Application of ferrous sulfate alleviates negative impact of cadmium in rice (<i>Oryza sativa</i> L.)

Soil contamination with toxic heavy metals [such as cadmium (Cd)] is becoming a serious global problem due to rapid development of social economy. Iron (Fe), being an important element, has been found effective in enhancing plant tolerance against biotic and abiotic stresses. The present study investigated the extent to which different levels of Ferrous sulphate (FeSO₄) modulated the Cd tolerance of rice (Oryza sativa L.), when maintained in artificially Cd spiked regimes. A pot experiment was conducted under controlled conditions for 146 days, by using natural soil, mixed with different levels of CdCl₂ [0 (no Cd), 0.5 and 1 mg/kg] together with the exogenous application of FeSO₄ at [0 (no Fe), 1.5 and 3 mg/kg] levels to monitor different growth, gaseous exchange characteristics, oxidative stress, antioxidative responses, minerals accumulation, organic acid exudation patterns of O. sativa. Our results depicted that addition of Cd to the soil significantly (P < 0.05) decreased plant growth and biomass, gaseous exchange parameters, mineral uptake by the plants, sugars (soluble, reducing, and non-reducing sugar) and altered the ultrastructure of chloroplasts, plastoglobuli, mitochondria, and many other cellular organelles in Cd-stressed O. sativa compared to those plants which were grown without the addition of Cd in the soil. However, Cd toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in O. sativa and was also manifested by hydrogen peroxide (H₂O₂) contents and electrolyte leakage to the membrane bounded organelles. Although, activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidants like phenolics, flavonoid, ascorbic acid, anthocyanin and proline contents increased up to a Cd level of 0.5 mg/kg in the soil but were significantly diminished at the highest Cd level of 1 mg/kg in the soil compared to those plants which were grown without the addition of Cd in the soil. The negative impacts of Cd injury were reduced by the application of FeSO₄ which increased plant growth and biomass, improved photosynthetic apparatus, antioxidant enzymes, minerals uptake together with diminished exudation of organic acids as well as oxidative stress indicators in roots and shoots of O. sativa by decreasing Cd retention in different plant parts. These results shed light on the effectiveness of FeSO₄ in improving the growth and upregulation of antioxidant enzyme activities of O. sativa in response to Cd stress. However, further studies at field levels are required to explore the mechanisms of FeSO₄-mediated reduction of the toxicity of not only Cd, but possibly also other heavy metals in plants.     

Low concentration short time ozonation of rapeseed seeds reduces the stability of the oil and content of some antioxidant components

Ozonation is an innovative way to preserve high quality of seed during storage and it is an alternative to harmful organophosphorus agents. Disclosure of changes in the rapeseed oil under the influence of oxidative action of ozone on the seeds was the aim of the work and is presented for the first time. Two ozone concentrations and different length of ozonation were applied. The changes in tocopherols, phenolics, flavonoids contents, antiradical activity and oxidative stability were examined. The average vitamin E concentration was 33 mg per 100 g of oil before and 31.7 after ozonation of seeds. The average content of phenolic compounds was 14.3 mg of sinapic acid g⁻¹ and 16.9 after the ozone treatment. Changes in the flavonoids content and antioxidant activity were observed too. Ozonation caused a decrease in the vitamin E concentration which resulted also in reducing the quenching of free radicals and reduction of oil induction time.     

Geographical discrimination of honeys through antioxidant capacity,mineral content and colour

The assessment of geographical origin of honey is economically important for producers and consumers as every region may present particular quality characteristics. In this study, honeys from the seven different regions of Buenos Aires province (Argentina) were characterised by their antioxidant capacity (DPPH, FRAP), total phenolic content (TPC), mineral composition, colour and ash. Honeys showed significant differences among their antioxidant capacity (DPPH), ash, colour and mineral content (P ≤ 0.05). Besides, a good antioxidant activity and low amounts of Cu and Zn (<1.0–1.5 and 0.7–1.8 mg kg^?1, respectively) were found in the samples. Significant Pearson's correlations (P ≤ 0.05) among the different parameters were found. Moreover, the linear discriminant analysis allowed the classification of honeys in their original groups with a prediction success of 98%. The present results suggest that honeys could be correctly classified by their geographical origin through their TPC, colour, ash and mineral concentrations.     

热裂解-气相色谱质谱联用法快速检测聚丙烯材料中5种抗氧剂

采用热裂解气质联用仪,建立了一种无需任何样品前处理、全程无溶剂的、同时对5种常用塑料抗氧剂的定量分析方法。结果表明:通过该方法分析的5种常用抗氧剂,在0.2~1μg之间有很好的线性关系,且该方法操作简单、快速准确,填补了热裂解气质联用技术在塑料助剂定量分析的空白。     

Effects of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria on growth and reactive oxygen metabolism of tomato fruits under low saline conditions

Land salinization is a major form of land degradation, which is not conducive to the growth and quality of fruits and vegetables. Plant salt tolerance can be enhanced by arbuscular mycorrhizal fungi (AMF) or plant growth-promoting rhizobacteria (PGPR). This study examined the effects of inoculation with PGPR singly or in combination with AMF, on the growth and quality of tomato fruits under low saline conditions. Tomatoes were cultivated in a greenhouse with sterilized soil, inoculated with PGPR, AMF, or co-inoculated with PGPR and AMF, and NaCl solution (1%) was added to the soil. The results indicated that AMF + PGPR decreased the roots and shoot biomass accumulation, and increased the number and fresh biomass in tomato fruits to a certain extent compared with non-inoculated plants. PGPR and AMF mediated the level of reactive oxygen and lipid peroxidation, the accumulation of antioxidants, and the activity of antioxidant enzymes, including proanthocyanidins, flavonoids, ascorbic acid, superoxide dismutase, peroxidase, and total antioxidant capacity. Furthermore, PGPR, AMF, and PGPR + AMF improved the overall osmotic adjustments and accumulation of soluble sugars and soluble proteins. Therefore, the AMF-Funneliformis mosseae and PGPR-Bacillus subtilis can potentially alleviate the adverse effects of salt stress and be applied as a biofertilizer in agricultural practice.     

“Arbequina” Olive Oil Composition Is Affected by the Application of Regulated Deficit Irrigation during Pit Hardening Stage

Three new regulated deficit irrigation (RDI) treatments were applied to “Arbequina” olive orchards during pit hardening. Oil quality was determined by measuring analytical parameters for olive oil grading, antioxidant activity, total phenol content, fatty acid profile, volatile compounds profile, and sensory analysis. Oils from RDI were classified as “extra virgin olive oil” and their quality was improved due to their higher antioxidant potential (ABTS⁺ [increased ~75%] and DPPH^˙ [increased ~25%] assays) and phenols (increased ~53%) than control. Concentration of total volatile compounds decreased (~27%) but RDI olive oils showed a more balanced profile (alcohols, aldehydes, and esters). Monounsaturated fatty acid content increased (~5%) and atherogenic and thrombogenic indexes decreased (~8.5%) in RDI olive oil. Regarding sensory analysis, RDI provided more balanced oils with higher fruit aroma than control. Other benefits of RDI olive oil, when compared with oil from full irrigated orchards are reduced use of water and improved functional and sensory quality.     

The influence of Ohmic-vacuum heating on phenol,ascorbic acid and engineering factors of kiwifruit juice concentration process

The antioxidant, phenol, ascorbic acid, electrode corrosion and engineering factors of concentration process of kiwifruit juice by ohmic heating-vacuum conditions (OHVC) were evaluated and compared with ohmic heating under atmospheric conditions (OHAC). Results showed that the total phenol content was decreased with an increasing voltage gradient for both heating modes. The OHVC can better save the antioxidant capacity and ascorbic acid of concentrated samples than the OHAC. The processing time of OHVC was significantly higher than the OHAC at the same voltage gradient (P < 0.05). The electrode corrosion rate at the vacuum mode was 7- to 40-fold higher than the atmospheric mode. The energy efficiency at OHAC was lower than the OHVC. The energy consumption was found in the range of 3.37 to 3.75 MJ kg⁻¹ water for OHAC and 4.08 to 11.09 MJ kg⁻¹ water for OHVC. The electrical conductivity under the vacuum mode was lower than the atmospheric mode.     

Development of vitamin E-enriched functional foods: stability of tocotrienols in food systems

Tocotrienols are members of the vitamin E family that provide many nutritional benefits. Developing tocotrienol-fortified functional foods introduces vitamin E into consumers diets without changing their food habits. The purpose of this study was to compare the stability of tocotrienols in bulk form and six food matrices at a fixed dose (40 mg kg⁻¹) under accelerated and conventional storage conditions. The delta- and gamma-tocotrienol content was measured using HPLC, and the sensory attributes were evaluated using triangle and hedonic tests. Tocotrienol in bulk powder was less stable under stressed conditions than in bulk oil, with the powders having approximately 40% and 80% reduction in δ- and γ- after storage and bulk oil with no significant degradation. HPLC analysis demonstrated that tocotrienol content remained unchanged in dry mix lemonade, yogurt, raw and UHT milk, and margarine over time; however, complete degradation of γ- and partial degradation (up to 50%) of δ-tocotrienol was observed in bread during ambient and stressed storage conditions. A significant decrease in the δ-tocotrienol relative concentration was also observed in HTST processed milk samples. Tocotrienol addition was not perceived, and no significant difference in the product attributes and overall liking was reported in the discrimination sensory testing.     

输液管用SEBS高效低毒抗氧体系的研究

以多次挤出、加速降解为评价方式,采用全自动白度仪、凝胶渗透色谱(GPC)、电子万能测试机、傅立叶变换红外光谱仪(FTIR)以及差示扫描量热分析仪(DSC)等手段,研究了不同抗氧剂对聚苯乙烯氢化二烯烃嵌段共聚物(SEBS)稳定性的影响。结果表明,纯SEBS的热稳定性差,经5次热加工后,氧化诱导期由初始的14.6min降到5.4 min,黄色指数从15.16增大至27.45,摩尔质量分布宽度从1.232增加到1.540,力学性能则降低至初始值的50%,且在热氧和剪切的作用下,SEBS易发生氧化降解生成羟基、羰基等含氧基团。加入四种不同抗氧体系后,输液管用SEBS的热稳定性均有一定程度的提高,而添加高效低毒抗氧体系E330/168的输液管用SEBS的热稳定性最好,随热加工次数增加,黄色指数无明显变化;经5次热加工后的重均摩尔质量为11.15万g/mol,较未加抗氧剂的SEBS高42%,摩尔质量分布为1.256,较未加抗氧剂的低18%;抗氧体系E330/168有效地抑制了SEBS在加工过程中的氧化降解,从而使其各项性能得到良好的保持。相对抗氧剂1010和626,抗氧剂E330/168不仅高效,而且具有低毒性、低致畸性和低水溶性,更适用于输液管用SEBS。