The development of a castor meal detoxification and deallergenation technology

Abstract

This research has led to development of techniques for a detoxification and deallergenation of castor meal suitable for commercial applications. An in vitro immunodiffusion method, in conjunction with a dilution technique, was found to be very sensitive, specific, and reproducible for quantitative determination of CB-1A contents. In order of preference, sodium hydroxide-sodium hypochlorite mixture, calcium hydroxide, sodium bicarbonate, and sodium hydroxide, at 2% level each, were very effective in destroying more than 98% of CB-1A when used in combination with proper heat treatment. Proper mixing of chemicals with the meal was of paramount importance for effective destruction of CB-1A. Extruders were found to be very effective high temperature-short time reactors for destruction of CB-1A if used with proper chemicals. Extrusion alone, however, was not as effective for CB-1A destruction. To be effective, the extrusion temperature should reach at least 130°C, and preferably 150°C. Extrusion processing of chemically-treated castor meal is readily adaptable for scaled-up commercial production of detoxified and deallergenated castor meal as demonstrated by Wenger X-20, X-25, and X-200 runs. The castor seed allergen could be reduced by about 90% of the original level when conventional castor seed processing steps were used. However, the small amount of CB-1A remaining in the meal was still able to give a positive allergenicity test for the meal. Ricin was completely destroyed during prepressing of castor seeds or desolventization of solvent extracted meals. The hemagglutinin reaction technique was relatively simple, sensitive, and reproducible and could be used as a routine analytical tool for ricin toxicity testing. Biochemical changes occurring during the deallergenation process were investigated. However, due to the limited time and scope of the current research, additional studies are still needed to elucidate the mechanism of deallergenation. As demonstrated by chick and swine feeding studies, the detoxified and deallergenated castor meal was determined to be safe for use as animal feeds. However, the low PER values indicated that the treated castor meal could not be used as the sole source of dietary proteins for animals or might have to be supplemented with amino acids.