Characteristics of Lactic Acid Bacteria as Potential Probiotic Starters and Their Effects on the Quality of Fermented Sausages.

The aim of this study was to explore the potential of commercial lactic acid bacteria (LAB) as probiotic starters in fermented sausages. We initially investigated the growth activity, acid production capability, and tolerance to fermentation conditions of Lactobacillus sakei, Lactiplantibacillus plantarum, and Pediococcus pentosaceus. All three LAB strains proved viable as starters for fermented sausages. Subsequently, we explored their potential as probiotics based on their antibacterial and antioxidant capabilities. L. plantarum exhibited stronger inhibition against Escherichia coli and Staphylococcus aureus. All three strains displayed antioxidant abilities, with cell-free supernatants showing a higher antioxidant activity compared to intact cells and cell-free extracts. Moreover, the activities of superoxide dismutase, glutathione peroxidase, and catalase were stronger in the cell-free supernatant, cell-free extract, and intact cell, respectively. Finally, we individually and collectively inoculated these three LAB strains into sausages to investigate their impact on quality during the fermentation process. External starters significantly reduced pH, thiobarbituric acid reactive substances, and sodium nitrite levels. The improvements in color and texture had positive effects, with the L. plantarum inoculation achieving higher sensory scores. Overall, all three LAB strains show promise as probiotic fermentation starters in sausage production.

Effect of compound dietary fiber of soybean hulls on the gel properties of myofibrillar protein and its mechanism in recombinant meat products.

Response surface methodology was used to determine the optimum ratio of rice husk dietary fiber, soybean hull dietary fiber, and inulin as 1.40, 1.42, and 3.24%. The effects of compound and single dietary fiber on water holding capacity, gel strength, secondary structure, rheological properties, chemical action force, and microstructure of myofibrillar proteins (MP) gel were investigated. The application of composite dietary fiber significantly (P < 0.05) improved the gel strength, water holding capacity and storage modulus (G') of MP gel. Fourier transform infrared spectrum analysis shows that the addition of compound dietary fiber can make the gel structure more stable. The effect of dietary fiber complex on the chemical action of MP gel was further studied, and it was found that hydrophobic interaction and disulfide bond could promote the formation of compound gel. By comparing the microstructure of the MP gel with and without dietary fiber, the results showed that the MP gel with compound dietary fiber had smaller pores and stronger structure. Therefore, the rice hull dietary fiber, the soybean hull dietary fiber and the inulin are compounded and added into the low-fat recombinant meat product in a proper proportion, so that the quality characteristics and the nutritional value of the low-fat recombinant meat product can be effectively improved, the rice hull dietary fiber has the potential of being used as a fat substitute, and a theoretical basis is provided for the development of the functional meat product.

A fast forward algorithm of azimuthal gamma imaging logging while drilling.

Logging while drilling (LWD) technology can evaluate the formation interface and stratigraphic properties around the borehole in real time, so as to adjust the drilling trajectory and effectively improve the reservoir encounter rate. Fast forward algorithm can be used with LWD, by comparing the fast forward results with the actual gamma LWD results, it can distinguish the formation interface more accurately. Fast forward algorithm also can provide a theoretical basis for geosteering and azimuthal gamma logging interpretation. In this paper, based on the spatial distribution law of gamma rays and The Monte Carlo N-particle code (MCNP)-driven spatial sensitivity function, a 3D fast forward method of gamma ray LWD is proposed. Compared with the traditional algorithms, the new method can realize the fast simulations of gamma ray logging in four sectors, which enables fast azimuthal imaging. The comparison shows that whether in vertical wells or high-angle wells, the results of the proposed method are in high agreement with the MCNP fine simulations. In addition, the new method improves the calculation speed by tens of thousands of times with comparable accuracy. Finally, the gamma logging-while-drilling data of a highly deviated well in a field case verifies the accuracy and applicability of the method. The algorithm can meet the requirements of LWD for fast forward modeling of azimuthal natural gamma ray logging, which is expected to be applied to geosteering and logging interpretation of high angle and horizontal wells.

Perception of Urban Environmental Risks and the Effects of Urban Green Infrastructures (UGIs) on Human Well-being in Four Public Green Spaces of Guangzhou, China.

Cities face many challenging environmental problems that affect human well-being. Environmental risks can be reduced by Urban Green Infrastructures (UGIs). The effects of UGIs on the urban environment have been widely studied, but less attention has been given to the public perception of these effects. This paper presents the results of a study in Guangzhou, China, on UGI users' perceptions of these effects and their relationship with sociodemographic variables. A questionnaire survey was conducted in four public green spaces. Descriptive statistics, a binary logistic regression model and cross-tabulation analysis were applied on the data from 396 valid questionnaires. The results show that UGI users were more concerned about poor air quality and high temperature than about flooding events. Their awareness of environmental risks was partly in accordance with official records. Regarding the perception of the impacts of environmental risks on human well-being, elderly and female respondents with higher education levels were the most sensitive to these impacts. The respondents' perceptions of these impacts differed among the different green spaces. The effects of UGIs were well perceived and directly observed by the UGI users, but were not significantly influenced by most sociodemographic variables. Moreover, tourists had a lower perception of the impacts of environmental risks and the effects of UGI than residents did. This study provides strong support for UGIs as an effective tool to mitigate environmental risks. Local governments should consider the role of UGIs in environmental risk mitigation and human well-being with regard to urban planning and policy making.