酸的低pH亲和度查:替代耗时的储存实验?
Mads Bjørlie1, Laura Pontoppidan1, Betül Yesiltas1
1National Food Institute, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Food chemistry
|March 21, 2025
概括
研究人员使用新技术选了在中的抗氧化活性. 然而,没有任何可以提高稳定性,有些是亲氧化剂,这凸显了预测食物抗氧化功效的挑战.
科学领域:
- 食品科学 食品科学 食品科学
- 分析化学 分析化学
- 生物化学 生物化学
背景情况:
- 金属催化脂质氧化缩短了饼的保质期.
- 对金属化抗氧化剂的需求正在增加.
- 需要有效的抗氧化剂选方法.
研究的目的:
- 选酸在内抗氧化活性.
- 在低pH下评估表面等离子体共振 (SPR) 和固定金属亲和色谱 (IMAC) 以抗氧化剂查.
- 与传统的储存实验相比,评估新的选技术的有效性.
主要方法:
- 结合SPR和IMAC在低pH下进行选.
- 进行了一项为期28天的菜储存实验.
- 分析了对Ni2+和Fe3+的-金属离子亲和力.
主要成果:
- 在低pH下,SPR面临非特异性结合的挑战.
- 在IMAC检测中,发现了-金属离子亲和力的显著差异.
- 没有测试过的增强了的氧化稳定性;有些作为氧化剂.
结论:
- 新的低pH SPR和IMAC技术显示出潜力,但需要改进.
- 在复杂的食物矩阵中预测抗氧化剂功效是具有挑战性的.
- 需要进一步的研究来改进低pH选方法的食品抗氧化剂.
相关概念视频
pH
The potential of hydrogen (pH) is a measure of the acidity or basicity of a water-based solution determined by the concentration of hydronium ions (H3O+). In one liter of pure water at neutral pH, there are 1×10−7 moles of hydronium ions. However, the extensive range of hydronium ion concentrations present in water-based solutions makes measuring pH in moles cumbersome. Therefore, a pH scale was developed to convert moles of hydronium ions into the negative logarithm of the hydronium ion...
Buffers
A solution containing appreciable amounts of a weak conjugate acid-base pair is called a buffer solution, or a buffer. Buffer solutions resist a change in pH when small amounts of a strong acid or a strong base are added. A solution of acetic acid and sodium acetate is an example of a buffer that consists of a weak acid and its salt: CH3COOH (aq) + CH3COONa (aq). An example of a buffer that consists of a weak base and its salt is a solution of ammonia and ammonium chloride: NH3 (aq) + NH4Cl...
Calculating pH Changes in a Buffer Solution
A buffer can prevent a sudden drop or increase in the pH of a solution after the addition of a strong acid or base up to its buffering capacity; however, such addition of a strong acid or base does result in the slight pH change of the solution. The small pH change can be calculated by determining the resulting change in the concentration of buffer components, i.e., a weak acid and its conjugate base or vice versa. The concentrations obtained using these stoichiometric calculations can be used...
Buffer Effectiveness
Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...
The buffer capacity is the amount of acid or base that can be added to a given volume...
pH
The potential of hydrogen (pH) is a measure of the acidity or basicity of a water-based solution determined by the concentration of hydronium ions (H3O+). In one liter of pure water at neutral pH, there are 1×10−7 moles of hydronium ions. However, the extensive range of hydronium ion concentrations present in water-based solutions makes measuring pH in moles cumbersome. Therefore, a pH scale was developed to convert moles of hydronium ions into the negative logarithm of the hydronium ion...
Titration of a Weak Base with a Strong Acid
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...


