Processing and quality evaluation of dry beans (Phaseolus vulgaris) in flexible pouches

Dry beans are a nutrient-dense food with a history of processing in metal cans to improve convenience for consumers. Flexible retort pouches have been gaining popularity as a food package to replace metal cans because they are lighter in weight and require less energy to process. While there are potential benefits of using pouches for processed bean products, a pilot-scale pouch processing protocol for beans is needed for testing to expand to wider commercial applications. To address that need, the objectives of this study were to optimize a pouch processing method for dry beans and assess the subsequent quality of pouch-processed beans. Black and kidney bean genotypes from different field trials and production years and harvested by different threshing methods were used in this study. Pouch processing was conducted with two types of pouches at a pilot facility, and processing quality included texture, appearance, and color. Cooking time of dry seeds was assessed to understand how variety and environmentally induced differences in cooking time influence pouch processing quality. Kidney beans that required longer dry seed cooking times had firmer texture when pouch processed (r = .72, p < .01). Both genotype and production year impacted cooking time and pouch processing quality. Threshing method had a significant impact on the appearance of processed kidney beans, while it had no significant impact on the processing quality of black beans. Pouch processing requires 42% (at 245°F/118.3°C retort temperature) or 60% (at 250°F/121°C) less retort processing time compared with canning. Both foil and non-foil pouches can be used to differentiate varieties for processing quality, but the non-foil pouches require much less effort to seal. This study provides a detailed methodology for pouch processing and quality evaluation of dry beans and useful information for researchers and processors in future applications of using pouches as alternative packaging for processed beans.