Search results

This study aims to describe a bibliometric analysis of recent articles addressing the applications of e- noses with particular emphasis on those dealing with fuel-related products. Documents covering the general area of e-nose research and published between 1975 and 2021 were retrieved from the Web of Science database, and peer-reviewed articles were selected and appraised according to specific descriptors and criteria.

Analyses were performed by mapping the knowledge domain using the software tools VOSviewer and RStudio. It was possible to identify the countries, research organizations, authors and disciplines that were most prolific in the area, together with the most cited articles and the most frequent keywords. A total of 3,921 articles published in peer-reviewed journals were initially retrieved but only 47 (1.19%) described fuel-related e-nose applications with original articles published in indexed journals. However, this number was reduced to 38 (0.96%) articles strictly related to the target subject.

Rigorous appraisal of these documents yielded 22 articles that could be classified into two groups, those aimed at predicting the values of key parameters and those dealing with the discrimination of samples. Most of these 22 selected articles (68.2%) were published between 2017 and 2021, but little evidence was apparent of international collaboration between researchers and institutions currently working on this topic. The strategy of switching energy systems away from fossil fuels towards low-carbon renewable technologies that has been adopted by many countries will generate substantial research opportunities in the prediction, discrimination and quantification of volatiles in biofuels using e-nose.

It is important to highlight that the greatest difficulty in using the e-nose is the interpretation of the data generated by the equipment; most studies have so far used the maximum value of the electrical resistance signal of each e-nose sensor as the only data provided by this sensor; however, from 2019 onwards, some works began to consider the entire electrical resistance curve as a data source, extracting more information from it.

This study opens a new and promising way for the effective use of e-nose as a fuel analysis instrument, as low-cost sensors can be developed for use with the new data analysis methodology, enabling the production of portable, cheaper and more reliable equipment.

The purpose of this study is to investigate the effect of a 15-week dietary intake of cactus flour on metabolic parameters, body weight and dietary intake of rats.

Male Wistar rats were divided into four experimental groups (n = 8-10): control or westernized diets added or not of cactus flour. The following parameters were evaluated during the period of dietary manipulation: body weight, food intake, glycemic and lipid profile (oral glucose tolerance test, metabolic parameters, hepatic and muscular glycogen dosage), visceral and body fat (relative weight to body weight). Data were analyzed using Graphpad Prism®5, p = 0.05.

Animals fed on a Western-style diet together with flour cactus presented lower weight gain (335.7 ± 20.0, p = 0.05) over the evaluated period, even when the volume of food intake was not different among the groups. The addition of cactus flour to a Western-style diet appears to lower glucose levels at 30 and 60 min (p = 0.05), as shown in the glucose tolerance curve. There was a downward trend does fat stores, cholesterol levels and triglycerides. Therefore, it was concluded that this addition cactus flour is effective even when the diet is hyperlipidic, demonstrating its ability to attenuate risk parameters for the occurrence of metabolic syndromes such as sub fraction high cholesterol levels and glucose tolerance.

The addition of functional foods to diets may work to improve the harmful effects of this type of diet. Opuntia ficus indica has high nutritional value and has hypoglycemic and hypolipemic properties besides being antioxidant.