*2.10. E*ff*ects of Roasting and Blanching on Sensory Characteristics of Almonds*

The main sensory attributes differentiating the six almond cultivars after roasting were found to be skin color, bitter almond flavor, bitter taste, skin roughness, and sweet almond flavor (Figure 1B). Skin color rated highest for the foreign cultivars (Ferragnès and Glorieta) and lowest for Molar and Pegarinhos. Relative to skin roughness, the skin of Molar and Pegarinhos were found to be rough whereas that of Casanova was found to be smooth. The sweet almond flavor was strongly associated with Ferragnès and barely perceived for Pegarinhos. Pegarinhos and Refêgo achieved the highest rating for bitter almond flavor and bitter taste whereas Glorieta was rated lowest for bitter almond flavor. Roasting is known to increase the levels of compounds such as pyrazines, furans, and pyrrols in food products. The above compound represents three groups of chemicals with nutty and roasted aromas [50,51] that are formed through non-enzymatic Maillard browning reactions [52]; these compounds are also known to enhance the aromas of roasted almonds [40]. In our previous work [14], pyrazines were not detected in any of the six cultivars studied; it was, however, detected in the Portuguese cultivar Amendoão. Xiao et al. (2014) [53] reported decreases in the levels of benzaldehyde and several alcohols in food products after roasting. For the six cultivars object of the present study an increase in the amount of benzaldehyde was observed after roasting. The above observation may partly account for the significant differences among cultivars relative to bitter sensorial characteristics.

In the case of blanched kernels, differences in sensorial characteristics among cultivars were only recorded for textural parameters, namely first chew hardness and force to grind pieces (Figure 1C). Both characteristics rated highest for Refêgo and Pegarinhos and lowest for Ferragnès and Molar. These changes in textural parameters are likely due to the low water content of blanched kernels which were subjected to two processing steps both involving heating. Indeed, water is known to directly influence the hardness, crispness, crunchiness and toothpack attributes of almonds [54]. Consumers usually show a preference for crispy, crunchy [54,55], and sweet almonds [55]. Hence, good ratings by the panelist for blanched kernels relative to textural properties could have positive implications for the almond industry. Indeed, hard, fracturable and crunchy almonds are used as cooking ingredients to improve food texture while moist and chewy almonds are suitable for beverages [56].
