Abstract
Two processing schemes for the production of protein products from commercial canola meal were developed in this study. One included extraction of the meal with trypsin treatment at pH 8 and caustic solution at pH 1 1, diafiltration followed by ultrafiltration to recover and concentrate the resulting protein hydrolysates, and freeze-drying. The other method consisted of washing of the meal with a 4% NaCl solution prior to the combined extraction without using the membrane separation step. The washing method was found to be effective for removal of phytic acid and the complete elimination of glucosinolates with about 20% nitrogen loss in the acidic pH range. A substantial improvement in nitrogen extractability of commercial canola meal was achieved by extraction with trypsin hydrolysis. Over 90% nitrogen extractability was obtained at the optimized trypsin-to-meal ratio of 1:200. The protein product prepared by the process involving membrane separation had 61.6% protein, 1.5% phytic acid, and 2.2mmole/g glucosinolate with nitrogen recovery of about 75%. However, the starting meal had 3.65% phytic acid and 1.77 mmole/g glucosinolate. The process which included washing with 4% NaCl resulted in a protein product containing about 62% protein and very low amounts of phytic acid (0.22%) with no detectable glucosinolates. A nitrogen recovery of 66.8% was achieved as well. The protein products produced by both processes exhibited excellent nitrogen solubility, almost 100% at both pH 7 and pH 10, and over 53% at pH 4.5. In comparison with commercial soy concentrate, these products exhibited good emulsifying capacity, excellent emulsifying activity, and foaming capacity. However, they had poor emulsion and foam stabilities.
Lin, Kuo-Min (1998). Preparation and selected functional properties of protein products from commercial canola meal. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1998 -THESIS -L56.