Stabilization of natural and synthetic indigo on nanocellulose network - Towards bioactive materials and facile dyeing processes

Publisher Copyright: © 2021 The AuthorsSynthetic dyes are vastly used for colouring numerous materials, although the adverse effects on environment are well recognized. In addition to developing the existing dyeing technologies more efficient and cleaner, the valorisation of natural dyes can enhance the sustainable development of dyeing industry. Natural indigo, derived from Isatis tinctoria, is a bio-based alternative for indigo produced via chemical synthesis routes. Owing to the insoluble character of indigo pigment, the dye requires conversion into soluble leucoindigo form prior to dyeing, which is often accomplished by using harsh sodium dithionite vat technique. During the processing from plant to dye attached on a fabric, indigo is transferred from the soluble leucoindigo form to the oxidized insoluble indigo and once more back to leucoindigo. Additionally, the oxidation is difficult to control and with traditional vat technique maintaining the leucoindigo through the dyeing often requires adding more reducing agent chemicals. Maintaining the soluble form throughout the process would enable lower number of processing steps and reduce the use of harmful chemical agents. In the present study, the stabilization of leucoindigo on nanocellulose matrix carrier was investigated with spectroscopic and photophysical methods. According to the results, leucoindigo was successfully stabilized on nanocellulose suspension, most likely due to the limited rate of oxygen diffusion into the viscous medium. Visual observations revealed that the leuco-form was retained even longer with natural indigo than synthetic indigo. This enhanced stability was attributed to the presence of radical scavenging species in natural indigo since the synthetic indigo did not show notable antioxidant properties. Given the promising results the paste formulation was demonstrated to be applicable for creating patterns on cotton using a screen-printing technique. Since the leucoindigo was stabilized on nanocellulose carrier, the need for re-reduction prior to dyeing was avoided and the amount of harmful reducing chemicals was reduced. These findings also show that the characteristics of natural dyes that are often considered disadvantageous compared to synthetic dyestuff, i.e. presence of co-products in the mixture, can however, create more value to the dyed material through new functionalities.Peer reviewe

Healthy and Unhealthy Food Consumption in Relation to Quality of Life among Finnish Female Municipal Employees: A Cross-Sectional Study

Aspects of good quality of life (QoL) have been found to motivate people to make lifestyle changes. There is also evidence that certain dietary patterns are associated with QoL. The aim of this work was to examine whether consumption frequencies of healthy and unhealthy food items are associated with QoL in female employees. A cross-sectional study was conducted among 631 Finnish female employees (mean age 49 years, SD = 10) from 10 municipal work units in 2015. Information about the participants was collected by physical examination, laboratory tests, self-administered questionnaires, including the Food Frequency Questionnaire (FFQ), and from medical history. QoL was assessed with the EUROHIS-Quality of Life 8-item index. A significant positive association was seen between consumption frequency of healthy foods and the EUROHIS-QOL mean score (p = 0.002). The association was small but comprehensive, also involving most dimensions of QoL. The consumption frequency of unhealthy foods was not associated with QoL. These findings are relevant when designing diet counselling, since QoL is an outcome that has been found to motivate people to change their health habits. Recommending abundant use of healthy foods could be a simple and convenient way of diet counselling at many health care appointments, where time consuming approaches are difficult to conduct

The Relationship between Dietary Habits and Work Engagement among Female Finnish Municipal Employees

Background: Work engagement reflects work-related well-being. It is positively associated with health, life satisfaction, work efficiency, income level, and occupational prospects. However, little is known about the relationship between work engagement and diet. Methods: A cross-sectional study was conducted among female Finnish municipal employees (n = 630) in 2015. Work engagement was assessed using the Utrecht Work Engagement Index. The consumption of healthy and unhealthy food items was determined using a food frequency questionnaire. Sociodemographic factors, health behaviors, depressive and anxiety symptoms were assessed with self-administrated questionnaires. Results: Work engagement had a positive relationship with the daily consumption of healthy food items. This association remained significant even after adjusting for age, education years, financial situation, and physical activity. The frequency of consuming unhealthy food items showed no relationship with work engagement. Anxiety and depressive symptoms decreased linearly with the greater consumption of healthy foods. Conclusion: Frequent consumption of healthy food items is associated with higher work engagement, irrespectively of the consumption of unhealthy nutrients. These results encourage health care professionals to recommend healthy food items instead of forbidding unhealthy food, as well as employers to support healthy dietary habits among employees

The Relationship between Dietary Habits and Work Engagement among Female Finnish Municipal Employees

Background: Work engagement reflects work-related well-being. It is positively associated with health, life satisfaction, work efficiency, income level, and occupational prospects. However, little is known about the relationship between work engagement and diet. Methods: A cross-sectional study was conducted among female Finnish municipal employees (n = 630) in 2015. Work engagement was assessed using the Utrecht Work Engagement Index. The consumption of healthy and unhealthy food items was determined using a food frequency questionnaire. Sociodemographic factors, health behaviors, depressive and anxiety symptoms were assessed with self-administrated questionnaires. Results: Work engagement had a positive relationship with the daily consumption of healthy food items. This association remained significant even after adjusting for age, education years, financial situation, and physical activity. The frequency of consuming unhealthy food items showed no relationship with work engagement. Anxiety and depressive symptoms decreased linearly with the greater consumption of healthy foods. Conclusion: Frequent consumption of healthy food items is associated with higher work engagement, irrespectively of the consumption of unhealthy nutrients. These results encourage health care professionals to recommend healthy food items instead of forbidding unhealthy food, as well as employers to support healthy dietary habits among employees

Territory Choice of Pied Flycatchers is Not Based on Induced Cues of Herbivore Damaged Trees

Passerine birds use a variety of indirect cues to make territory location decisions. These birds can also distinguish herbivore-damaged plants from undamaged ones during foraging, even when they cannot see the herbivorous larvae or damaged leaves. To test the possibility that also the territory choice of passerines is affected by herbivore-induced plant cues, we established territories with and without indirect cues of herbivore presence for migratory pied flycatchers (Ficedula hypoleuca) at the time of their arrival. Half of the territories had folivorous moth larvae hidden inside mesh bags to defoliate small trees (Betula spp.) and half had only empty mesh bags on trees. Hidden herbivory on the trees did not affect the mean date of territory choice by either male or female birds. Nonetheless, there was a trend that females, but not males, chose the territories in the same order in two consecutive years. Thus, it seems that pied flycatchers do not use indirect cues of larval presence as a basis for their choice of territory, but possibly some more general environmental cues.</p

Effects of Insect Herbivory on Bilberry Production and Removal of Berries by Frugivores

The evolutionary purpose of a fleshy fruit is to attract seed dispersers and get the seeds dispersed by frugivorous animals. For this reason, fruits should be highly rewarding to these mutualists. However, insect herbivory can alter plant reproductive success e.g. by decreasing fruit yield or affecting the attractiveness of the fruits to mutualistic seed dispersers. Under natural conditions, we tested the effects of experimental larval-defoliation on berry ripening and consumption of a non-cultivated dwarf shrub, the bilberry (Vaccinium myrtillus L.), which produces animal-dispersed berries with high sugar and anthocyanin concentration. Bilberry ramets with high fruit yield were most likely to have their berries foraged, indicating that frugivores made foraging choices based on the abundance of berries. Moreover, the probability for berries being foraged was the lowest for non-defoliated ramets that grew adjacent to larval-defoliated ramets, even though larval-defoliation did not affect the biochemical composition (total concentrations of anthocyanins, sugars and organic acids) or the probability of ripening of berries. We hypothesise that the lower probability for berries being foraged in these ramets may be a consequence of rhizome- or volatile-mediated communication between ramets, resulting in a priming effect of the herbivore defence and lower attractiveness of the non-defoliated ramets.Peer reviewe