Propolis application in food preservation: development of chitosan-based edible films

Edible films derived from chitosan highlight for its potential as coating packages, due to their antimicrobial activity and low oxygen permeability, while propolis has shown effective as a natural additive due to its antimicrobial and antioxidant properties. Thus, its combination to produce edible films, provides a promising approach to enhance the life spam of easily perishable foods. The present study describes the development of edible films based on chitosan produced from chitin extracted crawfish shell, modified with propolis. Chitosan-based films prepared incorporating different concentrations of poplar propolis extracts (0% to 20%), where characterized by FTIR, TGA and SEM. Additionally, mechanical properties, water-solubility, colour and optical transmittance tests were performed to assess the film specificities. The antioxidant and antimicrobial activity of the coating were also studied. The FTIR spectra of the extracted material enable the identification of all major peaks associated to chitosan, corroborating the extraction procedure of chitin/chitosan from crawfish. The addition of propolis to the films decreased the water solubility compared to control. Besides, all films exhibited antioxidant and antimicrobial activity. The output clear indicates that films enriched with propolis may be an alternative candidate for food packing.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020). National funding by FCT- Foundation for Science and Technology, through the institutional scientific employment program-contract with Soraia I. Falcão.info:eu-repo/semantics/publishedVersio

Sparse Sums of Positive Semidefinite Matrices

Recently there has been much interest in "sparsifying" sums of rank one matrices: modifying the coefficients such that only a few are nonzero, while approximately preserving the matrix that results from the sum. Results of this sort have found applications in many different areas, including sparsifying graphs. In this paper we consider the more general problem of sparsifying sums of positive semidefinite matrices that have arbitrary rank. We give several algorithms for solving this problem. The first algorithm is based on the method of Batson, Spielman and Srivastava (2009). The second algorithm is based on the matrix multiplicative weights update method of Arora and Kale (2007). We also highlight an interesting connection between these two algorithms. Our algorithms have numerous applications. We show how they can be used to construct graph sparsifiers with auxiliary constraints, sparsifiers of hypergraphs, and sparse solutions to semidefinite programs

Phonemic and semantic verbal fluency tasks: normative data for elderly Brazilians

This study aims to investigate the infl uence of sociodemographic characteristics on the performance of older people on two tasks of verbal fl uency and provide normative data for a Brazilian population of healthy elderly individuals with different educational levels. The initial sample included 521 individuals aged from 60 years, participating in the Program Family Health Strategy. Participants who had scores suggestive of cognitive decline on the Mini-Mental State Examination, depressive symptoms in Geriatric Depression Scale and self-reported neurological or psychiatric disorders were excluded. The fi nal sample consisted of 218 participants in phonemic verbal fl uency task (letters F, A and S) and 265 participants for semantic verbal fl uency task (animals). The performance in both tests was associated with age and education, but not with sex. Still, the education variable was shown to have a greater impact on scores in phonemic and semantic tests than age in both forms of evocation. The results of this study suggest the importance of providing normative data for elderly Brazilians appropriate to age and education on verbal fl uency tasks

Production of chitosan-based biodegradable active films using bio-waste enriched with polyphenol propolis extract envisaging food packaging applications

Developing biodegradable active films has been a promising green approach to overcoming global concerns over the environmental pollution and human health caused by plastic utilization. This study aimed to develop active films based on chitosan (CS), produced from waste crayfish (Procambarus clarkii) shells enriched with bioactive extract (5–20%) of propolis (PS) and to characterize its properties, envisaging food packaging applications. The chromatographic profile of PS extract confirmed its richness, with 41 phenolic compounds. With increasing extract addition to the chitosan, the thickness of the films increased from 61.7 to 71.7 μm, causing a reduction in the light transmission rate, along with a greenish colour shift. The interactions between PS extract and CS was confirmed by infrared spectroscopy, at the same time that the microstructural integrity of the films was checked on the scanning electron microscopy micrographs. The findings also showed that addition of PS enhanced the films thermal stability and mechanical properties e.g., tensile modulus, yield strength, and stress at break. Besides, it improved the antioxidant and antimicrobial activities. Overall, CS-based composite films seem a promising green alternative to petroleum-based synthetic plastics allowing to extend the shelf life of food products due to their eco-friendly nature.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and contracts through the individual and institutional scientific employment program-contract with Soraia I. Falcão and Arantzazu Santamaria Echart. Thanks to the Programa Apícola Nacional 2020-2022 (National Beekeeping Program) for funding the project “Standardization of production procedures and quality parameters of bee products” and to Project PDR2020-1.0.1- FEADER-031734: “DivInA-Diversification and Innovation on Beekeeping Production”. Finally, this work is funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project GreenHealth - Digital strategies in biological assets to improve well-being and promote green health, Norte-01-0145-FEDER-000042.info:eu-repo/semantics/publishedVersio

Desenvolvimento e caracterização de filmes comestíveis à base de quitosano incorporados com própolis para aplicação na conservação de alimentos

Mestrado de dupla diplomação com a UTFPR, Universidade Tecnológica Federal do ParanáTrabalho financiado pelo Projeto DivInA (PDR2020-101-031734), no âmbito de uma iniciativa comunitária promovida pelo PDR2020 e cofinanciada pelo FEADER, Portugal 2020. Este trabalho foi também financiado pelo projecto GreenHealth e parcialmente financiado pelo CIMO UID/AGR/00690/2019) através do FEDER no âmbito do PT2020

Sexual dimorphism in Diabrotica speciosa and Diabrotica viridula (Coleoptera: Chrysomelidae)

Diabrotica speciosa (Germar) and Diabrotica viridula F. (Coleoptera: Chrysomelidae) are the two most abundant species of the genus in South America, and belong to the fucata and virgifera groups, respectively. Here, we characterize the dimorphism of the setae present on the basitarsi of males and females of these species. Dimorphism was confirmed in both species, and it was related to the presence of adhesive setae exclusively in males, which possess these structures on the basal tarsomeres of the pro- and mesothoracic legs. Keywords: Morphology, Rootworms, Sexual behavio

Selection of Trichogramma species as potential natural enemies for the control of Opogona sacchari (Bojer)

The banana moth Opogona sacchari (Bojer) (Lepidoptera: Tineidae) is a polyphagous pest that can cause serious damage, especially to banana crops in southern Brazil. It attacks the fruit, lowering its quality and making bananas unsuitable for export. Current control measures are limited and the use of Trichogramma (Hymenoptera: Trichogrammatidae) for Applied Biological Control may be an alternative for the management of this pest. In this study, we investigated the potential parasitism effectiveness of eggs of O. sacchari by T. pretiosum, T. atopovirilia and T. galloi, three species of parasitoids commonly used in Applied Biological Control programs in Brazil. Eggs of O. sacchari were parasitized by all three Trichogramma species, and T. atopovirilia and T. galloi were the most aggressive, showing greater potential for control of this pest in the banana culture

INVENTÁRIO DE FELICIDADE NO TRABALHO: evidência de validade de critério

Scientific literature has indicated that men and women do not present significant differences in terms of happiness, both in general and at work. In observance of this evidence, the present study aims to verify evidence of criterion validity of the Happiness at Work Inventory (IFT), comparing the scores of 814 Brazilian adults, aged between 18 and 65 (M=38.1; SD=8.40), being 562 women. It was evident that both the total IFT score and the score of its three factors corroborate the trend in the literature, in which there are no significant differences between men and women regarding of happiness at work. The results indicate that happiness is a complex phenomenon, which cannot be explained exclusively by biological factors, such as sex, and the material contexts of existence and psychosocial relationships must be added, together with awareness and the recurrent practice of spirituality, while variables relevant to their assessment in the work.La literatura científica ha indicado que hombres y mujeres no presentan diferencias significativas en el constructo de la felicidad, ni en general ni en el trabajo. En conformidad con esta evidencia, el presente estudio tiene como objetivo verificar evidencias de validez de criterio del Inventario de Felicidad en el Trabajo (IFT), comparando las puntuaciones de 814 brasileños, con edades entre 18 y 65 años (M=38,1; SD=8,40), de los cuales 562 eran mujeres. Se evidenció que tanto la puntuación total de la IFT como la puntuación de sus tres factores corroboran la tendencia de la literatura, en la que no existen diferencias significativas entre hombres y mujeres en cuanto a la felicidad en el trabajo. Los resultados indican que la felicidad es un fenómeno complejo, que no puede explicarse exclusivamente por factores biológicos, como el sexo, y que es necesario añadir el contexto material de la existencia y el contexto psicosocial de las relaciones, junto con la conciencia y la práctica recurrente de la espiritualidad, como variables relevantes para su evaluación en el ámbito laboral.A literatura tem indicado que homens e mulheres não apresentam diferenças significativas em termos de felicidade, tanto no âmbito geral quanto no trabalho. Em observância a essa evidência, o presente estudo objetiva verificar evidência de validade de critério ao Inventário de Felicidade no Trabalho (IFT), comparando os escores de 814 brasileiros, com idades entre 18 e 65 (M=38,1; DP=8,40), sendo 562 mulheres. Evidenciou-se que tanto o escore total do IFT, quanto o escore de seus três fatores, corroboram a tendência da literatura, em que não há diferenças significativas entre homens e mulheres, quanto a felicidade no trabalho. Os resultados indicam que a felicidade é um fenômeno complexo, que não pode ser explicado exclusivamente por fatores biológicos, como o sexo, devendo-se acrescentar os contextos material de existência e psicossocial das relações, aliado a consciência e a prática recorrente da espiritualidade, enquanto variáveis relevantes à sua avaliação no âmbito do trabalho