Recently, the scientific community has recognized the potential application of lipophilic compounds of grain amaranth as an active ingredient in nutraceutical supplements and cosmeceutical formulations specifically squalene, sterols, tocols and polyphenols. This research study has actualised the optimisation of a novel methodology for eluting bioactive lipophilic compounds from grain amaranth by employing microwave assisted extraction (MAE). The study developed an approach to exploit the lipids of this unconventional pseudo-cereal for industrial applications. Experimentation of this study was carried out in three phases. In the first phase, pre-optimisation studies were conducted to identify the optimum parameters such as sample particle size, extraction solvent and microwave input power, which determined the experimental domain required to optimise the extraction of oil and its constituents, squalene & stigmasterol. For this purpose a full factorial screening design was operationalized. The second phase accomplished the optimisation process of extracting amaranth grain oil and its constituents, squalene & stigmasterol, by augmenting two consecutive central composite designs, considering factors which weren't included in the factorial design such as sample to solvent ratio, solvent to solvent ratio and extraction time, keeping the constant optimum values for the identified factors. The third phase compared the outcomes of optimised MAE process with optimised Soxhlet extraction quantitatively (oil yield %) and qualitatively (squalene, stigmasterol, polyphenols, α – tocopherol and DPPH free radical-scavenging activity). The optimised MAE method achieved the highest extraction yield of 9.1% amaranth grain oil containing 59.53, 3.17, 1.052 and 0.72 mg/g of squalene, stigmasterol, α - tocopherol and total polyphenol respectively with DPPH free radical scavenging activity of 86.24%, whereas, the optimised Soxhlet extraction achieved its highest extraction yield of 8.8% amaranth oil containing 58.78, 3.06, 0.983 and 0.407 mg/g of squalene stigmasterol, α – tocopherol and total polyphenol, respectively with a DPPH free radical scavenging activity of 70.11%. This attests MAE as a more industrially viable methodology for extracting lipids from amaranth grain over standard Soxhlet extraction methodology not just limited to higher oil yield with reduced extraction time and solvent consumption but also for preserving the best quality of its high value industrially applicable thermostable compounds, squalene & stigmasterol as well as the thermolabile compounds α–tocopherol and total polyphenol, maintaining higher antioxidant scavenging activity. / Les composés lipidiques issus de l'amarante sont maintenant reconnus posséder une bioactivité d'intérêt nutraceutique et cosméceutique, particulièrement pour la squalène, les stérols, tocols et polyphénols. Cette étude a visé l'optimisation de l'extraction microonde des composés bioactifs lipophiles de la graine d'amarante. Cette étude a voulu développer une raison industrielle aux composés lipidiques d'une pseudo-céréale non-conventionnelle. Les expériences de cette étude ont été menées en trois phases. La première étape s'est concentrée sur l'identification des paramètres importants tels la granulométrie, le type de solvant d'extraction, et la puissance microonde, jouant sur l'extraction de l'huile et de ses constituants, la squalène et le stigmastérol. Pour cette étude, un plan expérimental factoriel complet a été utilisé. Pour la seconde étape, l'optimisation de l'extraction a été visée en augmentant le plan expérimental en prenant en considération le ratio échantillon et solvant, le ratio solvant et solvant, et le temps d'extraction, tout en maintenant optimisé les paramètres étudiés à la première étape. La troisième étape a comparé les résultats des conditions optimales d'extraction microonde aux résultats des conditions optimales d'extraction Soxhlet, quantitatif (% rendement en huile) et qualitatifs (composition en squalène, stigmastérol, polyphénols, α-tocophérol et DPPH (capacité phagocyte des radicaux libres). L'extraction optimale microonde de la graine d'amarante a extrait 9.1% d'huile contenant 59.53, 3.17, 1.052 et 0.72 mg/g de squalène, stigmastérol, α-tocophérol et polyphénols totaux avec une capacité phagocyte des radicaux libres de 86.24%. L'extraction optimale Soxhlet a extrait quant à elle, 8.8% d'huile contenant 58.78, 3.06, 0.983 et 0.407 mg/g de squalène, stigmastérol, α-tocophérol et polyphénols totaux avec une capacité phagocyte des radicaux libres 70.11%. Ceci confirme la meilleure performance de l'extraction micro-onde pour l'extraction des lipides de la graine d'amarante sur l'extraction conventionnelle Soxhlet, autant pour le rendement que pour la conservation de la qualité de l'huile, et ses composés thermostable (tels la squalène) et thermolabiles (tels l'α-tocophérol), maintenant une meilleure capacité phagocyte des radicaux libres.

Complexes of the bovine whey protein alpha-lactalbumin and oleic acid that have been reported to have cytotoxic effects against tumor cells but not against healthy cells are of potential interest as new ingredients for functional foods. Understanding the relationship between the structures of the protein and lipid in alpha-lactalbumin-oleic acid complexes, as mediated by the conditions employed in their preparation, and their efficacy as cytotoxic agents against tumor cells is an important prerequisite for the production of such ingredients. The overall aim of the present study was to advance our understanding of this relationship by characterizing alpha-lactalbumin-oleic acid samples prepared under various pH and temperature conditions. Biophysical techniques were employed to examine the secondary and tertiary structures of alpha-lactalbumin, its oligomerization, and the charge state of oleic acid under these conditions. The data obtained were related to the cytotoxicity of these samples against the lymphocytic leukemia (L1210 mouse) cell line, as measured by a cell viability assay. Samples examined were prepared by dissolving millimolar quantities of food-grade alpha-lactalbumin and oleic acid in 25 mM sodium phosphate buffer at pH values: 6.5, 7.4, and 8.5, in order to provide different charge and physical states of oleic acid, and holding at 25, 50, 60, 70, or 80oC for 20 min. The Fourier transform infrared (FTIR) spectra of the samples showed that the oleic acid was in protonated form in the pH 6.5 samples, partly protonated and partly ionized in the pH 7.4 samples, and fully ionized in the pH 8.5 samples. The content of lipid relative to the protein was highest in the samples prepared at pH 8.5 and lowest in those prepared at pH 6.5. Electrospray ionization-mass spectrometric analysis confirmed that the samples prepared in this manner contained oleic acid bound to alpha-lactalbumin, with a binding ratio of up to 10 molecules of the fatty acid per monomer of the protein. FTIR spectroscopy and C:N-analysis showed that the number of lipid (oleic acid + oleate) molecules physically associated with the protein in these samples was much higher. At a concentration of 10 mg/mL, under the conditions of the cell viability assay, the alpha-lactalbumin-oleic acid samples prepared at pH 6.5 had the highest cytotoxicity against the L1210 cell line and the samples prepared at pH 8.5 were not cytotoxic. The cytotoxicity of the alpha-lactalbumin-oleic acid samples prepared at pH 6.5 and pH 7.4 was influenced by their preparation temperature and was highest in samples prepared at 60oC. In assays conducted in parallel with pure oleic acid and pure alpha-lactalbumin, the protonated form of oleic acid demonstrated a cytotoxic effect against the cell line that was independent of the preparation temperature, while neither the ionized form of oleic acid nor the pure protein had a cytotoxic effect. These results confirmed the findings of several other studies that oleic acid is the cytotoxic component in alpha-lactalbumin-oleic acid complexes. Thus, the charge state of the lipid, its concentration in the alpha-lactalbumin-oleic acid samples, and the preparation temperature conditions relative to the transition temperatures of the protein were identified as the combination of factors that influenced the cytotoxic effect on the tumor cell line under the conditions employed. By demonstrating preparation conditions whereby alpha-lactalbumin-oleic acid samples cytotoxic to a tumor cell line could be prepared from food-grade alpha-lactalbumin in millimolar quantities using a heat treatment process that could be adapted to commercial production, the present study has directed the study of cytotoxic alpha-lactalbumin-oleic acid complexes to the field of food science. / Les complexes d'alpha-lactalbumine (protéine de lactosérum bovin) et d'acide oléique, rapportés pour avoir des effets cytotoxiques sur des cellules tumorales, mais pas sur les cellules saines, ont un potentiel très intéressant en tant que nouvel ingrédient pour les aliments fonctionnels. La compréhension de la relation entre les structures de la protéine et des lipides dans les complexes alpha-lactalbumine-acide oléique en fonction des conditions de préparation, d'une part, et leur efficacité comme agents cytotoxiques contre les cellules tumorales, d'autre part, est une condition préalable importante pour la production de ces ingrédients. L'objectif global de la présente étude était de faire progresser notre compréhension de cette relation par la caractérisation des échantillons d'alpha-lactalbumine-acide oléique préparés sous diverses conditions de pH et de températures. Différentes techniques biophysiques utilisées pour étudier les structures secondaires et tertiaires et l'oligomérisation de l'alpha-lactalbumine ainsi que l'état de charge de l'acide oléique dans ces conditions, ont permis de relier les résultats aux données obtenues pour la cytotoxicité de ces échantillons par rapport à la lignée cellulaire souris à leucémie lymphocytaire (L1210), par l'entremise d'un test de viabilité cellulaire. Des quantités millimolaires d'alpha-lactalbumine de grade alimentaire et d'acide oléique ont été dissoutes dans un tampon phosphate de sodium 25 mM à pH: 6,5, 7,4, et 8,5, afin de fournir différentes charges et états physiques à l'acide oléique, et les échantillons ainsi préparés ont été maintenus à des températures de 25, 50, 60, 70, ou 80°C pendant 20 min. Les échantillons étudiés par la spectroscopie infrarouge à transformée de Fourier (FTIR) ont montré que l'acide oléique était entièrement protoné dans les échantillons à pH 6,5, partiellement protoné et partiellement ionisé dans les échantillons à pH 7,4, et complètement ionisé dans les échantillons à pH 8,5. Le ratio lipide:protéine assujetti au pH de préparation a augmenté dans l'ordre suivant: pH 6,5 <pH 8,5 < pH 7,4. L'analyse par ionisation par éléctronébuliseur couplé à un spectromètre de masse a confirmé que les échantillons ainsi préparés contiennent de l'acide oléique lié à l'alpha-lactalbumine, avec un taux de liaison d'un maximum de 10 molécules d'acide gras par monomère de protéine, alors que les analyses de C:N ainsi que les spectres FTIR ont montré que le nombre de molécules de lipides (acide oléique + oléate) physiquement associées à la protéine dans ces échantillons était beaucoup plus élevé. Lors de test de la viabilité des cellules, et à une concentration de 10 mg/mL, les échantillons d'alpha-lactalbumine-acide oléique préparés à pH 6,5 avaient la plus forte cytotoxicité contre la lignée cellulaire L1210 alors que les échantillons préparés au pH 8,5 n'étaient pas cytotoxiques. La cytotoxicité des échantillons d'alpha-lactalbumine-acide oléique préparés à pH 6,5 et pH 7,4 a été influencée par la température de leur préparation et elle était la plus élevée pour les échantillons préparés à 60oC. Dans des essais menés en parallèle avec de l'acide oléique pur et alpha-lactalbumine pure, la forme protonée de l'acide oléique a montré un effet cytotoxique contre la lignée cellulaire qui est indépendant de la température de préparation. Ni la forme ionisée de l'acide oléique, ni la protéine pure n'avaient un effet cytotoxique. Ces résultats confirment les conclusions de plusieurs autres études, c'est-à-dire que l'acide oléique est le composant cytotoxique dans des complexes d'alpha-lactalbumine-acide oléique. Ainsi, l'état de charge du lipide, sa concentration dans les échantillons d'alpha-lactalbumine-acide oléique, et les conditions de température de préparation par rapport aux températures de transition de la protéine ont été identifiées comme étant la combinaison de facteurs qui a influencé l'effet cytotoxique du complexe sur les lignées cellulaires tumorales.

The physicochemical, morphological, pasting and softening kinetics of rice varieties selected from West-African countries were investigated. The studies conducted were aimed at enhancing the adoption and use of these local varieties in improving food security in Africa through the development of acceptable new rice-based products .The varietal, morphological and physiochemical impacts on appearance, pasting, textural properties and softening kinetics were also analyzed. To unravel structural properties of the respective isolated rice starch from the selected rice varieties, scanning electron microscopic analysis was also carried out. The varieties studied were Faro 61, Faro 60, Faro 44, Tox 3145 and Nerica 3. Microscopic studies carried out on the isolated starch indicated that the starch granules were 4.43 -5.62 µm. The structural variations observed did not clearly provide an explanation for the pasting and textural properties of the studied rice varieties. Morphological studies also revealed that the rice granules were polyhedral, irregular in shape and tightly packed. Proximate studies indicated that the rice varieties were composed of 0.35 - 0.52% fat, 0.32 - 0.57% ash , 8.97 - 10.35% protein, 88.63 - 90.08% carbohydrate and 22.4 - 28.50% amylose. The proximate results indicates that these varieties are high protein containing waxy rice varieties. Color parameters (L*and b*) studies of uncooked rice flour samples indicated high values of L* and low values of b* for all the rice varieties. The order of increasing whiteness was found to be Faro 61 > Faro 44 > Faro 60 > Nerica 3 > Tox 3145 while the b* values ranged from 5.09 - 7.26. The high degree of whiteness and low values of yellowness of these rice varieties indicate that their flours would be highly acceptable by most consumers. Results of the pasting properties studies indicated significant differences in the peak viscosity , trough viscosity, final viscosity and set back viscosity of the rice flours. Faro 44 showed a higher peak viscosity value (3984.5 cP) while Nerica 3 indicated the lowest peak viscosity value (2850.5 cP). Faro 44 and Tox 3145 had the highest and lowest trough viscosities, respectively. Break down viscosities were within the 546.5 and 1164 cP range for the rice varieties. Faro 44 had significantly higher breakdown viscosities than other varieties. The result indicated that Faro 44 flour is suitable for the production of value added products such as noodles, due to the ability of its paste to swell sufficiently while remaining intact and stable during sheering. Setback viscosity varied from 865.5 to 2138.5 cP. Faro 44 showed the highest setback viscosity (2138.5 cP) while Faro 61 showed the least (865.5 cP). The pasting temperature of Faro 44 was higher than the other rice varieties and found to be 85.50C. Textural studies indicated hardness decreased with increase in cooking time. When cooked from 5 minutes to 25 minutes, there was gross disintegration of the rice granular structure . These structural changes provide an explanation for the corresponding changes in the tissue strength and elasticity of the studied rice varieties. In addition, the rate of textural changes related with the cooking temperature utilized in this study was found to confirm with two pseudo first-order kinetic mechanisms. The kinetic model utilized indicated that the apparent rate constants K1 a varied from 0.03776 to 0.4468 min-1 while K1 b varied from 0.008475 to 0.013665 min-1 . Over all, variations were observed in the morphological, physicochemical, pasting and softening kinetic properties of all the studied rice varieties. These studies are vital in ensuring an improving quality of rice by thermal processing. / Les variétés de riz étudie étaient Faro 61, 60 Faro, Faro 44, Tox 3145 et Nerica 3. Les observations microscopiques réalisées sur l'amidon isolé ont indique que les granules d'amidon variaient eutre 4.43 et 5.62 µm. Ces variations structurelles n'expliquait pas clairement les propriétés texturales et collantes des variétés de riz étudie. Des études morphologiques ont aussi révélé que les granules d'amidon de riz étaient polyédriques, serre et de forme irrégulière. L'analyse immédiate des macronutriments a révélé que les variétés de riz sont composées de 0.35 à 0.52% de matières grasses, de 0.32 à 0.57% de cendres, 8.97 à 10.35% de protéines, de 88.63 à 90.08% de glucides et, enfin, 22.4 à 28.50% d'amylose. Ces résultats indiquent que ces variétés sont les variétés de riz sont riches en protéines.L'étude sur les paramètres de couleur (L* et b*) des échantillons de farine de riz non cuite indique de valeurs élevées de L* et de faibles valeurs de b* pour toutes les variétés de riz. L'ordre croissant de blancheur a été jugée être Faro 61> Faro 44> Faro 60> Nerica 3> Tox 3145, tandis que les valeurs de b* variaient entre 5,09 et 7,26. Un haut degré de blancheur combine a un faible de jaunissement de ces variétés de riz indiquent que ces farines seraient bien acceptées par la plupart des consommateurs. Les résultats des études des propriétés collantes ont dénoté des différences significatives pour la viscosité maximale, minimale, finale et la viscosité de rechute des farines de riz. Faro 44 a montré une valeur de viscosité maximale élevée (3984,5 cP), tandis que le Nerica 3 indique la valeur du sommet de la viscosité moins grande (2850,5 cP). Faro 44 et Tox 3145 avaient respectivement les plus hautes et les plus basses viscosités minimales. Les viscosités de dégradation se rangeaient entre 546,5 et 1164 cps pour toutes les variétés de riz. Faro 44 avait une viscosité de dégradation nettement plus élevés que les autres variétés. Ce résultat indique que la farine de riz Faro 44 est appropriée pour la production des produits à valeur enrichie, tels que les nouilles, en raison de la capacité de la pâte de gonfler suffisamment tout en restant intacte et stable pendant le cisaillage. La viscosité de rechute varie de 865,5 à 2138,5 cP. Faro 44 a montré la viscosité de rechute la plus élevé (2138,5 cP), alors que Faro 61 a montré la moindre (865,5 cP). La température de gélatinisation de Faro 44 était plus élevée que les autres variétés de riz et établie à 85.5°C. Le etudes texturales ont indiqué que la dureté diminue avec la hausse du temps de cuisson. À la fin du cuisson de 5 minutes à 25 minutes, il y a eu une désintégration brute de la structure granulaire de riz. Ces changements structurels fournissent une explication pour les changements correspondants dans la solidité du tissu et l'élasticité des variétés de riz étudiées. En outre, le taux de changements de texture en rapport avec la température de cuisson utilisée dans cette étude correspond à deux mécanismes cinétiques de pseudo premier ordre. Le modèle cinétique utilisé a indiqué que les constantes de vitesse apparentes K1 a ont varie de 0,03776 à 0,4468 min-1, tandis que K1 b se rangeaient entre 0,008475 et 0,013665 min-1. Ces études sont essentielles afin d'assurer et améliorer la qualité du riz par traitement thermique. Dans l'ensemble, les variations des variétés du riz étudiées ont été observées en tant que leur caractéristiques morphologiques, physico-chimiques, les propriétés de gélatinisation, ramollissement ainsi que les propriétés cinétiques.

The optimization of the synthesis of phenolic lipids (PLs), obtained by the enzymatic transesterification of krill oil (KO) with selected phenolic acids (PAs) in solvent-free media (SFM), as well as their separation, characterization and encapsulation were investigated. Using high-performance liquid chromatography (HPLC), the evaporative light-scattering detector (ELSD) was shown to be a more appropriate tool of detection of PLs. The structural analyses of the synthesized PLs by HPLC/mass spectrometry (MS) suggested the formation of two phenolic monoacylglycerols. Using two immobilized commercial enzymes, Novozym 435 and Lipozyme TL IM, the enzymatic synthesis of PLs from KO with two phenolic acids (PAs), including 3,4-dihydroxyphenylacetic acid (DHPA) and dihydrocaffeic acid (DHCA), was investigated. The use of Novozym 435 and DHPA resulted in the highest bioconversion yield (BY). The central composite rotatable design (CCRD) was used to evaluate the effects of PA concentration (PAC) and lipase concentration (LC) as well as the agitation speed (AS) on the BY of PLs. For the models with PAC, fixed at 10 and 20 mM, the results revealed that LC had a significant quadratic effect (P <0.05) on the BY, whereas a significant linear effect was only obtained with PAC, fixed at 20 mM. The AS had a significant quadratic effect (P <0.05) on the BY, only for the model, with a PAC fixed at 10 mM. At fixed PAC of 20 mM, the response surface model predicted a BY of 75%, using a LC of 62 mg/mL and an AS of 154 rpm. The antioxidant capacity (AOC) and the oxidative stability of PLs, obtained by the enzymatic transesterification of PAs with the selected edible oils (EOs), including flaxseed (FSO), fish liver (FO) and krill (KO) oils, were determined. The statistical analyses of Tukey's test at P <0.05 revealed that the difference in AOC between that of the esterified oils of flaxseed (EFSO) and krill (EKO) and that of EOs was significant (P <0.05). The experimental findings showed that all esterified oils containing PLs had higher oxidative stability when they were subjected to light, oxygen and agitation at 50ºC as compared to that of the EOs; nevertheless, only the esterified fish oil (EFO) showed a significant difference in its peroxide value (PV), when it was placed in the dark at 25ºC. The development of a process to yield gelatin (GE)-gum arabic (GA) multinuclear microcapsules of KO, via complex coacervation, was investigated. A three-level-by-three factor Box-Behnken design (BBD) was used to evaluate the effects of the ratio of the core material to the wall (RCW), with x1 of 1.25:1 to 1.75:1, the stirring speed (SP) with x2 of 2 to 4, over a scale of 10 and the pH with x3 of 3.8 to 4.2, on the encapsulation efficiency (EE). The experimental findings indicated that x3 had the most significant linear and quadratic effects on the EE of KO and a bilinear one with x1; however, x2 did not have any effect. The optimal predicted conditions for a 92% of EE were 1.75:1 for RCW, 3.8 for pH and 3 for SP. The microcapsules, formed by complex coacervation and without any cross-linking agent, were multinucleated, circular in shape and had sufficient stability to maintain their structure. The microencapsulation of the esterified krill oil (EKO), obtained by complex coacervation, was carried out. The experimental findings showed that the presence of DHPA and PLs, in the EKO, affected the stability of GE-EKO emulsion. The ultrasonic liquid processor was found to be a more appropriate device for the emulsification of the EKO into GE, as compared to the high-shear homogenizer. In addition, the capsules prepared with a GE at pH 8.0 showed higher storage stability, with significantly (P <0.05) lower primary oxidative products, as compared to those prepared with a GE at pH 6.5. The microencapsulation of the EKO was effective in delaying the development of primary and secondary oxidation products during a period of 25 days of storage at room temperature. / L'optimisation de la synthèse de lipides phénoliques (PLs), obtenus par la transésterification enzymatique de l'huile de krill (KO) avec des acides phénoliques sélectionnés en milieu réactionnel sans solvant (SFM) ainsi que de leur séparation, caractérisation et encapsulation ont été étudiées. En utilisant la chromatographie en phase liquide (HPLC), le détecteur évaporatif à diffusion de lumière (ELSD) a été sélectionné pour les analyses des composants de KO et ses PLs estérifiés. Les analyses structurales des PLs synthétisés par HPLC/spectrométrie de masse (HPLC/MS) ont suggéré la formation de deux lipides phénoliques monoacylglycéroles. En utilisant deux enzymes commerciales immobilisées, Novozym 435 et Lipozyme TL IM et deux acides phénoliques (PA) modèles y compris l'acide 3,4-dihydroxyphénylacétique (DHPA) et l'acide dihydrocaffeique, la synthèse enzymatique des PLs à partir de KO, a été investiguée. Le meilleur rendement de bioconversion (BY) a été obtenu avec la Novozym 435 et le DHPA. Le plan composite central à caractère rotatif (CCRD) a été utilisé pour évaluer les effets de la concentration de l'acide phénolique (PAC) et de celle de la lipase (LC) ainsi que de la vitesse d'agitation (AS) sur le BY des PLs. Pour les modèles avec PAC, fixée à 10 et 20 mM, les résultats ont montré que la LC a un effet quadratique significatif (P <0,05) sur le BY, alors qu'un effet linéaire a été seulement obtenu avec PAC fixée à 20 mM. L'AS avait un effet quadratique significatif (P <0,05) sur le BY, seulement pour le modèle, avec une PAC fixée à 10 mM. Á PAC fixée à 20 mM, la surface de réponse du modèle a prédit un BY de 75%, en utilisant la LC de 62 mg/mL et la AS de 154 rpm. La capacité antioxydante (AOC) et la stabilité oxydative des PLs dans les huiles de lin (FSO), de poisson (FO) et de krill, ont été déterminées. Les analyses statistiques du test Tukey à P <0,05 ont révélé que la différence en AOC entre celle des huiles estérifiées de lin (EFSO) et de krill (EKO) et celle des blancs a été significative (P <0,05). Les résultats ont montré que tous les huiles estérifiées avec PLs avaient une stabilité oxydative plus élevée quant ils étaient exposés à la lumière et en présence de l'oxygène mais aussi soumis à l'agitation et à 50ºC comparée à celle des EOs. Le développement d'un processus pour produire des microcapsules multinucléaires, en utilisant l'association de gélatine (GE)-gomme arabique (GA) par la coacervation complexe a été investigué. Le plan Box-Behnken (BBD) à trois-niveaux-par-trois facteurs a été utilisé pour évaluer les effets du ratio huile/polymères (RCW) avec x1 de 1,25:1 à 1,75:1, la vitesse de la turbine (SP) avec x2 de 2 à 4, sur une échelle de 10 et un pH avec x3 de 3,8 à 4,2, sur l'efficience d'encapsulation (EE). Les résultats expérimentaux ont indiqué que x3 avait les effets linéaires et quadriques les plus significatifs sur la EE de KO et un effet bilinéaire avec x1; Par contre, x2 n'avait aucun effet. Les conditions optimales prédites pour une EE de 92% étaient 1,75:1 pour RCW, 3,8 pour pH et 3 pour SP. Les microcapsules, formées par la coacervation complexe et sans aucun agent d'articulation, étaient multinucléées, circulaires et assez stables pour maintenir leurs structures. La microencapsulation de l'huile de krill estérifiée par la coacervation complexe a été effectuée. Les résultats ont montré que la présence du DHPA et des PLs, dans l'EKO, avait un effet sur la stabilité de l'émulsion de GE-EKO. L'ultrason utilisé pour traitement liquide a été plus approprié pour l'émulsification de l'EKO dans GE, par rapport à l'homogénéisateur à haut débit. Les capsules préparées avec un GE à pH 8,0 ont montré une stabilité d'entreposage plus élevée avec une PV significativement (P <0,05) moins élevée que celles pour les capsules préparées avec un GE à pH 6,5. La microencapsulation de EKO a été effective pour retarder le développement de produits d'oxydation primaires et secondaires.

The decline of formal lunchtime eating is creating a new market segments and strong growth in the snack food market. Busy modern life with lunch at desks and night in front of computers is for snack food consumption. The unhealthy snacks are composed of sugars and fats and considered as "junk" increasing body weight whereas if these unhealthy snacks are supplemented or enriched with well-balanced nutrients, we can have healthy life with enhanced health benefits and consumer satisfaction. Such enrichments can be accomplished by naturally supplementing these foods with proteins, fiber and antioxidants. My thesis research aims to enhance the value of apple fruit snacks by adding soy protein, orange fiber and grape juice concentrate.The two methods were employed for preparing the fruit snack - direct sheet drying and extrusion-drying. Experimental procedure includes drying (fruit leather) and extrusion process (apple extrudates) of apple fruit to obtain apple fruit snack. This was further enhanced with (0-10%) fibre, (0-10%) antioxidant and (0-20%) protein. These three were varied within the range using a CCRD design and the balance was supplemented by applesauce to make it 100%. Nutritional assessment of snack bars was based on the total antioxidant, protein, water activity, Hunter L∗ a∗ b∗ colour, hardness, phenolic composition and sensory quality. The water activity values (<0.75) suggested that the resultant snack bars would possess a good shelf life. / Le déclin actuel du dîner formel est en train de créer des nouveaux secteurs de marché autant qu'une forte croissance dans le marché des collations. La vie modern occupée, avec ses dîners devant le bureau et ses nuits devant l'ordinateur, est devenue propice à la consommation des collations. Ces collations malsaines contiennent des sucres et du gras et sont considérées comme de la « malbouffe ». En revanche, si ces mêmes aliments étaient supplémentés ou enrichis avec des éléments nutritifs bien équilibrés, nous pourrions jouir d'une vie saine avec plus de bénéfices pour la santé et une meilleure satisfaction du consommateur. De tels enrichissements peuvent être obtenus en enrichissant ces aliments naturellement avec des protéines, de la fibre et des antioxydants. Ma recherche de thèse vise à améliorer la valeur des barres aux fruits aux pommes en y ajoutant des protéines de soya, de la fibre d'orange et du concentré de jus de raisin.Le processus expérimental inclut le séchage (pour produire une pâte de fruits) et l'extrusion du fruit pour obtenir une barre aux fruits aux pommes. Le produit est ensuite enrichi avec de la fibre (0 à 10 %), des antioxydants (0 à 10 %) et des protéines (0 à 20 %). L'analyse nutritionnelle des barres aux fruits est basée sur la teneur totale en antioxydants, en protéines et en humidité, autant que sur la couleur (Hunter L*a*b*), la dureté, la composition phénolique et la qualité sensorielle. L'activité de l'eau suggère que les barres aux fruits produites ainsi seront munies d'une durée de conservation adéquate. Les résultats de l'analyse spectrophotométrique donnèrent des résultats comparables et fortement corrélés (p < 0,05). Les barres aux fruits enrichies avec des éléments nutritifs peuvent donc être des aliments fonctionnels qui offrent une bonne source de protéines, d'antioxydants et de polyphénols.

Food intake in humans is guided by a variety of factors, which include physiological, cultural, economic and environmental influences. The sensory attributes of food itself play a prominent role in dietary behaviour, and the roles of visual, auditory, gustatory and tactile stimuli have been extensively researched. Other than in the context of flavour, however, olfaction has received comparatively little attention in the field of food acceptability. The investigation was designed to test the hypothesis that olfactory cues, in isolation of other sensory cues, play a functional role in food choice and acceptability. Empirical studies were conducted to investigate: the effects of exposure to food odours on hunger perception; the effects of exposure to food odours with both high and low hedonic ratings on food choice, consumption and acceptability; and the application of odour exposure in a restaurant environment. Results from these studies indicated that exposure to the food odours led to a conscious perception of a shift in hunger, the direction and magnitude of which was dependent on the hedonic response to the odour. Exposure to a food odour with a high hedonic rating prior to a meal significantly increased consumption and acceptability (p<0.05), and exposure to a food odour with a low hedonic rating had no significant effect (p>0.05). When applied to a restaurant environment, exposure to a food odour with a high hedonic rating significantly influenced food choice and acceptability (p<0.05). Subject and stimulus variables, contributing to the role of olfactory cues, were identified from the results, facilitating the development of a conceptual olfactory cueing model. The model demonstrates how a series of independent variables, relating to odour exposure, may lead to either an enhancement of dietary patterns or suppression of food intake. The application and implications of the model are discussed. As such this research establishes direct links between stimulus and response in an ecologically valid environment.

This study brings together two bodies of literature, one concerned with the character of services and the other concerned with the nature of quality, in order to explore the nature and possible forms of measurement of service quality. It uses the conference hotel service product as a vehicle for examining judgements about overall service quality. A systematic approach, through a multi-staged methodology, is evolved by first identifying what the product consists of; secondly by establishing what the evaluative attributes are; thirdly by assessing levels of perceived performance on the evaluative attributes and, crucially, the assessment of the overall performance of the product. By using statistical techniques, the evaluative attributes of perceived net quality are examined. This is achieved by analysing which attributes fulfil minimum requirements and which attributes can increase a positive perception of net quality. In addition, the impact of the attributes on net quality is established. The study shows that the specific product consists of a multi-dimensional combination of attributes in varying degrees. The crucial attribute is shown to be dependability of management and staff. In addition, the study reveals that net quality is not only a reflection of incidents of satistaction with the physical - commodities and performed activities. It also needs to take into consideration human interaction as a component in itself. In a wider context the study gives an indication of how the perceived net quality of a product , with a high degree of an activity component, can be examined.

A nation wide survey of the vending industry indicated that the shelf-life of chilled menu items served from vending machines rarely exceeded 24 hours. This necessitated food production and distribution to vending sites on a daily basis. The short life coupled with unpredictable consumer demand may result in high food wastage rates. Vacuum and modified atmosphere packaging (MAP) are known to improve stored raw food quality. In order to optimize the quality and shelf-life of vended foods, the effects of these techniques and length of storage time on menu items were studied. Chicken drumsticks and chicken a la king were either individually cling wrapped, vacuum packed or packed under modified atmosphere (70% CO , 30N 0) and stored for up to 21 days in a chilled foot vending machine. The growth of naturally occurring micro-organisms was delayed in vacuum packed samples, compared with cling wrapped samples. However, direct inoculation studies indicated that this effect was dependent on the nature of the initial microflora. The public health risk of serving cooked food from vending machines was assessed by means of a survey of the operating temperatures of chilled food vending machines and a review of the growth characteristics of the major food poisoning micro-organisms. Th8 surveyed machines were able to maintain temperatures below 5 C, although this temperature was not universally found. The sensory quality of the chicken samples was examined by two trained taste panels and also a consumer panel. Stepwise discriminant analysis of the trained panel scores indicated that packaging and length of storage had a distinctive and unique effect on the sensory quality of both products. The mean consumer scores were used to construct significant (p<0.05) regression models, which showed that on average consumers preferred the fresh unpackaged sample and least preferred the cling wrapped samples. However, when the consumer scores of individuals were examined by means of Prefmap analysis, subgroups were found to exist within the population that held polar viewpoints in opinion. The results show that MAP and vacuum packaging may be used in place of cling wrapping to extend the shelf-life of certain vended menu items, but of more immediate importance to the vending industry is the implementation of proper temperature control to ensure a hazard free syste

There have been a number of studies which have attempted to identify factors affecting successful technology transfer. However, empirical studies of technology transfer, at the level of the user, have been a much neglected area of research despite numerous promptings. Too much attention has been paid to single factor explanations of success, although it is widely accepted that success is a multi-faceted phenomenon. There is also an absence of a suitable definition of success which reflects its multi-dimensional character. This research, therefore, attempts to develop a suitable multi-faceted measure for success and an identification of factors affecting success in the study of the user uptake phase of a technology transfer process; namely the introduction of cook chill technology into catering operations in the UK. A survey of 80 cook chill operations in the UK was undertaken and detailed information was collected from each. A multi-faceted measure of success was developed by using 10 carefully selected success criteria. Each cook chill operation in the sample was allocated a 'score' for each success factor. This process culminated in the formation of a 'success table' of cook chill operations in the sample which enabled the identification of those units which were the most successful and those which were the least successful throughout the technology transfer process. There were numerous differences between the activities of the successful group and those of the unsuccessful group throughout the initiation, implementation and assessment phases of the technology transfer process. The findings of this research, therefore support the notion of success as being multi-faceted. Some of the major factors seen to affect success included: management stability, the extent, quality and efficiency of precook chill development work, communication and involvement with employees and appropriate training, adherence to the technical requirements of the system and a research and development orientation. The overriding finding, however, was the tendency shown by the managers in the successful group to be proactive and those in the unsuccessful group to be reactive.

Changes in intramuscular connective tissue brought about by conditioning were investigated in bovine muscles of different quality. Perimysial and endomysial collagens were solubilized to a small extent during conditioning and residual insoluble collagens in both connective tissue domains were damaged by proteolytic processing. Yields of soluble perimysial material from unconditioned muscles were significantly lower (p = 0.096) than from conditioned muscles. Solubilized perimysial collagen from unconditioned muscles was significantly lower (p = 0.015) than from conditioned muscles with 1±0.8 % of original collagen solubilized for unconditioned muscles and 3.4 ± 3.3 % for conditioned muscles. 87.5 % of the muscles examined showed an increase in percentage solubilized collagen due to conditioning. The main peptide components observed on analysis of insoluble perimysial fractions after CNBr digestion were derived from types I and III collagen. No changes were observed in the major peptide bands due to conditioning. Yields of soluble endomysial fractions representedo, n average,9 4.5 % of total extracted endomysial material for unconditioned muscles compared with 97.5 % for conditioned muscles. Soluble endomysial fractions contained, on average, 0.13 % collagen from unconditioned muscles and 0.22 % collagen from conditioned muscles. The main peptide components observed on analysis of insoluble endomysial fractions after CNBr-digestion were derived from types I and III collagen. Changes observed on the peptide maps, evident as the appearanceo f a number of new bandsf rom conditioned samples,a ppearedt o be muscle specific. % Type III collagen decreased on conditioning, indicating that endomysial type III collagen was preferentially destroyed during - conditioning. In model systems, insoluble perimysium treated with pepsin over 24 h resulted in little damage to the insoluble collagenous residue remaining. Insoluble perimysium treated with cathepsin resulted in changes to the major peptide bands on one-dimensional SDSpolyacrylamide gel electrophoresisw hich were evident after 24 h treatment. Two-dimensional peptide maps obtained from conditioned insoluble perimysium and from insoluble perimysium treated with cathepsin for 24 h were altered relative to the unconditioned insoluble perimysium, indicating proteolytic damage to high molecular weight fractions. The in vitro case was extreme, but was comparable with conditioned insoluble perimysium. In addition, new peptide material in conditioned perimysium and endomysium in the molecular weight range 40 000 to 50 000 was observed, while perimysial samples revealed loss of peptide material, due to conditioning. Percentage solubilized collagen was higher (p < 0.05) from three muscles of varying quality when pre-injected with 0.1 M lactic acid and conditioned from 1 to 14 days than from untreated muscles. Analysis of the high molecular weight collagen peptides from lactic acid treated muscles by two-dimensional SDS-polyacrylamide gel electrophoresis revealed increased incidence of degradation in this region compared with untreated controls. Sensory profiling using quality descriptive analysis (QDA) was carried out on three muscles of varying quality, pre-injected with 0.1 M lactic acid and results compared with untreated muscles. The results obtained failed to correlate the observed biochemical changes due to lactic acid treatment with perceived textural changes in these muscles. However, variability of the taste panel scores contributed significantly to the results obtained.