Yg. Liu et al., CRAMBE MEAL - REMOVAL OF GLUCOSINOLATES BY HEATING WITH ADDITIVES ANDWATER EXTRACTION, Animal feed science and technology, 48(3-4), 1994, pp. 273-287
In order to remove glucosinolates from dehulled and defatted crambe me
al, various treatments involving heating with or without chemical addi
tives and aqueous extraction were investigated on a laboratory scale.
The results showed that the levels of vinyl-oxazolidine-thione (OZT) a
nd isothiocyanates (ITC) in crambe cake were reduced by 60% after heat
ing at 100-110-degrees-C for 60-80 min and reduced by 95% upon additio
n of 2-3% sodium carbonate (Na2CO3) or 1% ferrous sulphate (FeSO4.7H2O
). Simultaneously, up to 2.5% dry matter of crambe cake was lost durin
g heating, which is mainly attributed to the evaporation of the glucos
inolates as well as their derivatives. More glucosinolates were decomp
osed in the presence of a high moisture content. A 10% reduction of ly
sine content was observed during heating and a further 10% by addition
of the chemicals. Water extraction removed nearly all the glucosinola
tes from the meal, but recovery of dry matter and protein was largely
dependent on sample pre-treatment and filter porosity. Prior heating i
ncreased dry matter recovery from around 50 to 80%, and crude protein
from 45 to about 90%. The palatability of the crambe meals was tested
in piglets (20-38 kg liveweight) during a 4 week period, in which the
proportion of crambe meal in the diet was increased by 1% daily. A min
imum dietary inclusion (3%) of untreated crambe meal made the diet unp
alatable and led to poor growth of the piglets (44 g day-1). However,
the intake of diets containing up to 20% toasted crambe meal was equal
to the control, resulting in the same growth rate (570 g day-1) as on
a commercial diet. The results suggest that adequate treatment of cra
mbe meal can result in a product with good property as an ingredient i
n pig diets.