长柄扁桃油的烹饪稳定性研究

为研究长柄扁桃油的烹饪稳定性,本文采用菜籽油作为对比对象,探究长柄扁桃油和菜籽油分别在100 ℃、130 ℃、160 ℃、180 ℃和210 ℃温度条件下高温烹饪不同时间后理化特性、营养成分和有害物质的变化。结果表明：长柄扁桃油的烹饪稳定性远高于菜籽油,适合作为一种高品质烹饪食用油。随着烹饪温度的升高和时间的延长,两种油的酸价和茴香胺值均增加,过氧化值先增加后降低;饱和脂肪酸和单不饱和脂肪酸含量均增大,而多不饱和脂肪酸含量和生育酚总量均显著下降;两种油均产生有害物质(反式脂肪酸、苯并芘和极性物质),但长柄扁桃油较菜籽油不易产生反式脂肪酸和极性物质,长柄扁桃油在整个高温烹饪过程中产生苯并芘含量≤10 μg/kg,未超出食用植物油卫生标准中对苯并芘的限量,而菜籽油在100 ℃下烹饪3 min后已超出规定限量。     

季节性运行人工湿地处理生活污水研究

污水经酸化预处理后进入两级垂直潜流人工湿地,进行间歇流运行.实验结果表明,一级人工湿地面积有机负荷率5.52～11.7gCOD/(m2.d),COD去除率大于60%;二级人工湿地有机负荷率5.87～8.7gCOD/(m2.d),COD去除率大于70%,总去除率大于90%.一级人工湿地NH4-N负荷率0.25～0.94gNH4-N/(m2.d),NH4-N去除率大于60%.二级人工湿地NH4-N负荷率0.68～0.83 gN4-N/(m2.d),NH4-N去除率大于70%,总去除率大于92%.     

保水缓释肥在药用植物板蓝根上的试验研究

为了解决干旱作物农业地区养分不足和水资源短缺的问题,将保水剂与化学肥料按比例配合制得了既能吸水保水抗旱保墒,又具有缓释肥料功效的保水缓释肥。采用药用植物板蓝根为试验对象进行盆栽试验,对其保水效应及板蓝根生长状况进行观察分析,得出了保水缓释肥可以提高土壤的水分利用率、合理释放土壤有效养分、促生长作用明显的结论。     

Inventory of water management practices in Harare, Zimbabwe

Lake Chivero, in Zimbabwe, is the major water supply source for the greater Harare area. This paper looks at the sustainability of current practices of the urban water cycle in relation to water quantity and quality management in the Chivero catchment. Data on population, water supply, water and wastewater treatment and river flows were obtained from urban councils and government departments. The data were used to assess water consumption, wastewater generation, treatment and disposal practices, river flow trends, raw water abstractions and water demand patterns. The results showed that the current situation is not sustainable as water quantity in the catchment will soon be a problem at current levels of consumption while water quality is already a problem, especially with regard to nutrient levels. Water and nutrient management strategies, which include water use efficiency, treatment and water recycling and nutrient reuse in controlled urban agriculture, are recommended as matters of urgency.     

不同品位沸石对肉鸭生产性能、养分消化率、血液生化指标及屠宰性能的影响

选取1日龄樱桃谷肉鸭540只,随机分成3组,每组设6个重复。第1组为对照组,饲喂基础日粮,第23、组在基础日粮中分别添加3%普通沸石和3%的高品位沸石,研究不同品位沸石对肉鸭生产性能、养分消化率、血液生化指标及屠宰性能的影响。结果表明:饲料中添加普通沸石和高品位沸石对肉鸭前期平均日增重、料重比影响差异不显著(P>0.05);高品位沸石使肉鸭后期平均日增重提高4.01%(P<0.05),料重比略有升高(P>0.05)。添加高品位沸石能显著提高肉鸭后期干物质、粗蛋白和能量的表观消化率(P<0.05),并使肉鸭前期血清总蛋白(TP)提高7.50%(P<0.05),三酰甘油(TG)提高47.42%(P<0.01),碱性磷酸酶(ALP)活性提高31.54%(P<0.05);肉鸭后期血清TP和TG分别提高10.87%、50.00%(P<0.05)。普通沸石和高品位沸石均显著降低了肉鸭后期血氨(BA)的浓度(P<0.05)。高品位沸石能显著提高肉鸭屠体率(P<0.05)。沸石对肉鸭生产性能、养分消化率、血液生化指标及屠宰性能有一定的改善作用,且高品位沸石优于普通沸石。     

竹笋加工中的营养成分变化及安全性研究进展

竹笋质鲜味美、是营养丰富的"森林蔬菜"之一,加工处理可以促使竹笋转化增值,延长商品期,满足消费者的食用需求。该文从竹笋产品品质入手,就不同加工处理后营养成分的变化、食用安全性及消除办法做以综述,并对竹笋的科学合理加工趋势进行展望。     

Top Food Sources Contributing to Vitamin D Intake and the Association of Ready-to-Eat Cereal and Breakfast Consumption Habits to Vitamin D Intake in Canadians and United States Americans

Abstract: This study aimed to determine dietary vitamin D intake of U.S. Americans and Canadians and contributions of food sources to total vitamin D intake. Total of 7‐ or 14‐d food intake data were analyzed for vitamin D by a proprietary nutrient assessment methodology that utilized food intake data from the Natl. Eating Trends^® service, portion size data from NHANES 1999–2004, and nutrient values using the Univ. of Minnesota's Nutrition Data System for Research software. Study participants were 7837 U.S. Americans and 4025 Canadians, ≥2‐y‐old males and females. The main outcome measures were total dietary vitamin D intake, percent contribution of foods to total vitamin D intake, and vitamin D intake by cereal and breakfast consumption habits. ANOVA was used to determine differences in means or proportions by age and gender and according to breakfast consumption habits. Mean vitamin D intake ranged from 152 to 220 IU/d. Less than 2% of participants in all age groups from the United States and Canada met the 2011 Recommended Daily Allowance (RDA) for vitamin D from foods. Milk, meat, and fish were the top food sources for vitamin D for both Americans and Canadians. Ready‐to‐eat (RTE) cereal was a top 10 source of vitamin D for Americans but not Canadians. Vitamin D intake was higher with more frequent RTE cereal and breakfast consumption in both countries, largely attributable to greater milk intake. Practical Application: Most U.S. Americans and Canadians do not meet the 2011 Inst. of Medicine recommended daily allowance (RDA) for vitamin D for their age groups from foods. Increasing breakfast and cereal consumption may be a useful strategy to increase dietary vitamin D intake to help individuals meet the RDA for vitamin D, particularly by increasing milk intake. However, it is likely that additional food fortification or vitamin D supplementation is required to achieve the RDA.     

Polyphenols and the Modulation of Gene Expression Pathways: Can We Eat Our Way Out of the Danger of Chronic Disease?

Plant-derived dietary polyphenols may improve some disease states and promote health. Experimental evidence suggests that this is partially attributable to changes in gene expression. The rational use of bioactive food components may therefore present an opportunity to activate or repress selected gene expression pathways and, consequently, to manage or prevent disease. It remains to be determined whether this use of bioactive food components can be done safely. This article reviews the associated controversies and limitations of polyphenol therapy. There is a paucity of clinical data on the rational use of polyphenols, including a lack of knowledge on effective dosage, actual chemical formulations, bioavailability, distribution in tissues, the effect of genetic variations, differences in gut microflora, the synergistic (or antagonistic) effects observed in extracts, and the possible interaction between polyphenols and lipid domains of cell membranes that may alter the function of relevant receptors. The seminal question of why plants make substances that benefit humans remains unanswered, and there is still much to learn in terms of correlative versus causal effects of human exposure to various nutrients. The available data strongly suggest significant effects at the molecular level that represent interactions with the epigenome. The advent of relatively simple technologies is helping the field of epigenetics progress and facilitating the acquisition of multiple types of data that were previously difficult to obtain. In this review, we summarize the molecular basis of the epigenetic regulation of gene expression and the epigenetic changes associated with the consumption of polyphenols that illustrate how modifications in human nutrition may become relevant to health and disease.     

Consumption,intake patterns,and exposure

Despite the wide public and scientific interest in antioxidant nutrients and their roles in disease prevention, limited data are available to assess population consumption, individuals’ intake patterns, and trends in exposure. This article reviews data on levels of these nutrients in the food supply, intake patterns from food and supplement use derived from national surveys, and trends in exposure. The food supply and intake data indicate that levels of vitamins E and C and the carotenoids in the diet have increased since the 1970s, but the increases are not consistent among all age groups. Dietary supplements make a major contribution to intakes of vitamins E and C. Nutrient and nonnutrient antioxidants added to the food supply do not contribute appreciably to antioxidant exposure. Groups at high risk of poor dietary intakes of antioxidant nutrients are the poor, tobacco users, nonsupplement users, and the elderly, especially those living alone.