Influence of Arabinoxylans and Endoxylanases on Pasta Processing and Quality. Production of High‐Quality Pasta with Increased Levels of Soluble Fiber

As part of a general study aiming to clarify the role of arabinoxylans (AX) in pasta processing and quality, AX were modified by the addition of endoxylanases during pasta processing. The influence on processing parameters and quality were determined. Pasta (800 g) was produced from two commercial semolinas (semA and semB) using dosages of Bacillus subtilis (XBS) and Aspergillus niger (XAN) endoxylanases of 0–0.225 Somogyi units/g of semolina. Increased dosages resulted in a drop of extrusion pressure. The endoxylanase treatments had no great effect on the resulting pasta quality (color of dry products and surface condition, viscoelastic index, and resistance to longitudinal deformations of cooked products). High dosages of XAN and XBS resulted in high levels of solubilized AX (as an extra source of soluble dietary fiber) of low molecular weight which were expected to easily leach out during the cooking process of pasta. Surprisingly, only low levels of AX were found in the cooking water, even with extremely high dosages of endoxylanases used and cooking beyond optimum time. A method is provided to obtain high‐quality pasta with increased levels of soluble fiber.     

Effects of Drying Processing Conditions on the Quality of Uncooked and Cooked Pasta Made Up of Nonconventional Raw Material

Drying process plays a fundamental role in pasta making. The greatest number of studies have been focused on the optimization of drying conditions for semolina pasta, and the obtained results have been applied in a similar way on pasta made up of nonconventional raw materials without considering a processing optimization. The aim of this research was to evaluate the influence of different drying treatments (low, medium, and high temperature) on the quality of uncooked and cooked soft wheat pasta enriched with oat flour. Results of total organic matter and dried residue showed no significant difference between samples dried by medium and high temperature treatments. Moreover, these last samples showed a slight improvement in cooking quality over samples dried at low temperature (total organic matter results were 1.31 versus 1.66 g/100 g of dried pasta). This study revealed that the improvement of cooking quality of pasta enriched with oat flour did not require the application of high drying temperature (>80°C) that involves a considerable consumption of energy and could favor the development of a Maillard reaction, decreasing quality characteristics of this kind of product.     

Effects of Modified Processing Conditions on Oxidative Properties of Semolina Dough and Pasta

During pasta making, semolina is subject to various modifications that are mainly related to oxidative activities with relative effects on some of its components. To evaluate the involvement of hydroperoxidation and bleaching of lipoxygenase (LOX) and peroxidase (POD) activities on loss of pigments and ‐SH groups, their behavior in semolina and during processing was analyzed. Processing was done in standard and four experimental conditions, applying chemical (pH 5.0 and 8.0) and physical (10 and 40°C) treatments, during the mixing and extrusion phases, to study their effects on components. Results pointed out that treatments principally affected hydroperoxidation and bleaching activities of LOX rather than the POD. During pasta making, enzymatic activities showed the same trend in all cultivars, and this was reproducible in all the experimental conditions. Temperature effects on preservation of components were modest, whereas pH 8.0 improved the residual pigment and ‐SH group content in pasta, probably because of the concomitant reduction of oxidative enzyme levels. Finally, out of the four investigated wheat cultivars, Cosmodur showed the best performance in the experimental conditions applied. In fact, high pigment content and yellow index associated with low oxidative activity levels in semolina and in processing samples resulted in better pasta color. Such findings have confirmed that breeding and technological approaches may play an important role in the control of oxidative activities during pasta making, preserving the constituents that positively influence the final pasta color.     

土壤质量评价方法进展

土壤质量评价是对土壤内部属性变化的总体描述,发展经历了定性到定量的过程,融合了多学科的特征。本文综述了国内外土壤质量评价方法及其研究成果。指数法简单易行,但是带有主观性,会掩饰土壤性质某些质的变化;动态评价方法比较真实地反映土壤质量动态变化的过程,同时还可以将评价结果用于经济学分析,研究范围拓宽;生命周期评价完整研究土壤发生发育的周期,时间尺度上考虑全面,但是没有考虑空间尺度;G IS用于土壤质量评价,能将定量分析与空间分析结合起来,评价结果更具科学性。     

Spelt (Triticum spelta L.) Pasta Quality: Combined Effect of Flour Properties and Drying Conditions

Three spelt genotypes (Rouquin, Redoute, and HGQ Rouquin= Rouquin improved for gluten quality), each characterized by either high or low protein content, were processed to manufacture spaghetti, which was dried at both low (60°C) and high temperature (90°C) to assess the effects of flour properties and drying conditions on spelt pasta quality. Protein content in the spelt flour was considered low at ≈11.4% db and high at ≈13.5% db. Gluten properties, assessed by SDS sedimentation and gluten index values and by alveograph and farinograph parameters varied widely, ranging from poor for Redoute to very good for HGQ Rouquin. Pasta quality was assessed by determining color (L*, a*, and b* values), furosine, and cooking quality (stickiness, bulkiness, firmness, and total organic matter [TOM]). Furosine and color (a* and b* values) were significantly influenced by the intensity of the drying process. TOM and organoleptic judgement (OJ) showed that spelt pastas dried at low temperature, independent of their protein levels, were very poor (TOM ≥ 2.7 g/100 g of dry pasta, OJ ≤ 40), except for HGQ Rouquin which was characterized by good gluten strength. On the other hand, the cooking quality of spelt pastas dried at high temperature showed good values (TOM ≤ 1.8 g/100 g of dry pasta, OJ ≥ 53). The combination of high protein content (≥13.5% db) and high‐temperature drying resulted in the production of satisfactory cooking quality pastas from spelt wheats (TOM ≤ 1.2 g/100 g of dry pasta, OJ ≥ 67).     

Combined Effects of Endoxylanases and Reduced Water Levels in Pasta Production

The combined effects on pasta properties of 1) varying dosages of endoxylanases (EC 3.2.1.8) from Aspergillus aculeatus and Bacillus subtilis and 2) lower levels of water during pasta dough processing were studied. The A. aculeatus endoxylanase has high selectivity toward water‐extractable arabinoxylan (WE‐AX), whereas B. subtilis endoxylanase preferentially hydrolyzes water‐unextractable arabinoxylan (WU‐AX). Pasta was produced on a microscale (50.0 g) from the semolinas of both a strong (AC Navigator) and a moderately strong (AC Avonlea) durum wheat cultivar. The levels of added water in endoxylanase‐treated pastas were adjusted to obtain the same maximal farinograph consistencies as for the control pastas. The extruded pastas were dried with drying cycles at 40, 70, or 90°C. Apart from increasing levels of solubilized arabinoxylans, these treatments had little effect on the color, optimal cooking time, and firmness of the resulting pasta. High enzyme concentrations and low (40°C) drying temperature resulted in clearly or much less checked final products for the B. subtilis and A. aculeatus enzyme, respectively. Upon cooking, the enzymically formed low molecular weight arabinoxylans were retained better in the pasta strands than their equally low molecular weight arabinogalactan counterparts.     

Changes in Semolina Yellow Pigment Content and Carotenoid Composition During Pasta Processing

Changes in total yellow pigment (TYP) content and carotenoid composition were examined at different stages of pasta processing. Semolina samples were milled from durum genotypes with and without the Lpx‐B1.1 gene deletion and then processed into dry pasta. Significant pigment loss (12.8–15.3%) based on TYP content was observed from semolina to dough in genotypes without the gene deletion. Such loss remained low (2.0–2.8%) for genotypes with the Lpx‐B1.1 gene deletion. Extrusion and drying processes did not result in substantial pigment loss. The overall pigment loss (from semolina to dried pasta) of genotypes with the gene deletion was 9.1–12.8%, in comparison with 19.0–21.7% in genotypes without the deletion. Changes in carotenoids examined by ultra‐performance liquid chromatography showed that lutein decreased gradually from representing 80% of total carotenoids to 70% of total carotenoids during pasta processing. The reduction of lutein was mostly during dough mixing, with a decrease of 16.7% in genotypes with the Lpx‐B1.1 deletion and 27.8% in genotypes without the deletion. Minor carotenoids increased during pasta drying, possibly at the expense of lutein. Results of this study showed that although breeding for elevated yellow pigments is the key, pasta color can be further improved by reducing pigment losses at different stages of pasta processing through selection of genotypes with Lpx‐B1.1 deletion and applying a vacuum during mixing and extrusion processes.     

REVIEW: An Overview on Fusarium Mycotoxins in the Durum Wheat Pasta Production Chain

Fusarium head blight (FHB) is one of the major diseases of wheat (both common and durum wheat) caused by various fungi including Microdochium nivale and different Fusarium species. Most of the Fusarium species associated with FHB (mainly F. graminearum, F. culmorum and F. sporotrichioides), under favourable environmental conditions, can produce various toxic secondary metabolites (mycotoxins) that can contaminate grains. The major Fusarium mycotoxins that can occur in wheat and derived products are deoxynivalenol, nivalenol, T‐2 and HT‐2 toxins, and zearalenone. Processing has generally significant effects on the levels of mycotoxins in the final products. Deoxynivalenol is typically concentrated in the bran coat which is removed in the production of semolina; consequently, a consistent reduction of deoxynivalenol levels has been observed during each of the processing steps, from raw durum wheat to pasta production. To allow monitoring programs and protect consumers' health, several analytical methods have been developed for Fusarium mycotoxins, based on chromatographic or immunometric techniques. The European Union has established maximum permitted levels for some Fusarium mycotoxins in cereals and cereal‐based products (including unprocessed durum wheat, bran, wheat flour, and pasta). Recommendations for the prevention and reduction of Fusarium mycotoxins contamination in cereals based on identification of critical risk factors and crop management strategies have been published by the Codex Alimentarius and the European Commission.     

Gluten Structural Evolution During Pasta Processing of Refined and Whole Wheat Pasta from Hard White Winter Wheat: The Influence of Mixing,Drying, and Cooking

An attempt was made to evaluate gluten structural changes in refined and whole wheat pasta from hard white winter wheat to elucidate the impact of whole wheat components on the formation and structure of the gluten network in pasta. Attenuated total reflectance–FTIR spectroscopy was used to track gluten secondary structure through most of the major steps in pasta processing: raw material, mixing, drying, and cooking. Protein solubility, accessible thiols, and SDS‐PAGE data were also collected to provide additional information on the nature of protein interactions and network composition. Few secondary structural differences were observed between refined and whole wheat flours from hard white wheat. However, mixing induced a significant shift to β‐sheet structures in refined dough that was not equally matched by whole wheat dough. Drying under both high temperature, short time (HT) and low temperature, long time (LT) conditions resulted in a reversion to structural distributions similar to those for flour in both pastas. However, greater protein denaturation in HT samples was indicated by lower protein solubility also in the presence of denaturants and disulfide reducing agents. Cooking generated a substantial increase in β‐sheet structures for both pasta systems. This structure was greatest in refined and LT samples. Thiol accessibility data indicate the presence of a highly aggregated, compact gluten network in refined pasta, mostly driven by hydrophobic association. Conversely, the network in whole wheat pasta was more loosely associated and dependent on disulfide bonding, both of which fit well with the secondary structural data.     

恩施地区玉米土壤环境质量评价

根据我国农业行业标准(NY5020-2001)规定的污染物控制指标及控制值,采用单因子污染指数和内梅罗综合污染指数法,对恩施州八个县市玉米产区土壤的8项污染指标进行了环境质量评价。结果表明,全州玉米土壤环境质量总体状况良好,达到"安全"等级,符合国家规定的无公害产品基地土壤环境质量的要求。     

云烟优质适产的气候条件分析

通过对云南主烟区与省外,国外主要区的气候条件对比分析,揭示烟优质适产的天气气候特点,为烤烟种植与区划提供科学的参考依据。     

Alkaline Processing (Nixtamalization) of White Mexican Corn Hybrids for Tortilla Production: Significance of Corn Physicochemical Characteristics and Process Conditions

Five white corn hybrids were processed (nixtamalized) using 10 different processing conditions; tortillas were prepared to establish relationships between corn composition, physical characteristics, and nixtamalization process or product properties. Corn hybrids were characterized by proximate analysis and by measuring Stenvert hardness, Wisconsin breakage, percent floaters, TADD overs, thousand‐kernel weight, and test weight. Corn characteristics were correlated with process and product variables (effluent dry matter loss and pH; nixtamal moisture and color; masa moisture, color, and texture; and tortilla moisture, color, and rollability). Process and product variables such as corn solid loss, nixtamal moisture, masa texture, and tortilla color were influenced not only by processing parameters (cook temperature, cook time, and steep time) but also depended on corn characteristics. Significant regression equations were developed for nixtamalization dry matter loss (P < 0.05, r² = 0.79), nixtamal moisture (P < 0.05, r² = 0.78), masa gumminess (P < 0.05, r² = 0.78), tortilla texture (P < 0.05, r² = 0.77), tortilla moisture (P < 0.05, r² = 0.80), tortilla calcium (P < 0.05, r² = 0.93), and tortilla color a value (P < 0.05, r² = 0.87).     

影响板栗产量的气象条件分析及产量评估方法

统计近24年兴隆县板栗的产量资料与生育期的气象资料,分析了板栗产量与气温、降水、日照等气象条件的相关关系,选取与板栗产量相关好的气象要素为预报因子,用多元回归的方法建立了板栗气象产量评估方程,并进行了回代和检验。     

不同工艺制法对茶叶风味品质化学轮廓的影响

为探明不同工艺制法对茶叶风味品质化学轮廓的影响,本研究对福建4种茶类(绿茶、白茶、红茶和乌龙茶)及其鲜叶原料中的主要滋味和香气品质成分进行了检测分析和可视化模式识别。结果表明,基于茶叶主要滋味品质成分的主成分分析(PCA)可将全部供试茶样划分成3种类群:Ⅰ型:绿茶、白茶和一芽二、三叶鲜叶样;Ⅱ型:乌龙茶和中、小开面2~4叶鲜叶样;Ⅲ型:红茶。采用偏最小二乘增强判别分析(PLS-EDA)可进一步放大不同类群茶样的组间差异,乌龙茶及其鲜叶原料有较高含量的水溶性碳水化合物(WSCs),而红茶中多酚类(TPs)和表没食子基儿茶素没食子酸酯(EGCG)含量相对较低;(茶多酚×游离氨基酸)含量二维散点视图可作为茶叶分类识别的一种重要判别工具。4种茶类以乌龙茶的香型种类最为丰富,绿茶与鲜叶原料的香气组成化学模式较为接近,白茶与红茶香气组成在种类和数量上存在一定的相似特征。2,6-二叔丁基对甲苯酚、苯乙腈、4-乙基苯甲酸-2-苯基乙酯类似物、反式-橙花叔醇、α-法呢烯、吲哚等可视为乌龙茶有别于其他3种茶类(绿茶、白茶和红茶)的主要特征香气成分。本研究结果为茶叶化学分类及其工艺品质的目标控制提供了参考依据。     

Assessment of Horizantal and Vertical Variabilities of Soil Quality using Multivariate Statistics and Geostatistical Methods

The aim of this study is to examine the horizantal and vertical spatial changes of soil quality (SQ) in rice-cultivated soils located on the Bafra Deltaic Plain—one of the most important alluvial deltaic plains and production centers of Turkey. The study examines these spacial changes by calculating the soil quality index (SQI) for soils 0–30 cm and 30–60 cm deep. For SQI calculations, seventeen potential physicochemical SQ indicators of eighty-three soil samples were assessed. Quality indicators to be used in these calculations were selected by considering the clay content, correlation relationship, and principal components analysis (PCA) of potential quality indicators. Clay, silt, sand, electrical conductivity (EC), exchangeable calcium (Ca_exc), and exchangeable magnesium (Mg_exc) were selected as quality indicators, and silt was found to be the most important quality indicator for both soil depths. The SQ of researched soils changed from low to high for both soil depths.     

Assessment of Boron Application in Chestnuts: Nut Yield and Quality

A field trial was conducted between 2006 and 2009 in order to quantify the effect of boron (B) application on the yield and quality of chestnuts. The trial was established in an acid soil derived from siliceous schist and two levels of B were applied. Fruit abortion and nut yield per tree were measured, and nut quality parameters and chemical composition of the kernel were determined. Foliar B concentration was 8.6 mg kg^?1 in the control trees and 48.4 mg kg^?1 in fertilized chestnuts. Boron improved fruit setting and promoted nut production by 77%. In 2008, the occurrence of cold temperatures enhanced the effect of B on fruit setting, which was four-fold, whereas with the normal temperatures of 2009 the increase was lower. The drought of 2009 was responsible for the ruinous chestnut caliber and shell cracking. Boron induced a significant increase in the crude fat of chestnut kernel.     

中国农户小麦施肥水平和效应的评价

小麦是中国重要的粮食作物,然而近些年却在不断萎缩,肥料投入不合理导致成本过高是主要原因。本文利用农户调查数据,通过主成分分析筛选出同一类农户,通过建立肥料效应函数定量评价了中国小麦施肥水平。结果发现如果按照经济效益来评价,我国75%的小麦种植户已经超量使用化肥,而如果从产量效率来说,却有74%农户需要增加化肥。这些结果都说明中国化肥过量使用已经比较明显,施肥不经济,盲目追求高产。未来应从产量、收益甚至环境保护等角度综合引导农户合理施肥。     

REVIEW: Hulled Wheats: A Review of Nutritional Properties and Processing Methods

There is renewed interest in adopting hulled wheats (emmer, einkorn, and spelt) into our food system, because of their nutritional qualities and improved organoleptic properties. Current research findings have been concisely put together in this review to show the extent of the current and past work in this area and suggest additional research areas. Breeding programs for hulled wheats have received a great deal of attention, and their research findings have shown potential to generate genotypes with improved qualities. More work is required to investigate the changes in nutritional and structural composition of hulled wheats during and after processing and to develop suitable processing methods.     

安兴村的优化梯田配套增产措施

安兴村的优化梯田配套增产措施高维明（甘肃省庆阳地区水保站甘肃西峰７４５０００）正宁县水和乡安兴村共有８个村民小组，４６０户，农业人口２２０３人，农业劳动力１２０７个；总耕地面积３４８．７ｈｍ２，其中山地１５７．８ｈｍ２，占总耕地面积的４５．２％；人均...     

甘肃省水平梯田建设优化技术研究与推广

为了推动梯田建设向科学化、规范化方向发展，甘肃省进行了梯田建设优化技术的试验研究和推广。梯田优化技术包括治理规模化、工程配套化、田块断面设计优化、施工规范化和增产服务全程化。１９９０～１９９３年四年间，甘肃省推广优化梯田建设技术涉及５０个县，３１１个乡，共完成优化梯田７４８３３ｈｍ２，累计经济效益７９７９．９万元。