Flavour Quality Evaluation of Processed Saskatoon Berries

chromatographic methods when the samples were analysed immediately after spiking with cyanide. Disappearance of cyanide on standing in a fruit matrix was noted by both methods. With the kit, the added cyanide at 500 ppm level was undetectable after about two days. The chromatographic however, showed residual cyanide even after two weeks. Capillary gas chromatography / mass spectrometry (GC/MS) was used to identify flavour components of frozen saskatoon berries. Juices were prepared by both hot and cold press methods and samples were obtained for GC/MS by solvent extration. FLAVOUR QUALITY EVALUATlON OF PROCESSED SASKATOON BERRIES. S.E. Lutz', L.R.J. Dowdell, l.J. Hawrysh and P. Sporns, Depl. of Foods and Nutrition, University of Alberta, Edmonton, Alberta T6G 2M8. Capilary gas chromatography/mass specrometry (GC/MS) was used to identify flavour components of frozen saskatoon berries. Juices were prepared by both hot and cold press methods and samples were obtained for GC/MS by solvent extraction. Major peaks identified in the juice extracts include benzaldehyde, methyl and ethyl esters of benzoic acid, benzeneethanol, benzenemethanol, 2-methoxy-4-2-propenyl phenol, and linalool oxide. Results indicate significant differences between the hot and cold pressed juices. Relationships between sensory and GC/MS are being examined. QUATlFICATION OF PENICILLIUM ROQUEFORTJ (PR) TOXIN BY REVERSE PHASE HIGH PERFORMANCE LIQUID CHROMATOGRAPHY. K. Siemens' and J. lawistowski, Agri-Food Biotechnology Laboratory, Manitoba Research Council, University of Manitoba, Food Science Dept., Winnipeg, MB R3T 2N2. PR toxin is secreted by some strains of Penicillium roqueforti used in the production of blue-veined cheeses. A new method for the detection and quantification of PR toxin using a reverse phase HPLC has been established. The proposed method can be used for the quantification of PR toxin with sensitivity of 5 mg per run and qualitative analysis of about 2 mg toxin. The precision of this method based on 20 runs was good. Retention times for PR toxin were highly reproductible with the coefficient of variation of 0.4070. NUCLEAR MAGNETIC RESONANCE AND HYDROPHOBICITY PARAMETERS OF THE CORN PROTEIN ZEIN. G.E. Arteaga' and S. Nakai, Depl. Food Science, University of British Columbia, 6650 N.W. Marine Dr., Vancouver, B.C. V6T IW5. Uses of zein in food products is limited by its insolubility caused by its high hydrophobicity. In this study the effect of different treatments (sonication, solvent extraction, hydrolysis and peroxide addition) on proton Nuclear Magnetic Resonance spectra (NMR), fluorescence probe hydrophobicity (FPH) properties, and solubility of zein was investigated. Most treatments affected the NMR spectra parameters, the FPH values and increased the solubility. In addition, FPH could be related to peak areas of the aliphatic and aromatic regions of the NMR spectra. Sharpening of NMR peaks suggested that leucines in zein have a high mobility after sonication and solvent extraction. THE EFFECT OF ENVIRONMENTAL MANIPULATION ON THE MICELLE RESPONSE OF THE 12S CANOLA GLOBULIN. D.A. Burgess', S.D. Arntfield, M.A.H. Ismond, and E.D. Murray, Dept. Food Science, University of Manitoba, Winnipeg, MB RH 2N2. The effect of pH, ionic strength and protein concentraction on the capacity of the 12S canola globulin to form micelles was investigated using light microscopy. Upon diluting the salt extract, micelles formed. Differential scanning calorimatry, electrophoresis and chromatography were used to assess protein conformation. In most environments considered, the protein remained relatively 190/ AB

native. The observed micelle response was characterized by various combinations of individual micelles, micelle aggregates and protein sheets. The goal of solvent manipulation studies is to predict and manipulate the protein interactions governing the formation of micelles into protein structural networks in food systems. EVALUATION DE LA PERMEABILITE A L'ETHYLENE DU CHLORURE DE POLYVINYLE. E. Savoie', G. Doyon', C. Gagnon' et F. Brunet 2, ICampus Haute technologie de St-Hyacinthe et 2Agriculture Canada, 3600 boul. Casavant ouest, St-Hyacinthe, Quebec J2S 8E3. Le but du projet etait d'evaluer rapidement la migration de l'ethylene (C 2H 4) 11 travers un film plastique alimentaire. Le materiel utilise (PVC) a ete etudie 11 3, 10, 17 et 25°C. Les taux de desorption et de transmission ont ete calcules pour obtenir les constantes de permeabilite (P) aux diverses temperatures. La permeabilite 11 I'ethylene passe de 120, 307 11 366, 662 cm 3 .um/m 2.jr.atm avec I'augmentation de la temperature. De plus les rapports de selectivite (p) des QIO et de l'energie d'activation (Ea) sont presentes et compares avec d' autres gaz (02 et CO 2) pour le meme polymere. EFFET DE LA TRANSFORMATION SUR LES RESIDUS DE THIABENDAZOLE DANS LES POMMES DE TERRE. France Blouin', Joseph Makhlouf et Fran~ois Castaigne, Departement de science et technologie des aliments, Universite Laval, Ste-Foy, Quebec GIK 7P4. L'etude visait 11 verifier I'influence de differentes methodes de preparation et de cuisson sur les residus de thiabendazole, TBl, dans la pomme de terre. Deux cultivars, Kennebec et Superieur, ont ete traites avec du TBl, aux doses de 0 - 42 - 84 et 189 ppm. Les methodes de transformation etant: lavage, pelage, friture, cuisson au four conventionnel et au four micro-onde, cuisson dans I'eau. Les residus de TBl ont ete mesures dans la chair de la pelure. Les residus de TBl se retrouvent principalement dans la pelure. Le niveau de TBl etant de dix 11 cent fois plus important dans la pelure. La variete influence I'accumulation de TBl. Le pelage elimine environ 99% des residus de TBl, le lavage jusqu'1I 90% tandis que les autres traitements permeltent d'eliminer la totalite des residus dans la chair. STRUCTURAL CHANGES IN BLUEBERRIES (VACCINJUM MYRTJLLOJDESJ EXPOSED TO MODIFIED ATMOSPHERES. D. Montpetit', K. Lapsley, Agriculture Canada, Centre de recherche et de developpement sur les aliments, St-Hyacinte, Quebec J2S 8E3. Mature blueberries were exposed to three modified atmospheres (10% O 2/20% CO 2; 30% O2/20% CO 2; 20% 02) for a period of twenty-one days. Samples were taken weekly for optical and electron microscopy, to monitor any visible structural changes occuring in the region of the epiderm. Variations in cellular organization resulting to loss of integrity and redistribution of anthocyanins content were observed and related to chemical analysis. Des fruits matures de Vaccinium myrtilfoides (bleuets) furent soumis 11 trois atmospheres modifees (10% O2/20% CO 2; 30% 02/20% CO 2, 20% 02) durant vingt et un jours. Des prelevements hebdomadaires furent effectues pour la microscopie optique et electronique, dans le but de cerner tout changement visible dans la region de l'epiderme. Des variations dans I'organisation cellulaire generale resultant en une perte d'integrite, ainsi qu'une redistribution des anthocyanes. MODIFIED ATMOSPHERE PACKAGING OF MINIMALLY PROCESSED BUTTERNUT SQUASH. S.L. Wang' and c.L. Chu, Horticultural Products Lab, Horticultural Research Institute of Ontario, Vineland Station, ON LOR 2EO. A passive modified atmosphere packaging method using polystyrene foam trays and PVC wrapping films was tested for its adaptability to current trade practice. Packages with known volume and weight of produce were heat-sealed and stored at 6°C 1. Ins(. Can. Sci. Techno/. Aliment. Vcl. 24, No. 5, 1991