Fate of Singrin in Methanol/Ammonia/Water-Hexane Extraction of B. juncea Mustard Seed

The individual glucosinolates present in B. juncea mustard seed were determined. Sinigrin (allyl glucosinolate) was the major glucosinolate of mustard seed and constituted 92.9% of the total glucosinolates. The effect of CH₃OH/NH₃/H₂O-hexane treatment on the concentration of glucosinolates was studied. Over 97% of sinigrin originally present in the seed was removed by the above solvent extraction system, mainly in the intact form. Breakdown products of sinigrin were quantified in the treated meal, in the extracted oil and in the polar phase (gums). Aglycon products were allyl cyanide, allyl isothiocyanate and 2,3-epithiopropane cyanide. Sugar breakdown products were glucose, thioglucose, thioglucose dimer and furfuryl alcohol. Desulfosinigrin was a minor decomposition product and might have acted as an intermediate in the decomposition of sinigrin.     

Effect of Lectins on Salivary and Pancreatic Amylase Activities and tlhe Rate of Starch Digestion

Digestion of wheat starch (WS) and red kidney bean (RKB) starch by pancreatic (PA) and salivary (SA) amylase in the presence or absence of lectins was determined. Compared with WS, digestion of RKB starch by PA and SA was 70.0% and 66.6% lower, respectively. RKB lectin added to WS at the hemagglutinin activity level in RKB starch resulted in significantly decreased digestion with PA (63.9%) and SA (43.8%) as did heated RKB lectin with insignificant hemagglutinin activity (41.1% with PA, 35.8% with SA). Jack bean lectin (concan-avalin A) also resulted in reduced rate of starch digestibility. Kinetic analyses revealed noncompetitive inhibition by RKB lectins on both amylases. Results confirmed the role of lectin in reducing the rate of starch digestion and its possible health benefit.     

Effect of Methanol-Ammonia-Water Treatment on the Concentration of Individual Glucosinolates of Canola

The effect of methanol-ammonia-water/hexane extraction of canola seed on the content of individual glucosinolates of their resulting meals was investigated. The level of original glucosinolates retained in the treated meals varied between 6% to 15% as determined by gas chromatography and high performance liquid chromatography. These correspond to values of about 4% to 10% for the aliphatic glucosinolates found in seeds routinely analyzed for canola designation. The concentration of these aliphatic, nonindole, glucosinolates in the treated meals was less than 1.8 μmol per gram while their total concentration did not exceed 4.3 μmol per gram of meal.     

INDIVIDUAL GLUCOSINOLATES IN SIX CANOLA VARIETIES

The glucosinolate composition of canola varieties ofAltex, Candle, Regent, Tower, Triton and Westar were determined by gas chromatography (GC) and high-performance liquid chromatography (HPLC). Twelve glucosinolates were detected and their identities confirmed by comparison with the retention times of known glucosinolates and by mass spectrometry (MS). The major glucosinolates present in canola meals were gluconapin (3-butenyl), progoitrin (2-hydroxy-3-butenyl), glucobrassicanapin (4-pentenyl), glucobrassicin (3-indolylmethyl) and 4-hydroxyglucobrassicin (4-hydroxy-3-indolylmethyl). Indole glucosinolates were quantified better by HPLC than GC method of analysis. Sulphinyl glucosinolates were determined only by the HPLC methodology due to the yield of multiple peaks by GC.