Effects of electron-beam generated X-ray irradiation on the postharvest storage quality of Agaricus bisporus

The objective of this study was to investigate the effects of electron-beam generated X-ray irradiation on the postharvest storage quality and antioxidant capacity of Agaricus bisporus. All mushrooms were treated with different doses of electron-beam generated X-ray irradiation (0, 0.5, 1.0, 1.5 and 2.0 kGy) followed by stored at 4 °C for 21 days. Results showed that when compared with the control group at the end of storage, the firmness of Agaricus bisporus treated with 1.0 kGy was increased by 43.68%, the cell membrane permeability and malondialdehyde (MDA) content were decreased by 14.48% and 32.27% respectively, and the polyphenol oxidase (PPO) activity was reduced by 44.30%. One-kGy treatment was better than the control group to maintain superoxide dismutase (SOD) and catalase (CAT) activity. The finding suggested that the dose of 1.0 kGy generated by electron beam was suitable for keeping the postharvest quality for 21 days of Agaricus bisporus.Industrial relevanceThis study stated that electron-beam generated X-ray pretreatment could be a green and safe technology to improve the overall quality of Agaricus bisporus at 4 °C for 21 days.     

Effect of Drosophila suzukii on Blueberry VOCs: Chemical Cues for a Pupal Parasitoid,Trichopria anastrephae

Journal of Chemical Ecology - Biocontrol agents such as parasitic wasps use long-range volatiles and host-associated cues from lower trophic levels to find their hosts. However, this chemical...     

Extraction of biomolecules from Coelastrella sp. LRF1 biomass using Ohmic Heating technology

Ohmic heating (OH) allows a natural synergy between thermal and electrical effects, appearing as an efficient approach to the thermal extraction of biocompounds. Different electrical field intensities (e.g., 12 and 217 V/cm), treatment temperatures (from 50 to 100 °C) and heating strategies (continuous and pulsed heating) were combined to enhance for the first time the extraction of nutrients from microalgae Coelastrella sp. LFR1, which is highly adapted to extreme survival conditions. Results showed that OH applied at 217 V/cm, through a fast and single heating pulse (OHP), and at maximum peak temperature of approximately 100 °C (with <1 s of holding time), resulted in the maximum recovery of 50% of chlorophyll a (e.g., 1.02 mg/g_DW) and 20.4% of proteins (29.4 mg/g_DW) from biomass; lipids and carbohydrates were equally extracted resulting on extraction of 40 and 52%, respectively. OHP allowed to obtain nutrient rich extracts from Coelastrella sp. LFR1 with a significant radical scavenging activity ranging from 20 to 60%.     

Pulsed electric field processing of a pomegranate (Punica granatum L.) fermented beverage

The aim of this study was to evaluate the effect of pulsed electric field (PEF) (11.7 or 18 kV/cm) and pasteurization (batch or slow (VAT) and high-temperature-short time (HTST)) on the microbial, physicochemical, bioactive and sensory characteristics of a pomegranate (Punica granatum) fermented beverage (PFB) through storage at 4 °C. Bioactive compounds (antioxidant capacity, phenolic compounds, flavonoids, anthocyanins content) and color were measured. The microbiological counts (initial mesophilic aerobic bacteria (MAB) of 9.77 × 10³ CFU/mL and initial molds plus yeasts (MY) of 2.04 × 10³ CFU/mL) showed that applying 6 ms of bipolar PEFs at 18 kV/cm with 200 Hz repetition frequency reduced the microbial loads in approximately 4-log cycles, remaining <10 CFU/mL of both types of microorganisms in the PFB. PEF barely affected the total soluble solids, pH, ethanol, total acidity and color. All PEF-treated and pasteurization samples showed a slight reduction in bioactive compounds during storage. In sensory acceptability, the lowest score was given to the VAT pasteurized sample; however, still acceptable (between like slightly and like moderately).Industrial relevanceThis research provides essential information on the microbiological, physicochemical, bioactive and sensory characteristics of a pomegranate fermented beverage processed with pulsed electric fields. The pulsed electric field processing of fermented beverages may provide criteria to the processing industry to use this novel technology as a processing method for delivering a microbiological safe beverage with good sensory and antioxidant characteristics to consumers.     

Analysis of stepwise charging limits and its implementation for efficiency improvement in switched capacitor DC–DC converters

In this work we analysed the stepwise charging technique to find the limits from which it is beneficial in terms of load capacitance and charge–discharge frequency. We included in the analysis practical limitations such as the consumption of auxiliary logic needed to implement the technique and the minimum size of auxiliary switches imposed by the technology. We proposed an ultra-low-power logic block to push these limits and to obtain benefits from this technique in small capacitances. Finally, we proposed to use a stepwise driver in the driving of the gate capacitance of power switches in switched-capacitor (SC) DC–DC converters. We designed and manufactured, in a 130 nm process, a SC DC–DC converter and measured a 29% energy reduction in the gate-drive losses of the converter. This accounts for an improvement of 4% (from 69 to 73%) in the overall converter efficiency.

     

A practical development of engineering simulation-assisted educational AR environments

Engineering simulations have opened several gates for today’s chemical engineers. They are powerful tools to provide technical content as physics-based numerical solvers. Augmented reality (AR) and virtual reality (VR), on the other hand, are already underway to digitize environments in many fields. The combination of AR/VR environments and simulations in engineering education has been attracting widespread interest. Literature has demonstrated a massive amount of digital educational environments in several contexts as being complementary to conventional educational methods. Nevertheless, hosting technical content produced by engineering simulations with educational AR/VR is still challenging and requires expertise from multiple disciplines throughout the technical development. Present work provides a facile and agile methodology for low-cost hardware but content-wise rich AR software development. Inspired by the Covid-19 pandemic, a case study is developed to teach chemical-engineering concepts using a liquid-soap synthesis process. Accordingly, we assess and conclude the digital development process to guide inexperienced developers for the digitalization of teaching content. The present contribution serves as an example of the power of integrating AR/VR with traditional engineering simulations for educational purposes. The digital tool developed in this work is shared in the online version.