Predicting functional properties of fresh and aged dry common beans from near infrared spectra: A focus on antinutrient mineral ratios and cooking behaviour

Common dry beans are among the most commonly consumed legumes in many parts of the world as important sources of essential nutrients. However, a storage-induced defect called Hard-to-Cook (HTC) adversely affects their consumption desirability in terms of cooking behaviour, texture and colour. Knowledge on the effect of storage and subsequent processing on macronutrient digestibility, micronutrients bio-accessibility and bioactive components activity is not well developed. This calls for concerted efforts in research to unlock the relationship between HTC defect and nutrient absorption and uptake among the most commonly consumed legumes. Correlations between the latter information and consumer preference studies can contribute to effective utilization of legumes in rural and peri-urban communities in Kenya eventually leading to improved nutrition and health outcomes. The main objective of this study will be to determine the influence of storage conditions and processing on the physico-chemical characteristics and sensory properties of whole and value added common bean based products for improved nutrition and health. In the first step, screening tools for identifying the sensitivity of beans to the hard-to-cook defect will be developed using texture analyser, finger pressing and Near Infrared Reflectance spectroscopy (NIRS) techniques. In the next step, two popular common bean varieties obtained from the VLIR-UOS funded Legume breeding project at JKUAT will be subjected to storage and processing experiments. One of the varieties will be easy to cook while the other one will be hard-to-cook. The bean varieties will be divided into two batches. The first batch will undergo analysis and processing immediately after harvest thus referred to as fresh sample. The second batch will be stored under accelerated storage conditions typically at and above 25°C and 75% relative humidity to induce the HTC defect at different levels and referred to as the aged samples. Lastly, the effect of variety, storage and processing on nutrient bio-accessibility will be evaluated using in vitro digestion experiments. It is anticipated that this will result in the development of quick guidelines for legume storage and processing that can be utilized by consumers and legume processors.