Influence of liposome encapsulated essential oils on properties of chitosan films

[EN] The effect of the encapsulation of eugenol and cinnamon leaf essential oil (CLEO) in lecithin liposomes on the losses of these compounds during the chitosan film formation process by casting was evaluated. Film-forming dispersions and films with eugenol or CLEO (either free or encapsulated) were obtained and characterized. The content of eugenol in active films was quantified by means of solvent extraction and gas chromatograph analysis. The encapsulation of eugenol or CLEO in lecithin liposomes led to the films retaining 40% −50% of the incorporated eugenol, whereas only 1%−2% was retained when eugenol was incorporated by direct emulsification. Films with liposomes exhibited a lamellar microstructure which improved film extensibility and increased water vapour barrier capacity with respect to those with free emulsified compounds. Liposomes also modified the optical properties of the films, reducing their gloss, increasing colour saturation and making them redder in colour. The encapsulation of volatile active compounds in liposomes appears to be a good strategy for obtaining antimicrobial films with essential oils.The authors acknowledge the financial support provided by the Ministerio de Economía y Competitividad (Project AGL2013-42989-R). Cristina Valencia Sullca thanks the Programa Nacional de Becas del Perú (Pronabec) for the completion of her doctoral thesis.Valencia-Sullca, CE.; Jiménez Serrallé, M.; Jiménez Marco, A.; Atarés Huerta, LM.; Vargas, M.; Chiralt, A. (2016). Influence of liposome encapsulated essential oils on properties of chitosan films. Polymer International (Online). 65(8):979-987. https://doi.org/10.1002/pi.5143S979987658Jiménez, A., Fabra, M. J., Talens, P., & Chiralt, A. (2013). Physical properties and antioxidant capacity of starch–sodium caseinate films containing lipids. Journal of Food Engineering, 116(3), 695-702. doi:10.1016/j.jfoodeng.2013.01.010Zhai, M., Zhao, L., Yoshii, F., & Kume, T. (2004). Study on antibacterial starch/chitosan blend film formed under the action of irradiation. Carbohydrate Polymers, 57(1), 83-88. doi:10.1016/j.carbpol.2004.04.003Perdones, Á., Vargas, M., Atarés, L., & Chiralt, A. (2014). Physical, antioxidant and antimicrobial properties of chitosan–cinnamon leaf oil films as affected by oleic acid. Food Hydrocolloids, 36, 256-264. doi:10.1016/j.foodhyd.2013.10.003Singh, G., Maurya, S., deLampasona, M. P., & Catalan, C. A. N. (2007). A comparison of chemical, antioxidant and antimicrobial studies of cinnamon leaf and bark volatile oils, oleoresins and their constituents. Food and Chemical Toxicology, 45(9), 1650-1661. doi:10.1016/j.fct.2007.02.031Bajpai, V. K., Baek, K.-H., & Kang, S. C. (2012). Control of Salmonella in foods by using essential oils: A review. Food Research International, 45(2), 722-734. doi:10.1016/j.foodres.2011.04.052Shah, B., Davidson, P. M., & Zhong, Q. (2013). Nanodispersed eugenol has improved antimicrobial activity against Escherichia coli O157:H7 and Listeria monocytogenes in bovine milk. International Journal of Food Microbiology, 161(1), 53-59. doi:10.1016/j.ijfoodmicro.2012.11.020Sebaaly, C., Jraij, A., Fessi, H., Charcosset, C., & Greige-Gerges, H. (2015). Preparation and characterization of clove essential oil-loaded liposomes. Food Chemistry, 178, 52-62. doi:10.1016/j.foodchem.2015.01.067Atarés, L., & Chiralt, A. (2016). Essential oils as additives in biodegradable films and coatings for active food packaging. Trends in Food Science & Technology, 48, 51-62. doi:10.1016/j.tifs.2015.12.001Sánchez-González, L., Chiralt, A., González-Martínez, C., & Cháfer, M. (2011). Effect of essential oils on properties of film forming emulsions and films based on hydroxypropylmethylcellulose and chitosan. Journal of Food Engineering, 105(2), 246-253. doi:10.1016/j.jfoodeng.2011.02.028Bakkali, F., Averbeck, S., Averbeck, D., & Idaomar, M. (2008). Biological effects of essential oils – A review. Food and Chemical Toxicology, 46(2), 446-475. doi:10.1016/j.fct.2007.09.106Wu, J., Liu, H., Ge, S., Wang, S., Qin, Z., Chen, L., … Zhang, Q. (2015). The preparation, characterization, antimicrobial stability and in vitro release evaluation of fish gelatin films incorporated with cinnamon essential oil nanoliposomes. Food Hydrocolloids, 43, 427-435. doi:10.1016/j.foodhyd.2014.06.017Imran, M., Revol-Junelles, A.-M., René, N., Jamshidian, M., Akhtar, M. J., Arab-Tehrany, E., … Desobry, S. (2012). Microstructure and physico-chemical evaluation of nano-emulsion-based antimicrobial peptides embedded in bioactive packaging films. Food Hydrocolloids, 29(2), 407-419. doi:10.1016/j.foodhyd.2012.04.010Zhang, H. Y., Arab Tehrany, E., Kahn, C. J. F., Ponçot, M., Linder, M., & Cleymand, F. (2012). Effects of nanoliposomes based on soya, rapeseed and fish lecithins on chitosan thin films designed for tissue engineering. Carbohydrate Polymers, 88(2), 618-627. doi:10.1016/j.carbpol.2012.01.007Jiménez, A., Sánchez-González, L., Desobry, S., Chiralt, A., & Tehrany, E. A. (2014). Influence of nanoliposomes incorporation on properties of film forming dispersions and films based on corn starch and sodium caseinate. Food Hydrocolloids, 35, 159-169. doi:10.1016/j.foodhyd.2013.05.006Olasupo, N. A., Fitzgerald, D. J., Gasson, M. J., & Narbad, A. (2003). Activity of natural antimicrobial compounds against Escherichia coli and Salmonella enterica serovar Typhimurium. Letters in Applied Microbiology, 37(6), 448-451. doi:10.1046/j.1472-765x.2003.01427.xMcHUGH, T. H., AVENA-BUSTILLOS, R., & KROCHTA, J. M. (1993). Hydrophilic Edible Films: Modified Procedure for Water Vapor Permeability and Explanation of Thickness Effects. Journal of Food Science, 58(4), 899-903. doi:10.1111/j.1365-2621.1993.tb09387.xHutchings, J. B. (1999). Food Colour and Appearance. doi:10.1007/978-1-4615-2373-4Falguera, V., Quintero, J. P., Jiménez, A., Muñoz, J. A., & Ibarz, A. (2011). Edible films and coatings: Structures, active functions and trends in their use. Trends in Food Science & Technology, 22(6), 292-303. doi:10.1016/j.tifs.2011.02.004Leceta, I., Guerrero, P., & de la Caba, K. (2013). Functional properties of chitosan-based films. Carbohydrate Polymers, 93(1), 339-346. doi:10.1016/j.carbpol.2012.04.031Pérez-Gago, M. B., & Krochta, J. M. (2001). Lipid Particle Size Effect on Water Vapor Permeability and Mechanical Properties of Whey Protein/Beeswax Emulsion Films. Journal of Agricultural and Food Chemistry, 49(2), 996-1002. doi:10.1021/jf000615fFabra, M. J., Talens, P., & Chiralt, A. (2008). Tensile properties and water vapor permeability of sodium caseinate films containing oleic acid–beeswax mixtures. Journal of Food Engineering, 85(3), 393-400. doi:10.1016/j.jfoodeng.2007.07.022Sánchez-González, L., Vargas, M., González-Martínez, C., Chiralt, A., & Cháfer, M. (2009). Characterization of edible films based on hydroxypropylmethylcellulose and tea tree essential oil. Food Hydrocolloids, 23(8), 2102-2109. doi:10.1016/j.foodhyd.2009.05.006McHugh, T. H., & Krochta, J. M. (1994). Water vapor permeability properties of edible whey protein-lipid emulsion films. Journal of the American Oil Chemists’ Society, 71(3), 307-312. doi:10.1007/bf02638058Ma, X., Chang, P. R., & Yu, J. (2008). Properties of biodegradable thermoplastic pea starch/carboxymethyl cellulose and pea starch/microcrystalline cellulose composites. Carbohydrate Polymers, 72(3), 369-375. doi:10.1016/j.carbpol.2007.09.002Fabra, M. J., Talens, P., & Chiralt, A. (2010). Water sorption isotherms and phase transitions of sodium caseinate–lipid films as affected by lipid interactions. Food Hydrocolloids, 24(4), 384-391. doi:10.1016/j.foodhyd.2009.11.004Shen, Z., & Kamdem, D. P. (2015). Development and characterization of biodegradable chitosan films containing two essential oils. International Journal of Biological Macromolecules, 74, 289-296. doi:10.1016/j.ijbiomac.2014.11.046Ojagh, S. M., Rezaei, M., Razavi, S. H., & Hosseini, S. M. H. (2010). Development and evaluation of a novel biodegradable film made from chitosan and cinnamon essential oil with low affinity toward water. Food Chemistry, 122(1), 161-166. doi:10.1016/j.foodchem.2010.02.033Fabra, M. J., Talens, P., & Chiralt, A. (2009). Microstructure and optical properties of sodium caseinate films containing oleic acid–beeswax mixtures. Food Hydrocolloids, 23(3), 676-683. doi:10.1016/j.foodhyd.2008.04.015Cano, A., Jiménez, A., Cháfer, M., Gónzalez, C., & Chiralt, A. (2014). Effect of amylose:amylopectin ratio and rice bran addition on starch films properties. Carbohydrate Polymers, 111, 543-555. doi:10.1016/j.carbpol.2014.04.075Van Roon, A., Parsons, J. R., & Govers, H. A. . (2002). Gas chromatographic determination of vapour pressure and related thermodynamic properties of monoterpenes and biogenically related compounds. Journal of Chromatography A, 955(1), 105-115. doi:10.1016/s0021-9673(02)00200-5Devlieghere, F., Vermeulen, A., & Debevere, J. (2004). Chitosan: antimicrobial activity, interactions with food components and applicability as a coating on fruit and vegetables. Food Microbiology, 21(6), 703-714. doi:10.1016/j.fm.2004.02.00

Psychometric Properties of an Assessment for Mental Health Recovery Programs

The concept of recovery can be operationalized from either the point of view of the consumer, or from the perspective of the agency providing services. The Milestones of Recovery Scale (MORS) was created to capture aspects of recovery from the agency perspective. Evidence establishing the psychometric properties of the MORS was obtained in three efforts: Inter-rater reliability using staff at The Village, a multi-service organization serving the homeless mentally ill in Long Beach, California; inter-rater reliability was also obtained from Vinfen Corporation, a large provider of housing services to mentally ill persons in Boston, Massachusetts. A test–retest reliability study was conducted using staff rating of clients at The Village, and evidence for validity was obtained using the Level of Care Utilization System (LOCUS) as a validity measure. The intra-class correlation coefficient for the inter-rater reliability study was r = .85 (CI .81, .89) for The Village and r = .86 (CI .80, .90) for Vinfen Corporation; test–retest reliability was r = .85 (CI .81, .87); and validity coefficients for the LOCUS were at or above r = .49 for all subscales except one. There is sufficient evidence for the reliability and validity of the MORS

Should methodological filters for diagnostic test accuracy studies be used in systematic reviews of psychometric instruments? a case study involving screening for postnatal depression

<p>Abstract</p> <p>Background</p> <p>Challenges exist when searching for diagnostic test accuracy (DTA) studies that include the design of DTA search strategies and selection of appropriate filters. This paper compares the performance of three MEDLINE search strategies for psychometric diagnostic test accuracy (DTA) studies in postnatal depression.</p> <p>Methods</p> <p>A reference set of six relevant studies was derived from a forward citation search via Web of Knowledge. The performance of the 'target condition and index test' method recommended by the Cochrane DTA Group was compared to two alternative strategies which included methodological filters. Outcome measures were total citations retrieved, sensitivity, precision and associated 95% confidence intervals (95%CI).</p> <p>Results</p> <p>The Cochrane recommended strategy and one of the filtered search strategies were equivalent in performance and both retrieved a total of 105 citations, sensitivity was 100% (95% CI 61%, 100%) and precision was 5.2% (2.6%, 11.9%). The second filtered search retrieved a total of 31 citations, sensitivity was 66.6% (30%, 90%) and precision was 12.9% (5.1%, 28.6%). This search missed the DTA study with most relevance to the DTA review.</p> <p>Conclusions</p> <p>The Cochrane recommended search strategy, 'target condition and index test', method was pragmatic and sensitive. It was considered the optimum method for retrieval of relevant studies for a psychometric DTA review (in this case for postnatal depression). Potential limitations of using filtered searches during a psychometric mental health DTA review should be considered.</p

Vision Impairs the Abilities of Bats to Avoid Colliding with Stationary Obstacles

Background: Free-flying insectivorous bats occasionally collide with stationary objects they should easily detect by echolocation and avoid. Collisions often occur with lighted objects, suggesting ambient light may deleteriously affect obstacle avoidance capabilities. We tested the hypothesis that free-flying bats may orient by vision when they collide with some obstacles. We additionally tested whether acoustic distractions, such as ‘‘distress calls’ ’ of other bats, contributed to probabilities of collision. Methodology/Principal Findings: To investigate the role of visual cues in the collisions of free-flying little brown bats (Myotis lucifugus) with stationary objects, we set up obstacles in an area of high bat traffic during swarming. We used combinations of light intensities and visually dissimilar obstacles to verify that bats orient by vision. In early August, bats collided more often in the light than the dark, and probabilities of collision varied with the visibility of obstacles. However, the probabilities of collisions altered in mid to late August, coincident with the start of behavioural, hormonal, and physiological changes occurring during swarming and mating. Distress calls did not distract bats and increase the incidence of collisions. Conclusions/Significance: Our findings indicate that visual cues are more important for free-flying bats than previously recognized, suggesting integration of multi-sensory modalities during orientation. Furthermore, our study highlight

The fire toxicity of polyurethane foams [Review]

Polyurethane is widely used, with its two major applications, soft furnishings and insulation, having low thermal inertia, and hence enhanced flammability. In addition to their flammability, polyurethanes form carbon monoxide, hydrogen cyanide and other toxic products on decomposition and combustion. The chemistry of polyurethane foams and their thermal decomposition are discussed in order to assess the relationship between the chemical and physical composition of the foam and the toxic products generated during their decomposition. The toxic product generation during flaming combustion of polyurethane foams is reviewed, in order to relate the yields of toxic products and the overall fire toxicity to the fire conditions. The methods of assessment of fire toxicity are outlined in order to understand how the fire toxicity of polyurethane foams may be quantified. In particular, the ventilation condition has a critical effect on the yield of the two major asphyxiants, carbon monoxide and hydrogen cyanid

Rapid testing versus karyotyping in Down's syndrome screening: cost-effectiveness and detection of clinically significant chromosome abnormalities

In all, 80% of antenatal karyotypes are generated by Down's syndrome screening programmes (DSSP). After a positive screening, women are offered prenatal foetus karyotyping, the gold standard. Reliable molecular methods for rapid aneuploidy diagnosis (RAD: fluorescence in situ hybridization (FISH) and quantitative fluorescence PCR (QF-PCR)) can detect common aneuploidies, and are faster and less expensive than karyotyping

Adult cognitive outcomes in phenylketonuria:explaining causes of variability beyond average Phe levels

OBJECTIVE: The objective was to deepen the understanding of the causes of individual variability in phenylketonuria (PKU) by investigating which metabolic variables are most important for predicting cognitive outcomes (Phe average vs Phe variation) and by assessing the risk of cognitive impairment associated with adopting a more relaxed approach to the diet than is currently recommended. METHOD: We analysed associations between metabolic and cognitive measures in a mixed sample of English and Italian early-treated adults with PKU (N = 56). Metabolic measures were collected through childhood, adolescence and adulthood; cognitive measures were collected in adulthood. Metabolic measures included average Phe levels (average of median values for each year in a given period) and average Phe variations (average yearly standard deviations). Cognition was measured with IQ and a battery of cognitive tasks. RESULTS: Phe variation was as important, if not more important, than Phe average in predicting adult outcomes and contributed independently. Phe variation was particularly detrimental in childhood. Together, childhood Phe variation and adult Phe average predicted around 40% of the variation in cognitive scores. Poor cognitive scores (> 1 SD from controls) occurred almost exclusively in individuals with poor metabolic control and the risk of poor scores was about 30% higher in individuals with Phe values exceeding recommended thresholds. CONCLUSIONS: Our results provide support for current European guidelines (average Phe value = < 360 μmol/l in childhood; = < 600 μmo/l from 12 years onwards), but they suggest an additional recommendation to maintain stable levels (possibly Phe SD = < 180 μmol/l throughout life). PUBLIC SIGNIFICANCE STATEMENTS: We investigated the relationship between how well people with phenylketonuria control blood Phe throughout their life and their ability to carry out cognitive tasks in adulthood. We found that avoiding blood Phe peaks was as important if not more important that maintaining average low Phe levels. This was particularly essential in childhood. We also found that blood Phe levels above recommended European guidelines was associated with around 30% increase in the risk of poor cognitive outcomes

What explains gender inequalities in HIV/AIDS prevalence in sub-Saharan Africa? Evidence from the demographic and health surveys

Abstract Background Women are disproportionally affected by human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) in sub-Saharan Africa (SSA). The determinants of gender inequality in HIV/AIDS may vary across countries and require country-specific interventions to address them. This study aimed to identify the socio-demographic and behavioral characteristics underlying gender inequalities in HIV/AIDS in 21 SSA countries. Methods We applied an extension of the Blinder-Oaxaca decomposition approach to data from Demographic and Health Surveys and AIDS Indicator Surveys to quantify the differences in HIV/AIDS prevalence between women and men attributable to socio-demographic factors, sexual behaviours, and awareness of HIV/AIDS. We decomposed gender inequalities into two components: the percentage attributable to different levels of the risk factors between women and men (the “composition effect”) and the percentage attributable to risk factors having differential effects on HIV/AIDS prevalence in women and men (the “response effect”). Results Descriptive analyses showed that the difference between women and men in HIV/AIDS prevalence varied from a low of 0.68 % (P = 0.008) in Liberia to a high of 11.5 % (P < 0.001) in Swaziland. The decomposition analysis showed that 84 % (P < 0.001) and 92 % (P < 0.001) of the higher prevalence of HIV/AIDS among women in Uganda and Ghana, respectively, was explained by the different distributions of HIV/AIDS risk factors, particularly age at first sex between women and men. In the majority of countries, however, observed gender inequalities in HIV/AIDS were chiefly explained by differences in the responses to risk factors; the differential effects of age, marital status and occupation on prevalence of HIV/AIDS for women and men were among the significant contributors to this component. In Cameroon, Guinea, Malawi and Swaziland, a combination of the composition and response effects explained gender inequalities in HIV/AIDS prevalence. Conclusions The factors that explain gender inequality in HIV/AIDS in SSA vary by country, suggesting that country-specific interventions are needed. Unmeasured factors also contributed substantially to the difference in HIV/AIDS prevalence between women and men, highlighting the need for further study