Sensory preferences among general Japanese consumers and physicochemical evaluation of deep-fried peanuts

The development of food that satisfies consumer preferences is very important for producing commodities. In the present study, 132 Japanese consumers carried out sensory evaluation of deep-fried peanuts with varying frying times (2, 4, 6, 9, 12 and 15 min) at 150 °C, and the relationships among sensory elements and physicochemical properties were investigated.

The sensory scores for colour, bitterness, and deep-fried peanut aroma increased (darker or stronger) with frying time, whereas the sweetness score was relatively high (strong) for frying times of 2, 4, 6 and 9 min, and then decreased (weaker) with increasing frying time. Frying times of 4, 6 and 9 min scored higher in overall liking than other times. Multiple-regression analysis indicated that the overall liking score was positively correlated with sweetness (standardised regression coefficient, β = +0.51) and deep-fried peanut aroma (β = +0.26) scores but negatively correlated with bitterness score (β = -0.25). Multiple-regression analysis also indicated a difference in sensory preference by gender. Sensory elements were closely related to the physicochemical properties, including the colour indexes (CIELAB colour space) and the sucrose and water contents. When L(*) (CIELAB colour space, lightness index) was 53-64 and water content was 10-30 g kg(-1), the mean overall liking score was relatively high implying acceptable fried peanut quality.

Relationships among individual sensory elements were confirmed. Multiple-regression analysis indicated a strong positive correlation between sweetness and overall liking and a small difference in sensory preference by gender. Sensory evaluations can thus be expressed by physicochemical properties.