Combination system of pulsed ohmic heating and 365-nm UVA light-emitting diodes to enhance inactivation of foodborne pathogens in phosphate-buffered saline,milk, and orange juice

This study developed and investigated the combination system of pulsed ohmic heating (POH) and ultraviolet A light-emitting diode (UVA-LED) to enhance inactivation of pathogens in phosphate-buffered saline, milk, and orange juice. When Escherichia coli O157:H7 and Salmonella Typhimurium (6–8 log CFU/ml) in samples were subjected to the simultaneous combination of POH and UVA-LED at 50–65°C, the reduction levels increased >1 log CFU/ml compared with each treatment alone. After pathogens in PBS were subjected to the combination treatment at 65°C (50 s), the degree of intracellular ROS generation and lipid peroxidation were increased approximately 1.6 times than each treatment alone. Moreover, propidium iodide uptake values, which indicated cell membrane damage, for E. coli O157:H7 were 0.92, 14.22, and 19.92 after UVA-LED, POH, and their combination treatment, respectively. Therefore, the combination of POH and UVA-LED may possibly be applied as an effective hurdle technology for food safety.Industrial relevanceIt was identified that the combination treatment induced the generation of intracellular ROS; thereby causing lipid peroxidation and cell membrane damage of pathogens. However, the combination system has no effect on DNA damage of pathogens. In addition, there was no significant difference in the content of vitamin and malondialdehyde in milk and orange juice before and after the combination treatment. Thus, this research provides a fundamental database for the applicability of the combination system of POH and UVA-LED to the pasteurization process in the food industry.     

Understanding the influence of PEF treatment on minerals and lipid oxidation of wet- and dry-aged venison M. longissimus dorsi muscle

Pulse electric fields (PEF) treatment can be used to improve meat quality attributes, such as tenderness and mass transfer kinetics of dry ageing of meat. This study investigated the effect of PEF (high-PEF 10 kV, 50 Hz, 20 μs; low-PEF 2.5 kV, 50 Hz, 20 μs) and ageing method (wet- and dry-ageing) on venison mineral profiles, and lipid and conjugated linoleic acid (CLA) oxidative stability. Twelve loins from six red deer were assigned to six groups: no-PEF dry-aged control, no-PEF control, wet-aged Low-PEF, dry-aged Low-PEF, dry-aged High-PEF, wet-aged High-PEF. Secondary oxidation products contents were not affected by PEF treatment (p > 0.05), but were affected by dry ageing (p < 0.05). CLA was stable across PEF treatments and different ageing regimes (p > 0.05). PEF treatments did not have any effect on minerals (p > 0.05). This study validates the safety of using PEF in venison processing with limited detrimental oxidative modifications.Industrial relevance - PEF treatment and the dry-ageing regimes applied to venison in the present study did not produce excessive oxidative by-products that could compromise product quality. The application of both PEF treatments (HPEF 10 kV, 50 Hz, 5 μs; LPEF 2.5 kV, 50 Hz, 5 μs) could potentially improve the drying of venison with a low risk of increasing oxidation.     

不同的处理方法对红枣汁澄清效果影响的研究

探讨了采用果胶酶-滤纸结合法、果胶酶-单宁明胶结合法、果胶酶-皂土结合法3种澄清工艺技术制取红枣清汁的方法,通过对比确定了较好的澄清方法和最佳工艺条件。试验表明皂土的澄清效果最好。皂土澄清红枣汁的最佳工艺条件为：皂土添加量1.3g/L、澄清12h。所得的红枣清汁澄清透亮,枣香浓郁,呈现出自然的枣红色。     

水酶法提取南瓜子油工艺研究

以南瓜子为原料,建立以水酶法提取南瓜子油新工艺.研究表明,其最佳提取工艺为:选用纤维素酶,加酶量0.8％、酶解温度55℃、酶解时间3h、酶解pH 6.0,在该工艺条件下,提油率可达40.6％.     

Purification and characterization of a new 11S globulin-like protein from Chinese jujube (<Emphasis Type="Italic">Ziziphus jujube</Emphasis> Mill.) seeds

Around 8 million tons of jujube pomace containing seeds was produced each year in China; so how to utilize these residual matters has been receiving great attentions. The 11S globulins are the major storage proteins, and it can be used as additive agents in many food products with gelling and caking functionality. In the present study, an 11S globulin-like protein (ZSG) was isolated and purified from Chinese jujube (Ziziphus jujube Mill.) seeds by two consecutive anion exchange and size exclusion chromatography. A yield of 8 mg of the ZSG from 1 kg seeds was obtained. The apparent molecular mass of the native ZSG was found to be about 210 kDa. The protein consisted of two subunits with molecular masses of 26.0 kDa and 26.5 kDa, respectively. Amino acid composition analyses indicated that ZSG contained all eight essential amino acids, while lysine was the first limiting amino acids. N-terminal amino acid sequences of 26.0- and 26.5-kDa subunits are GVEETICTLRLLENI and GLEETVCSLRLKENI. The two peptide fragments of 26.0-kDa subunit are ANPDQVLENAFQISR and GVEETICTLR by LC–MS/MS. To the best of our knowledge, this is the first report on the purification of 11S globulin-like protein from Chinese jujube (Ziziphus jujube Mill.) seeds.     

大豆醇溶性磷脂制备中浸提温度对产品指标的影响

考察了大豆醇溶性磷脂制备中,浸提温度对醇溶性磷脂产品酸值、过氧化值、磷含量及氮含量的影响。结果显示,采用95%乙醇作为浸提溶剂时,其浸提温度不宜太高,浸提温度最好控制在40℃,结合氮气驱氧,能较好地控制大豆醇溶性磷脂的品质指标。     

Solution plasma-assisted preparation of highly dispersed NiMnAl-LDO catalyst to enhance low-temperature activity of CO2 methanation

In this work, the solution plasma-assisted method was used to prepare NiMnAl-LDO (layered double oxides) catalysts with different treatment times, which were used for the CO₂ methanation reaction. Solution plasma treatment can enhance the dispersibility of the catalyst, create oxygen defects and improve the chemical adsorption capacity of the catalyst. The results show that the low-temperature activity of the catalyst has been improved after the solution plasma treatment. We demonstrate that the NiMnAl-LDO-P(20) catalyst with high dispersion has the highest catalytic activity in CO₂ methanation (81.3% CO₂ conversion and 96.7% CH₄ selectivity at 200 °C). Even though working for 70 h, the catalyst is still highly stable. This work provides a great promise for improving the low-temperature activity of Ni-based catalysts.     

Dielectric response and energy storage efficiency of low content TiO2-polymer matrix nanocomposites

TiO₂/epoxy nanocomposites were prepared at different filler concentrations varying from 3 to 12 phr (parts per hundred resin per weight). The dispersion of TiO₂ was examined by Scanning Electron Microscopy and proved to be adequate. Differential Scanning Calorimetry was implemented to determine the glass to rubber transition temperature of the polymer matrix. The dielectric analysis was performed via Broadband Dielectric Spectroscopy in a wide frequency and temperature range. Five different mechanisms were observed in the spectra of the examined composites which are identified, in terms of increasing temperature at constant frequency, as γ, β, Intermediate Dipolar Effect (IDE), α and Interfacial Polarization (IP) relaxation modes. The activation energies of all relaxation modes were calculated. Finally, the dielectric response of the TiO₂ nanocomposites compared to that of the TiO₂ microcomposites reveals that the former exhibit significantly higher energy storage efficiency even at lower TiO₂ concentration than the corresponding of the microcomposites.     

Synthesis of highly active and stable Pd/C catalysts toward HCOOH dehydrogenation by a simple NH3 adsorption method

Pd catalysts supported on activated carbon (Pd/C–NH₃) toward HCOOH dehydrogenation were prepared by a simple adsorption method using ammonia (NH₃) and Ar as the working gas. The results show that the TOF_initial of Pd/C–NH₃ was 459.8 h⁻¹ at 50 °C. When the reaction was carried out for 4 h, the HCOOH dehydrogenation ratio over Pd/C–NH₃ was about 81.2%, which was 1.15 and 1.13 times, respectively, as that of the as-prepared Pd/C catalyst without any treatment (Pd/C–As) and the Pd/C catalyst purchased from Sigma-Aldrich (Pd/C-CM). The total amount of H₂ and CO₂ produced by using Pd/C–NH₃ to decompose HCOOH in the third cycle was 99.4% of the gas produced by the first reaction cycle, and 1.80 and 12.60 times, respectively, as that of Pd/C–As and Pd/C-CM. The characterization results indicated that the Pd active species in Pd/C–NH₃ migrated to the outer surface of the carbon support during the reaction, and the pore volume of the carbon support became larger, which were beneficial to the reaction. These factors made Pd/C–NH₃ exhibit excellent HCOOH dehydrogenation activity and stability. NH₃ adsorption is a simple and effective method for preparing high-performance Pd/C HCOOH dehydrogenation catalysts, and has important guiding significance for the preparation of other carbon supported noble metal catalysts.     

Scalable Yielding of Highly Stable Polyelectrolyte-Coated Copper Sulfide Nanoparticles by Flash Nanoprecipitation for Photothermal-Chemotherapeutics

Photothermal-chemotherapeutic nanoparticles (NPs) are attracting increasing attention and becoming more widely used for cancer therapy in the clinic due to their noninvasiveness, notable tissue penetration abilities, and low systemic adverse effects. However, functional ligands are conventionally modified onto photothermal NPs to well stabilize the inorganic particles suffering from complex chemical modifications, low productivity, and batch-to-batch inconsistencies, and thus significantly restricting their clinical applications. Herein, flash nanoprecipitation (FNP) is taken advantage of to afford rapid and uniform mixing for generating local supersaturated CuS clusters for small and highly stable CuS NPs effectively stabilized by polyacrylic acid through a continuous strategy. It greatly reduces the complexity for CuS NPs synthesis and functionalization in a facile intensified mixing process. These as-synthesized particles are high-drug loading, scalable, and most importantly, it is easy to control their sizes and charges through external conditions. Toxicity and tumor inhibition experiments confirm the high cell toxicity and good suppression of tumor growth under near-infrared irradiation indicating a promising prospect of FNP in the large-scale and continuous yielding of highly stable and high-performing photothermal-chemotherapeutic NPs for cancer therapy.