2-Hydroxy-4-methoxybenzaldehyde inhibits the growth of Aspergillus flavus via damaging cell wall,cell membrane,manipulating respiration thus creating a promising antifungal effect on corn kernels

This study investigated the antifungal activity and the potential antifungal mechanisms of 2-hydroxy-4-methoxybenzaldehyde (HMB) against Aspergillus flavus (A. flavus). The minimum inhibitory concentration (MIC) of HMB in preventing spore germination was 70 μg mL⁻¹. HMB at MIC disrupted cell wall integrity by reducing the number of septa by 86.66% (P < 0.05) in mycelia and increased cell membrane permeability by about 14-fold (P < 0.05) evidenced by propidium iodide (PI) staining. Furthermore, HMB at MIC inhibited respiration by 33.33%. These results revealed that the antifungal activity of HMB against A. flavus could be attributed to the damaged cell wall integrity, cell membrane permeability and respiration metabolism. What’s more, A. flavus was completely restrained in corn kernels due to HMB. Therefore, HMB could be applied as an effective antifungal agent.     

Study on retrogradation of maize starch–flaxseed gum mixture under various storage temperatures

This study aimed to investigate the effect of flaxseed gum (FG) on the retrogradation of maize starch (MS) gels under different storage temperatures. In this work, MS‐FG gels with 0–0.4% FG were stored under different temperatures (–20, 4 and 20 °C). Under all storage temperatures, the addition of FG inhibited the retrogradation process of MS, suppressed the recrystallisation of starch molecules, reduced the water loss of starch gels and improved the texture of the gels. Among the three storage temperatures, ?20 °C could almost stop the starch retrogradation but leading it results in the hardest gel texture. The retrogradation of MS‐FG gels stored under 4 °C was most serious with the fastest rate of recrystallisation. When stored at 20 °C, the gels had a retrogradation degree that was lower than when they were stored at 4 °C and also had the softest texture.     

玉米淀粉对大蒜中大蒜素的包合及其复合物的抑菌活性

以玉米淀粉和鲜大蒜为原料,尝试高速剪切混合制备淀粉-大蒜素复合物,并对其抑菌活性进行评价。结果表明,当高速剪切混合处理时间为40 min,大蒜(干基)/淀粉质量比为3:2时,复合物中大蒜素的含量为1.17±0.02μg/mg,包埋率为89.71%±1.20%。碘结合实验表明,淀粉与大蒜中的大蒜素通过主客体相互作用形成复合物。玉米淀粉经高速剪切混合处理后颗粒形态的变化不大,但是与大蒜共同处理后淀粉颗粒的形态发生较大的变化。形成复合物后淀粉的结晶度降低;淀粉复合物比大蒜粉具有较高的热稳定性。抑菌实验表明,复合物的抑菌活性良好,当大蒜(干基)与玉米淀粉质量比为3:2时,其对E.coli,S.aureus,B.subtilis和S.Typhimurium的抑菌圈直径分别为19.92±0.03、23.02±0.03、34.51±0.20、23.21±0.15 mm。淀粉-大蒜素复合物的形成,提高了大蒜素的生物活性。     

Do metal grain silos benefit women in Kenya,Malawi, Zambia and Zimbabwe?

Metal silos can reduce maize losses during storage in smallholder farm systems, contributing towards international goals of reducing food waste and moving towards Sustainable Development Goal 2, Zero Hunger. However, technologies are introduced into farming systems with complex sets of relationships. These may differentially affect the ability of women and men to secure the expected benefits of metal silos. This, in turn, may affect adoption rates and expected outcomes. To better understand these relationships, a mixed methods study was conducted in Kenya, Malawi, Zimbabwe and Zambia where metal silos were introduced through the Effective Grain Storage Project (EGSP). EGSP distributed 1717 metal silos across the four countries.Quantitative surveys using random sampling were conducted in Kenya (124 respondents) and Malawi (100 respondents) with metal silo owners. Qualitative surveys, using purposive sampling, were conducted in all four countries covering 14 ethnic groups using focus group discussions (360 respondents), key informant interviews (62 respondents), and household case studies (62 respondents). The aim was to understand gendered post-harvest management and storage strategies in traditional systems and to map changes when metal silos were introduced.The findings suggest roles and responsibilities regarding the ownership and management of storage structures are strongly gendered with some differences between ethnic groups and countries. Men benefit more than women from the introduction of metal silos. Ownership of the grain storage facility, and the benefits attached to ownership, can switch from women to men with women having less scope for bargaining over their rights to use the stored grain for their own needs and the benefit of all household members. Women and men fail to fully follow guidelines for effective use of metal silos. They differ in their preferred attributes for their ideal storage system. Whilst some attributes are shared, women’s preferences were sharply differentiated from men in others.     

Insect-corn kernel interaction: Chemical signaling of the grain and host recognition by Sitophilus zeamais

In living organisms, the cuticle has structural functions and is involved through chemical signaling in biological interactions such as plant-insect and provides protection against biotic and abiotic factors, thereby avoiding desiccation or the attack of predators. The objective of this study was to investigate the participation of the epicuticle in the maize kernel-Sitophilus zeamais interaction. The GC-MS analysis of the epicuticle extract demonstrated the presence of aliphatic hydrocarbons, alcohols, ethers, fatty acids, sterols and their derivatives. The results of bioassays show that the epicuticle of maize has a primordial role in its interaction with S. zeamais, and participates in the recognition and attraction to the food source, as well as regulating its reproduction. In addition the compounds present in the epicuticle extract may act as signal molecules and development regulators. This study reveals the effect of the maize kernel cuticle on Sitophilus behavior and contributes to the understanding of the interaction.     

Modeling the effect of a superabsorbent polymer material as desiccant in maize drying using CFD

Maize is an important foodstuff in many countries, and one of most susceptible crops to mold and aflatoxin contamination, which results in considerable postharvest losses and is a burden to consumers’ health, especially in developing countries. The timely drying of harvested maize is essential to halt mold development, ensuring safe storage. The effect of the incorporation of a superabsorbent polymer (SAP) as desiccant in a maize dryer was studied using computational fluid dynamics simulations which accounted for heat and mass transfer between maize, SAP and air. The adsorption capacity and adsorption rate of a commercial SAP material were experimentally determined at different temperature and relative humidity levels, which served as basis for the adsorption model required in the simulations. A maize bulk with SAP packages distributed in it was modeled. Results showed that the SAP material increases the drying rate substantially, particularly in the upper bulk zone where the air reaching it is dehumidified the most. The maize closer to the upper bulk surface starts drying from the beginning of the process instead of lagging for hours or days before the drying front reaches it. An inconvenience of the SAP material is the tendency of granules to swell and stick together as moisture reaches a threshold, which may reduce its performance. Thus, provided this issue is resolved or minimized, SAP materials could successfully assist the rapid drying of maize and other crops. They may also be used during storage to avoid rewetting of the crops during periods of high relative humidity.     

Development and quality evaluation of a cereal-based breakfast product from yellow maize (Zea mays), sesame (Sesamum indicum) and mushroom (Pleurotus ostreatus) flour blends

Composite flours were prepared from blends of yellow maize (Zea mays), sesame seed (Sesamum indicum) and oyster mushroom (Pleurotus ostreatus) powder in the ratio of 80:20:0; 75:20:5; 70:20:10; 65:20:15 and 60:20:20, respectively to produce the cereal-based breakfast product coded as YSB, SMB, TMB, PMB and OMB with YSB as the control. The breakfast cereals were produced by hydration and toasting of yellow maize and sesame to 160°C for 25 min and blended together with oven-dried and packaged oyster mushroom. The developed products were analysed for proximate, vitamins, minerals and sensory properties. The proximate composition (%) of different blends ranged as moisture (4.07–7.08), ash (3.09–2.28), crude fat (16.04–12.83), crude fibre (4.30–8.22), protein (16.14–22.54), carbohydrate (56.34–47.04) and energy (434.34–393.83 Kcal). Vitamin A (7.99–5.98 mg/100 g), vitamin B₁ (0.08–0.42 mg/100 g), vitamin B₂ (0.06–0.15 mg/100 g), vitamin B₃ (1.91–4.52 mg/100 g) and vitamin C (3.55–3.32 mg/100 g) were u while minerals (mg/100 g) were calcium (75.31–58.02), potassium (0.65–4.01), magnesium (12.25–12.62), iron (1.21–4.15) and zinc (0.40–1.32). Sensory scores revealed that the cereal-based breakfast product were acceptable to the panellist with oyster mushroom supplementation up to 10%.     

三维激光扫描技术对接种菌根植株形态的影响规律

三维激光扫描技术建立的植物三维立体模型,可精确、全面、原位地反映植物形态特征,对于揭示接菌植物的微观形态特性具有比传统测量方法更明显的优势。以玉米为供试材料,在低磷条件下(20 mg/kg),设置接种菌根与对照两个处理,研究三维激光扫描技术对接种丛枝菌根真菌的植株形态特征在不同生长期的动态变化规律,分析比较不同处理的植株侵染率、菌丝密度、土壤酸性磷酸酶活性和土壤有效磷等理化指标及玉米形态特征的变化。研究结果表明,在低磷条件下丛枝菌根在30 d时侵染率已经达到82%,菌丝密度增加,酸性磷酸酶活性增强。在生长到30 d的时候,接菌组的株高、冠幅分别比对照组提高52%,47%,生长到60 d时接菌组茎杆横截面积为对照组的124%,玉米活叶面积、叶宽、叶片垂高等都得到提高,并且随着生长期延长接菌和对照处理的差异增大。以曲率半径表示叶片弯曲程度,在生长到60 d时接菌组曲率半径比对照组增加46.5%,接种丛枝菌根真菌促使叶片更加坚挺。