolidation within the dairy industry has led
to fewer and larger plants, distributing over wider geographic areas. ESL
technology allows dairies and other manufacturers to exploit the economies of
scale that result from such consolidation. Indeed, exploitation of economies of
scale has become the key to growth and even survival for many producers in the
dairy industry. Longer runs translate into less product wastage during
changeovers while the improved hygiene and longer shelf life that ESL
technology offers result in fewer returns for the dairies and considerable cost
savings.
ESL technology allows wider distribution of chilled
products, allowing for national distribution in major dairy markets such as the
USA, pan-European
distribution in Europe, or export to other regions.
ESL technology allows entry into higher margin "Value Added" product sectors
within the dairy industry. Examples of higher margin value added products include
flavored milks and active functional dairy products.
High heat treatment or ultra-pasteurisation, the dominant ESL technology used in North
America, offers good processing flexibility when it comes to
product quality and shelf life range. Direct heat treatment is commonly used
due to what is perceived to be better sensory quality. Processing temperatures range typically from 120°C/248F up to around 140°C/284F, with holding times between 0.5 and 4 seconds.
Shelf life potential
The shelf life potential with ultra-pasteurisation is influenced by both environmental and operational factors. At a distribution temperature of 4C/40F, a shelf life of 30 - 90 days is possible, depending on the type of product. To leverage the full shelf life
potential of this type of processing, re-contamination must
be minimized, e.g. ESL fillers (including filler sterilization and packaging
material disinfect ion) must be used and package integrity and stability must
be maintained. A gas and light barrier in the packaging material would also be
required.
Non-thermal processing technologies
While the dairy industry under current high temperature/ultra-pasteurisation conditions and sanitary standards achieves a safe product with excellent quality, combining non-thermal technologies such as UV illumination with pasteurization, could achieve a similar level of quality and safety, but with a smaller carbon footprint as a result of less energy used for processing.
The future for chilled products?
The global trend towards dairy industry deregulation has created a competitive market situation for local dairies as well as for multinationals. Consolidation and exploiting the economies of scale have become the key to growth and even survival for many dairies.
In this new scenario, ESL technology is a key tool to ensure that the milk can travel the greater distances required by wider distribution areas, while remaining fresh and having the required shelf life after arrival at its destination. In a generally highly commoditized and low profit industry, ESL technology also allows entry into and leveraging of highly profitable, value added segments.
With the current focus on food safety issues in the food industry, and with the recent well-documented food scares and consumer food poisoning incidents, product safety is fast becoming the major driver for ESL technology in many markets.
