Consumer Acceptability of Fresh‐Market Muscadine Grapes

The objective of this research was to investigate the acceptability of muscadine grape (Vitis rotundifolia) genotypes (cultivars and selections) and to correlate overall liking to other quality measurements to determine the main drivers of liking. Twenty‐two genotypes grown at the Univ. of Georgia–Tifton Campus were evaluated. Four retail commercial grape genotypes (Vitis vinifera and “Concord”) were also evaluated for comparison. Panelists familiar with muscadine grapes used the hedonic general labeled magnitude scale (HgLMS, –100 = strongest disliking of any kind ever experienced, +100 = strongest liking of any kind ever experienced) to rate overall liking and the liking of appearance, flavor, pulp texture, and skin texture. Puncture testing was done to assess grape berry texture, and compositional attributes soluble solids and pH were also measured. The sensory results indicated that the grapes were variable with overall liking scores from 12.2 to 39.6. The factors highly correlated with overall liking scores were muscadine flavor, pulp and skin liking, while a significant negative correlation was found between skin liking and skin texture and mechanical texture measures. The muscadine grapes with the highest overall liking scores were Ga. 5‐1‐34 and Ga. 2‐8‐21. Principal component analysis confirmed that grapes with a thinner skin and a higher pH tended to group around overall liking and flavor points. These results indicate that even among panelists familiar with muscadine grapes, skin thickness is a negative characteristic. Breeding for thinner skins may be a positive step in muscadines gaining a more widespread appeal in the fresh fruit market.     

NaCl thresholds in man: Thresholds for water taste or NaCl taste?

Notes that water is not tasteless to humans, but rather can produce any of the 4 basic taste qualities if it is preceded by adaptation to an appropriate substance. After adaptation to the NaCl in saliva, water tastes predominantly bitter. Results of detection threshold experiments with 9 male undergraduates and the author as Ss demonstrate that this bitter water taste can be confused with solute tastes so that some detection thresholds for NaCl may actually represent water thresholds instead. Water also appears to have a taste after adaptation to saliva in the rat. Just as with humans, some apparently low thresholds for NaCl detection in rat may be water-taste thresholds. The apparently high preference threshold for NaCl in rat may be a true NaCl threshold based on adaptation to saliva. (116 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Farm to Sensory Lab: Taste of Blueberry Fruit by Children and Adults

The average American child eats fewer fruits than recommended. Although taste is the primary motivator for food intake among children, little research has systematically measured children's liking of fruit and determined whether their preferences differ from adults. We phenotyped 49 children and their mothers to determine: (1) their liking of the taste of 3 blueberry cultivars (“Arcadia,” “Keecrisp,” and “Kestrel”) from 2 harvests for which total soluble solids were determined using a handheld Brix refractometer; (2) the association between liking and blueberry sugar content; and (3) the most preferred level of fructose, one of the primary sugars in blueberry fruit. Multiple methods, identical for all participants, assessed which cultivar they liked best. Dietary intake, determined via 24‐h dietary recall, revealed most children (73%) and adults (92%) did not meet dietary guidelines for fruit intake. We found that during the 1st harvest, Keecrisp was sweeter by 4° Brix than either Arcadia or Kestrel and was the cultivar most preferred by both children and adults. For the 2nd harvest, mothers liked each of the cultivars equally, but children preferred Arcadia, which was 2° Brix sweeter than the other 2 cultivars. Like other sugars, children's most preferred concentration of fructose was significantly higher than that of adults. In sum, children appear to be more sensitive to smaller variations in sweetness than are adults. Identifying drivers of fruit preference and assessing children's liking for whole fruits are important steps in developing strategies to increase fruit consumption among children.     

Obituary: Carl Pfaffmann (1913–1994).

Memorializes C. Pfaffmann, a leader in research on taste sensitivity. His early interest in recording from taste nerves led to an interest in following taste through the CNS, along with behavioral analysis in a variety of animal species and psychophysical studies with humans. His experiments exploring the sensory–hedonic distinction led to clinical discoveries of taste projections into the limbic system, an area known to be associated with emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of the Hedonic General Labeled Magnitude Scale with the Hedonic 9‐Point Scale

The hedonic 9‐point scale was designed to compare palatability among different food items; however, it has also been used occasionally to compare individuals and groups. Such comparisons can be invalid because scale labels (for example, “like extremely”) can denote systematically different hedonic intensities across some groups. Addressing this problem, the hedonic general Labeled Magnitude Scale (gLMS) frames affective experience in terms of the strongest imaginable liking/disliking of any kind, which can yield valid group comparisons of food palatability provided extreme hedonic experiences are unrelated to food. For each scale, 200 panelists rated affect for remembered food products (including favorite and least favorite foods) and sampled foods; they also sampled taste stimuli (quinine, sucrose, NaCl, citric acid) and rated their intensity. Finally, subjects identified experiences representing the endpoints of the hedonic gLMS. Both scales were similar in their ability to detect within‐subject hedonic differences across a range of food experiences, but group comparisons favored the hedonic gLMS. With the 9‐point scale, extreme labels were strongly associated with extremes in food affect. In contrast, gLMS data showed that scale extremes referenced nonfood experiences. Perceived taste intensity significantly influenced differences in food liking/disliking (for example, those experiencing the most intense tastes, called supertasters, showed more extreme liking and disliking for their favorite and least favorite foods). Scales like the hedonic gLMS are suitable for across‐group comparisons of food palatability.     

Taste rejection of nonnutritive sweeteners in cats.

Cats reject saccharin and cyclamate and are indifferent to dulcin, although they, like other mammals, prefer sucrose. The rejection threshold for saccharin found for 10 cats in the present 2 experiments, 0.0001 M, was about 2 log steps lower than a previously reported rejection threshold for sodium saccharin. Water produced a taste in Ss adapted to their own saliva. The high sodium saccharin was masked by the taste of the water solvent; however, saccharin may also be somewhat more aversive to the cat than sodium saccharin. Saccharin may produce an aversive taste because it stimulates receptor sites sensitive to substances bitter to man as well as those sensitive to sugars. In addition, saccharin may not be an effective stimulus for all sugar-sensitive sites. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From psychophysics to the clinic: missteps and advances

People live in different oral sensory worlds. This variation affects health and quality of life. The need to make valid comparisons across individuals/groups to reveal this variation highlighted invalid use of conventional labeled scales (e.g., visual analogue, category scales). Valid comparisons can be made with magnitude matching and the general Labeled Magnitude Scale (gLMS) employing multiple standards (real and remembered), thus permitting associations between oral sensation, preferences, intake (e.g., fats, vegetables), and health outcomes (e.g., cancer, phantoms, burning mouth syndrome). These measurement insights broadly apply to sensory/hedonic assessment of differences across groups in many different fields. As an illustration, we assess differences across groups experiencing different types of pain.     

Propylthiouracil tasting: determination of underlying threshold distributions using maximum likelihood

The ability to taste low concentrations of propylthiouracil (PROP) and related bitter compounds is heritable. The current analysis determines whether the distribution of PROP taste thresholds is consistent with an additive or a dominant mode of Mendelian transmission. To that end, the lowest concentration of PROP detectable was determined for 1015 subjects and models of bi- or tri-modal distributions of PROP taste thresholds were tested. The model with the greatest likelihood had three distributions and followed an additive model of PROP taste sensitivity if the variances associated with the distributions were assumed to be equal. However, if the taste thresholds were transformed to remove skewness, or if the variances were unequal, then three- or two-distribution models were equally likely. Resolution of the mode of inheritance for bitter taste perception awaits additional family studies and the characterization of the molecular basis of taste perception for these bitter compounds.