Sensory and instrumental analysis of eight genotypes of red raspberry ( Rubus idaeus L.) fruits

BACKGROUND: There is a search for raspberry cultivars with high sensory quality. The best way to determine sensory quality is by descriptive analysis. To perform sensory analysis by a trained panel is, however, not always feasible. Therefore, there is a need for instrumental measurements that correlate with sensory attributes. OBJECTIVE: To characterize eight genotypes of raspberry (Rubus idaeus L.) and to correlate sensory attributes with instrumentally determined quality. METHODS: Raspberry fruits were analysed by descriptive sensory analysis and by instrumental measurements, i.e. colour, total monomeric anthocyanins, soluble solids (SS), pH, titratable acidity (TA) and volatile compounds. The relationships between sensory attributes and instrumentally measured quality were determined by partial least square regression and by univariate correlation analysis. RESULTS: Sour and green odours/flavours versus chemical and cloying odours/flavours described most of the sensory variation of the raspberry genotypes. TA correlated with acidic taste, astringency and flavour intensity. SS/TA was positively correlated with sour flavour and sweet taste and negatively correlated with acidic taste and astringency. C6-aldehydes and (Z)-3-hexen-1 -ol correlated positively with green flavour. beta-ionone and alpha-ionone correlated with flower odour and flavour, respectively. CONCLUSIONS: Eight raspberry genotypes were characterized. Important sensory attributes could be predicted by instrumental measurements.