2014 Annual Meeting Abstract - Milling moisture treated black beans ( Phaseolus vulgaris L.) using a burr mill/roller mill milling system

Poster Presentation
Milling & Baking

84-P

Milling moisture treated black beans (Phaseolus vulgaris L.) using a burr mill/roller mill milling system
H. ANDO (1), C. E. Carter (1), F. A. Manthey (1)
(1) North Dakota State University, Fargo, ND, U.S.A.

Utilization of dry bean flour in food products is increasing. Hence, understanding the effect of milling on final dry bean flour quality is important. Black beans are often cooked or soaked in order to reduce antinutritional factors. Black beans were moisture treated by cooking in boiling water (5, 10, 15, and 20 min), soaking in distilled water (6, 12, 18, and 24 h) and tempering to 6, 8, 10, 12, and 14% moisture. The cooked and soaked samples were dried in a forced-air oven to 10% moisture. Moisture treated black bean seeds were milled using a burr mill/roller mill system. The burr mill was used as a prebreak system that reduced black bean to a size similar to a kernel of wheat and removed most of the seed coat. The broken black bean cotyledons were fed onto the roller mill where they were reduced in size and adhering seed coat was removed. Total cotyledon flour extraction ranged from 74.9 to 72.1% for beans that were cooked 5 and 20 min, respectively; 73.3 to 72.4% for beans that were soaked 6 and 24 h, respectively; and 74.9 to 49.4% for seed tempered to 6 and 14% moisture, respectively. Bulk density of cotyledon flour was 0.79 and 0.73 g/cm³ for beans cooked 5 and 20 min, respectively, and 0.86 and 0.68 g/cm³ for beans tempered to 6 and 14%, respectively. Soaked-dried treatments did not affect bulk density of cotyledon flour. Cotyledon flour color (CIE L-value) was affected most by cooked-dried or soaked-dried seed treatments, as anthocyanins leached from seed coat and stained the cotyledons. Moisture treatments did not affect total starch or protein content (AACCI Approved Methods 76.13.01 and 46-30.01, respectively) of cotyledon flour. However, starch damage (AACCI Approved Method 76-31.01) increased from 0.3 to 3.1% as cooked time increased from 5 to 20 min. Little starch damage occurred in cotyledon flour from soaked or tempered seed.