Effects of frying, roasting and boiling on aroma profiles of adzuki beans (Vigna angularis) and potential of adzuki bean and millet flours to improve flavor and sensory characteristics of biscuits.

Volatile compounds of raw and cooked adzuki beans under three cooking methods namely frying, roasting, and boiling were extracted and identified. The odorants in raw beans changed from "green" and "grassy" to "roasted" and "nutty" in fried and roasted beans. Roasted adzuki beans had the greatest number of volatile compounds and best flavor properties. Because volatiles improve biscuit flavor profiles, biscuits were prepared in which wheat flour was substituted with adzuki bean flour and/or millet flour. The effects of grain flours on the sensory acceptability and aroma of biscuits were evaluated. Descriptive sensory analysis showed that the adzuki bean-millet biscuit had the best sensory quality. Correlation of volatile compounds, biscuit sensory attributes, and biscuit samples showed that maltol contributed to the "caramel-like" aroma of adzuki bean-millet biscuits. Adzuki bean and millet flours have potential in the development of biscuits that meet flavor and nutritional requirements.

Effect of cooking on aroma profiles of Chinese foxtail millet (Setaria italica) and correlation with sensory quality.

The effects of roasting, boiling, and freeze-drying after boiling on volatile aroma compounds in three varieties of Chinese foxtail millet (Setaria italica), namely, Jingu 21, Fenghonggu and Dongfangliang were determined. During boiling significant (p < 0.05) increases in the contents of several unsaturated aldehydes, alcohols, and benzene derivatives were observed, unlike roasting that mainly increased in the contents of pyrazines. Freeze-drying after boiling decreased complexity of flavors, with a reduction in the contents of volatile compounds. Descriptive sensory analysis showed that the maximum intensity of 'popcorn-like' and 'smoky' odors was observed for roasted samples, whereas boiled and pre-boiled-freeze-dried samples were characterized by 'boiled rice' and 'boiled potatoes' odors, respectively. A correlation of odor-active profile data with descriptive sensory analysis clearly established the role of pyrazines such as 2-ethyl-3,5-dimethylpyrazine in contributing to the 'popcorn-like', 'boiled beans', and 'smoky' odors, whereas dienals such as (E,E)-2,4-decadienal were responsible for the 'boiled rice' aroma.