Influence of redox potential on the accumulation of poly(3-hydroxybutyrate) by Bacillus megaterium.

The main goal of the present study was to evaluate the oxidation-reduction potential (ORP) on the production of poly(3-hydroxybutyrate) (P(3HB)) by Bacillus megaterium. Each microorganism has an optimal ORP range, and changes to the culture medium's ORP may redistribute the cell's metabolic flux, as such, the measurement and control of the ORP profile allows one to, in a way, manipulate the microbial metabolism, affecting the expression of certain enzymes and allowing for better control over the fermentative process. The ORP tests were carried out in a fermentation vessel coupled with an ORP probe, containing 1 L of mineral medium added with agroindustry byproducts (60% v/v of confectionery wastewater, and 40% v/v of rice parboiling water). The system's temperature was kept at 30 °C, with an agitation speed of 500 rpm. The vessel's airflow rate was controlled via a solenoid pump based on the ORP probe's data. Different ORP values were evaluated to verify their impact on biomass and polymer production. Cultures using OPR levels of 0 mV displayed the highest amounts of total biomass (5.00 g L-1) when compared to - 20 mV and - 40 mV (2.90 g L-1 and 0.53 g L-1, respectively). Similar results were also found for P(3HB)-to-biomass ratio, with polymer concentration being reduced when using ORP levels below 0 mV and with a maximum amount of polymer-to-biomass ratio of 69.87% after 48 h of culture. Furthermore, it was possible to observe that the culture's pH can also affect total biomass and polymer concentration, albeit to a lesser extent. Thus, when considering the data found during this study, it is possible to observe that ORP values can greatly impact B. megaterium cell's metabolism. Furthermore, the measurement and control of ORP levels may be an invaluable asset when trying to maximize polymer production under different culture conditions.

Functional meat products: Trends in pro-, pre-, syn-, para- and post-biotic use.

In recent years, many studies have been conducted to develop functional meat products, focusing on strategies to maximize health-promoting compounds and reduce the presence of those that may cause negative impacts on the consumer's health. As such, the use of prebiotic, probiotic, and synbiotic agents in meat products has grown considerably. In addition, the use of new generation probiotics in meat products is a novel field that can be explored. With the most recent paraprobiotics/postbiotics update, several components could be tested in meat products. Some interventional studies using meat products added with biotic agents have shown great potential as functional foods by reducing the formation of nitrous compounds in the gut and improving the functionality of the gut microbiota. Although there are few studies focusing on synbiotic meat products, the results are also very promising in this field. As such, this review seeks to describe how probiotics, prebiotics, paraprobiotics and postbiotics can be employed in meat products to give them functional properties, as well as some of the major issues that may arise when using these agents.

Campomanesia spp. native fruits as potential source of health-promoting compounds

Campomanesia xanthocarpa var. littoralis, Campomanesia xanthocarpa (Berg), and Campomanesia eugenioides are native fruit plants found in Brazil. Due to the scarce number of controlled scientific studies comparing different native Campomanesia species, this study sought to determine their bioactive compounds and antioxidant properties. C. eugenioides proved to be a rich source of total phenolic compounds, also showing the best antioxidant capacity by the ABTS, DPPH and molybdenum reduction power methods. On the other hand, C. xanthocarpa var. littoralis showed the best results for total flavonoids content, and Iron(II) chelation power. The phenolic compounds contents present in C. eugenioides could be responsible for the best antioxidant activity. This study provides key scientific data regarding the use of valuable fruits from different edible Campomanesia species to produce bioactive ingredients, as well as natural preservatives for food products. Thus, our results contribute to the discovery of the potential application of these native Campomanesia Brazilian fruits, as a natural product with functional and antioxidant properties.

Structural and Techno-Functional Properties of BovineCollagen and Its Application in Hamburgers.

The objective of this work is to characterize two types of bovine collagen (fibre and powder), evaluating its application in mixed hamburger formulations, as well as the quality characteristics of the products. The collagen fibre had a fibrillar structure, molecular mass 100 kDa and greater gel strength (146 315 Pa) and protein content (97.81%) than the powdered collagen, which had molecular mass from 50 to 100 kDa, greater hydroxyproline content, and a morphological structure with spherical microparticles more amorphous than the collagen fibre. In this study we found that the addition of 1.5% powdered collagen and 2.5% flocculated soybean flour and/or 0.75% powdered collagen and 3.5% flocculated soybean flour did not deteriorate the technological properties or the sensory attributes of hamburgers. The use of collagen is a promising alternative, since it has functional properties, improves the texture characteristics of a product, and is of low cost.