SensoGram 22: A Sensory Smorgasbord!   Last week the triennial Pangborn Sensory Science Symposium was held in Davis, California.  The symposium addresses all aspects of sensory science - theoretical, methodological and practical - and attracts academic and industrial sensory scientists from around the globe (including a delegation from SensoMetrics).  Here is a taste of the proceedings: -   Could Taste Preferences be Genetically Determined?   This paper presented the notion that individual taste preferences may be determined by the individual anatomy of the tongue.  Researchers measured the density of certain types of taste buds on the front of the tongue and found that this correlated with individual differences in the perception of basic tastes.  Thus, if one individual tolerates bitter foods and another doesn't, this may relate to differing numbers of bitterness receptors on their tongues.  This is an intriguing finding and we will watch for further developments.   Will No-fat Products Last the Distance?   These days the supermarket is full of no-fat or reduced-fat versions of regular products.  Are these here to stay?  Maybe not.  One study showed that putting people on low fat diets does not mean that they will eventually prefer low-fat products; indeed, they will still prefer to eat the regular versions, given the chance.  This finding stands in contrast to studies on low salt products, which show that consumers will eventually prefer a lowered level of salt if they hold to a low salt diet. Scepticism of no-fat foods came from another angle.  One presenter claimed that even if we can make no-fat products taste good and `fool' our tastebuds, we cannot fool our stomachs. Our `gut receptors' tell the brain whether or not they are satisfied.  So, even though a no-fat product may taste good, it may not provide the overall feeling of satisfaction necessary to engender long-term repeat purchase.   Sensory Outsells Conceptual    Product claims come in two kinds:  sensory, in which the claim relates to some perceptible product difference (eg "new improved fragrance", "now with more fruit", "new convenient size",etc); and conceptual, in which the claim is not perceptible but is there to be believed (eg "no additives", "organically grown", "now with more active ingredients").  This paper suggested that sensory claims are far more compelling to the consumer than conceptual claims, provided they are delivered.  Thus, `new improved fragrance' will work well only if consumers do, in fact, perceive the fragrance to be new and improved.  If they don't, they will be irritated by the claim (and the brand).  Conceptual claims are `safer' in that they cannot be rebuked by the consumer - but they are also weaker in impact.   Are a Few Sips Enough?   In central location tests, respondents are typically given only a small amount of product on which to base their evaluation.  Is this OK?  Absolutely, according to a large study on fruit drinks.  This study compared condition (a) in which respondents were given only a small quantity of product, and condition (b) in which they were allowed to drink as much as they wanted of each variant over extended periods.  The consumer reaction was not affected by the methodology:  the ratings for the products were the same regardless of experimental condition.   What Suppresses Astringency - Sweetness or Viscosity?   Some products such as tea and red wine can evoke astringency, that mouth-puckering sensation that most people find harsh and unpleasant.  How can astringency be suppressed?  One view is that astringency can be reduced by increasing the sweetness; another is that increasing the viscosity of the product (making it thicker) will reduce astringency.  Which is it?  A study on wine showed clearly that increasing the viscosity, not sweetness, reduces astringency.  This is consistent with the observation that a fuller-bodied red wine is less likely to be astringent than a thinner one.  It would explain, also, why adding milk to tea suppresses the astringency - it increases the viscosity.   The `Overall Liking' Attribute:  Should it be Asked First or Last?   There is some conjecture in sensory circles as to when respondents should be asked to rate their overall opinion of a product (Overall Liking).  Should it be an initial reaction, or should it made at the end of the evaluation after a good many other attributes have been evaluated?  This study suggested that it really does not matter a great deal - the reactions were much the same regardless of attribute position. This is also what we have found at SensoMetrics over years of testing:  it usually does not matter.  There are, however, a few instances in which it can matter.  Asking Overall Liking as a first impression does not allow for a sensation that builds up over time.  Bitterness, for example, is generally a negative sensation but it takes time to build up.  If Overall Liking were asked only at the commencement of tasting, the negative impact of the bitterness would be missed and the liking score would be artificially inflated.  To be safe, then, it is good to have some kind of overall liking attribute near the start and near the end of the evaluation.