核桃油储藏氧化稳定性研究进展

核桃油中不饱和脂肪酸含量高,在储藏期间易氧化酸败,其氧化稳定性较低,影响核桃油产品的质量与安全,制约着核桃油产业的发展。本文较为系统地阐述了核桃油自身脂肪酸组成、抗氧化物质、储藏环境条件、抗氧化剂等因素对核桃油储藏氧化稳定性的影响,为核桃油抗氧化相关研究提供参考。     

植物甾醇对油脂的抗氧化作用研究

目的:探讨植物甾醇对油脂的抗氧化作用。方法:以花生油为对象,采用高温诱导其发生脂质过氧化反应,以过氧化值和酸价为指标,并与二丁基羟基甲苯(BHT)和VC进行比较,研究了植物甾醇对油脂的抗氧化作用。结果:植物甾醇可有效地延缓油脂脂质过氧化反应,抑制油脂酸价和过氧化值的升高,其抗氧化作用明显优于BHT和VC。结论:植物甾醇是一种天然、安全、高效的油脂抗氧化剂。     

鸡蛋的抗氧化活性研究进展

目前普遍认为通过饮食摄入抗氧化剂对减少机体细胞的氧化损伤,促进人体的健康有十分重要的意义。本文阐述了鸡蛋的营养成分、鸡蛋中各种抗氧化剂的抗氧化机理以及加工、贮存条件和消化代谢过程对鸡蛋抗氧化剂的影响,为鸡蛋抗氧化功能的研究提供参考。     

花生油涨价谁获益

食用油尤其是花生油价格的快速上涨，到底谁是最大的受益者？一桶花生油的利益是如何分配的？花生油还能不能“挤出”一些价格空间让利消费者？记者找到山东一家年加工能力10万吨的花生油加工企业负责人，与他细算了一桶花生油的利益分配账。他认为花生油上涨农民获益最大，加工企业赚取的仅是微利，流通环节还有价格“水分”可挤。     

多因素致花生油价高烧不退

随着中秋、国庆两节临近，消费者发现花生油价格涨了不少：5升装花生油价格半年内上涨了两三成。业内人士认为，生产成本增加、花生油需求旺盛、定价权旁落等多个因素共同推高花生油价格。由于涨价因素短时期内不会消除，未来一段时间花生油仍然存在较大上涨压力。     

青岛5升装花生油均价超120元提价13％生产商喊赔

伴随着花生价格的节节攀升，近期全国纯花生油的价格涨幅又创2008年3月以来的新高，5L瓶装花生油已经突破120元大关，部分企业的花生油价格涨幅高达13％左右，却仍勉强维持运营。业内人士分析，花生价格的上涨导致花生油成本上涨利润下降，一些花生油企以成本价向超市供货“赔本”保市场。     

花生油要涨价

新一季花生收成下降，花生米（仁）价格上涨，厂商已向超市下发涨价通知。花生油价格开始了新一轮的上涨。记者从花生油生产企业鲁花及北京多家大卖场获悉，北京花生油价格面临着5％-10％的上涨。     

健康压榨油识别

目前，越来越多的消费者选择安全、无污染、营养丰富的“压榨油”，“压榨油”成了“健康油”的代称。真正的“压榨油”是采用纯物理压榨制油工艺，经过精心选料、焙炒、物理压榨，最后经天然植物纤维过滤技术生产而成。此工艺保留了油料内的丰富营养，无化学溶剂污染，不含任何化学防腐抗氧化剂，保证产品的安全、纯正、营养、美昧，符合人体健康需求。“压榨油工艺”目前在国内基本用于花生油、橄榄油、坚果油、芝麻油等高档油品。     

北京花生油批发价格下调

就在豆油市场期货与现货“短兵相接”之际，今年以来一直保持“中立”的花生油也首次加入到了大幅降价潮中。北京专业粮油批发市场锦绣大地玉泉路市场近日发布最新监测数据显示，市场上主要花生油品牌价格全线下调。     

怎样制取花生油

怎样制取花生油花生是主要的油料作物之一，花生仁含油５０％左右。花生油由２０５４的饱和脂肪酸和８０％的不饱和脂肪酸组成，花生仁含蛋白质３０％左右，可消化率高，含有人体必需的各种氨基酸，有利于人体的健康。花生油的制取过程如下：１、筛选先用簸箕簸出花生壳和...     

Multifactor productivity growth and the Australian mining sector

A commonly used, but unadjusted, measure of Australian mining multifactor productivity (MFP) fell by about one‐third over the first decade of the mining boom, coinciding with very large increases in resource prices. Using growth accounting methods and our own adjustments, based on energy use and capital‐output lags to account for depletion effects we find (i) the Australian annual average MFP growth in mining was 2.5 per cent a year between 1985–1986 and 2009–2010 compared to ?0.65 per cent for the unadjusted measure and (ii) productivity growth was positive in the 2000s, albeit at a lower rate than in the 1990s. Our adjusted MFP growth measures at a state level and subsector level are greater than unadjusted productivity measures. In a complementary study using an econometric decomposition of mining MFP at a state level, we find no statistically significant effect of technological change on MFP growth in the sector, but positive and statistically significant effects of technical efficiency and scale over the period 1990–1991 to 2009–2010. Our results do not support specific policy interventions to increase productivity growth in the mining sector beyond appropriate incentives for resource exploration including the provision of precompetitive resource data.     

Measuring agricultural total factor productivity in China: pattern and drivers over the period of 1978‐2016

The Chinese agricultural sector has experienced a substantial increase in total output since dramatic reforms were introduced in 1978. This paper uses the index method to measure agricultural total factor productivity (TFP) for China’s crop and livestock industries, based on the gross output model from 1978 to 2016. We construct production accounts for the industries using input‐output relationships for the 26 main agricultural commodities and commodity groups, which account for over 90 per cent of the total agricultural inputs and outputs. The results show that China’s agricultural TFP grew at a rate of approximately 2.4 per cent a year before 2009, which is comparable to the main OECD countries and is double the world average. TFP growth accounts for approximately 40 per cent of output growth, suggesting that input growth was the main driver of output growth in the past. However, average productivity growth slowed down after 2009 though it has gradually recovered since 2012. The slowdown reflects the emerging challenges to existing farm production practices in Chinese agriculture, suggesting the need for further institutional reform.     

Towards a theory for a practical optimisation model for a farm

Abstract

Total factor productivity in communal agriculture in Zimbabwe grew at 1.73% per annum from 1975 to 1990. Growth was negative before independence in 1980 and then reached over 8% a year, but turned negative again after 1985. The success following independence can be explained by the widespread adoption of modern technology, especially in maize production. Adoption was driven by the reorientation of government policy towards the communal sector, which led to improved price incentives and public provision of essential infrastructure investments, such as marketing depots and farm credit facilities. However, the high costs of support proved to be unsustainable and productivity declined from 1985.     

黑龙江省农业碳排放、科技投入与经济增长关系研究

[目的]以黑龙江省为例,首先对其农业碳排放总量进行测度,再研究农业碳排放同经济增长、科技投入之间的关系。[方法]利用1996~2013年的统计数据,从4个方面估算了黑龙江省农业碳排放量,进而采用自回归滞后分布模型(ARDL模型)对农业碳排放量、经济增长以及科技投入之间的关系进行实证分析。[结果]农业碳排放量、GDP增长和科技投入存在长期稳定关系,但长期来讲农业碳排放量增长速率远大于GDP增长速率;GDP增长对农业碳排放总量存在显著的正向影响,且长期影响程度远大于短期;科技投入对农业碳排放具有抑制作用且存在滞后效应,其中长期的抑制作用为12.4%,短期为3.9%,当滞后期为两年时,抑制作用尤为显著。[结论]经济增长会促进黑龙江省农业碳排放的增加,而科技投入则能对农业碳排放产生有效地抑制作用,因而黑龙江省可以通过增加农业科技投入来降低农业碳排放。     

黔中喀斯特地区农业生产碳排放实证研究

[目的]以贵阳市为例,测算其2007—2016年农业碳排放量,分析时序变化特征、脱钩关系并预测未来10年农业碳排放量,为我国西南喀斯特地区农业减源增汇以及经济发展提供参考。[方法]文章运用碳排放系数法计算2007—2016年贵阳市农业碳排放量;基于Tapio脱钩模型分析区域农业碳排放量与农业GDP的脱钩关系;利用GM (1.1)模型预测贵阳市未来10年农业碳排放量。[结果] 2007—2016年贵阳市农业碳排放量呈下降趋势,年均递减0.75%;三大类碳源中水稻种植占比例最大,为67.37%,其次为畜禽养殖,为17.08%,最后为农地投入,占比为15.55%;细分碳源,除水稻外,化肥与牛碳排放量较高,但农膜、农用柴油、农地灌溉以及羊碳排放都呈增加趋势;脱钩分析表明,贵阳市农业碳排放与农业经济增长间的脱钩类型呈现强脱钩、弱脱钩、强负脱钩、扩张负脱钩4种状态,脱钩类型以强脱钩为主,说明近年来农业碳减排取得一定成效;根据GM (1.1)模型预测,贵阳市农业碳排放量逐年下降,由2017年的50.14万t下降至2026年的47.76万t。[结论]贵阳市农业碳减排效果明显,未来还需进一步采取措施以实现农业减源增汇。     

Is there a slowdown in agricultural productivity growth in South America?

This article estimates agricultural productivity growth in 10 South American countries in 1969–2009 with the objective of investigating if the slowdown being measured in other countries is present in the region. Results show that productivity growth accounts for half of the three‐fold increase in agricultural output during this period and that performance is sensitive to R&D investments in the sector. The slowdown found for the 1990s to 2000s in the U.S. and some European economies does not seem to be present yet in South America. The region's total factor productivity (TFP) growth rate increased steadily from 1.07% during the 1970s to 2.29% during the 2000s. Given lags in adoption and the adaptive nature of innovations in these economies, we have yet to see the potential effects in South American agriculture of decreases in R&D in advanced economies.     

Total factor productivity change in hog production and Quebec's revenue insurance program

Quebec's hog industry is supported by a revenue insurance program that guarantees a minimum price, but it also faces strict environmental constraints. Under price volatility, risk-averse farms may contract their output enough to produce under increasing returns. We show that the subsidy and downside risk reduction effects of the revenue insurance program tend to stimulate output and increase the likelihood of production under increasing returns. Environmental constraints that raise the cost of manure management and limit areas under cultivation also increase the likelihood of decreasing returns. Scale efficiency and technical efficiency measures are obtained through a parametric decomposition of total factor productivity (TFP) obtained from the estimation of an output distance function. As in hog studies pertaining to other countries, we found a TFP average annual growth of 5.2% between 2004 and 2012. Scale efficiency is much lower than in other countries, as per our prior about the program's distortions and environmental constraints. Integrating annual TFP gains into the setting of the minimum guaranteed price could reduce program costs by $12 million per year. About $70–80 million per year could be saved by investing in extension activities that would bring increase the level of technical efficiency of inefficient farms to the provincial average. A metatechnology frontier approach allowing for an endogenous input was also implemented to assess the robustness of the scale efficiency results.     

Australia's consumption‐based greenhouse gas emissions

We use data from the World Input‐Output Database in a multiregional input–output model to analyse Australian consumption‐based greenhouse gas emissions for the years 1995 to 2009. We find that the emission content of Australian macroeconomic activity has changed over the 15‐year period. Consumption‐based emissions have been growing faster than production‐based emissions since 2001. We show that emissions embodied in Australian imports are increasingly becoming a significant source of emissions. We investigate emissions in Australian imports and find that increased trade with China contributed substantially to the increase in Australia's consumption emissions. China was the largest exporter of emissions to Australia and accounted for almost half of emissions embodied in Australian imports since 2002. The growth of trade with China coincides with the increase in imported emissions as well as the increase in aggregate consumption emissions. Our results suggest that tracking consumption emissions together with production emissions provides a more complete picture of Australian emissions.     

2015—2019年北京市农业氧化亚氮排放变化与分析

[目的]温室气体排放是农业绿色发展的重要指标,而氧化亚氮(N₂O)是农业温室气体的重要组成部分。为了了解北京市农业N₂O的排放情况,并为北京市低碳农业发展提出建议。[方法]文章运用文献调研与数据统计方法,收集了2015—2019年北京市各区种植业与畜牧业基础数据,进行全市和各区的农业N₂O排放核算工作,并对核算结果及其不确定性进行分析。[结果](1) 2015—2019年北京市农业N₂O排放呈下降趋势,2019年北京农业N₂O排放量为26.1万tCO₂e,较2015年减少了46.88万tCO₂e,减排率高达64.2%;(2)种植业N₂O为北京市农业N₂O最大排放源,占2015—2019年北京市农业N₂O排放年均贡献率的58.3%;(3) 2015—2019年北京市种植业N₂O与畜牧业N₂O排放均呈下降趋势,它们的最大排放源分别...     

Geographic disparities in rural land appreciation in a transforming economy: Chile, 1980 to 2007

This paper reports on a research effort to gather and analyze rural land value data during a period of unprecedented growth in Chilean agriculture. This information is important to understand the geographical distribution of gains associated with the transformation of the rural sector during a period of rapid development, trade liberalization and transition toward a predominant emphasis on export earnings in agriculture. A large set of data of rural land transactions for 1980, 1990, 1997 and 2007 were collected from a sample of land registry offices. Results show notable declines in the physical size of transactions, significant average annual rates of increase in real per-hectare values, and a small-parcel premium for rural land associated with non-farm land use. Overall real land values have increased faster than the average annual growth rates in the agricultural sector’s value added, suggesting that land owners have gained proportionately more than other claimants to sectoral income. Tests show significant geographic disparities in annual rates of land appreciation across regions and municipalities. Consistent with differential net gains due to integration into world markets and the geographic heterogeneity of suitability for different land uses, northern areas, with greater emphasis on export-oriented crops, have experienced the highest average rates of annual real per-hectare value growth, in the order of 7 percent, while southern areas, emphasizing traditional crops and pastures/livestock, have experienced growth rates of half that. Geographic disparities are also explained by proximity to urban population and income centers.