Applications of natural ingredients in savoury food products - Natural Food Additives, Ingredients and Flavourings - page 301

them in their choice of ingredients. Many chefs prefer to use liquid bouillons and
stocks rather than dry ingredients in the belief that the liquid product is more
'natural' than a dry alternative, although in many cases, the dry product is found
to give many of the desirable fl avour characteristics of the liquid product.
Nonetheless liquid products have the propensity to be natural more easily than
does a dry seasoning due to the greater availability of natural ingredients in liquid
format. A number of liquid formats are now available such as stocks, bouillons,
seasonings, marinades and sauces. Undoubtedly liquid products afford an ease of
use to the food processor and a route to easier dispersion throughout a product
than does a dry product.

13.5.1 Liquids: stability, safety and shelf life
There are a number of constraining factors when formulating liquids, none more
important than their microbiological safety and stability which ultimately
determines the storage criteria and shelf life of the liquid product. A hazard
analysis and critical control points (HACCP) based approach is generally used
based on the following criteria:
• Acid content (generally the acetic acid content from vinegars)
• pH value
• Sugar content (calculated as simple hexose sugars such as dextrose or as
disaccharides such as sucrose)
• Salt content (as sodium chloride)
• Manufacturing environment
• Storage temperature (chilled, ambient or frozen)
• Fill temperature and/or cooling method employed
•

End packaging.

In order to assign a shelf life to a liquid, a model to predict the preservation of cold
processed emulsions using acetic acid and stored in ambient conditions has been
produced by the Comité des Industries des Mayonnaises et Sauces Condimentaires
de la Communauté Économique Européenne (CIMSCEE) (Anon. 1993). An
equation from this model is used by savoury food developers to determine the
microbiological safety ( Σ sf) and stability ( Σ st) of liquid products. The model
indicates whether both pathogenic and spoilage bacteria will reproduce or be
controlled.
The model gives a good prediction of microbiological safety and stability for
cold processed liquids and may also be used for heat pasteurised liquids by regard
to HACCP criteria in particular pH, fi ll temperature and storage conditions to
predict a safe shelf life for a liquid product. Mullan (2009) discusses the CIMSCEE
code in more detail.
For liquids not preserved by acetic acid, the HACCP-based approach becomes
more signifi cant in determining the shelf life of the product.
Table 13.13 shows an example of assigning a shelf life and storage to a number
of different situations.

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