APPLICATION OF NEW METHODOLOGY TO CANOLASEED PROTEIN ISOLATION. B. Welsh* and M.A.H. Ismond,Food Science Department. University of Manitoba, Winnipeg,Manitoba R3T 2N2.

New methodology is being developed to isolate protein fractionsfrom canola meal with almost complete elimination of antinutri­tional factors. Modifications of a unique protein micellar mass(pM M) procedure developed initially for pulse storage proteins hasresulted in canola extracts of 95% protein. Isolate phytic acid andglucosinolate levels have been reduced to 5 and 10010 of the originalmeal, respectively. In addition, the average phenolic reduction inthe extract has been found to be 12.9% of the raw meal. An enthal­phy of denaturation value (6H) of9.67 J/g for the extract reflectsthe mildness of the isolation. Commercialization of this process mayimpact the economics of canola production; the value of the pro­tein component would increase if it were suitable for human con­sumption.

EFFECT OF PALM OIL ON THE POLYMORPHIC STABIL·ITY OF HYDROGENATED CANOLA OIL: A KINETICAPPROACH. V. D'Souza* and J.M. deMan, Department of FoodScience, University of Guelph, Guelph, Ontario NIG 2WI.

The effect of adding 15% palm oil to non-selectively hydrogenatedcanola oil was investigated. Polymorphic transition was observedby x-ray diffraction and quantitated using soft laser scanning den­sitometer. Polarized light microscopy was used for observing crys­tal growth. Differential scanning calorimetry at heating rates of 5and 8°C per minute was used for demonstrating crystallizationbehavior. Kinetic parameters were obtained by analyzing peaks inthe DSC thermograms using the Borchardt and Daniels method.Palm oil had an effect on the polymorphic stability of hydrogenatedcanola oil which is most likely due to the diglyceride content of palmoil.

QUANTITATIVE ANALYSIS OF GLUCOSINOLATES INRAPESEED CULTIVARS BY MEANS OF HIGH PERFOR·MANCE LIQUID CHROMATOGRAPHY. R.R. Barefoot*,Q.Y. Deng, L.L. Diosady and L.J. Rubin, Department of ChemicalEngineering and Applied Chemistry, University of Toronto,Toronto, Ontario M5S IA4.

The glucosinolate compositions of several new varieties of rapeseedhave been determined by modified liquid chromatographic methods.Quantitative analyses of desulphoglucosinolates by means of highperformance liquid chromatography, of intact glucosinolates bymeans of reversed-phase ion-pair liquid chromatography, and ofsilyl derivatives of desulphoglucosinolates by means of gas chro­matography were compared. Sample preparation time for the anal­ysis of intact glucosinolates was less than for desulphoglucosino­lates. An advantage of the liquid chromatographic methods was thatindolyl glucosinolates are less liable to decomposition than in thegas chromatographic method.

LYSINOALANINE CONCENTRATIONS IN RAPESEED PRO·TEIN MEALS AND ISOLATES. R.R. Barefoot*, Q.Y. Deng,L.L. Diosady, L.J. Rubin and Y-M. Tzeng, Department of Chemi­cal Engineering and Applied Chemistry, University of Toronto,Toronto, Ontario M5S IA4.

Concentrations of Iysinoalanine in rapeseed meal and rapeseedprotein isolates were determined as dansyl derivatives by means ofhigh performance liquid chromatography. The method of analysiswas optimized to give a high, reproducible yield of the derivative.Rapeseed meal samples were prepared by simultaneous extractionof canola seed with hexane and methanol containing dissolvedammonia. Rapeseed protein isolates were prepared by the extrac­tion of the oil-free meal with aqueous alkaline solutions, then byisoelectric precipitation and purification by membrane processing,followed by drying. When mildly alkaline conditions were used, themeal and isolates contained very low concentrations of lysinoalanine.

ALTERNATIVE OILS AND FATS: MICROBIAL L1PIDS.G. Turcotte, Department of Chemical Engineering, University ofOttawa, Ottawa, Ontario KIN 6N5.

The degree of unsaturation of the oil produced intracellularly bythe mature cells of the red yeast Rhodosporidium toru/oides wasfound to be similar to that of many vegetable oils. The composi­tion of the oil varied slightly when the incubation temperature and

362 / Abstract

the pH ranged from 25 to 35°C and from 4.5 to 7, respectively.However, 35-60% (w/w) of the oil was present as polyunsaturatedC 18 fatty acids in the exponential phase of growth as opposed to20% in mature cells. These results will be discussed with respect toapplications in the food industry.

PHASE TRANSITIONS IN MICROSOMAL MEMBRANESFROM CHILLING SENTITIVE AND RESISTANT TOMATOPLANTS AND FRUIT. A.G. Marangoni and D.W. Stanley,Department of Food Science, University of Guelph, Guelph, OntarioNIG 2WI.

The thermal response of microsomal membranes from the leavesand mature green fruit pericarp of two tomato varieties differingin their chilling sensitivity was determined by electon spin resonance(ESR) and fluorescence polarization (FP) spectroscopy. Lipid phasetransitions in the membranes were determined by EPR at 12°C forboth the sensitive leaf and fruit and at 4QC and 8°C for the resis­tant leaf and fruit respectively. Phase transitions were determinedby FP at 10°C and 5°C for the resistant fruit and leaf and at 12°Cand 15°C for the sensitive leaf and fruit membranes respectively.Membrane structural parameters were complemented with chlo­rophyll fluorescence and ultrastructural studies. Phase transition tem­peratures can be used as an indicator of resistance towards chilling.

MODIFIED ATMOSPHERE STORAGE OF SWEETCHERRIES. CA. Thompson*, CH. Wu and W.D. Powrie, Depart­ment of Food Science, University of British Columbia, Vancouver,British Columbia V6T 2A2.

The storage stability of sweet cherries (Prunus avium cv. Lambert)under modified atmosphere packaging was studied. Fruit was packedin bags composed of single component and laminated plastic filmsof low, intermediate, or high permeability. Bags were flushed witha gas mixture of carbon dioxide, oxygen, and nitrogen, and storedat 1°C for up to eight weeks. The concentrations of phenolics, acids,sugars, and vitamin C were monitored during the eight-week storageof the cherries. Texture was measured by a compression methodwith the Instron texturometer, and surface colour was assessed bythe Hunter colorimeter. Physico-chemical changes were related tochanges in the sensory characteristics of the fruit.

EFFECT OF CATECHIN AND ACETALDEHYDE ONCOLOUR OF SASKATOON BERRY PIGMENT IN AQUEOUSAND ALCOHOLIC SOLUTIONS. R.C Green* and G. Mazza,Department of Food Science, University of Manitoba, Winnipeg,Manitoba R3T 2N2, and Food Science and Technology Laboratory,Agriculture Canada Research Station, Morden, Manitoba ROG IJO.

The effect of catechin and acetaldehyde addition to aqueous andalcoholic solutions of saskatoon berry pigments was investigatedby UV/vis spectrometry, high performance liquid chromatographyand Hunterlab colourimetry. In both solvent systems addition ofcatechin alone had no effect on the colour characteristics of the pig­mented solutions. Presence of acetaldehyde alone and with cate­chin, however, increased colour intensity of both aqueous and alco­holic solutions. In all colour intensified samples the maximumconcentration of anthocyanin-acetaldehyde-catechine complex(es)was found 12-15 days after addition of acetaldehyde and catechin.Hue angle of the solutions accurately measured the colour inten­sification reaction.

QUALITY ASPECTS OF SASKATOON BERRIES: POSSIBIL·ITIES FOR IMPROVEMENTS THROUGH PLANT BREED·ING. C Davidson* and G. Mazza, Agriculture Canada ResearchStation, P.O. Box 3001, Morden, Manitoba ROG IJO.

Saskatoon berries from 4 species, 20 cultivars and 25 seedlingswere analysed for fruit size, seed and pulp content, acidity, moisturecontent and soluble solids. Size (fresh weight) ranged from 0.49 to1.25 gm/berry; seed content varied from 4.1 to 17.3% (fresh weight)and 8.3 to 27.0% (dry weight); moisture content ranged from 68to 84%, pH varied from 3.4 to 4.6; and soluble solids ranged from10 to 26% (fresh weight). Potential for improvement through plantbreeding will be discussed with emphasis on berry quality charac­teristics.

J. Inst. Can. Sei. Teehnol. Aliment. Vo!. 21, No. 4. t988