Combined treatments of chestnut shell extract, fumaric acid, and mild heat to inactivate foodborne pathogens inoculated on beetroot (Beta vulgaris L.) leaves

Natural Clerodendrum-derived tick repellent: learning from Nepali culture

Ticks attaching to ear canals of humans and animals are the cause of otoacariasis, common in rural areas of Nepal. The plant Clerodendrum viscosum is used in multiple indigenous systems of medicine by ethnic communities in the Indo-Nepali-Malaysian region. Visiting the Chitwan National Park, we learned that in indigenous medicine, flower extract of C. viscosum is utilized to treat digestive disorders and extracts from leaves as tick repellent to prevent ticks from invading or to remove them from the ear canal. The objective of our study was to provide support to indigenous medicine by characterizing the in vivo effect of leave extracts on ticks under laboratory conditions and its phytochemical composition. We collected plant parts of C. viscosum (leaves and flowers) and mango (Mangifera indica) leaves at the Chitwan National Park, previously associated with repellent activity to characterize their effect on Ixodes ricinus ticks by in vivo bioassays. A Q-ToF high-resolution analysis (HPLC-ESI-QToF) was conducted to elucidate phenolic compounds with potential repellent activity. Clerodendrum viscosum and M. indica leaf extracts had the highest tick repellent efficacy (%E = 80-100%) with significant differences when compared to C. viscosum flowers extracts (%E = 20-60%) and phosphate-buffered saline. Phytochemicals with tick repellent function as caffeic acid, fumaric acid and p-coumaric acid glucoside were identified in C. viscosum leaf extracts by HPLC-ESI-QToF, but not in non-repellent flower extracts. These results support the Nepali indigenous medicine application of C. viscosum leaf extracts to repel ticks. Additional research is needed for the development of natural and green repellent formulations to reduce the risks associated with ticks resistant to acaricides.

Co-composting of forest and industrial wastes watered with pig manure

Co-composting of forest-derived wastes (chestnut forest burr, CST; scrubland biomass, SRB; industrial sludge, MDFS, from the Medium Density Fibreboard production process) watered with pig manure (PM) may constitute a feasible management technique for both solid and liquid streams. PM provided water and improved the carbon to nitrogen (C/N) ratio. Four piles of 1.8-2.4 m³ were conformed: A (SRB, with compaction bulk density), B (SRB, without compaction), C (SRB and MDFS at a volumetric ratio of 3:1) and D (CST). Thermophilic temperatures were maintained for 8 (B), 16 (A), 28 (C) and 40 (D) days. Stable compost was obtained after 35 (A, B, C) and 48 (D) days. Hygienization was only complete in piles C and D. N losses were higher in piles A (39.3%) and B (33.6%) in relation to C (17.0%) and D (8.9%) which could be attributed to the characteristics of MDFS and CST. Increasing the matrix size from 340 L to around 2000 L led to a higher intensity of the thermophilic phase. Besides, compaction significantly increased the temperature during composting. PM was added at ratios ranging from 1.8 to 2.5 L/kg dry matter, being favoured by pre-drying of solid wastes.

Antibacterial activity of the noni fruit extract against Listeria monocytogenes and its applicability as a natural sanitizer for the washing of fresh-cut produce

This study was conducted to investigate the antibacterial activity of the noni fruit extract (NFE) against Listeria monocytogenes (ATCC, 19111 and 19115) and assess its applicability for the washing of fresh-cut produce. Based on the results of the disc diffusion test, L. monocytogenes (ATCC, 19111 and 19115) was susceptible to the activity of NFE than other pathogens studied. Additionally, results of the time-kill assay indicated that NFE at a concentration of 0.5-0.7% effectively killed L. monocytogenes within 7 h. Furthermore, analysis of the intracellular components such as nucleic acids and proteins released from the bacterial cells and their SEM imaging revealed that NFE could increase the membrane permeability of cells resulting in their death. Compared to their unwashed samples, washing of romaine lettuce, spinach, and kale with 0.5% NFE gave a reduction of 1.47, 2.28, and 3.38 log CFU/g, respectively against L. monocytogenes (ATCC, 19111 and 19115), which is significantly different to that of NaOCl. A significant correlation was observed between the antibacterial effect induced due to NFE washing with the surface roughness of the fresh-cut produce than its surface hydrophobicity. Moreover, washing with NFE was not found to affect the color of the samples. These results indicated that NFE demonstrates good antibacterial activity against L. monocytogenes and can be used as a natural sanitizer to ensure the microbiological safety of fresh-cut produce.