RESUMEN

Increasing meat demand in terms of both quality and quantity in conjunction with feeding a growing population has resulted in regulatory agencies imposing stringent guidelines on meat quality and safety. Objective and accurate rapid non-destructive detection methods and evaluation techniques based on artificial intelligence have become the research hotspot in recent years and have been widely applied in the meat industry. Therefore, this review surveyed the key technologies of non-destructive detection for meat quality, mainly including ultrasonic technology, machine (computer) vision technology, near-infrared spectroscopy technology, hyperspectral technology, Raman spectra technology, and electronic nose/tongue. The technical characteristics and evaluation methods were compared and analyzed; the practical applications of non-destructive detection technologies in meat quality assessment were explored; and the current challenges and future research directions were discussed. The literature presented in this review clearly demonstrate that previous research on non-destructive technologies are of great significance to ensure consumers' urgent demand for high-quality meat by promoting automatic, real-time inspection and quality control in meat production. In the near future, with ever-growing application requirements and research developments, it is a trend to integrate such systems to provide effective solutions for various grain quality evaluation applications.

RESUMEN

A number of mitigation techniques exist to reduce the emissions of pollutant gases and greenhouse gases (GHGs) from anaerobic storage of livestock manure. Nanoparticle (NP) application is a promising mitigating treatment option for pollutant gases, but limited research is available on the mode of NP application and their effectiveness in gaseous emission reduction. In this study, zinc silica nanogel (ZnSNL), copper silica nanogel (CuSNL), and N-acetyl cysteine (NACL) coated zinc oxide quantum dot (Qdot) NPs were compared to a control lacking NPs. All three NPs tested significantly reduced gas production and concentrations compared to non-treated manure. Overall, cumulative gas volumes were reduced by 92.73%-95.83%, and concentrations reduced by 48.98%-99.75% for H2S, and 20.24%-99.82% for GHGs. Thus, application of NPs is a potential treatment option for mitigating pollutant and GHG emissions from anaerobically stored manure.

Asunto(s)

RESUMEN

Bioelectricity generation from biodegradable compounds using microbial fuel cells (MFCs) offers an opportunity for simultaneous wastewater treatment. This study evaluated the synergy of electricity generation by the MFC while reducing pollutants from sugar beet processing wastewater (SBPW). A simple dual-chamber MFC was constructed with inexpensive materials without using catalysts. Raw SBPW was diluted to several concentrations (chemical oxygen demand (COD) of 505 to 5,750 mg L-1) and fed as batch-mode into the MFC without further modification. A power density of 14.9 mW m-2 as power output was observed at a COD concentration of 2,565 mg L-1. Coulombic efficiency varied from 6.21% to 0.73%, indicating diffusion of oxygen through the cation exchange membrane and other methanogenesis and fermentation processes occurring in the anode chamber. In this study, >97% of the COD and up to 100% of the total suspended solids removals were observed from MFC-treated SBPW. Scanning electron microscopy of anode indicated that a diverse community of microbial consortia was active for electricity generation and wastewater treatment. This study demonstrated that SBPW can be used as a substrate in the MFC to generate electricity as well as to treat for pollutant removal.

Asunto(s)

RESUMEN

Hydrogen sulfide (H2S) and greenhouse gases' emission from livestock production facilities are of concern to human welfare and the environment. Application of nanoparticles (NPs) has emerged as a potential option for minimizing these gaseous emissions. Application of bare NPs, however, could have an adverse effect on plants, soil, human health, and the environment. To minimize NPs' exposure to the environment by recovering them, NPs were entrapped in polymeric beads for treating livestock manure. The objectives of the research were to understand the mechanism of gaseous reduction in swine manure treated for 33 days with zinc oxide nanoparticles (nZnO) or nZnO-entrapped alginate (alginate-nZnO) beads by different characterization techniques. Headspace gases from treated manure flasks were collected in 2-6-day intervals during the experimental period and were analyzed for methane (CH4), carbon dioxide (CO2), and H2S concentrations. The microbial analysis of manure was carried out using bacterial plate counts and Real-Time Polymerase Chain Reaction methods. Morphology and chemical composition of alginate-nZnO beads were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Photoelectron Spectroscopy (XPS). Alginate-nZnO beads or bare nZnO proved to be an effective NP in reducing H2S (up to 99%), CH4 (49-72%), and CO2 (46-62%) from manure stored under anaerobic conditions and these reductions are likely due to the microbial inhibitory effect from nZnO, as well as chemical conversion. Both SEM-EDS and XPS analysis confirmed the presence of zinc sulfide (ZnS) in the beads, which is likely formed by reacting nZnO with H2S.

Asunto(s)

RESUMEN

BACKGROUND: Dietary manipulation is a common practice to mitigate gaseous emission from livestock production facilities, and the variation of fat level in the diet has shown great influence on ruminal volatile fatty acids (VFA) and enteric methane generation. The changes in dietary fat levels influence rumen chemistry that could modify manure nutrient composition along with odor and gaseous emissions from manure management facilities. METHODS: A field experiment was carried out on beef cattle feedlots to investigate the effect of four levels of dietary fat concentrations (3 to 5.5 %) on the manure composition and gaseous emissions (methane-CH4, nitrous oxide-N2O, carbon dioxide-CO2 and hydrogen sulfide-H2S) from the feedlot pen surface. The experiment was carried out over a 5-month period from June to October during North Dakota's summer-fall climatic condition. Air and manure sampling was conducted five times at a 20-30 day intervals. RESULTS: Overall, this research indicated that fat levels in diet have no or little effect on the nutrient composition of manure and gaseous emission from the pens with cattle fed with different diet. Though significant variation of gaseous emission and manure composition were observed between different sampling periods, no effect of high fat diet was observed on manure composition and gaseous emission. CONCLUSIONS: It can be concluded that addition of fat to animal diet may not have any impact on gaseous emission and manure compositions.

RESUMEN

There is a global interest to quantify and mitigate greenhouse gas (GHG) (e.g. methane-CH4, nitrous oxide-N2O and carbon dioxide-CO2) emissions in animal feeding operations. The goal of this study was to quantify GHG emissions from the feedlot pen surface under North Dakota climatic conditions. In this study gaseous flux from the pen surfaces was generated using a custom-made wind tunnel at different times of the year (summer, fall, winter and spring). Gaseous fluxes (air samples) were drawn in the Tedlar bags using a vacuum chamber and gas concentrations were measured using a gas chromatograph within 24 h of sampling. The CH4 concentrations and flux rates (FRs) or flux among the months were not significantly different. Overall CH4, CO2 and N2O concentrations over a 7-month period were 2.66, 452 and 0.67 ppm, respectively. Estimated overall CH4, CO and N2O FRs were 1.32, 602 and 0.90 g m(-2) d(-1), respectively. Estimated emission rates using the wind tunnel were 38 g hd(-1) d(-1), 17 kg hd(-1) d(-1) and 26 g hd(-1) d(-1) for CH4, CO2 and N2O, respectively. The emission factors for GHG estimated in the research for North Dakota climate were the first of its kind, and these emission estimates can be used as a basis for planning and implementing management practices to minimize GHG emissions.

Asunto(s)