Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Other
Publication Acceptance Date: 2/9/1995
Publication Date: N/A
Interpretive Summary: When dry seeds of common bean (Phaseolus vulgaris L.) are processed in tin cans differential amounts of nutrients are leached in the broth. Often the broth is thick, grainy and cloudy in appearance. Poor broth appearance often leaves consumers with the impression of inferior quality. It is thought that the thickness and grainy appearance is due to the leaching of starch which composes about 55% of the bean. A better understanding of the relationship between canned bean quality and broth composition would enable plant breeders to be more efficient in selecting bean breeding lines to release as culitvars with exceptional culinary quality. A study was conducted to investigate navy bean breeding lines that differed in canned bean broth characteristics to characterize the leached components. Soluble protein was higher in thick brine than in thin brine. Starch leakage was not dependent on bean breakage. Breeding lines with intact seed often had a ahigher starch content in the broth than lines with a more broken appearance. Soluble fiber, a compound composed of complex carbohydrates, also had an effect on broth thickness. Since there was no one specific seed component which determined the thickness of broth among these navy bean lines, it is suspected that soluble fiber and protein and starch and their interactions determine broth thickness and graininess. This finding will make it more difficult for plant breeders to develop navy bean varieties that have good broth appearance because now they must consider several other seed components rather than just starch.
Technical Abstract: During thermal processing of dry beans, nutrients leach into the cooking brine and lower consumer acceptability because of cloudy, viscous, or grainy appearance. Moreover, the nutritional value is lowered if the brine is discarded. A better understanding of the relationship between canned bean quality and brine composition would aid in the selection of breeding lines. A study was conducted to investigate navy bean breeding lines that differed in canned bean and brine characteristics to characterize the leached components present in the brine. Eight cultivar/breeding lines were canned and evaluated for visual quality characteristics. Total solids content of brine was measured and eighty-five percent ethanol was used to separate soluble sugars from macromolecules in the brine. Protein content was determined using the ASCC method; starch content was quantitatively determined using beta-amylase and pullulanase. Both insoluble (IDF) and soluble dietary fiber (SDF) were measured. Pectic substances were determin as the uronic acid content in the brine. The total solid and ethanol precipitable material in viscous brine were higher than those in fluid brine. The amount of protein in viscous brine was usually higher than that in thin brine. Most starch leakage from the bean was not dependent upon bean breakage. Fleetwood was mostly intact but had higher starch content in the brine whereas N905989 has severely split beans but had less starch in brine. In general, viscous brine contained more SDF and starch than did the fluid brine. The amount of IDF appeared to have some effect on viscosity of the brine. There was no one specific component which determined the viscosity of the brine. Protein, soluble dietary fiber and starch and their interactions are suspected to determine brine viscosity.