Influence of pH on colour and iron content of peptide fractions obtained from bovine Hb concentrate hydrolysates

The effect of pH on colour and iron content (Fe) of peptide fractions obtained from bovine haemoglobin concentrate (BHC) hydrolysates was studied. Four hydrolysates were obtained using three enzymes: Protex‐6‐L (P), Fungal–Protease–Concetrate (FC) and Flavourzyme (F). BHC and its hydrolysates (P, FC, P + F, FC + F) were fractioned at pH 4.5, 7.0 and 9.5. Solubility and Fe from different fractions were measured. Correlations between CIELAB colour parameters and Fe from different fractions were analysed. The colour from different fractions varied from red to yellow (a* and b* positives). Lightness values (L*) ranged from twenty‐four to seventy. FC4.5 and FC + F4.5 fractions were the clearest and yellow (higher L*, b*, h), while BHC9.5 and P + F9.5 fractions had the lowest values of L*, b* and h. There was an inverse linear relationship between b* and L* parameters and Fe from fractions. This relationship could be associated with the pH of extraction. As pH increases Fe significantly increases and lower b* and L* values were obtained.     

钢铁锌系磷化液变黑原因分析及预防措施

分析钢铁锌系磷化液在生产中变黑的原因和磷化液变黑的危害.磷化液变黑的主要原因是溶液成分配比不合理,工作负荷偏大,工作温度偏低,游离酸度偏高,促进剂浓度偏低和Fe2+浓度偏高等.给出预防磷化液变黑的措施:(1)设计时多配备1个磷化槽,以防止磷化液超负荷工作;(2)通入空气或加强磷化液搅拌;(3)对磷化液进行加热;(4)加...     

啤酒中的铁离子

铁离子可促进酵母生长发育;又可引起啤酒混浊、产生金属味,降低啤酒质量.啤酒中的铁离子主要来源于原辅材料、设备管件及酿造用水等.铁离子在酿造过程易发生氧化还原、催化和络合反应,对麦汁糖化、发酵及成品啤酒质量产生影响.控制铁离子含量的方法有:控制原辅料及所用水的铁离子含量;适当提高糖化醪液的pH值;选用优良、强壮的酵母种;选用含铁较少的硅藻土助滤剂;选用耐酸不锈钢容器和管道,并作好防腐措施.(孙悟)     

Evaluation of the effect of Ultra Rice® EDTA supplementation on the soluble iron,visual acceptance and vitamin A stability of commercial milled rice blends

The addition of NaFeEDTA at only 5% of total iron to ferric pyrophosphate‐fortified Ultra Rice^® increased the in vitro soluble iron ten‐fold. Ultra Rice^® formulated with NaFeEDTA at 2–7% of total iron, or with Na₂EDTA·2H₂O at 0.5× the total iron equivalents, increased the soluble iron seven‐ to thirty‐fold. The colour of the batches was acceptable through 20 weeks at 21 °C, but colour stability needs to be evaluated under authentic storage conditions. Although only 34–46% of the initial vitamin A remained after extrusion, 18‐week storage at 30 °C/70% relative humidity, and simulated cooking, there were indications that losses could be decreased by raising the pH (to ~5) and/or using a better protected vitamin A ingredient. The enhancement of soluble iron afforded by low‐level NaFeEDTA or Na₂EDTA·2H₂O supplementation suggests that this fortification strategy may merit further study as a means of increasing absorbable iron in Ultra Rice^®.     

Geographical discrimination of honeys through antioxidant capacity,mineral content and colour

The assessment of geographical origin of honey is economically important for producers and consumers as every region may present particular quality characteristics. In this study, honeys from the seven different regions of Buenos Aires province (Argentina) were characterised by their antioxidant capacity (DPPH, FRAP), total phenolic content (TPC), mineral composition, colour and ash. Honeys showed significant differences among their antioxidant capacity (DPPH), ash, colour and mineral content (P ≤ 0.05). Besides, a good antioxidant activity and low amounts of Cu and Zn (<1.0–1.5 and 0.7–1.8 mg kg^?1, respectively) were found in the samples. Significant Pearson's correlations (P ≤ 0.05) among the different parameters were found. Moreover, the linear discriminant analysis allowed the classification of honeys in their original groups with a prediction success of 98%. The present results suggest that honeys could be correctly classified by their geographical origin through their TPC, colour, ash and mineral concentrations.     

钢铁行业CCPP装置中的高炉煤气压缩机的选型和应用

分析了燃气蒸汽联合循环发电装置（ＣＣＰＰ）中的煤气压缩机的主要特点,以及采用轴流＋离心串联形式的优点,介绍了我国第一台上海宝钢ＣＣＰＰ煤气压缩机的工艺流程及相关参数。     

组合模块式燃油燃气铸铁锅炉的设计

文章分析了组合模块式燃油燃气铸铁锅炉的结构和性能特点,介绍了燃油燃气铸铁锅炉的结构设计和计算。     

光电光谱法测定高铬铸铁中多元素的研究

利用Ｂａｉｒｄ公司的Ｓｐｅｃｔｒｏｖａｃ ２０００（ＤＶ５,ＨＲ４００光源）光电直读光谱仪测定高铬铸铁中的多元素,开拓了光电光谱仪在无相同材质标样下定量分析的应用。采用容量法测定高铬铸铁基体及主要元素的含量。通过选用基体元素作内标样下定量对谱结进行基体和干扰校正以及材质的诱导校正和空白校正,绘制校正,建立了光电光谱法测定高铬铸铁中多种元素的方法。其测定值基本与容量法值一致,相对标准偏差（ＲＳＤ）均     

氧化铁与碳酸钾对煤温和气化的影响

对神木煤进行了流化床煤温和气化研究,考察了氧化铁、碳酸钾对煤温和气化产物产率,气体组成,半焦组成的影响。试验结果表明：添加氧化铁后,煤气中Ｈ２产率显著增加,ＣＯ产率明显下降,添加碳酸钾后,Ｈ２产率增幅较小,ＣＯ,ＣＨ４及其它气态烃产率基本不变,表明碳酸钾对烃类裂解反应无明显催化作用。通过对所得半焦组成分析,发现添加碳酸钾所得半焦中硫,氮含量比原煤热解半焦有所增加,添加氧化铁的得半焦中硫,氮含量无明