Optical detection of microbial infestation and mycotoxins in beans (Phaseolus vulgaris L.)

The common bean (Phaseolus vulgaris L.) belongs to a group of the Fabaceae family known as pulses, which are legumes used exclusively for the production of dry grains. Common beans are widely consumed because of their nutritional benefits, such as high protein and dietary fiber contents. Despite their growing commercial and nutritional relevance, research on microbiological spoilage and subsequent mycotoxin buildup has lagged behind compared to cereals. Mycotoxins are secondary metabolites produced by certain filamentous fungi that threaten animal and human health. These molecules can cause acute intoxications, chronic effects, and even cancer. Therefore, many countries have set thresholds to prevent them from entering the human diet. Traditional mycotoxin detection methods are time-consuming and often require highly skilled personnel. To address this, optical detection methods can help to provide fast and reliable results. Nonetheless, research in this area has mainly focused on cereals. Therefore, this study aimed to test the feasibility and reliability of optical detection methods to measure microbial infestation and mycotoxin contamination in common beans. This dissertation is composed of three parts that focus on describing the advances in research related to fungal contamination and mycotoxin accumulation in pulses, followed by the detection of Fusarium verticillioides, and its mycotoxin, fumonisin B1, in common black beans using optical detection methods.