Introduction. Pitaya peel has been applied as a functional ingredient for food due to the presence of betacyanins. However its polysaccharides can also contribute as a texture agent for food. The aim of this work was to evaluate the chemical characteristics and rheological behavior of the pitaya peel. Materials and methods. The samples were analyzed with regard to moisture and mineral content, protein, lipids, sugar, fiber, vitamin C, titratable acidity, soluble solids content and pH. Rheological measurements were performed on rheometer through flow curve, stress sweep, frequency sweep and the variation of temperature. Results and discussion. The results showed that pitaya peel is rich in insoluble fibers and exhibits non-Newtonian behavior, characteristic of a strong gel with a predominance of solid character. Furthermore, samples showed thermal resistance at the conditions of frequency, tension and temperature analyzed. Conclusion. Considering our results, in addition to use as a natural colorant in food, pitaya peel can also contribute to the nutritional value and texture of the products.

In this study, the system of care for 4907 irreversible dementia (ID) sufferers in Metropolitan Toronto and the Region of Peel was investigated. Mail survey data were compiled from senior administrative personnel (data include observation ratings by clinical and direct service staff) within 41 long-term care facilities, 15 acute care hospitals, and 30 community services. Consistent with the results of other descriptive studies, the findings reveal that: 1) long-term care facilities had the highest average proportion of ID sufferers; 2) the majority of ID sufferers were 75 years and older and predominantly female; and 3) ID sufferers on community service caseloads were less impaired than those in long-term care facilities. The study findings also indicate that the following factors may be important in assessing the care and management of ID sufferers within long-term care facilities and acute care hospitals: type of facility, admission criteria, arrangements for accommodation, number and nature of special programs, extent of inservice training, levels of staffing, and number and nature of family support services. In addition to these variables, the location and size of the catchment area and eligibility criteria may be important factors in similar community service assessments. The findings pertaining to the frequently used inpatient and community resources, additional resources required, and unmet needs of ID sufferers and family are discussed with respect to health care and senior support service planning and implementation within the outlined regions.

Introduction. Canada is an important avocado importer from Mexico. For most of the harvest season, fruit reach adequate pulp dry matter content, ripen properly and, consequently, quality and shelf life are excellent. However, after January, fruit dry matter content increases and blackened skin occurs. Shipments to Canada containing blackened fruit are rejected because this characteristic is wrongly associated with low pulp firmness and short shelf life. The objective of our research was to determine the effect of harvest time and ripening degree on initial quality and shelf life of Hass avocado. Materials and methods. Fruit were harvested from October 2007 to April 2008, and grouped into five ripening categories according to the degree of blackened skin. Fruit were then refrigerated for 7 d to simulate shipment to Canada. Thereafter, fruit were stored under simulated market conditions until they reached the edible ripening stage. Dry matter content was calculated only at the beginning of the storage period while quantification of weight loss, fruit with blackened skin, pulp firmness, and pulp color was done at the beginning of the storage period, at the end of the refrigeration period, and every three days during market conditions. Results and discussion. Dry matter content, skin color and pulp hue angle significantly increased with harvest date and ripening degree. Weight loss decreased with harvest date but increased with ripening degree, while firmness was affected by harvest date but was not associated with ripening degree. Conclusion. There is no reason to reject or downgrade blackened fruit, since quality and shelf life are not affected.

Introduction. The peel of bananas that ripen at ≥ 24 ℃ does not turn fully yellow, but retains a green colour, reducing the commercial value of the fruit. Historically, in experimental studies of this problem, fruit are ripened at constant temperatures; for example, either 20 ℃ or 30 ℃. In our experiments, we systematically varied the temperature of banana storage during ripening to investigate early events in ripening that may determine whether or not the peel remained green. Materials and methods. Fruits were exposed to temperatures of 20 ℃ or 30 ℃ for short periods before then storing at 30 ℃ or 20 ℃ to complete ripening. The L* a* b* colour system was used to measure change in green colour in the banana peel. Results. If the temperature of the fruit stored was 20 ℃ for the first few hours (≥ 14 h), then the peel became fully yellow, even in fruit subsequently ripened at 30 ℃. Conversely, if the temperature of the bananas stored was 30 ℃ for the first few hours of ripening, then full yellow colour was not obtained even if fruits were subsequently ripened at 20 ℃. Conclusion. The temperature of the first few hours of banana ripening determines whether or not the peel reaches full yellow colour.

Introduction. L’orange (Citrus aurantium sinensis) est une source de composés bioactifs : vitamines C et E, flavonoïdes (flavanes et flavanones glycosylés et polyméthoxylés). Pour valoriser les déchets des peaux d’orange, nous avons mesuré l’activité antiradicalaire du jus et des peaux sèches et fraîches de cinq variétés d’orangers de Tunisie afin d’évaluer leur concentration en composés antioxydants utilisables dans l’industrie. Matériel et méthodes. Le pouvoir antiradicalaire du jus et des extraits des peaux a été évalué en suivant, en fonction du temps, la disparition du radical stable DPPH• par spectrophotométrie d’absorption UV-visible à 515 nm. L’activité antiradicalaire mesurée a été exprimée en concentration efficace (CE50). La détermination du volume V50 de vitamine C d’une solution d’acide ascorbique de concentration connue et d’un volume V50 des extraits de jus et des peaux sèches et fraîches d’orange a permis d’estimer la concentration molaire et massique de vitamine C équivalente dans les extraits. Résultats. Les jus d’orange contiennent environ 400 mg·L–1 d’équivalent de vitamine C. Dans le cas de réactions très rapides avec le radical DPPH•, la totalité de l’activité antiradicalaire peut être attribuée à la vitamine C. Dans le cas de réactions plus lentes, en plus de la vitamine C, ce sont les polyphénols (citroflavonoïdes) qui contribuent à l’activité antioxydante totale. Les extraits méthanoliques des peaux fraîches (flavédo) contiennent plus de vitamine C que les extraits de peaux sèches. Conclusion. Les peaux d’oranges constituent d’immenses sources d’antioxydants qui peuvent trouver leur application dans différents domaines : agroalimentaire, cosmétique, pharmaceutique et autres.

Self-adhesive materials are called, in the adhesives trade, “pressure-sensitive adhesives” (PSAs). PSAs are designed to stick on almost any surface by simple contact under light pressure. This special class of adhesives does not undergo any physical transformation or chemical reaction during the bonding process. Because of this, the rheological properties of the adhesive must be finely tuned for the application, combining a carefully chosen polymer architecture and monomer composition with the proper addition of small molecules called tackifying resins. PSAs are soft, deformable solids and, depending on the formulation, easily form bridging fibrils between two surfaces upon debonding. They are safe to use and easy to handle and thus are increasingly replacing more conventional types of adhesives. In this article, we review both the primary material characteristics of PSAs and the main physical principles that make them work effectively.

Introduction. Les dommages provoqués par la cercosporiose des agrumes, dus à Phaeoramularia angolensis, sont à l'origine de pertes de récolte ou d'écarts de tri pouvant varier entre (50 et 100) % de la production. Or tous les organes attaqués par la maladie - pétales des fleurs, feuilles et surtout peau des fruits - renferment des huiles essentielles à haute valeur marchande. Une étude a été réalisée pour connaître l'influence des attaques de cette maladie sur le rendement d'extraction et la qualité des huiles essentielles de peau d'orange. Matériels et méthodes. L'extraction d'huile essentielle a été réalisée par hydrodistillation à partir de fruits récoltés à maturité et les extraits ont été analysés par chromatographie en phase gazeuse afin de déterminer leur composition chimique. Résultats et discussion. Le rendement d'extraction des huiles essentielles a diminué en fonction de la gravité des attaques (jusqu'à 40 % de baisse). Cette baisse n'a été significative que lorsque les attaques dépassaient deux lésions par fruit. Les extraits obtenus de fruits attaqués à divers degrés ont présenté quelques variations quantitatives de leurs constituants. Une diminution de certains composés dans les fruits malades s'est accompagnée d'une augmentation de leur forme oxygénée. L'augmentation de la quantité globale d'aldéhydes a été observée dans les fruits malades, ce qui pourrait se traduire par une amélioration de la qualité des huiles essentielles. Mais, en même temps, les oxydes caractéristiques de la dégradation de ces huiles essentielles ont augmenté. Conclusion. Ce travail qui doit être approfondi a permis d'acquérir de premières données sur les pertes de rendement et l'évolution de la composition des huiles essentielles de peau de fruits pouvant être attribuées aux attaques de la cercosporiose.

Introduction. Essential oils represent an increasing economic importance in the citrus by-product industry. Flash vacuum-expansion, a process leading to the disintegration of plant tissues, was applied to the recovery of essential oils from fruits of four Citrus species. Materials and methods. The flash vacuum-expansion process (steam-heating, then rapid introduction into a vessel under vacuum) was applied to peels of lemon, sweet orange, mandarin and grapefruit. Essential oils were recovered with a condenser, then separated by centrifugation. Oil volatile compounds were separated and identified by coupled capillary gas liquid chromatography/mass spectrometry. Results and discussion. Peel essential oil yields were (2.41, 1.43, 0.64 and 0.73) kg × t-1 of fruit for lemon, sweet orange, mandarin and grapefruit, respectively. Oils were enriched in limonene and other monoterpenes, while relative concentrations of monoterpene alcohols (linalool, α-terpineol, β-citronellol, nerol, geraniol) and aldehydes (neral, geranial) were lower in comparison with the volatile compounds of native peels. Conclusion. The flash vacuum-expansion process allowed production of citrus peel essential oils with yields comparable to the Food Machinery Corporation (F.M.C.) process. Oils were enriched in monoterpene hydrocarbons and correlatively impoverished in oxygenated volatile constituents.