|Pasting properties of dry bean powders from 25 Michigan-grown cultivars from two crop years|
C. CAPPA (1), E. Gailey (2), J. Kelly (3), P. Ng (2) (1) Department of Food Science and Human Nutrition - Michigan State University, East Lansing, MI, U.S.A.; (2) Department of Food Science and Human Nutrition - Michigan State University, , U.S.A.; (3) Department of Plant, Soil and Microbial Sciences - Michigan State University, , U.S.A..
It is well known that dry beans are rich in protein (20 – 50%) and fiber (23 – 32%), low in fat (0.5 –1.5%), and lower in carbohydrates as compared to cereals (25 – 40%), making them a good nutritional food source for people around the globe. Michigan is the second largest producer of edible dry beans in the U.S. The objective of this study was to explore the utility of the Rapid Visco Analyzer (RVA) to discriminate 25 bean cultivars, grown in 2014 and 2015 in Michigan, for their unique pasting properties. Surface contact area of particles is related to particle size and affects hydration rate: smaller sized particles have greater surface contact area and generally higher hydration rates. Higher content of carbohydrates (including starch) in powder samples would increase the range of pasting viscosities using the RVA. Accordingly, bean samples were ground to two particle sizes, fine (= 0.5 mm) and coarse (= 1 mm), for studying the effects of hydration, and starch content was increased in the bean powder samples by blending bean powder with corn starch (70:30) to increase the pasting viscosity range. The blended bean powder samples were characterized by the RVA. It was evident that particle size affected pasting properties among the studied cultivars, e.g., final viscosity values ranged from 1730 to 3100 cP and from 1160 to 2160 cP for fine and coarse blended powders, respectively. A wide range of pasting properties was observed among the cultivars but with little variation between years for the same cultivar. Thus, genotype appears to have a greater effect than environment on the studied pasting properties. Furthermore, different retrogradation behaviors (setback values from the pasting curves) were observed among the studied cultivars, and hence the dry bean powders present potential opportunities for a wide array of food applications.