Preference mapping of frozen and fresh raspberries.

The purpose of the study was to identify key sensory attributes that influence consumer liking for frozen and fresh red raspberries using preference mapping. Sensory profiling of different raspberry cultivars and selections from the Washington State Univ. and Oregon State Univ. breeding programs was carried out using a trained panel (frozen, n = 12 and fresh, n = 10). In addition, a subset of frozen and fresh raspberries of each cultivar was assessed by consumers for sensory acceptability (n = 105 and n = 100, respectively). Based on overall hedonic ratings, cluster analysis identified 3 clusters of frozen raspberry consumers from day 1 (41% "nondistinguishers," 34% "likers," and 25% "nonlikers") and day 2 (41% "group 1 likers," 26% "nonlikers," and 34% and 33% group 2 likers"). For fresh raspberry consumers, 2 clusters were detected from day 1 (54% "likers" and 46% nondistinguishers") and day 2 (54% "group 1 likers" and 46% "group 2 likers"). Preference mapping was applied on the descriptive sensory and acceptability of clustered consumer data. Partial least squares regression results showed that liking of frozen raspberries was driven by high raspberry flavor, firmness, and sweetness. Conversely, disliking of frozen raspberries was related to high sour and aftertaste intensity. In the case of fresh raspberries, high color uniformity, raspberry aroma, raspberry flavor, floral aroma, green flavor, bitter, astringency, and aftertaste increased the acceptability, whereas high color intensity and green aroma were associated with negative drivers of liking. The information obtained in this study can be a useful guide for breeders in the selection of characteristics for growing superior quality raspberries.

Pea genes associated with non-host disease resistance to Fusarium are also active in race-specific disease resistance to Pseudomonas.

A given plant species is able to resist most of the potentially pathogenic microorganisms with which it comes in contact. This phenomenon, known as non-host resistance, can be overcome only by a very small number of 'true pathogens' which can use that plant as a host. In some cases, plants have developed mechanisms for overcoming infection by specific races or strains of a true pathogen. This race-specific resistance can be easily manipulated into agronomically important cultivars by plant breeders. We have previously described nine cDNA clones which represent pea genes active during non-host resistance against the fungus Fusarium solani f. sp. phaseoli. In the present work, we have used these cDNAs as probes to compare non-host resistance with race-specific responses of peas against three races of Pseudomonas syringae pv. pisi. Five of the genes most active during non-host resistance were also active in direct correlation with the phenotypic expression of resistance in race-specific reactions of five differential pea cultivars against three races of Pseudomonas syringae pv. pisi.