不同产地丹参药材干燥前后化学成分含量变化

目的为了验证不同产地丹参中丹酚酸类成分是否都是采后干燥诱导的产物,分别测定四川、山东、陕西三个主要产区新鲜样品晒干后主要化学成分含量的变化。方法采用高效液相色谱法测定了新鲜和晒干丹参中6种酚酸和4种丹参酮类成分的含量。结果新鲜丹参样品中丹酚酸类成分含量甚微（丹酚酸B〈0．41％）,但晒干样品中含量显著增加（丹酚酸B≥3．0％）。晒干后样品中丹参酮类成分含量也有明显增加。结论不同产地丹参的重要成分丹酚酸B都是采后干燥胁迫诱导的产物。     

HIV and Severity of Seasonal Household Food-Related Coping Behaviors in Rural Ghana

In-depth research was conducted to evaluate the seasonal food insecurity of HIV-positive and HIV-negative farm households in the Eastern Region, Ghana. A Coping Strategy Index (CSI) was used to assess household food-related coping behaviors. HIV-positive farm households often relied on both less severe and more severe coping behaviors, had a higher CSI, cultivated a smaller field area, harvested fewer food species from farms and gardens, and obtained income from fewer sources than HIV-negative farm households in both the post-harvest and lean seasons. We conclude that food insecurity is more severe in HIV-positive than in HIV-negative farm households in both seasons.     

The Inhibitory Effect of Pseudomonas stutzeri YM6 on Aspergillus flavus Growth and Aflatoxins Production by the Production of Volatile Dimethyl Trisulfide

Aspergillus flavus and the produced aflatoxins cause great hazards to food security and human health across all countries. The control of A. flavus and aflatoxins in grains during storage is of great significance to humans. In the current study, bacteria strain YM6 isolated from sea sediment was demonstrated effective in controlling A. flavus by the production of anti-fungal volatiles. According to morphological characteristics and phylogenetic analysis, strain YM6 was identified as Pseudomonas stutzeri. YM6 can produce abundant volatile compounds which could inhibit mycelial growth and conidial germination of A. flavus. Moreover, it greatly prevented fungal infection and aflatoxin production on maize and peanuts during storage. The inhibition rate was 100%. Scanning electron microscopy further supported that the volatiles could destroy the cell structure of A. flavus and prevent conidia germination on the grain surface. Gas chromatography/mass spectrometry revealed that dimethyl trisulfide (DMTS) with a relative abundance of 13% is the most abundant fraction in the volatiles from strain YM6. The minimal inhibitory concentration of DMTS to A. flavus conidia is 200 µL/L (compound volume/airspace volume). Thus, we concluded that Pseudomonas stutzeri YM6 and the produced DMTS showed great inhibition to A. flavus, which could be considered as effective biocontrol agents in further application.     

Biological Control and Mitigation of Aflatoxin Contamination in Commodities

Aflatoxins (AFs) are toxic secondary metabolites produced mostly by Aspergillus species. AF contamination entering the feed and food chain has been a crucial long-term issue for veterinarians, medicals, agroindustry experts, and researchers working in this field. Although different (physical, chemical, and biological) technologies have been developed, tested, and employed to mitigate the detrimental effects of mycotoxins, including AFs, universal methods are still not available to reduce AF levels in feed and food in the last decades. Possible biological control by bacteria, yeasts, and fungi, their excretes, the role of the ruminal degradation, pre-harvest biocontrol by competitive exclusion or biofungicides, and post-harvest technologies and practices based on biological agents currently used to alleviate the toxic effects of AFs are collected in this review. Pre-harvest biocontrol technologies can give us the greatest opportunity to reduce AF production on the spot. Together with post-harvest applications of bacteria or fungal cultures, these technologies can help us strictly reduce AF contamination without synthetic chemicals.     

Impact of Season,Region, and Traditional Agricultural Practices on Aflatoxins and Fumonisins Contamination in the Rice Chain in the Mekong Delta,Vietnam

The current study aimed to evaluate the impact of the crop season, cultivation region, and traditional pre- and post-harvest agricultural practices on mycotoxin contamination in the Mekong Delta rice chain of Vietnam. The results showed that aflatoxins (AFs) and fumonisins (FBs) were predominantly detected in both paddy (n = 91/184, 50%) and white rice (n = 9/46, 20%). Aflatoxin B1 (AFB1)-contaminated paddy samples (n = 3) exceeded the regulatory threshold (5 µg·kg⁻¹). The contamination of paddy with AFs and FBs was not significantly different by growing seasons and cultivation localities. Evidently, in the winter–spring season, fumonisins frequently occurred in paddy planted in Can Tho, while AFs were found in paddy planted in regions Dong Thap and An Giang, and such toxins were absent in Can Tho. Furthermore, the selection of paddy varieties strongly impacted the occurrence of these toxins, especially AFs, for example, line DT8 and Jasmine were susceptible to AFs and FBs. In addition, poor pre- and post-harvest practices (such as crop residue-free fields, fertilizer application, unsanitary means of transport, delayed drying time) had an impact on the AFs and FBs contamination. Our findings can help to understand the dynamics of AFs and FBs in the rice chain in the Vietnamese Mekong Delta, leading to the mitigation of the contamination of AFs and FBs in rice.     

Effect of gamma radiation as a post-harvest disinfestation treatment against life stages of the coffee berry borer,Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae)

Abstract

Purpose: Gamma radiation is mainly used for disinfesting insect pests as an alternative for harmful fumigants. The specific dose of radiation is known to affect different developmental stages of insect pests. The study was conducted to determine the effective irradiation doses for inhibition of developmental stages and adult longevity of the coffee berry borer, Hypothenemus hampei (Ferrari).

Materials and methods: Irradiation was carried with the following doses: five levels between 0.01 and 0.16?kGy for eggs, seven levels between 0.10 and 2.00?kGy for larva and prepupa, six levels between 0.10 and 1.60?kGy for pupa and ten levels between 0.10 and 3.20?kGy for adults.

Results: Egg development was completely arrested at 0.160?kGy. A dose of 2.00?kGy caused 100% mortality in the first and second instar larva and 98.99% mortality in prepupa. The dose of 1.60?kGy prevented adult eclosion from the irradiated pupa. The adult mortality was 100% at 3.20?kGy.

Conclusion: A dose of 3.20 kGy could successfully provide complete security from all developmental stages of H. hampei and prevent yield loss in green coffee as well as the spread of the pest.     

Chili post-harvest residue-derived nanocellulose composite as a matrix for in vitro cell culture and Hemigraphis colorata blended nanocellulose extends antimicrobial potential

Nanocellulose is becoming a wonderful biomaterial with wider applications in food, biomedical, cosmetics, and other sectors. Nanocellulose is easily degradable, bio-derived and can be effectively used for constructing novel bioplastics which finds applications in food packaging and wound dressing. Nanocellulose was isolated from Chili post-harvest residue and its properties were evaluated using FESEM, XRD and FTIR. Cytotoxicity and viability of cells are critical characteristics defining a material for biomedical applications and these properties were investigated for Chili post-harvest residue derived nanocelluose. The cell viability of HEK293 cells was assessed and the results demonstrated that the cell viability was normal, with no cytotoxicity and DNA damaging effects. Next we examined the antimicrobial potential of NC films after blending with Hemigraphis colorata extract. The nanocellulose blended with Hemigraphis colorata extract provided effective antimicrobial activity by inhibiting the growth of Bacillus cereus, E. coli, Pseudomonas sp. and Saccharomyces cerevisiae. The antimicrobial property of NC composite suggests its potential for use in food packaging and in wound dressing material.     

土壤水分对新鲜和采后干燥丹参根中活性成分含量的影响

目的：进一步验证丹参药材中丹酚酸类成分尤其是丹酚酸B是采后干燥的产物;了解栽培过程中土壤水分状态对新鲜和阴干后丹参药材中丹酚酸类和丹参酮类成分的影响。方法采用高效液相色谱法测定了不同土壤水分条件栽培的新鲜和采后阴干丹参样品中6种酚酸类和4种丹参酮类成分的含量。结果新鲜丹参样品中,均含有较高含量丹参酮类成分,但只有极度干旱胁迫时（土壤水势＜30％）,才可检测到丹酚酸B（＜1％）,且无其他酚酸类成分。阴干样品中丹酚酸类成分含量均显著增加,其中丹酚酸B含量达4．2％;丹参酮类成分也增加了30％以上。阴干后丹参中丹酚酸B及总酚酸含量与栽培过程中土壤水势呈现显著负相关。结论采后干燥有利于丹参中活性成分积累。丹参药材中丹酚酸类成分尤其是丹酚酸B是栽培和采后极度干旱（干燥）的产物,栽培过程中适度的干旱胁迫有利于药材中酚酸类成分的产生。     

白芍初加工方法和质量控制研究进展

本文系统回顾了白芍初加工过程中涉及的去皮、水煮、硫磺熏蒸、干燥和灭菌,以及质量评价方法等方面的研究现状,分析了当前白芍初加工和质量评价中存在的主要问题,探讨了改进方法和措施,为规范白芍的加工,确保药材质量稳定和用药安全提供参考。     

百合采后加工包装贮藏环节的调查

目的:针对市售百合质量差异较大的情况,通过深入调查百合在采收、初加工、包装、贮藏环节的现状,全面了解百合在采后各环节影响其质量的因素,为其规范化生产提供参考。方法:以多个主产区、中药材专业市场的实地调查为主,结合文献检索和分析,综合分析影响百合质量的各种因素。结果:通过调查结果的汇总、分析,归纳总结了百合在采收、初加工、干燥技术、包装、贮藏等方面的现状和具体操作中存在的不足。结论:百合的采收涉及生长年限、采收期、采收方法;初加工涉及剥片、清洗、硫磺熏蒸、多种制熟和干制方法;热风干燥、真空冷冻干燥、远红外线干燥、微波干燥等现代干燥技术均得到了一定程度的应用。包装与贮藏环节的主要变质现象是褐变、虫蛀和腐烂。市售百合以散装为主、塑料袋包装为辅,兼有真空鲜品包装。因操作过程的不规范,制熟和干制技术对其质量的影响最为关键。需要探索并制定科学统一的标准操作规程(Standard Operating Procedure,SOP),从多个环节进行百合质量的全过程控制。