Using Flavor Chemistry, Sensory, and Texture to Determine Domestic Edamame Quality

Persistent interest in edamame, vegetable soybean (Glycine max (L.) Merr.), by U.S. consumers has continued to fuel the development of a domestic edamame supply chain. Studies have shown edamame to be a nutritious specialty crop with potential to provide economic benefit to local growers. Domestically bred and grown edamame has shown to be preferred by growers and consumers with competitive agronomic traits. While domestic varieties of edamame will encourage growers to produce a product catered towards the domestic market, additional considerations of final product quality are necessary to positively influence the market success.

Domestically grown and store-bought edamame samples were utilized to research quality attributes including flavor, taste, and texture of edamame representative of domestic market and supply chain. Solid phase microextraction was utilized for aroma extraction prior to gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) analyses to obtain (1) impactful volatile compounds present, (2) changes in these compounds by stink bug feeding injury, and (3) volatile contributions to sensory characteristics. Sensory methods were utilized to (1) evaluate differences in perception of edamame with and without stink bug feeding injury, and (2) understand important sensory characteristics for domestic edamame.

Volatile analysis recognized 16 volatile compounds when investigating edamame genotypes with 14 compounds having significant differences in contents by genotype. Only 10 compounds were consistently detected through GC-O by panelists, so called aroma-active compounds, and only one compound (E)-2-octenal was significantly different in odor intensities across genotypes. Stink bug injured samples showed dramatic differences in volatile profile compared with the not injured counterpart, from mass chromatogram; however, no noticeable differences were perceived by GC-O or sensory difference testing. An instrumental texture analysis method was proven to be sensitive enough to detect the textural differences of edamame beans after processing. The multi-dimensional sensory characteristics including taste, aroma, and texture, were established showing significant differences by edamame variety and growing location. Domestically bred edamame was found to be sweeter, as is preferred by domestic consumers, confirming encouraging breeding outcome. Despite significant differences in edamame volatile profiles by genotype and stink bug feeding injury, sensory discrimination of these differences seems to be less noticeable than changes from taste and texture. Utilizing our findings toward future research and product development will support the domestic edamame supply chain by providing a foundational understanding of quality attributes and their impacts.