Evaluating the Impact of Cultivar and Processing on Pulse Off-Flavor Through Descriptive Analysis, GC-MS, and E-Nose

Abstract

Pulses are nutrient-dense and have a low carbon and water footprint but remain underutilized in the United States. A potential strategy to boost pulse consumption involves milling pulses into flour and incorporating them into convenience products traditionally made from wheat flour. However, acceptance of pulse-based products often decreases due to beany off-flavors. Hence, addressing off-flavors-commonly described as green/vegetative, musty/earthy, or beany-is essential for sustained adoption. This study evaluated the impact of cultivar selection and processing methods (boiling, roasting) to reduce off-flavors in eight pulse cultivars using descriptive analysis (DA) and rapid volatile profiling with gas chromatography-mass spectrometry (GC-MS) and electronic nose (e-nose). DA revealed significant differences (p < 0.05) across cultivars and processing treatments for 20 sensory attributes, with roasting reducing green/vegetative and earthy/mushroom/musty off-flavors but increasing beany characteristics, especially in roasted navy bean flour. We identified eight key volatiles via GC-MS, including ketones, aldehydes, and alcohols, which were strongly correlated with green/vegetative and musty/earthy flavors. However, GC-MS had limitations in predicting beany off-flavors, likely due to the chosen targeted analytical approach. In contrast, the untargeted e-nose approach effectively identified discriminant ions that correlated with sensory attributes such as toasted and beany odors in roasted flours. E-nose data aligned better with DA results, highlighting its potential as a first screening tool for rapid flavor profiling. Findings highlight the importance of refining pretreatment methods and selecting cultivars with milder flavors. E-nose and GC-MS can be used to optimize the sensory quality of pulse flour, supporting increased consumer acceptance of pulse-based products. PRACTICAL APPLICATIONS: Despite widespread production of common beans, their consumption is often limited due to off-flavors. While pulse flavor research has largely focused on peas, chickpeas, and faba beans, there is a need to explore cultivar selection and processing strategies for beans. This study demonstrates that lighter-colored bean cultivars and pretreatment with roasting can reduce known off-flavors. Additionally, e-nose offers a rapid alternative compared to traditional sensory and GC-MS methods, helping breeders and product developers to efficiently screen large sample sets for off-flavors. These findings can support the development of pulse-based products with reduced off-flavors, ultimately improving consumer acceptance and consumption.