2017—2019年北京市大兴区主产水果中39种农药残留量监测结果分析

目的 了解大兴区主产水果中39种农药的残留现状.方法 2017—2019年从大兴区不同地点采集546份水果样品,按照NY/T 761—2008《蔬菜和水果中有机磷、有机氯、拟除虫菊酯和氨基甲酸酯类农药多残留的测定》对39种常用农药的残留量进行检测.结果 在546份样品中,西瓜的农残检出率为12.78％,葡萄的农残检出率...     

Fruit Polyphenols: A Review of Anti-inflammatory Effects in Humans

Underlying etiological factors in the development of obesity-related chronic diseases are long-term imbalances of oxidative and inflammatory stress leading to tissue dysfunction, damage, and ultimately failure. Poor dietary quality contributes significantly to the oxidative and inflammatory status of an individual. Conversely, various dietary approaches, including specific dietary factors can mitigate or prevent the occurrence of these risk-conferring imbalances brought about by modern lifestyle. Plant-derived polyphenolic compounds are well known for their antioxidant properties. Recent evidence indicates these compounds may confer anti-inflammatory and/or inflammatory response stabilizing activities, which would have important implications in health maintenance and disease risk reduction. Commonly consumed fruits, such as grapes, berries, and oranges/orange juice, contain polyphenolic compounds that have been studied for their effects on inflammation, but the nature and extent of their effects in humans remain unclear. Therefore, this article aims to provide a comprehensive overview of human clinical trials investigating the acute and chronic (feeding) effect of polyphenols from commonly consumed fruits or their derived products on inflammation.     

Recent Food Drying R&D at Jiangnan University: An Overview

Drying of fresh produce and marine products to develop high-quality dried products cost-effectively has been the theme of extensive research carried out at the School of Food Science & Technology of Jiangnan University, Wuxi, China. Both conventional and innovative hybrid drying techniques encompassing the enhancement of drying rates and quality through utilization of modern ultrasonic and nanotechnology have been examined in detail and reported in the open literature. Some of the work was funded by the industry and eventually utilized in industrial-scale processing. The objective of this article is to summarize the key developments for a wider global readership. An outline of ongoing drying R&D will be provided in the closing section.     

Ozone-induced changes of antioxidant capacity of fresh-cut tropical fruits

The effect of ozone treatment on total phenol, flavonoid, and vitamin C content of fresh-cut honey pineapple, banana ‘pisang mas’, and guava was investigated. The fresh-cut fruits were exposed to ozone at a flow rate of 8 ± 0.2 ml/s for 0, 10, 20, and 30 min. The antioxidant capacity of the fruits was evaluated by measuring the ferric reducing/antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. Total phenol and flavonoid contents of pineapple and banana increased significantly when exposed to ozone for up to 20 min, with a concomitant increase in FRAP and DPPH values. The opposite was observed for guava. Ozone treatment significantly decreased the vitamin C content of all three fruits. The study shows promising results for enhancing antioxidant capacity of some fresh fruits by ozone treatment although the positive effect is compromised by a reduction in vitamin C content.Industrial relevanceThe preservation of antioxidant properties, storage stability and safety is of utmost importance in the minimally processed fresh food industry. Ozone has been looked into as an alternative sanitizing technology in the fresh produce industry. The results of this study indicate that ozone can be used in the minimally processed fresh food industry to enhance the antioxidant status of fresh-cut fruits.     

Anti-inflammatory activity of extracts from fruits,herbs and spices

Inflammation plays an important role in various diseases with high prevalence within populations such as rheumatoid arthritis, atherosclerosis and asthma. Here we demonstrate the anti-inflammatory activity of various fruits, herbs and spices in a lipopolysaccharide-stimulated macrophage model. These compounds acted by reduction of pro-inflammatory interleukin (IL)-6 or tumour necrosis factor (TNF)-alpha production, enhancement of anti-inflammatory IL-10 production, or reduction of cyclooxygenase-2 or inducible nitric oxide synthase expression. The highest anti-inflammatory potential was detected with chili pepper. Among the plants that improved the secreted cytokine profile were allspice, basil, bay leaves, black pepper, licorice, nutmeg, oregano, sage and thyme. The compounds apigenin, capsaicin, chrysin, diosmetin, kämpferol, luteolin, naringenin, quercetin and resveratrol moderately reduced IL-6 and TNF-alpha secretion. Resveratrol and rosmarinic acid increased secretion of IL-10. Our findings further the idea that a diet rich in fruits, herbs and spices may contribute to the reduction of the inflammatory response and related diseases.     

The effect of fruit extracts with polyphenol oxidase (PPO) activity on the in vitro accessibility of iron in high-tannin sorghum

Dephytinized high-tannin sorghum flour was incubated with crude extracts from pear, banana or avocado, respectively, followed by investigation of the effects on the phenolic content and on in vitro accessible iron. All fruits contained polyphenol oxidase (PPO) activity and incubation resulted in significant reduction of phenolic compounds. Incubation with avocado extract resulted in the lowest levels of phenolic compounds, as well as the highest amount of in vitro accessible iron. Peroxidase activity and some organic acids in the fruit extracts might also have contributed to the positive effect on iron accessibility. Nevertheless, incubation of the sorghum flour with the fruit extracts under conditions enabling the PPO to oxidize phenolic compounds, resulted in the highest accessibility of iron. The results from this study suggest that the PPO activity in simple fruit extracts can be utilized to increase the accessibility of iron in dephytinized polyphenol-containing cereal foods.     

毛泽东关于学习利用资本主义的思想

提出学习、利用资本主义文明成果的具体内容和制定学习、利用资本主义的策略原则,是毛泽东关于学习、利用资本主义思想的主要之点。     

QuEChERS-液相串联质谱法快速测定蔬菜水果中氟吗啉和烯酰吗啉残留量

目的建立基于QuEChERS与液相串联质谱(liquidchromatographytandemmassspectrometry,LC-MS/MS)联用技术快速测定蔬菜水果中氟吗啉和烯酰吗啉残留量的分析方法。方法样品经乙腈提取后,用QuEChERS法净化, Symmetry C18色谱柱分离, LC-MS/MS外标法定量。结果方法学验证,该方法具有较高的灵敏度,氟吗啉和烯酰吗啉的检出限为0.05μg/kg,定量限为0.1μg/kg;在0.1～25μg/kg浓度范围,线性相关系数大于等于0.9963,回收率在82.4%～106.3%之间,相对标准偏差为1.5%～8.8%,该方法具有较好的回收率和良好的再现性,满足国家相关标准要求。结论该方法处理过程快速简便,灵敏度高、专属性强。     

Effect of a Siraitia grosvenori extract containing mogrosides on the cellular immune system of type 1 diabetes mellitus mice

The purpose of this study was to observe the islet changes of pancreas in insulin-dependent diabetes mellitus (IDDM) mice in comparison to normal mice after application of an extract from Siraitia grosvenori fruits containing mogrosides, in particular, mogroside V. We hypothesized that mogroside extract (MG) attenuates the severity of alloxan-induced IDDM by effects on the immune system. Our data show that IDDM mice exhibited significant injury to pancreatic islets cells, which were atrophic. In addition, alloxan induced a notable increase in the expression of CD8+ lymphocytes to form a dramatic decrease in CD4+/CD8+ ratio (while CD4+ was unchanged). MG, administered to normal and experimental diabetic mice for 4 wk, effectively attenuated the early clinical symptoms, biochemical abnormalities, and pathological damages in pancreatic islets. Furthermore, at low dose, MG regulated the immune imbalance observed in alloxan-induced IDDM mice by up-regulating the CD4+ T-lymphocyte subsets and CD4/CD8 ratio, and altering the intracellular cytokine profiles. The expression of the pro-inflammatory Th1 cytokines: IFN-gamma, TNF-alpha in splenic lymphocytes was altered toward a beneficial Th2 pattern. MG therapy had no effect on normal mice, except that low dosage MG could up-regulate the IL-4 expression levels. The results revealed that MG exhibited antidiabetic effects presumably due to the presence of mogrosides.     

Quality of electron beam irradiation of blueberries (Vaccinium corymbosum L.) at medium dose levels (1.0-3.2 kGy)

We assessed the effect of electron beam irradiation of packaged fresh blueberries at doses greater than 1.0 kGy on the quality attributes of the fruits. Irradiation experiments were conducted using a 10 MeV (18 kW) linear accelerator with single beam fixture. Fruits were stored at 5 °C and 70.4% RH for 14 days and tested at days 0, 3, 7 and 14 for physico-chemical, textural, microstructural, and sensory characteristics. Control samples consisted of non-irradiated fruits. Irradiation at doses higher than 1.1 kGy did affect (P<0.05) the texture of blueberries as the fruits became considerably softer and less acceptable throughout storage. Only irradiation at 3.2 kGy affected the color of blueberries by the end of storage. Irradiation slightly reduced the respiration rates of the blueberries by the end of storage. In terms of overall quality, texture and aroma, only fruits exposed to 3.2 kGy were found unacceptable by the sensory panelists. Irradiation at the dose levels used in this study did not affect the density, pH, water activity, moisture content, acidity and juiciness of blueberries. Electron beam irradiation of blueberries up to 1.6 kGy is a feasible decontamination treatment that maintains the overall fruit quality attributes.