氯化钠与硫酸钠在彩色羊皮纸中的应用

探讨了在彩色羊皮纸生产过程中,氯化钠和硫酸钠作为促染剂的促染机理及注意事项,并且比较了氯化钠和硫酸钠在生产应用中的差异。实践表明,除两者溶解度、用量不同外,对系统的影响也不相同,硫酸钠还可降低成纸颜色的亮度。     

食用盐中硫酸根含量品质波动与氯化钠含量品质波动的关系研究

目的探讨食用盐中硫酸根含量品质波动和氯化钠含量品质波动之间的变化关系,从多方面考察食用盐的均匀性。方法选取市场上比较普遍的、具有代表性的不同种类食用盐产品,采用国家标准检验方法,对批量盐产品的硫酸根含量和氯化钠含量进行检测,通过统计方法计算出硫酸根含量的品质波动和氯化钠含量的品质波动。结果发现硫酸根含量的品质波动和氯化钠含量的品质波动这2个参数在表示不同盐产品的均匀性时呈现一致性。结论硫酸根含量的品质波动也可以作为考察盐产品的均匀性的指标,这对抽样检验的代表性和生产过程中品质波动的考察有指导意义。     

几种制汁葡萄在新疆生长情况调查及果汁品质分析

试验采用田间调查、果汁品质测定等方法对奥托玫瑰(Muscat Ottonel)、康拜尔早生(CampbellEarly)、卡它巴(Catawba)、白香蕉(Triumph)、玫瑰香(Muscat Hamburg)、香槟(Champion)、康太、黑虎香、一品香、郑果25号、柔丁香、黑贝蒂12个制汁葡萄品种在新疆的生长情况及果汁品质进行了相关的研究。结果表明:郑果25号、康太、卡它巴、康拜尔早生、黑贝蒂、黑虎香、一品香、柔丁香、香槟、白香蕉的综合性状优良,具有生长好、抗病性强、果实性状好和果汁品质优良等特点。     

Effect of different sterilization methods on the appearance,composition, and flavor of sugarcane juice

Cold-pressed sugarcane juice (SCJ) is a beverage rich in vitamins, carbohydrates, and antioxidants. Various sterilization methods impact fruit juice's appearance, nutrients, and flavor. Hence, this study aims to assess how different sterilization techniques affect the flavor, appearance, and nutritional value of SCJ. Freshly prepared SCJs were subjected to two sterilization methods: pasteurization (referred to as PTG) and autoclaving (referred to as HTHP). The pasteurization process was carried out at 63°C for 30 min, whereas the HTHP process was applied at 115°C for 30 min. The appearances, Brix value, colors, sugar, organic acid content, and aromatic compounds were determined. The Brix and pH values of the juice show little variation across different heat treatments. The color index of PTG was similar to that of the control group, whereas the L* value of HTHP increased about 21%, resulting in a significant color change. The glucose and fructose contents of HTHP were 7.03 and 5.41 mg/mL, which were much higher than those of PTG (3.26 and 2.33 mg/mL) and control group (3.33 and 2.48 mg/mL). A total of 77 aromatic compounds were identified in the SCJ after various heat treatments. Among them, pentanoic acid, octanal, and β-damascenone were the most abundant substances contributing to the overall flavor in the control group, PTG, and HTHP. Pasteurization preserved the original flavor of the juice, whereas autoclaving triggered the Maillard reaction, forming pyrazine and furan-like compounds that altered the SCJ's flavor. In conclusion, pasteurization retained SCJ's original characteristics, whereas HTHP induces changes in nutrition and imparts a distinct flavor.     

Irrigation of grapevines with saline water at different growth stages: Effects on leaf,wood and juice composition

Background and Aims: This study reports on the effects that timing of saline irrigation has on leaf and wood tissue concentrations of Na⁺ and Cl^– and on juice composition. Methods and Results: Colombard vines on Ramsey rootstock were drip irrigated with saline water during any one of four annual growth stages: pre‐flowering, berry formation, berry ripening and postharvest. At other times, vines were irrigated with non‐saline water as was the control. Salts were annually flushed from the rootzone. Over six seasons, saline irrigation caused five‐ and sevenfold rises, respectively, in the leaf and juice Na⁺ concentrations and two‐ and fourfold rises in respective Cl^‐ concentrations. Saline irrigation raised juice pH and this was associated with a rise in juice Na⁺. Normalising responses for inter‐treatment differences in the seasonal salt load to isolate the effects of timing showed that juice Cl^‐ concentration was most sensitive to saline irrigation during berry formation and juice malate concentration most sensitive to saline irrigation pre‐flowering. Conclusion: Cl^‐ uptake was greatest when saline irrigation was applied early in organ formation, whereas Na⁺ uptake reflected seasonal salt load in irrigation water. Significance of the Study: In vines on the chloride excluding rootstock Ramsey, yield loss under saline irrigation was associated with high concentrations of sodium in the leaf.     

食盐中氯化钠测定的研究

食盐是人们日常生活中必备的调味品,氯化钠是食用盐的主要成分,是食盐咸味的主要来源。作为食盐生产企业必须控制的指标,氯化钠项目的检测尤为重要,但是不同产品标准规定的氯化钠的检测方法存在着或多或少的差别,常用的氯化钠测定方法为计算法,一个项目涉及到5个项目的检测,且计算过程繁琐。本研究根据食盐中杂质化合物的不同将食用盐分成几个类型,将复杂的计算过程列表表示,使计算过程变得清晰明了。同时汇总了现行食用盐标准中氯化钠含量的测定方法幵迚行了比较分析,以期给管理部门、生产企业及检验人员提供更多的参考和思考。     

葡萄汁中鞣花酸的定性与定量分析

鞣花酸的含量是影响葡萄汁感官指标的重要因素。对鞣花酸的测定有多种方法, 以纸色谱分析法、ＨＰＬＣ 分析法、光学分析法、质谱分析法等对葡萄汁中的鞣花酸作定性和定量分析。     

Assessment of the validity of maturity metrics for predicting the volatile composition of Concord grape juice

Total soluble solids (TSS) are typically used as the sole metric for maturity of Concord grapes. However, the reliability of TSS in predicting the aroma composition of finished juice for grapes sourced from multiple sites has not been investigated. This study sought to determine the validity of TSS in predicting the aroma composition of the juice while also investigating other potentially useful indicators, including pH, titratable acidity (TA), and TSS:TA ratio. Grapes were harvested from 9 sites in the Lake Erie Concord Grape Belt and stratified from north to south and east to west. The key aroma compounds methyl anthranilate ("grapey") and trans-2-hexenal ("herbaceous") were quantified along with several other odorants. It was observed that while TSS was a robust predictor of monomeric anthocyanin content across sites, it was a poor predictor of aroma compounds in the finished juice. Conversely, pH, TA, and TSS:TA ratio were all significantly correlated with methyl anthranilate and trans-2-hexenal concentrations (P < 0.05) in samples equal to or exceeding 15 Brix, the industry minimum for grape maturity. These results indicate that parameters related to acidity are better predictors of aroma composition than TSS, which may aid in efforts to minimize herbaceous off-aromas and optimize the aroma composition of the finished juice.     

染色废水中元明粉浓度的软测量模型

元明粉浓度是影响电导率最主要的因素,为了能在线测量染料废液中的元明粉浓度,通过对试验数据进行曲线拟合,建立了元明粉浓度-电导率曲线模型的染液浓度软测量方法,对染色废液中元明粉残存量实现较精确的测量.     

葡萄汁澄清工艺的研究

本文研究了葡萄汁澄清工艺。分别采用果胶酶、明胶、羧甲基纤维素钠、黄原胶对葡萄汁进行澄清处理,以透光率、可溶性固形物含量和单位明胶沉淀量为指标对其澄清效果进行评价。结果表明,果胶酶和明胶复配使用效果最为理想。最佳工艺:明胶的添加量为0.06%,果胶酶的添加量为0.03g/L,酶解温度为40℃,酶解时间为30min,此时,葡萄汁的透光率达到84.92%,可溶性固形物含量为2.38%。      

二氧化硫在葡萄汁中的作用

SO2在葡萄汁中主要以两种形式存在：游离SO2和结合SO2。许多研究研究表明，游离SO2在葡萄汁中起到杀菌和澄清的作用；SO2与空气中的氧气或葡萄汁中的还原物质结合不仅起到了抗氧的作用，还提高了酸度，增加了浸提效果，对葡萄汁的色泽及香气产生良好的影响。     

青梅、红枣、杏、葡萄、沙枣复合果汁饮料的研制

针对青梅、红枣、杏、葡萄、沙枣复合果汁饮料的配方、稳定性以及最佳口感风味进行研究,并制定复合果汁的生产工艺。复合果汁的最佳配方为:青梅∶红枣∶杏∶葡萄∶沙枣为10∶4∶5∶3∶3(质量比),最佳口感风味配方为柠檬酸0.23%、蔗糖用量10%、复合稳定剂用量为0.3%,所得产品为营养、保健型饮料,风味独特,酸甜可口。     

硝皮脱硝方法及其软化效果的研究

讨论了硝皮工艺的特点 ,分析了硝皮工艺成革丰满性、泡感差的原因。研究了猪硝皮的脱硝方法 ,考察了温度、液比、时间等因素对硝皮脱硝效果的影响 ,得出了理想的硝皮脱硝方法。液比 2 .0 ,温度 3 0 -3 0℃ ,水洗 3次 ,每次 1 5 -2 0min ,基本可以脱净皮内的硫酸钠。对硝皮的软化效果及硝皮中硫酸钠含量对软化效果的影响进行了研究 ,结果表明 :硫酸钠对常用的软化用胰酶具有抑制作用 ,溶液中硫酸钠的浓度越高 ,酶活力降低越大 ;用软化液中蛋白质和羟脯氨酸的含量来定量表征酶软化效果 ,硝皮水洗程度越完全 ,软化效果越好     

自动标准加入法测定乳粉、乳饮料及果汁中的钠含量

目的建立自动标准加入法测定乳粉、乳饮料和果汁中钠含量的方法。方法采用自动标准加入法对全脂奶粉、脱脂奶粉、浓缩乳清粉、婴幼儿配方奶粉以及市场上各类果汁饮料及乳饮料进行钠含量的测定,研究样品中钠离子的提取方式和滴定剂浓度对检测结果的影响,并将测定结果与火焰原子发射光谱法进行对比。结果自动标准加入法用于乳粉、浓缩乳清粉、果汁饮料及乳饮料中钠含量的测定结果重复性好,相对标准偏差均小于5%;而且与火焰原子发射光谱法的测定结果之间无显著性差异,两者之间的相对偏差小于5%。结论自动标准加入法重复性好、准确度高,可用于食品与饮料中钠含量的检测。     

真空制盐制硝中淘洗的作用

文章结合苏盐集团“十二五”时期“品牌制胜”发展战略要求,联系瑞洪盐化股份公司实际,针对目前市场行情提高自身生产技术,生产高纯度优质产品来加强企业竟争优势.     

食盐中氯化钠测定结果计算方案的建立

目的 补充标准中氯化钠检测方法的计算过程。方法 依据标准GB 5009.42-2016《食品安全国家标准 食盐指标的测定》和系列标准GB/T 13025《制盐工业通用试验方法》测定食盐中各离子含量, 然后根据产品中所含离子的优先结合次序, 利用质量守恒定律构建氯化钠结果的计算模型。结果 明确了硫酸根离子与钙离子含量差异。根据化合物结合的3种可能性; ①硫酸钙、硫酸镁、硫酸钠、氯化钠; ②硫酸钙、硫酸镁、氯化镁、氯化钠; ③硫酸钙、氯化钙、氯化镁、氯化钠, 正确选择计算方案。结论 本研究便于检测操作者对标准的理解, 为快速、批量计算氯化钠结果提供参考。     

Influence of sodium chloride and glucose on acid-induced gelation of heat-denatured ovalbumin

ABSTRACT:  We examined the effects of NaCl and glucose on cold-set ovalbumin gelation. Cold-set gels were prepared by adding glucono-δ-lactone (GDL) to a 2% heated ovalbumin solution. For the gel prepared from ovalbumin heat-denatured with NaCl and glucose, the gel with 10 mM NaCl was most transparent and had high gel strength. Its maximum complex shear modulus ( G *) and turbidity were 2.5 times greater and 3 times lower, respectively, than those of the gel without NaCl. The turbidity of the gel with the higher NaCl content increased steeply after the addition of GDL and did not change during the experimental period. The maximum G * of the gel exhibited positive correlations with the molar mass, radius, and surface hydrophobicity of soluble aggregates and the NaCl content, but the turbidity exhibited negative correlations with these factors. The presence of glucose did not significantly affect the turbidity or rheological properties of the gel. For the gel prepared by adding NaCl and glucose with GDL, the presence of glucose did not affect the turbidity, but the maximum G * decreased in inverse proportion to the glucose content. The turbidity of the gel with higher NaCl content (≥ 50 mM) was the greatest among all samples, and the increased turbidity was maintained throughout the measurements. The gels with 50 and 100 mM NaCl exhibited thixotropy during shearing at a constant shear rate. Therefore, the presence of NaCl and glucose during cold gelation could facilitate the preparation of cold-set gels having various properties for food applications.