The pH of most acid food products depends on undefined and complex buffering of ingredients but is critically important for regulatory purposes and food safety. Our objective was to define the buffer capacity (BC) of ingredients in salad dressing products. Ingredients of salad dressings were titrated individually and in combination using concentrations typical of dressing products. Titration curves from pH 2 to 12 were generated with sodium hydroxide and hydrochloric acid, which were then used to generate BC curves. A matrix of concentration and pK values for a series of monoprotic buffers approximated the pH of each ingredient. Some buffer series required anion or cation corrections for accurate pH prediction, possibly due to the presence of salts of acid or bases. Most buffers had BC values less than 10-fold the BC of acetic acid (0.25 β) typically in dressing formulations and had little influence on the final product pH of the dressings tested. Unexpectedly, we found that sugars in dressing formulations, including sucrose or corn syrup, exhibited buffering at pH values greater than 11 (0.035 β and 0.059 β, respectively), which was likely due to weakly acidic hydroxyl groups on the sugar molecules. However, the concentration and pK for buffers above pH 11 or below pH 2 were difficult to quantify due to the BC of water. The BC data may help to quantify the effects of salad dressing ingredients on the final product pH and benefit regulatory agencies and manufacturers in assessing product pH and safety. PRACTICAL APPLICATION: Buffer capacity data for salad dressing ingredients may help determine the influence ingredient addition will have on the final pH of a salad dressing product. The addition of low acid ingredients with little or no buffering may not significantly alter pH. The modeling method may be useful for regulatory purposes to estimate the effects of low acid ingredients on pH changes for food safety and may also be useful for product development of acid and acidified foods.

中文翻译：

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模拟沙拉酱产品中成分的缓冲能力

大多数酸性食品的 pH 值取决于成分的不确定和复杂的缓冲，但对于监管目的和食品安全至关重要。我们的目标是定义沙拉酱产品中成分的缓冲容量 (BC)。沙拉酱的成分使用调味产品的典型浓度单独和组合滴定。用氢氧化钠和盐酸生成从 pH 2 到 12 的滴定曲线，然后将其用于生成 BC 曲线。一系列单质子缓冲液的浓度和 pK 值矩阵近似于每种成分的 pH 值。一些缓冲液系列需要阴离子或阳离子校正才能准确预测 pH 值，这可能是由于存在酸或碱的盐。大多数缓冲液的 BC 值小于乙酸 BC 的 10 倍（0. 25 β) 通常在敷料配方中，对所测试敷料的最终产品 pH 值几乎没有影响。出乎意料的是，我们发现调味品配方中的糖，包括蔗糖或玉米糖浆，在 pH 值大于 11（分别为 0.035 β 和 0.059 β）时表现出缓冲作用，这可能是由于糖分子上的弱酸性羟基。然而，由于水的 BC，pH 11 以上或 pH 2 以下的缓冲液的浓度和 pK 难以量化。BC 数据可能有助于量化沙拉酱成分对最终产品 pH 值的影响，并使监管机构和制造商在评估产品 pH 值和安全性方面受益。实际应用：沙拉酱成分的缓冲容量数据可能有助于确定成分添加对沙拉酱产品的最终 pH 值的影响。添加很少或没有缓冲的低酸成分可能不会显着改变 pH 值。该建模方法可用于监管目的，以估计低酸成分对食品安全 pH 值变化的影响，也可用于酸性和酸化食品的产品开发。