Effect of retort processing, containers and motion types on digestibility of black beans (Phaseolus vulgaris L.) starch

Abstract

With the growing demand for convenient and shelf-stable canned beans, understanding the changes in starch digestibility due to retort processing is crucial for optimising nutritional quality and enhancing consumer health. The present study investigated the impact of retort processing, specifically container type and agitation, on the digestibility of black bean starch. Retort pouches exhibited a more rapid heat transfer rate to the enclosed product than cans, which reduced the overall processing duration. Also, the processing time to achieve a Fo = 6 of Clostridium botulinum was almost 2.5 min (pouches) and 3.2 min (cans) faster for the oscillating than the static mode. The in vitro digestibility data revealed that the retort processing of black beans led to an increase in rapidly digestible starch (RDS) from 10.51% to 32.11%. However, slowly digestible starch (SDS) decreased from 15.67% to 7.89%, and resistant starch (RS) decreased from 47.91% to 11.86%, regardless of the container type and motion involved. Processing enhanced starch digestibility in all the combinations of container and motions; nevertheless, black beans in pouches with oscillatory motion still contain a relatively significant amount of SDS and RS than the other combinations. These findings have important implications for the food industry in optimising processing techniques and packaging strategies to preserve the nutritional value of black beans. The findings of this study can have practical implications for food producers engaged in the retort processing of foods contained in pouches and cans. The investigation will provide insights into how the process of retort sterilisation affects digestibility, including slowly digestible starch and resistant starch of different types of starch.