Cereals & Grains Association
Log In

Effects of pretreatments on removing the seed coat from the cotyledon of black bean
S. FERNANDO (1), C. Hall (1), F. Manthey (1) (1) North Dakota State University, Fargo, ND, U.S.A..

Separation of seed coat from the cotyledon might result in additional black bean ingredients that could be used in food products. The objective of this study was to determine the effects of cooking and tempering pretreatments in combination with drying on the ability of removing the seed coat from the cotyledon of black bean using a burr mill. Black beans were cooked in boiling distilled water for 0, 5, 10, and 20 min and dried to the original moisture content in ambient air and at 90°C in a forced-air oven. Also black beans were tempered with distilled water to ‘as is’ and 10, 20, 30, 40 and 50% moisture, allowed to equilibrate for 24 hours and dried to the original moisture content in ambient air and at 90°C in a forced-air oven. Pretreated black beans were milled using a laboratory-type Burr mill and aspirated to remove the seed coat from the prebreak seed fraction. Seed coat yield after burr mill, seed size and seed hardness were significantly (P<0.05) affected by the boiling time and tempering moisture levels. The boiling time had no significant (P<0.05) effect on the cotyledon flour color but 30% temper moisture level had given the lightest cotyledon flour color. The results of this study indicate that cooking and tempering pretreatments enhanced seed coat removal during milling on a burr mill.  In general, seed coat removal was greater with tempering than with boiling pretreatments. Seed coat removal was greatest with 10 min cooking or with 30% tempering pretreatments that were dried at 90°C.