• legal requirements are met;

• the product is safe and fit for use;

• there is compliance with nutritional guidelines and tolerances;

• the agreed/declared weight is provided;

• deviation from expected quality is kept within an acceptable tolerance.

Visual characteristics

Because visual characteristics are the most ‘tangible’ of all the sensory attributes these tend to receive the most attention with physical features (e.g. depth of a sponge layer, number of nuts on top of a Dundee cake) often taking precedence over the true sensory attributes such as depth and uniformity of colour, degree of clarity and brightness.

Flavour, texture and mouth-feel characteristics

Descriptions relating to these modalities are often written in vague, generalised terms (e.g. ‘typical flavour’, ‘freshness of flavour’, ‘standard texture’) which can lead to varied assumptions being made across assessors about the interpretation. Even when individual attributes are listed, issues can still arise, especially if the author of the specification is not familiar with sensory evaluation principles and the need for precise, unambiguous terminology.

Terms can remain bundled and confusing (e.g. confectionery flavour, ripe flavour) or be too technical for general application (e.g. diacetyl instead of ‘buttery’, dimethyl sulphide instead of ‘cabbagey’, 2,4,6-trichloroanisole instead of ‘musty’).

Relevance and priority of sensory attributes

To aid initial focus when defining the specification, the sensory quality attributes can be considered as falling into two main groupings: those which relate to the key characteristics that affect consumers’ acceptance of a product and those which are of internal importance to a business in order for it to maintain cost-effective control of the production process and avoid unnecessary wastage of materials.

The relevance of the attributes under the ‘internal’ listing does not ordinarily pose an issue as the association within a business of a defined term with a specific processing factor or raw material is usually readily understood and its need accepted. Visual defects and also off-flavour characteristics are typically most relevant in the ‘internal’ attribute list. Particular visual defects can, for example, indicate the need to reset peeling, cutting or slicing equipment which if left unchecked would lead to increased waste of raw material. The monitoring of specific off-flavours can aid suitable control of factors such as processing temperatures and flow rates, water conservation, fats and oil quality, etc.

Failings are more common regarding specification of the characteristics that relate to consumer acceptance. Attributes that are of no particular importance are often specified whilst those that are key to consumers’ degree of liking can be given low priority or completely overlooked. To ensure that the most appropriate attributes are specified and avoid the risk of subjective influences, the key features that relate to a target market’s expectations of the sensory quality need to be understood by those responsible for setting and applying the specification. The most reliable way to achieve this is for the information gained from consumer and sensory research conducted during a products development or re-development to be communicated to the Quality and Production teams before routine production commences. Unfortunately a common failing is that this information is not transferred, even after the running of detailed and lengthy product development programs. This increases the risk of the sensory quality of routinely produced product deviating from its quality and hence eroding any quality advantage originally established at launch.

Attribute weighting

In addition to defining an appropriate set of sensory characteristics priorities can also be given to specific attributes to aid the most effective and efficient use of the specification. Again if a consumer-focused approach has been used to determine the main sensory criteria this will also enable weightings of importance to be designated more objectively for each and identify which are the most critical to control.