Effects of Nitrogen and Calcium Nutrition on Oxalate Contents,Forms, and Distribution in Spinach

ABSTRACT

A hydroponic experiment was conducted to study the effects of nitrogen (N) and calcium (Ca) nutrition on oxalate contents of different forms in spinach tissues. Results showed that leaves were the main locations of oxalates in spinach. Total oxalate, soluble oxalate, and insoluble oxalate contents were highest in leaves, followed by petioles and then roots. Soluble oxalate was the dominant form of oxalate in spinach. Nitrogen and Ca²⁺ (calcium ion) concentrations could markedly affect oxalate contents. Soluble oxalate contents in leaves increased obviously with the increase of N concentration until 8 mmol L^?1, above which oxalate content started to decrease. Supplied with the same amount of N, increasing Ca²⁺ concentration reduced soluble oxalate content in leaves. Total oxalate reached the lowest with 5 mmol L^?1 of Ca²⁺ supply. Leaves and petioles had lower total oxalate and lower proportion of soluble oxalate when N and Ca²⁺ concentrations were 8 and 5 mmol L^?1.     

Effect of Cooking on Lignans Content in Whole‐Grain Pasta Made with Different Cereals and Other Seeds

Lignans are of increasing interest because of their potential anticarcinogenic, antioxidant, estrogenic, and antiestrogenic activities. In this work, mixed‐cereal pastas manufactured by adding 60% whole‐grain flours of different cereals (wheat, oat, rye, barley, and rice) to durum wheat semolina, a multigrain pasta with different grains (cereals, legumes, and flaxseed), and a traditional industrial durum wheat semolina were analyzed for their lignans content both in the raw and in the cooked state, ready for consumption. For raw mixed‐cereal pastas, total lignans were within the range 94.91–485.62 μg/100 g d.w. After cooking, total lignans losses of about 35.5, 18.31, and 5.46% were observed respectively in oat‐, rye‐, and rice‐added pastas, whereas increases of 5.74 and 13.62% were observed in barley‐added and whole durum wheat pastas. Interesting results were obtained for the multigrain pasta: the raw product exhibited a total lignans content of 9,686.17 ± 287.03 μg/100 g d.w., and the major contribution was given by secoisolariciresinol. This highest total lignans value resulted from its rich and varied composition in seeds of different origin, legumes, and flaxseed in particular. Our findings showed that mixed‐cereal and multigrain pastas can be considered a good source of lignans. The effect of cooking was not the same for each product, and it depended on the different lignans profile of each grain, on the different chemical structure of each lignan, and on the nature of the food matrix.     

Influence of Kernel Damage on Corn Nutrient Composition,Dry Matter Losses,and Processability During Alkaline Cooking

The nutrient losses of corn containing 0–30% damaged kernels that occurred during alkaline cooking into tortillas were examined. Samples from different stages during processing were tested for chemical composition and protein fractionation. The most prevalent type of kernel damage was mechanical, followed in decreasing order by molds, insects, heat, and rodent damage. Corn with higher content of damaged kernels was susceptible to overcooking, resulting in cracked or fully open nixtamal kernels and sticky masa that were difficult to handle during processing. Nutrient losses increased with increasing levels of kernel damage. Most nutrient losses from sound corn kernels occurred during washing as the pericarp and attached solids were removed. During simmering, damaged corn kernels were fully cooked into physically opened kernels with more nutrients being extracted into the water. About 15% of total solids and 50% of both crude fiber and fat were lost during cooking of corn with 30% kernel damage. The greatest losses were consistently observed for albumins and globulins from both sound and damaged kernels at all stages of cooking. Appropriate control of kernel damage level is required to improve yield of product with consistent quality. The susceptibility to overcooking of excessively damaged corn increases the complexity to consistently meet product quality specifications. Excess dry matter losses in the cooking liquor can significantly increase the risk of environmental contamination and cost of sewage water treatment.     

Influence of Pyrolysis Temperatures on FTIR Analysis,Nutrient Bioavailability,and Agricultural use of Poultry Manure Biochars

This study was conducted to investigate the effect of pyrolysis temperature on chemical properties of poultry manure (PM) biochar over the range of 200–500°C. Chemical properties of biochar produced at 200°C were almost the same as PM, but significant changes were observed in higher-temperature-produced biochars. According to elemental and fourier transformation infrared analyses, the degree of carbonization in biochar was accelerated with increasing pyrolysis temperature. Biochar yield decreased, while its pH, cation exchange capacity, and P, K, Fe, Mn, Zn, and Cu contents increased with increasing pyrolysis temperature. The biochar produced at 400°C or 500°C was highly alkaline. Also, due to high electrical conductivity, these types of biochars may not be suitable for salt-sensitive crops. It was concluded that the pyrolysis temperature of more than 300°C reduces the quality of PM biochar for use in calcareous soils, although it may be suitable for acidic soils or environmental application.     

猪场废水灌溉对地下水中钾、钙、钠、镁含量的影响

应用猪场废水处理工程中产出的厌氧水不同灌溉量和3个处理阶段出水与地下水按体积比1∶5混合对冬小麦-夏玉米轮作系统进行3年的小区灌溉试验,监测地下水的总矿化度及钾、钙、钠、镁等含量的变化。结果表明：（1）地下水中钾含量在厌氧水不同灌溉量条件下呈现高量厌氧水（Ha）〉中量厌氧水（Ma）〉低量厌氧水（La）的变化趋势,在混水灌溉处理地下水中钾含量均呈厌氧水与地下水1∶5混合（Tag）〉原水与地下水1∶5混合（Tog）〉仿生态塘水与地下水1∶5混合（Teg）的变化趋势;（2）地下水中钠、钙、镁含量大致呈现低量厌氧水（La）〉中量厌氧水（Ma）〉高量厌氧水（Ha）,仿生态塘水与地下水1∶5混合（Teg）〉原水与地下水1∶5混合（Tog）〉厌氧水与地下水1∶5混合（Tag）的变化趋势。     

Significance of Dietary Fiber on the Viscometric Pattern of Pasted and Gelled Flour‐Fiber Blends

The aim of this research was to optimize mixtures of fibers from different sources and degree of processing meeting acceptable dough viscometric standards to design low‐calorie wheat bread formulations. Effects of soluble (inuline [FN]), partially soluble (sugar beet [FX]), pea cell wall (SW), and insoluble (pea hull [EX]) dietary fibers on wheat dough pasting and gelling profiles have been investigated. Impact of fibers added singly and in associated mixtures at different levels on the investigated viscometric parameters retrieved from a Rapid Visco Analyser curve has been assessed by response surface methodology, and the thermal parameters derived from the cooking and cooling functional profile were correlated. Flour replacement up to 34% by fibers significantly provided a deleterious effect on pasting and gelling viscosity profiles of the resulting hydrated high fiber‐flour blends. The magnitude of the reduction in dough viscometric characteristics during gelatinization, pasting, and setback closely depended on the nature of the fibers in the blend and on the extent of the flour substitution. A delayed and restricted swelling of starch granules and amylose leaching process preferentially achieved by the pair FN‐FX resulted in higher pasting temperatures and reduced peak viscosities during cooking and a sharp decrease of the setback on cooling. Single addition of FX, FN, and EX, respectively, provided a significant decrease in both breakdown viscosity and viscosity at the end of 95°C. Simultaneous presence of FN and EX that exhibit medium or low hydration properties allowed a partial restoration of initial breakdown viscosity and a simultaneous decrease in holding strength. Caution should be paid to the pairs FN‐FX and EX‐SW because of the adverse extra decline they induced in the viscosities of both hot paste and cold gel.     

Bioavailability of Silicon from Different Sources and Its Effect on the Yield of Rice in Acidic,Neutral, and Alkaline soils of Karnataka,South India

Several silicon (Si) sources have been reported to be effective in terms of their effectiveness on rice growth and yield. Apart from that, it is crucial to understand the bioavailability of silicon from different silicon sources for adequate plant uptake and its performances in varying types of soils. In this point of view, a pot experiment was conducted to assess the bioavailability of silicon from three Si sources and its effect on yield of rice crop in three contrasting soils. Acidic (pH 5.86), neutral (pH 7.10), and alkaline (pH 9.38) soils collected from different locations in Karnataka were amended with calcium silicate, diatomite, and rice husk biochar (RHB) as Si sources. Silica was applied at 0, 250, and 500 kg Si ha^?1, and the pots were maintained under submerged condition. There was a significant increase in the yield parameters such as panicle number pot^?1, panicle length pot^?1, straw dry weight pot^?1, and grain weight pot^?1 in acidic and neutral soils with the application of Si over no Si treatment, whereas only straw dry weight pot^?1 increased significantly with the application of Si sources over control in alkaline soil. Higher Si content and uptake was noticed in neutral soil followed by acidic and alkaline soils. The bioavailability of Si increased with the application of Si sources but varied based on the types of soil. Application of calcium silicate followed by diatomite performed better in acidic and neutral soils whereas RHB was a better source of Si in alkaline soil. A significant difference in plant-available silicon status of the soil was noticed with the application of Si sources over control in all three studied soils.     

Influence of Jet‐Cooking Prowashonupana Barley Flour on Phenolic Composition,Antioxidant Activities,and Viscoelastic Properties

The objective was to study the influence of jet‐cooked Prowashonupana barley flour on total phenolic contents, antioxidant activities, water‐holding capacities, and viscoelastic properties. Barley flour was jet‐cooked without or with pH adjustment at 7, 9, or 11. Generally, the free phenolic content and antioxidant activity decreased after jet‐cooking, while the bound phenolic content and antioxidant significantly increased regardless of pH. Detectable levels of gallic acid, caffeic acid, ferulic acid, and p‐coumaroyl‐pentose in the jet‐cooked barley flour hydrolysates along with vitexin were found among 21 phenolics by LC‐ESI‐Q‐TOF‐MS analysis. Jet‐cooking at an elevated pH resulted in increased pasting viscosities. The oil content was decreased after jet‐cooking and continued to decrease with increased pH values. Jet cooking dramatically increased water holding capacity from 179% for unprocessed flour to 643% for jet‐cooked flour without pH adjustment, and water‐holding capacity was greatly increased to 914% by jet‐cooking at pH 11. The combination of jet‐cooking and pH adjustment had tremendous influence on water‐holding and pasting properties. This increase in functionality should contribute to food applications such as bakery and frozen products because of the release of the bound phenolic content, antioxidant activities, and improved water‐holding and pasting abilities.     

Influence of Early and Delayed Transplantation of Paddy on Physicochemical,Pasting, Cooking,Textural, and Protein Characteristics of Milled Rice

Milled rice of four indica cultivars (PR114, PR116, PR118, and PAU201) obtained from early (June 5 and 15) and delayed (June 25 and July 5) transplanted paddy was evaluated for physicochemical, pasting, cooking, and protein characteristics. During the grain‐filling and development stage, early transplanted paddy experienced average maximum and minimum temperatures of 32.8 and 22.3°C, respectively, against 30.8 and 15°C, respectively, for delayed transplanted paddy. Lightness (L*) value, protein content, and lipid content of milled rice were lower, whereas apparent amylose content, cooked grain hardness, final viscosity, and setback viscosity were higher in the delayed transplanted paddy. Whiteness of milled rice of PR114, PR116, and PR118 from delayed transplanted paddy was lower than milled rice from early transplanted paddy. PAU201 did not show any change in whiteness with delayed transplantation. Cooked rice of PAU201 showed exceptionally higher adhesiveness and lower hardness compared with other cultivars. Protein profiling showed a lower accumulation of prolamines in milled rice from PR114 and PAU201 upon delaying the transplantation from June 5 to July 5, whereas PR116 and PR118 showed a decrease in prolamine accumulation from transplantation on June 25. The changes in milled rice caused by delayed transplanting of paddy might be because of cool nighttime air temperature that affected the accumulation of starch, protein, and lipid.     

Influence of Cooking Conditions on the Protein Matrix of Sorghum and Maize Endosperm Flours

To understand the influence of the sorghum and maize endosperm protein matrix honeycomb structure on starch hydrolysis in flours, three‐dimensional fluorescence microscopy was applied to floury and vitreous endosperm flours cooked under various conditions. Cooking caused the collapse and matting of the sorghum and maize vitreous endosperm matrices, with the effect being greater in sorghum. The effect of cooking was rather different in the floury endosperm in that the protein matrices expanded and broke up to some extent. These effects were a consequence of expansion of the starch granules through water uptake during gelatinization. Cooking in the presence of 2‐mercaptoethanol caused an expansion of the vitreous endosperm matrix mesh due to breakage of disulfide bonds in the protein matrix. Mercaptoethanol also caused an increase in the proportion of β‐sheet structure relative to α‐helical structure of the endosperm proteins. Increased energy of cooking caused collapse of the sorghum matrix. Disulfide bonding and an increase in β‐sheet structure occurred with cooking, with the increase in disulfide bonding being greatest in sorghum vitreous endosperm. The tendency for the sorghum protein matrix to collapse and mat more with cooking than the maize matrix appears to be due to greater disulfide bonding. This is responsible for the observed low starch digestibility of cooked sorghum flour as a result of the more disulfide‐bonded protein matrix limiting the expansion of the starch granules and hence amylase access.     

Effect of the Nixtamalization Process on the Dietary Fiber Content,Starch Digestibility,and Antioxidant Capacity of Blue Maize Tortilla

Nixtamalization is an ancient process developed by the Mesoamerican cultures. Initially, volcanic ashes were used and then calcium hydroxide in commercial production, and more recently nixtamalization with calcium salts (NCS) has been proposed. The aim of this study was to evaluate the effect of NCS on carbohydrate digestibility and antioxidant capacity in the elaboration of blue maize tortillas. NCS in blue tortillas showed a high amount of total dietary fiber (14.27 g/100 g), the main fraction being insoluble dietary fiber. The contents of resistant starch and slowly digestible starch did not change with the nixtamalization process. The predicted glycemic index value was lower in blue tortillas with the NCS process (58) than with the traditional nixtamalization process (71). In general, NCS in blue tortillas presented a higher antioxidant capacity than traditional tortillas (ferric reducing antioxidant power method), indicating that phenolics present in blue maize maintain their activity after cooking. It can be concluded that the nutraceutical features (high dietary fiber content and antioxidant capacity) of blue maize tortillas are enhanced when they are elaborated with the NCS process.     

不同茶园土壤中外源铅的形态转化及其生物有效性

为了明确外源铅进入不同茶园土壤后其形态的转化及其生物有效性,采用盆栽试验及连续浸提形态分级方法,研究了外源铅在不同茶园土壤中的形态分布规律及其在茶树体内的累积分布规律。结果表明,不同母质茶园土壤中铅总量及各形态的含量有明显差异,无外源铅污染的情况下,临安凝灰岩与金华红壤母质茶园土壤以残渣态占主导地位,嵊州玄武岩和梅家坞鞍山母质茶园土壤则以铁锰态铅占主导地位,4种土壤的交换态含量均较低,均在总量的10%以内。当受外源铅污染后,4种茶园土壤中各形态铅均有不同程度的增加,转变为以铁锰态为主,碳酸盐态及可交换态含量在总量中所占比例明显增加,但不同母质土壤类型差异较大。在小于500mg·kg-1土的外源铅污染下,交换态以嵊州玄武岩、临安凝灰岩增幅最大,金华红壤最小;但外源铅达到2500mg·kg-1土时,金华红壤中的交换态铅急剧增加。低浓度外源铅对金华红壤、梅家坞鞍山斑岩茶园土中的茶树生长发育有促进作用,但对嵊州玄武岩和临安凝灰岩茶园土壤中的茶树生长刺激作用并不明显。高浓度的外源铅则对4种土壤中的茶树生长均产生明显的抑制作用,且碳酸盐态与交换态对茶树生长的抑制作用最大。对新梢中的铅而言,金华红壤茶园土壤以有机态铅对其贡献最大,其余3种母质茶园土壤均以碳酸盐态贡献最大;对老叶与茎杆中的铅而言,嵊州玄武岩母质茶园土壤以有机态贡献最大,其余3种土壤均以铁锰态贡献最大;对须根中的铅而言,梅家坞鞍山斑岩茶园土以有机态贡献最大,其他3种土壤均以铁锰态贡献最大。     

Influence of Raw Materials and Processing Conditions on Spaghetti Hydration Kinetic During Cooking and Overcooking

A study of the influence of raw materials and processing conditions on the hydration kinetic during cooking and overcooking of spaghetti is presented. Water sorption tests on commercially available spaghetti and on three different types of homemade spaghetti were run at 100°C. In particular, the weight, diameter, and length of spaghetti strands were monitored over time for ≈200 min. The spaghetti hydration process was quantitatively resolved into the controlling phenomena (i.e., water diffusion, macromolecular matrix relaxation kinetic, and residual deformation release kinetic) by fitting a novel mathematical model to the experimental data. The different behavior of spaghetti was analyzed for each of the phenomena involved during hydration. Results suggest that processing conditions highly influence the quality of spaghetti with respect to raw materials.     

宁波市辖区水稻土硅钙镁锌铜有效性评价及其影响因素研究

研究分析了宁波市辖区(江北、镇海、北仑)水稻土耕层中的有效Si、Ca、Mg、Zn、Cu含量及其影响因素。结果表明,研究区内土壤有效硅、有效钙、有效镁、有效锌和有效铜均属中等变异强度,变异系数介于27.6%~71.1%,有明显缺硅、缺铜现象。相关分析表明,各元素有效含量与土壤有机质含量呈一定正相关性;有效硅、有效钙、有效镁与土壤pH呈极显著正相关性,有效锌和有效铜与土壤pH呈一定负相关性。因此,在一定程度上,土壤有机质和pH水平可以反映出有效Si、Ca、Mg、Zn、Cu含量的丰缺程度。     

Influence of Gluten Proteins and Drying Temperature on the Cooking Quality of Durum Wheat Pasta

It is well known that gluten plays a major role in determining cooking quality in durum wheat pasta. This work is an attempt to systematically elucidate the role of gluten quantity and nature in determining cooking quality as a function of the drying cycle used in the manufacturing process. Gluten and starch were fractionated from two durum wheat cultivars possessing good and poor gluten quality. Either of them were then added back to the original base semolina to alter its protein content and to produce two semolina series with identical protein contents. Semolinas were processed into pasta and dried following three drying programs (low, medium, and high temperature). Cooking quality was determined with sensorial, chemical, and instrumental methods. The results indicate that optimum cooking time is governed by gluten quality. The positive effect on cooking quality of increasing gluten contents and of the application of HT drying is evident in weak gluten samples, but it is not significant in the strong gluten samples.     

Influence of Silicon on Growth,Relative Water Contents and Uptake of Silicon,Calcium and Potassium in Wheat Grown in Nutrient Solution

Growth performance, relative water contents (RWC), and mineral nutrition were studied in Triticum aestivum L. treated with different concentrations of silicon (25, 50, 100, 200, 400 and 800 ppm). Lower administrations of silicon (25–200 ppm) resulted in an enhancement in relative yield, relative water contents, calcium, and potassium contents. A significant (0.1% level) direct relationship between tissue silicon content and applied silicon concentrations and an inverse relationship between relative yield and higher applied silicon concentrations (400 and 800 ppm) were observed. Shoots were significantly richer in silicon content than roots. The results indicate a possible requirement of silicon for higher plants.     

硼钙营养对不同品种柑桔糖代谢的影响

连续 2年对胡柚和柑桔进行叶面喷施硼 (B)、钙 (Ca)及硼加钙 (B +Ca)溶液试验 ,以探讨B、Ca及其互作对柑桔果实糖酸代谢的影响。结果表明 ,硼 (B)、硼加钙 (B +Ca)处理能提高柑桔果实成熟前的还原糖、滴定酸含量 ,降低果实收获期的还原糖和滴定酸含量 ,并提高了果实成熟期总糖含量 ;增强柑桔果实发育初期酸性转化酶活性和果实发育后期中性转化酶活性 ;钙 (Ca)处理对柑桔糖代谢的影响效果不明显     

Influence of soil properties on microbial populations, activity and biomass in humid subtropical mountainous ecosystems of India

 Microbial populations, biomass, soil respiration and enzyme activities were determined in slightly acid organic soils of major mountainous humid subtropical terrestrial ecosystems, along a soil fertility gradient, in order to evaluate the influence of soil properties on microbial populations, activity and biomass and to understand the dynamics of the microbial biomass in degraded ecosystems and mature forest. Although the population of fungi was highest in the undisturbed forest (Sacred Grove), soil respiration was lowest in the 7-year-old regrowth and in natural grassland (approximately 373 μg g^–1 h^–1). Dehydrogenase and urease activities were high in "jhum" fallow, and among the forest stands they were highest in the 7-year-old regrowth. Microbial biomass C (MBC) depended mainly on the organic C status of the soil. The MBC values were generally higher in mature forest than in natural grassland, 1-year-old jhum fallow and the 4-year-old alder plantation. The MBC values obtained by the chloroform-fumigation-incubation technique (330–1656 μg g^–1) did not vary significantly from those obtained by the chloroform-fumigation-extraction technique (408–1684 μg g^–1), however, the values correlated positively (P<0.001). The enzyme activities, soil respiration, bacterial and fungal populations and microbial biomass was greatly influenced by several soil properties, particularly the levels of nutrients. The soil nutrient status, microbial populations, soil respiration and dehydrogenase activity were greater in Sacred Grove, while urease activity was greater in grassland. Received: 14 October 1998