Sensory characterisation enabled the first classification of dessert bananas.

BACKGROUND: Knowledge of the sensory diversity of a wide range of dessert bananas would be helpful in breeding programmes and so diversify the banana market. Descriptive sensory profiling was thus used to assess 13 cultivated bananas and four new triploid hybrids at an eating stage. RESULTS: A specific vocabulary was defined to describe the sensory traits of dessert bananas. The 17 cultivars assessed were ranked in five sensory clusters, which differed mainly in the intensity of sourness and sweetness. The first cluster, which contained the standard banana (Cavendish), received the lowest sourness and the highest sweetness and banana flavour scores. The second cluster was the sourest and firmest and had the highest chemical flavour score. The third cluster was characterised by the highest melting score, the fourth by the highest mealiness, astringency, grassy odour and flavour scores and the fifth by a balance between sourness and sweetness and the highest heterogeneous texture score. Firmness and sourness were correlated with rheological pulp firmness and titratable acidity respectively. CONCLUSION: The results led to the identification of relevant attributes that grouped the sensory diversity of dessert banana into five clusters. Combined with hedonic data, these results should help breeders to select banana hybrids.

EIN3-like gene expression during fruit ripening of Cavendish banana (Musa acuminata cv. Grande naine).

Ethylene signal transduction initiates with ethylene binding at receptor proteins and terminates in a transcription cascade involving the EIN3/EIL transcription factors. Here, we have isolated four cDNAs homologs of the Arabidopsis EIN3/EIN3-like gene, MA-EILs (Musa acuminata ethylene insensitive 3-like) from banana fruit. Sequence comparison with other banana EIL gene already registered in the database led us to conclude that, at this day, at least five different genes namely MA-EIL1, MA-EIL2/AB266318, MA-EIL3/AB266319, MA-EIL4/AB266320 and AB266321 exist in banana. Phylogenetic analyses included all banana EIL genes within a same cluster consisting of rice OsEILs, a monocotyledonous plant as banana. However, MA-EIL1, MA-EIL2/AB266318, MA-EIL4/AB266320 and AB266321 on one side, and MA-EIL3/AB266319 on the other side, belong to two distant subclusters. MA-EIL mRNAs were detected in all examined banana tissues but at lower level in peel than in pulp. According to tissues, MA-EIL genes were differentially regulated by ripening and ethylene in mature green fruit and wounding in old and young leaves. MA-EIL2/AB266318 was the unique ripening- and ethylene-induced gene; MA-EIL1, MA-EIL4/Ab266320 and AB266321 genes were downregulated, while MA-EIL3/AB266319 presented an unusual pattern of expression. Interestingly, a marked change was observed mainly in MA-EIL1 and MA-EIL3/Ab266319 mRNA accumulation concomitantly with changes in ethylene responsiveness of fruit. Upon wounding, the main effect was observed in MA-EIL4/AB266320 and AB266321 mRNA levels, which presented a markedly increase in both young and old leaves, respectively. Data presented in this study suggest the importance of a transcriptionally step control in the regulation of EIL genes during banana fruit ripening.