Prediction of moisture content for a single maize kernel based on viscoelastic properties.

BACKGROUND: The rapid and accurate detection of moisture content is important to ensure maize quality. However, existing technologies for rapidly detecting moisture content often suffer from the use of costly equipment, stringent environmental requirements, or limited accuracy. This study proposes a simple and effective method for detecting the moisture content of single maize kernels based on viscoelastic properties. RESULTS: Two types of viscoelastic experiments were conducted involving three different parameters: relaxation tests (initial loads: 60, 80, 100 N) and frequency-sweep tests (frequencies: 0.6, 0.8, 1 Hz). These experiments generated corresponding force-time graphs and viscoelastic parameters were extracted based on the four-element Maxwell model. Then, viscoelastic parameters and data of force-time graphs were employed as input variables to explore the relationships with moisture content separately. The impact of different preprocessing methods and feature time variables on model accuracy was explored based on force-time graphs. The results indicate that models utilizing the force-time data were more accurate than those utilizing viscoelastic parameters. The best model was established by partial least squares regression based on S-G smoothing data from relaxation tests conducted with initial force of 100 N. The correlation coefficient and the root mean square error of the calibration set were 0.954 and 0.021, respectively. The corresponding values of the prediction set were 0.905 and 0.029, respectively. CONCLUSIONS: This study confirms the potential for accurate and fast detection of moisture content in single maize kernels using viscoelastic properties, which provides a novel approach for the detection of various components in cereals. © 2024 Society of Chemical Industry.

Detection of Specific Volatile Organic Compounds in Tribolium castaneum (Herbst) by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry.

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a major storage pest that could lead to a wide range of damage. Its secretions have a significant impact on the quality of stored grain and food, leading to serious food safety problems such as grain spoilage and food carcinogenesis. This study investigates new detection techniques for grain storage pests to improve grain insect detection in China. The primary volatile organic chemicals (VOCs) in these secretions are identified using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The specific VOCs that are unique to T. castaneum are selected as criteria for determining the presence of T. castaneum in the granary. To obtain more specific VOCs, experiments were designed for the analysis of T. castaneum samples under different extraction times, two types of SPME fibers and two GC-MS devices of different manufacturers. The experimental results showed that 12 VOCs were detected at relatively high levels, seven of which were common and which were not detected in other grains and grain insects. The seven compounds are 1-pentadecene, 2-methyl-p-benzoquinone, 2-ethyl-p-benzoquinone, 1-hexadecene, cis-9-tetradecen-1-ol, m-cresol and paeonol. These seven compounds can be used as volatile markers to identify the presence of T. castaneum, which could serve as a research foundation for the creation of new techniques for T. castaneum monitoring.

Binding of the polysaccharide from Acanthopanax giraldii Harms to toll-like receptor 4 activates macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional Chinese medicine, Acanthopanax giraldii Harms, is commonly used to treat arthralgia due to wind, cold and dampness, as well as weakness in the feet and knees. Its other reported effects include eliminating flatulence, strengthening muscles and bones, and delaying aging. The polysaccharides in A. giraldii Harms are the major bioactive substances that confer the herb's antioxidant properties as well as anticancer and antiviral effects. AIMS OF THE STUDY: To elucidate the underlying mechanism and signaling cascade involved in the homogeneous A. giraldii Harms polysaccharide II (AHP-II)-mediated immunomodulation of mice macrophages. MATERIALS AND METHODS: The phagocytosis of neutral red and the production of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were measured to determine AHP-II-induced macrophage activation. Confocal microscopy and flow cytometry were used to confirm the binding of AHP-II to macrophages. The involvement of Toll-like receptor (TLR) 4 in AHP-II-induced macrophage activation was demonstrated using antibody blocking and macrophages from C3H/HeJ TLR4-mutant mice. Western blotting was used to map AHP-II-induced downstream signaling pathways. RESULTS: AHP-II increased the phagocytosis of macrophages and the release of nitric oxide, IL-6 and TNF-α cytokines. Direct, saturable and reversible binding of AHP-II to macrophages was observed, while it can be inhibited by the anti-TLR4 antibody. In addition, the presence of the anti-TLR4 antibody inhibited AHP-II-induced macrophage IL-6 and TNF-α production in the peritoneal macrophages of C3H/HeJ mice. Moreover, AHP-II-TLR4-stimulated macrophages activate the downstream intracellular ERK and JNK/nuclear factor (NF)-κB signaling pathways. In addition, the AHP-II-mediated regulation of IL-6 and TNF-α production from macrophages was greatly affected by specific ERK, JNK and NF-κB inhibitors. CONCLUSION: Our study elucidated the immunomodulatory mechanism of AHP-II in macrophage activation and identified TLR4 as the main receptor coordinating AHP-II binding. Our findings suggest AHP-II may be used as a novel immunopotentiator for medical purposes.