PROTEINS FROM CRAMBE ABYSSINICA OILSEED - I - ISOLATION PROCEDURE

Crambe abyssinica is a promising new oil crop because of the specific properties of its oil. However, little information is available concer ning the properties of the proteins, which constitute a major componen t of the seed. Therefore, a method for the isolation of proteins from Crambe seeds was developed. Protein extractability for whole and dehul led Crambe meal was studied as a function of pH. Highest extractabilit y was obtained with dehulled meal at pH 11. Double extraction at this pH increased the extractability to about 66%. Protein precipitation fr om the above-mentioned extract was studied as a function of pH with an d without addition of a precipitating agent, i.e., carboxymethylcellul ose (CMC). Addition of CMC resulted in a protein recovery of about 75% at pH 4.4. Without CMC, about half of the protein was recovered by is oelectric precipitation. The remaining soluble protein could be concen trated by ultrafiltration with a recovery of about 65%. The developed process, not including CMC addition, results in two protein fractions, i.e., an isoelectric precipitate (protein content 75%) and a retentat e (protein content 87%), which together account for about 50% of the p rotein present in Crambe meal. Application of heat decreased protein e xtractability, but the protein contents of the resulting fractions wer e comparable to those from non-heat-treated meal.