Structure formation in sugar containing pectin gels - influence of tartaric acid content (pH) and cooling rate on the gelation of high-methoxylated pectin.
The aim of the study was the application of a recently published method, using structuring parameters calculated from dG'/dt, for the characterisation of the pectin sugar acid gelation process. The influence of cooling rate and pH on structure formation of HM pectin gels containing 65 wt.% sucrose were investigated. The results show that the structure formation process as well as the properties of the final gels strongly depended on both parameters. With increasing cooling rates from 0.5 to 1.0 K/min the initial structuring temperature slightly decreased and the maximum structuring velocity increased. The lower the cooling rates, the firmer and more elastic were the final gels. With increasing acid content (decreasing pH from 2.5-2.0) the initial structuring temperatures were nearly constant. The final gel properties varied visibly but not systematically. Gels with the lowest and highest pH were less elastic and weaker compared to those with medium acid concentrations.
Physico-chemical properties, rheology and degree of esterification of passion fruit (Passiflora edulis f. flavicarpa) peel flour.
BACKGROUND
The peel of yellow passion fruit is as an agro-industrial waste of great environmental impact, representing more than 50% of the total weight of the fruit. For this reason, and also considering its importance as a source of functional components such as pectin, this organic waste is increasingly attracting the attention of researchers. The aim of this study was to investigate the physico-chemical composition and physical properties of this material, which may be of interest to the food industry.


RESULTS
We obtained two samples of passion fruit peel flour applying different processes: flour without treatment (FWOT) and flour with treatment by maceration (FWT). It was found that the flour samples contain, respectively, 372.4 g kg-1 and 246.7 kg-1 of soluble fiber and, according to the FTIR analysis, this material corresponds to high and low methoxyl pectins, respectively.


CONCLUSION
The flour obtained by maceration (FWT) offers greater benefits for industrial use, with 60% fewer tannins and greater thermal stability. In addition, this sample does not reabsorb moisture as easily, although FWOT also shows potential for use in dietary products. Considering the pseudoplastic properties of the flours, the application of both samples could be expanded to many industrial sectors. © 2017 Society of Chemical Industry.
Conflictual Media Events, Eyewitness Images, and the Boston Marathon Bombing (2013)
The proliferation of camera phones over the past decade has created an unprecedented landslide of visual information in the online public sphere, transforming the form and amount of communication in relation to crisis events. International research on this subject has primarily centered on the way in which the production and dissemination of eyewitness images convert mainstream media's coverage of crisis. This article broadens the perspective by focusing on eyewitness images in relation to “conflictual media events.” The article contributes to discussions on the definition of conflictual media events in today's mediatized and connective media environment, which has undergone radical changes from the era of mass media hegemony when Daniel Dayan and Elihu Katz first outlined media events. The article further examines the ways in which the circulation of eyewitness images erodes established boundaries between experts and laymen and between professionals and non-professionals in relation to conflictual media events. The bombing of the Boston Marathon in April 2013 constitutes the empirical point of departure.