Size classification of precipitated calcium phosphate using hydrocyclone technology for the recovery of minerals from deproteinised acid whey

Acid whey is generated during the manufacture of acidified dairy products, such as soft cheeses, acid casein ingredients and strained yoghurts. Examples of these whey‐based by‐products include Cottage cheese acid whey and Greek yoghurt acid whey. Alkalisation of acid whey at elevated temperatures (60 °C) precipitates calcium phosphate, which can be recovered and used as an ingredient. The novel application of a liquid–solid hydrocyclone in the size classification of calcium phosphate from heated and neutralised acid whey was investigated in this study. Factors influencing hydrocyclone performance were tested, and the technology was integrated into a membrane filtration‐based process for the production of milk mineral powders.     

四川甘孜地区矿产资源开发的环境地质防治措施与对策

四川甘孜地区矿业开发已成为地区经济发展的主要支柱产业，本文就甘孜地区矿业活动引起的环境污染、资源环境破坏和矿山地质灾害等环境问题，提出对这些环境问题进行防治的措施和对策。     

新疆卡拉塔格红海VMS型矿床矿石空间变化特征及分带性*

红海VMS型矿床位于卡拉塔格古生界火山隆起区西南边缘的斜坡地带。矿体产于海相火山碎屑岩层中,受多组断裂构造控制,具有典型的上部块状铜锌矿体,下部网脉状铜矿体的二元结构特征,成矿元素具有明显的空间分带特征。从块状矿体到矿体上盘呈块含铜黄铁矿矿石→黄铜矿石→铜锌矿石的变化规律,矿物组合变化规律为:黄铁矿+黄铜矿→黄铜矿±黝铜矿→黄铜矿+闪锌矿±黝铜矿±方铅矿±黄铁矿。从块状矿体核部向边部,矿石中Cu的含量呈递减趋势,Zn的含量与Cu的含量成负相关关系;网脉状矿体Cu含量变化不大。块状矿体的Cu品位大于网脉状矿体。     

Substrates for phosphorus removal-potential benefits for on-site wastewater treatment?

A large number of substrates potential for removal of phosphorus (P) in wastewater has been reviewed. The substrates consist of natural materials, industrial by-products and man-made products. Most substrates have been investigated in batch and column studies in the laboratory; others have also been tested in field trials. The results from these investigations vary, but a few substrates, e.g. wollastonite, slag material and, to some extent, light weight aggregate products, have demonstrated promising properties with regard to P-sorption capacity and hydraulics. The problems of normalisation of data are discussed, as well as the substrates potential benefits for on-site wastewater treatment.     

Inductively coupled plasma emission spectrometric determination of minerals in catfish frame

The concentration of 14 major and trace elements in catfish (Ictalurus punctatus) frames was determined and analyzed for differences. Three frames were obtained each week for five consecutive weeks in the spring and the fall of 2000. The frames were freed of remaining flesh, dried, treated by microwave dissolution technique and the minerals determined by inductively coupled plasma optical emission spectrometry (ICP‐OES). The mean calcium concentration (mg/kg, dry basis) in the spring (140 400) was not significantly (P > 0.05) different from that in fall (167 000). Among the heavy metals (Cd, Pb, and Al) the concentration of Cd varied significantly (P < 0.05) from week to week but not from season to season. The concentration of all the above‐mentioned heavy metals did not exceed the critical level for human consumption.     

The roles of cell wall polymers and intracellular components in the thermal softening of cassava roots

Cassava varieties Iapar 19 – Pioneira (short cooking time, domestic vegetable), Taquari (medium-to-long cooking time, domestic vegetable), and Branca de Santa Catarina (long cooking time, industrial vegetable), were selected in order to investigate the cell wall and compositional basis for these textural differences. Pioneira had lower levels of Ca²⁺ and Mg²⁺, and higher levels of phytic acid and monovalent cations than the longer cooking time varieties. Detailed cell wall analysis indicated that the longer cooking Branca cultivar had higher levels of chelator-insoluble pectic polysaccharides. The potential causative roles of these different features were evaluated using vortex-induced cell separation (VICS) studies. Time to achieve the complete VICS of Branca cultivar was reduced to that of Pioneira with externally-supplied chelating agents (CDTA) and Na₂CO₃. Taquari roots did not respond in this way indicating a different biochemical basis for the maintenance of cell adhesion. The results are discussed in relation to the thermal stability of texture in these cassava varieties.     

Correlations of the Composition,Minerals, and RVA Pasting Properties of Various Potato Starches

Multiple linear regression equations were developed to correlate the granule size distribution, composition, and minerals content with the Rapid Visco Analyser (RVA) pasting properties of potato starches of different cultivars. From the experimental values and the values of the regression coefficients, it could be observed that a higher level of amylose resulted in a lower peak viscosity (PV) and breakdown (BD) and higher setback (SB) and peak viscosity temperature (PVT) in the potato starches. The reverse was observed when the phosphorus content was higher. Smaller granule size was associated with a decrease in the PVT, whereas larger granules demonstrated higher PV, BD, and SB values in the potato starches. A higher calcium content was associated with a decrease in PV and an increase in BD, SB, and PVT. On the other hand, higher potassium was associated with an increase in PV, BD, SB, and PVT. The sodium contents demonstrated a higher PV and SB, and the reverse was observed in the BD and PVT. It is difficult to conclude the precise role of magnesium ions to the RVA properties although as divalent cations, they may have similar effect as calcium. From the positive and negative values of the regression coefficients it was shown that the correlation is useful for determining more precise values of the RVA pasting properties using a multiple linear regression equation. The correlations were also useful for predicting the effects of the starch composition and minerals on the RVA pasting properties.     

储层矿物上表面活性剂损耗规律的研究

本文在结合大庆油田三元复合驱（ASP）的地质条件下,系统评价了在ASP体系中表面活性剂测定方法,确定了储层中不同单矿物与表面活性剂相互作用机理、损耗规律及其影响因素,复合矿物组合对表面活性剂损耗的协同效应。研究表明储层中粘土矿物的表面活性剂损耗量通过大于储层中其它矿物颗粒的表面活性剂损耗量,为其4－5倍;ASP复合体系中表面活性剂的损耗量为单一表面活性剂体系中的2－5倍,表面活性剂损耗量大的矿物,其矿物组合的损耗量也大。     

The concentration of minerals and physicochemical contaminants in conventional and organic vegetables

In this study, we performed a comparative analysis of the physical-chemical composition and pesticide residue content of lettuce, peppers, and tomatoes that were grown in organic and conventional systems. The vegetables were purchased at the Food Supply Centre of Pernambuco [Centro de Abastecimento Alimentar de Pernambuco – CEASA/PE], Pernambuco state, Brazil. The physical-chemical composition of the vegetables was determined according to the analytical procedures of the Association of Official Analytical Chemist. The minerals (Cu, Cr, Fe, K, Mn, Mg, Na, and Zn) and the heavy metals (Cd, Ni, and Pb) were assessed using atomic absorption spectrometry, and the pesticide residues were determined using a multi-residue analysis. The results were compared by means of a Student's t-test. Principal component analysis was performed to investigate the correlations between the minerals and the heavy metals. The measurements of weight, length, and width of all three of the vegetables that were assessed were higher in the conventional group. There were significant differences (p < 0.05) in the proximate composition of conventional and organic lettuces (moisture, ash and protein) and in all the parameters of conventional and organic peppers. To tomatoes there wasn't significant difference (p > 0.05). All three of the organic vegetables were higher in total dietary fibre. The composition of the minerals and heavy metals varied between all three vegetables. Contamination by pesticide residues was found in conventional peppers and organic tomatoes.     

文庆鲤酶解蛋白(EAP)营养成分的分析与评价

文庆鲤酶解蛋白(EAP)是一种高蛋白低脂肪的产品,通过对其氨基酸及无机质的测定分析,知其必需氨基酸和支链氨基酸含量丰富,且与非必需氨基酸的比例合理,同时富含铁、锌等元素.