5.7.2 Product attributes evaluation

The problem in product development is identifying what are the critical attributes of a food to the consumer and then measuring them in the design process. Three questions can be asked:

    1. Is there a difference between two food samples? Used when trying
        to duplicate a product or to see if there is a difference between
        product prototypes. Difference tests such as triangle tests,
        paired comparisons can be used.

    2. Is the product acceptable? How acceptable? Used for the
        optimum prototype products when testing by large consumer groups
        or smaller, representative panels.

    3. What are the characteristics of the products? How strong are they?
        Used when building up the product concept and also in designing
        the product prototypes. This can be called descriptive analysis or
        product profiling. The profile method is designed to give a profile of the
        overall sensory properties by describing and determining the
        relative magnitudes of the attributes.

The sensory attributes of the product are designed to find not only the ideal magnitude ('bliss point') for the individual sensory attribute, but also the combination of sensory attributes and their magnitudes for the optimum combined sensory attributes, which gives a high hedonic acceptance (Moskowitz, 1994). After optimising the sensory attributes, there is still the acceptance test to see if the total product concept has been achieved. Formerly in product development, there were many hedonic tests with consumers in developing the product, but with today's analytical sensory and other techniques, the product design specifications can be detailed so that much testing can be done with physical, chemical, thermal tests or with analytical sensory testing. Perception tests such as ideal product profile tests are conducted with consumers at a set stage in the product design, and then total product testing when all the specified consumer attributes in the product are nearing optimum. Having identified the attributes, the method of testing must be selected.

Sensory science has developed a great deal in the last 30 years and there are many techniques which have been tested and recognised (Meilgaard et al.,1999). Descriptive analysis techniques are used in product development because they describe and measure the multiple attributes in the product, and determine the magnitude of the attribute - in other words they are quantitative. The results from a trained panel can be replicated and therefore can be used in the statistical analysis of data, using linear relationships, which can be used to optimise the product prototypes. The use of ideal profile for following design is useful in determining whether the optimum product prototype is being achieved. 'Just right' scales are also used to determine if the product is nearing an optimum. The selection of type of stimuli, type of respondent and measurement procedure (Table 5.14) is important in ensuring the validity of the sensory results (Schutz, 1993).


Table 5.14 Attribute evaluation in product development

Product stage   • Product description • Product concept • Product design specifications • Basic product • Product prototypes • Unidentified final product • Identified final product • Commercial product Type of respondent   • Expert judges • Trained panels • Company staff • Focus consumer panels • Representative consumers • Randomly selected consumers • Target market Measurement procedure   • Attribute selection • Quantitative measurement of    attributes • Hedonic measurement • Total product acceptance • Buy/use intention • Sale/use

Source: From Moskowitz, Benzaquen and Ritacco, 1981, by permission of Business News Publishing, West Chester, PA.

Think Break In developing a new tomato pork sausage, a product developer had five prototypes which are being tested by a small 30 member panel of the target consumers - teenagers. The sausages had two levels of salt and two levels of pepper. A simple 2 x 2 experimental design was used with Product A low salt, low pepper, Product B low salt, high pepper, Product C high salt, low pepper, Product D high salt, high pepper, Product E medium salt, medium pepper. The panellists were asked to study the flavour level, whether any flavour is dominant, and the level of salt. A B C D E   Number of people Flavour level           Too high 3 5 15 18 11 Just right 10 14 8 5 7 Too low 17 11 7 7 12 Flavour balance Some very dominant flavours 3 7 10 11 8 Some slightly dominant flavour 2 5 5 10 7 Rounded/balanced flavour 25 18 15 9 15 Harshness Very harsh flavour 0 3 5 7 3 Slightly harsh flavour 1 5 3 9 3 Mild flavour 29 22 22 14 24 Saltiness Too salty 1 2 10 12 8 Just right 12 11 11 10 14 Too low 17 17 9 8 8 They identified the dominant flavours in each product as: Product A - meatiness, Product B - spiciness, pepperiness, Product C - salt, Product D - salt, pepperiness, Product E - spiciness. Study these results and discuss what is happening with increase of salt and pepper. What levels of salt and pepper would you use in optimising the sausage formulation? Discuss how you would experiment further with the sausages. .