G. C. Mustakas

Crambe seed processing: Improved feed meal by ammoniation

An improved crambe meal has been developed by using an ammonia-heat treatment to give significantly better nutritive value and acceptability. The quantity of ammonia permanently bound as nitrogen in the processed meal was from 0.5 to 1.5% of the meal weight and varied with conditions of reaction. Destruction of the undesirable thioglucoside fraction of the meal was demonstrated by paper chromatograph changes and by the absence of the thioglucoside conversion product thiooxazolidone. Ultraviolet-absorbing compounds in the meal, at least one of which is associated with bitterness, were also modified. Feeding experiments with chicks and cattle show the improved palatability and nutritional quality. Incorporation of the ammonia reaction into desolventizer-toaster operations should be possible to provide an economical means of improving the feeding value of crambe meal.

Methods for determining thioglucosides inCrambe abyssinica

Four methods are described for the determination of thioglucosides inCrambe abyssinica: sulfate ion, sulfur balance, silver complexing, and hot-water extraction. The analytical results of all four methods agree closely as to the thioglucoside content in dehulled, defatted meal, from 11–12%. Any one of these methods should be useful in studying new plant species because approximate thioglucoside content is obtained even though the specific thioglucosides and isothiocyanates involved may not be known.

Phytic acid removal from soybeans by a lipid protein concentrate process

Over 90% of phytic acid has been removed from full-fat soy flour by a lipid-protein concentrate process previously reported in 1974 by the Northern Regional Research Center. In the current study, parameters for optimizing phytic acid removal were evaluated. By changing both the molar concentration of the calcium chloride solution used and the pH of the initial acid slurry, various amounts of phytic acid and mineral elements were recovered in the acid-precipitated curd. A mathematical treatment of the data using multiple regression analusis showed phytic acid removal possible from 10 to 90%, zinc recovery from 10 to 90%, and calcium concentrations equalling twice that of the original starting flour. All variable conditions introduced into the process had no effect on protein (90–93%), fat (98–100%), and iron (94–96%) recoveries. The results presented in this report can be applied to a large number of processes now being used for making edible soy proteins, and thereby low phytin-containing products can be acheived.

Crambe seed processing: Decomposition of glucosinolates (thioglucosides) with chemical additives

Crambe meal was cooked with a variety of bases and metal salts to study decomposition of the undesirable glucosinolate (thioglucoside),epi-progoitrin. Salts of iron and copper were preferred because they were the most active decomposers and because they did not reduce the lysine content as did the alkalies. An unsaturated hydroxy nitrile, representing about 25 mole per cent of the decomposedepi-progoitrin, was the major reaction product left in the cooked meal. A thionamide product, representing about 7 mole per cent of the decomposedepi-progoitrin, was also observed in meals cooked with metallic salts. The thionamide was relatively unstable in moist, hot crambe meal, especially at basic pH, and may therefore be an intermediate in a complex decomposition path. Rats fed ferrous sulfate-treated crambe meal as 30% of a protein sufficient diet gained 70% compared with a basal control. Enlargement of thyroid, liver and kidneys was about 1.5 times that of the control organs. A crambe meal heated under the same conditions but without ferrous sulfate and fed at the same diet level caused 100% mortality within two weeks.

Crambe seed processing. improved feed meal by soda ash treatment

Crambe seed, like rapeseed, is characterized by having thioglucosides and perhaps other antigrowth factors that diminish feed value and palatability. A soda ash cooking process was developed that modifies the thioglucosides in crambe meal and significantly improves its feeding value. Destruction of the undesirable thioglucoside fraction of the meal was demonstrated, not only by paper Chromatographic changes but also by negative results in tests which were based on conversion of the thioglucoside to thiooxazolidone. Sodium carbonate, added at a level of 1.4% (whole seed basis), destroys both the goitrin precursor,epi-progoitrin thioglucoside, and the ultraviolet-absorbing compounds in the meal, at least one of which is associated with bitterness. Animal-feeding tests demonstrated the improved palatability and nutritional quality of the meal.

Processing ofcrambe abyssinica seed in commercial extraction facilities

Crambe abyssinica seed was processed in four commercial oilseed crushing facilities, two utilizing prepress solvent extraction and two utilizing straight solvent extraction techniques. Mill capacities ranged from several T/day to 200 T/day. Crambe throughput in the larger facilities ranged from 30 to 150 T/day. Seed, press cake, flakes and finished meal samples were collected and analyzed during and following the runs. On-site testing included measurements of moisture, oil, glucosinolate and temperature and estimates of thioglucosidase enzyme activity. Three to 7 T of defatted meal were produced for each of four beef cattle feeding studies, and oil produced was blended into commercial erucic acid production streams. Except for one run, thioglucosidase inactivation had to be completed in the desolventizing/toasting (DT) unit, and the high temperatures required resulted in destruction of glucosinolate and the formation of aglucon product, 1-cyano-2-hydroxy-3-butene, and glucose in the finished meals. Protein solubility and lysine levels decreased with excessive heat. Regression analysis was used to examine some of the data for relationships between temperature, moisture, glucosinolate, nitrogen solubility and aglucon products. The results of these runs further demonstrate the feasibility of processing Crambe in commercial oilseed facilities.

Crambe seed processing: Removal of glucosinolates by water extraction

A method is reported for removingepi-progoitrin, the major glucosinolate, from crambe seed meal. Defatted meal was cooked and water extracted or treated with soda ash and then water extracted. Although soda ash aided destruction and removal of glucosinolate factors, there was a 28% reduction in total lysine. In animal feeding tests designed to reflect differences due to toxic factors, soda ash treated and water extracted meals gave the best results. No toxicity was apparent in rats and chicks fed these meals in nutritionally adequate diets. The rat diet included 30% crambe meal for 90 days; the chick diet, 20% crambe meal for 4 weeks. Pathological examinations in both series showed no organ damage.

Critical processing factors in desolventizing-toasting soybean meal for feed

Even though it is well established that both underheated and overheated meals are of inferior nutritive value, comparatively little is known of the fundamental nature of the changes brought about in the protein and how these correlate with the processing conditions during toasting. In the present study we examined the interrelation of several factors in the commercial desolventizing-toasting process for toasting soybean meal and determined how these relate to protein quality of the meal. A total of 48 test runs were made in the pilot plant from two cultivars of soybeans (one high and one low in protein) that were dehulled, flaked, and defatted in a continuous extractor using hexane. The solvent-wet flakes were desolventized and toasted under a variety of conditions. In a simulation of commercial operation, independent variables such as moisture, temperature and time of toasting were mathematically converted to equations for computer fitting of the data, which were used to predict several dependent measurements. Quality of the meal was improved by increasing heating time, jacket steam pressure and moisture content. Moisture level in the toasting operation was directly affected by the hexane level in the feed material to the toaster.

Mustard seed processing: Improved methods for isolating the pungent factor and controlling protein quality

A modified cooking and extraction process for mustard seed is reported in which the pungent factor, allyl isothiocyanate, is separated from the seed to yield triglyceride oil and protein meal. Although removal of the pungent factor from the oil and meal products was previously reported, investigations were continued to develop critical improvements in the process. A reduction in conversion time, combined with steam stripping and shorter heating preiods, resulted in quantitative recovery of the essential oil and in improved protein quality, as measured by the basic amino acids. Biological testing with rats showed the processed meals to be free of toxic and goitrogenic factors and to be well utilized nutritionally. Preliminary estimates indicate that process costs are nearly the same as for a comparable soybean plant.

Crambe processing: Glucosinolate removal by water washing on a continuous filter

Abstract and SummaryCrambe seed was dehulled and screw pressed to remove approximately two-thirds of the oil, and then it was hexane-extracted to remove the rest. The defatted meal was toasted in the presence of moisture to form a crisped meal possessing fast drainage characteristics required for continuous filtration. The crisped meal was slurried with four parts of water, filtered, and washed on a continuous pilot-plant filter. Water washing removed about one-fourth of the meal solids, which contained 92-96% of the glucosinolates. Estimated processing costs for water-washing crambe meal are 22-23 dollars per ton of unwashed defatted meal, in addition to the cost of crushing the seed to oil and meal.