Agriculture group symposium the agricultural research council recommendations for the protein and major mineral requirements of ruminants, 1980

The following are summaries of papers presented at a meeting of the Agriculture Group held on 17 March 1981 at the Society of Chemical Industry, 14 Belgrave Square, London SW1X 8PS. The papers so published are entirely the responsibility of the authors and in no way reflect the views of the Editorial Board of the Journal of the Science of Food and Agriculture.     

Variation of mineral contents with nutritional interest in a collection of Solanum tuberosum group Phureja tubers

Colombia has a biodiversity centre of diploid potatoes located at south of the country. This study evaluated the amounts of potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) in a biodiversity panel of potato tubers, constituting native cultivars, accessions of the Working Collection of Potato Breeding Program at the Universidad Nacional de Colombia (CCC) and commercial cultivars. The highest quantity of minerals found were as follows: 34 333 ± 4509 mg K kg⁻¹ potato dry weight (DW; CCC112), 1965 ± 898 mg Ca kg⁻¹ potato DW (CCC23), 87.5 ± 8.8 mg Fe kg⁻¹ potato DW (CCC116) and 60.7 ± 5.1 mg Zn kg⁻¹ potato DW (CCC31). As compared to those in commercial cultivars, the currently evaluated tubers had an increase of 1.4, 12.5, 3.5 and 3.6-fold in K, Ca, Fe and Zn. These genotypes can be used in the future breeding programmes to enhance specific mineral contents in tubers.     

Agriculture group and the british society of soil science symposium. Soil microbiology in relation to current problems

The following are summaries of papers and posters presented at a joint meeting of the Agriculture Group and the British Society of Soil Science held at the Society of Chemical Industry, 14 Belgrave Square, London SW1X 8PS on 18 November 1980. The papers so published are entirely the responsibility of the authors and in no way reflect the views of the Editorial Board of the Journal of the Science of Food and Agriculture.     

二氧化氯通过激活苯丙烷代谢加速马铃薯块茎的愈伤过程

二氧化氯（ClO2）是一种安全高效的消毒剂,广泛用于果蔬保鲜和疾病的防治,但ClO2处理对马铃薯采后块茎的愈伤效果尚不明确。本研究采用25 mg/L ClO2浸泡切半‘大西洋’马铃薯块茎10 min,然后于室温黑暗条件下愈伤0、3、5、7、14、21 d。测定损伤块茎在愈伤期间的质量损失率以及损伤接种硫色镰刀菌（Fusarium sulphureum）块茎的病情指数,观察伤口处聚酚软木脂和木质素的积累,测定伤口处苯丙烷代谢关键酶和过氧化物酶活力,以及苯丙烷代谢产物和H2O2的含量。结果表明,25 mg/L ClO2处理加速了聚酚软木酯和木质素的沉积,增加了愈伤期间损伤组织的细胞层厚度。此外,ClO2处理降低了损伤块茎的质量损失率以及损伤接种硫色镰刀菌（F. sulphureum）后块茎的病情指数,第14天时,处理块茎的质量损失率和病情指数分别低于对照20.8%和45.3%。另外,ClO2处理通过提高块茎伤口组织处苯丙氨酸解氨酶、肉桂酸-4-羟化酶与肉桂醇脱氢酶的活力,增加了5 种酚酸（肉桂酸、p-香豆酸、咖啡酸、阿魏酸和芥子酸）及3 种木质素单体（p-香豆醇、芥子醇和松柏醇）的含量;ClO2处理还显著促进了总酚、类黄酮和木质素的合成,提高了H2O2含量和过氧化物酶（peroxidase,POD）活力。综上所述,ClO2处理加速了愈伤期间马铃薯损伤块茎伤口处聚酚软木酯、木质素的沉积,降低了损伤块茎的质量损失率及病情指数,激活了苯丙烷代谢,提高了H2O2含量和POD活力。这些发现为ClO2处理加速马铃薯块茎的愈伤提供了理论依据。     

快速热激处理对甘薯愈伤层形成及代谢的影响

为探究快速热激处理（rapid heat treatment,RHT）对促进采后甘薯块根愈伤的影响及机理,本研究以‘大叶红’甘薯为材料,经人工损伤处理后,以传统愈伤处理（35 ℃、2 d,CK＋）和未愈伤处理（CK－）为对照,采用65 ℃热空气对甘薯块根热激15 min,于13 ℃下贮藏7 d,观察愈伤期间甘薯块根伤口处木质素和软木脂的沉积情况;同时,测定块根伤口处组织活性氧代谢中间产物含量和相关酶活力;此外,测定抗氧化活性以及苯丙烷代谢途径关键酶活力和木质素、酚类物质含量。结果表明,RHT能有效促进甘薯块根伤口处木质素和软木脂沉积,与传统愈伤处理效果相近,愈伤并贮藏6 d后块根的木质素和软木脂沉积厚度显著高于对照组（P＜0.05）。RHT处理能显著促进H2O2、·OH和O2－·的快速积累,诱导超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶、过氧化物酶和多酚氧化酶活力上升,显著提高愈伤期间甘薯愈伤组织的1,1-二苯基-2-三硝基苯肼和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)阳离子自由基清除能力（P＜0.05）。RHT还能诱导愈伤期间苯丙氨酸解氨酶、肉桂酸-4-羟基化酶、4-香豆酸辅酶A连接酶和肉桂醇脱氢酶活力上升并提前达到峰值,促进总酚、芦丁和木质素的积累。此外,RHT还显著增加了块根愈伤组织中新绿原酸、儿茶素、绿原酸和表儿茶素含量。综上,RHT不仅可以通过促进活性氧成分的积累和抗氧化活性上升来维持愈伤组织中活性氧的动态平衡,还能激活苯丙烷代谢途径中关键酶,产生大量的次生代谢产物,加速木质素和软木脂沉积,从而促进甘薯块根伤口的快速愈合。     

采后不同温度预贮对雾化栽培微型马铃薯的愈伤效果及其机理

研究采后不同温度预贮对雾化栽培（以下简称雾培）微型马铃薯愈伤的影响,并进一步探讨其促进愈伤的可能机理。以‘通薯1号’雾培微型马铃薯为试材,在无损伤的条件下,分别于4、15 ℃和25 ℃（相对湿度86%～88%）黑暗环境中预贮20 d。测定预贮期间块茎的质量损失率,观察块茎周皮细胞中软木脂（包括聚酚软木脂（suberin polyphenolics,SPP）和聚酯软木脂（suberin polyaliphatics,SPA））的积累及木栓化情况,分析块茎周皮组织苯丙烷和活性氧代谢的变化。结果表明,15 ℃预贮显著促进了周皮组织处SPP、SPA的积累和木栓化。预贮第5天,与4、25 ℃预贮相比,15 ℃预贮块茎周皮组织处SPP细胞层厚度分别显著增加50.90%和26.94%（P＜0.05）,SPA细胞层厚度分别显著增加44.89%和30.23%（P＜0.05）,木栓化细胞层厚度分别显著增加27.66%和8.18%（P＜0.05）。相同预贮时间,15 ℃预贮显著提高了块茎周皮组织苯丙氨酸解氨酶（phenylalanine ammonia lyase,PAL）的活力（P＜0.05）,增加了总酚、类黄酮和木质素的含量。第5天时,15 ℃预贮块茎PAL活力较4 ℃和25 ℃分别显著增加了34.46%和12.64%（P＜0.05）;总酚和类黄酮含量较4 ℃预贮分别增加11.93%和40.05%,较25 ℃预贮分别增加2.72%和15.50%。第20天时,15 ℃预贮块茎木质素含量较4 ℃和25 ℃分别显著增加24.50%和8.24%（P＜0.05）。此外,相同预贮时间下,15 ℃预贮明显增加了块茎周皮组织处H2O2、超氧阴离子的含量以及过氧化物酶（peroxidase,POD）活力。综上,采后15 ℃预贮可通过激活周皮组织苯丙烷和活性氧代谢,增强周皮组织处软木脂的积累和木栓化,进而加速雾培微型马铃薯的愈伤。     

Biodiversity of psychrotrophic bacteria of the Bacillus cereus group collected on farm and in egg product industry

The aim of the present study was (i) to type, by genotypic and phenotypic methods, a collection of psychrotrophic bacteria belonging to the Bacillus cereus group collected in a farm and in 6 egg breaking companies during a period covering a warm and a cold season, and (ii) to characterize the growth potential in liquid whole egg, and the sanitary risk potential (cytotoxic activity on Caco-2 cells and adhesion on stainless steel) of each isolate of the collection. The investigation of specific psychrotrophic and mesophilic signatures together with the study of ability to grow at 6 °C and/or at 43 °C on optimal agar medium allowed highlighting twelve profiles, the major one corresponding to the species Bacillus weihenstephanensis (46.2% of the collection). The diversity of the profiles depended on the season and on the origin of the isolates. All the isolates were able to grow at the same level in liquid whole egg and in optimal medium, even at low temperature. Under the same conditions, the cytotoxic activity depended on the isolate, the medium and the temperature. At 10 °C, no isolate was cytotoxic in liquid whole egg and only one, belonging to the Bacillus weihenstephansensis species, in the optimal medium. All the isolates were able to adhere on stainless steel at various levels, from 2.6 ± 0.2 log cfu/cm² to 4.9 ± 0.1 log cfu/cm². A large majority (80.8%) was strongly adhering and could lead to the formation of biofilms in industrial equipments.     

Nitrogen excretion factors of livestock in the European Union: a review

Livestock manures are major sources of nutrients, used for the fertilisation of cropland and grassland. Accurate estimates of the amounts of nutrients in livestock manures are required for nutrient management planning, but also for estimating nitrogen (N) budgets and emissions to the environment. Here we report on N excretion factors for a range of animal categories in policy reports by member states of the European Union (EU). Nitrogen excretion is defined in this paper as the total amount of N excreted by livestock per year as urine and faeces. We discuss the guidelines and methodologies for the estimation of N excretion factors by the EU Nitrates Directive, the OECD/Eurostat gross N balance guidebook, the EMEP/EEA Guidebook and the IPCC Guidelines. Our results show that N excretion factors for dairy cattle, other cattle, pigs, laying hens, broilers, sheep, and goats differ significantly between policy reports and between countries. Part of these differences may be related to differences in animal production (e.g. production of meat, milk and eggs), size/weight of the animals, and feed composition, but partly also to differences in the aggregation of livestock categories and estimation procedures. The methodologies and data used by member states are often not well described. There is a need for a common, harmonised methodology and procedure for the estimation of N excretion factors, to arrive at a common basis for the estimation of the production of manure N and N balances, and emissions of ammonia (NH₃) and nitrous oxide (N₂O) across the EU. © 2015 Society of Chemical Industry     

试论隋唐黄河中游地区的食物加工与烹饪

隋唐时期，黄河中游地区的食物加工与烹饪有了较大地进步。主食烹饪的进步主要表现在各种面食的制作技术有了较大提高，面食的花色品种进一步增多。副食烹饪水平的进步主要表现在三个方面：第一，传统的煮、烤、脍等烹饪技术已炉火纯青，新兴的炒菜技术也日益成熟；第二，菜肴烹饪原料得到了极大地扩展；第三，象形花色菜的出现和食品雕刻的进一步发展。     

运动营养品中的有机酸对体育运动能力的提升作用及检测技术研究进展

近年来随着竞技体育及全民健身的发展, 运动爱好者为了在运动中保持较好的状态及提升运动能力, 对运动营养品的需求正逐步上升。目前研究表明一些有机酸如肌酸、支链氨基酸、茶氨酸等能通过延缓疲劳, 提升运动能力的功效。而且随着现代仪器设备的发展, 一些新的技术如高效液相色谱及毛细管电泳等方法逐渐应用于这类有机酸的检测, 为这类营养品质量的保证提供了有力的技术支持。本文将对近年来有关运动营养品中的有机酸对运动能力的提升作用及其检测技术方面的研究进展做一综述, 以促进含有有机酸的运动营养品在运动爱好者中的应用。     

Effect of the region of origin on the perceived quality of olive oil: An experimental approach using a control group

This study attempts to measure the overall effect of the image of an olive oil producing region and the effect of the components of this image on consumers’ perceived quality of an olive oil. Two successive experiments were performed in two different cultural contexts (France and Tunisia). To test the overall effect of the image, a quasi-experimental, pre-test/post-test type research design was developed, using a control group while the discrete choice method was used to study the effect of the components. The results confirm that the image of the product’s region of origin influences perceived overall quality regardless of the respondents’ nationality. The results partially confirm that each dimension of the image of the region of origin has a specific influence on consumers’ selection behaviors. The authors discuss the limitations of the results and the measurements commonly used to assess perceived quality.     

Major advances in nutrition: relevance to the sustainability of the dairy industry

The typical cow has a maintenance requirement of about 10 Mcal of net energy for lactation (NE_L) per day. Each kilogram of milk takes an additional 0.7 Mcal of NE_L. Thus, the cow producing 45 kg of milk per day needs 4 times as much total energy as she needs for her maintenance requirement alone. The elite cow producing 90 kg/d needs 7 times as much total energy as she needs for maintenance alone. Consequently, the efficiency of using feed energy is much greater for the elite cow than it was for the cow of 100 yr ago consuming a diet of mostly forage. With increased productivity has come the need for fewer cows to produce milk on a per capita basis and increases in net income per cow. However, compared with energetic efficiency, the efficiency of using feed protein to make milk protein has not increased as dramatically, partly because cows are often fed protein in excess. This nitrogen waste is an environmental concern; N losses in manure contribute to water pollution and ammonia emissions from dairy farms. However, the complexities of protein nutrition and limitations in measuring feed N fractions make accurate specifications for feed protein fractions difficult. The economic risk of underfeeding protein is greater than the risk of overfeeding protein, so protein efficiency has not been maximized in the past, nor is it likely to be maximized in the near future. Most cows also are fed excess P, a notable contaminant of surface waters, but several recent studies have shown that feeding P above NRC recommendations has no utility for milk production or fertility. The goal of this article is to examine the impact of nutrition on productivity, efficiency, environmental sustainability, and profitability of the dairy industry.     

Short communication: Farm and socioeconomic characteristics of the top 100 dairy farm counties in the United States

The objectives of this study are to describe dairy farm demographic and socioeconomic conditions in the top 100 counties in the United States for dairy sales in 2007, and to describe the association of dairy farm demographics with socioeconomic conditions. The top 100 counties were responsible for 56% of all US dairy sales in 2007 with a median growth rate of 78% compared with 1997. Counties varied widely for farm demographics with as few as 5 very large dairy farms that averaged $17,924,000 in dairy sales per farm to as many as 1,730 dairy farms with less than $250,000 in dairy sales per farm. Most of the top 100 dairy counties had higher illiteracy rates, a higher proportion of residents without a high school degree, and lower median incomes than state averages, but unemployment rates were similar to the state average. The socioeconomic measures were from public records and not collected specifically for this research. Nevertheless, the top dairy counties in the western states tended to have poorer socioeconomic conditions than the top dairy counties in other regions, and significant associations were observed between dairy farm demographics and socioeconomic conditions. Having many dairy farms was associated more favorably with county socioeconomic conditions than having high dairy sales.     

Short communication: Identification of the pseudoautosomal region in the Hereford bovine reference genome assembly ARS-UCD1.2

In cattle, the X chromosome accounts for approximately 3 and 6% of the genome in bulls and cows, respectively. In spite of the large size of this chromosome, very few studies report analysis of the X chromosome in genome-wide association studies and genomic selection. This lack of genetic interrogation is likely due to the complexities of undertaking these studies given the hemizygous state of some, but not all, of the X chromosome in males. The first step in facilitating analysis of this gene-rich chromosome is to accurately identify coordinates for the pseudoautosomal boundary (PAB) to split the chromosome into a region that may be treated as autosomal sequence (pseudoautosomal region) and a region that requires more complex statistical models. With the recent release of ARS-UCD1.2, a more complete and accurate assembly of the cattle genome than was previously available, it is timely to fine map the PAB for the first time. Here we report the use of SNP chip genotypes, short-read sequences, and long-read sequences to fine map the PAB (X chromosome:133,300,518) and simultaneously determine the neighboring regions of reduced homology and true pseudoautosomal region. These results greatly facilitate the inclusion of the X chromosome in genome-wide association studies, genomic selection, and other genetic analysis undertaken on this reference genome.