Acidulants in Hot-Pack Products
1.What is the effect of pH to food flavor?

Most acids will reduce the pH of a food when they are used in sufficient amounts -- as long as those amounts are legally allowed. Therefore, flavor ranks high on the list of deciding factors. Two factors influence the flavor of the food: the acidity level, or tartness; and the type of acid used.Often, sweeter products can be formulated at a lower pH while maintaining palatability. Using the correct sugar:acid ratio softens the impact of acidity in the mouth. If the balance is right, the product does not come across as sour.Besides their acidity, acidulants may impart their own characteristic flavor. Acetic acid, or vinegar, is the most familiar and obvious example.These differences in acid flavor delivery affect the way other ingredients taste. Malic acid complements aspartame-sweetened products. Using citric acid for the same product brings out bitter, metallic notes. Acidity also can mask certain flavor notes or make them less pronounced.

2.What is the function of buffer?
Buffers are substances that resist change in pH. They typically are comprised of a weak acid and its conjugate base -- citric acid and sodium citrate, for example. Because it can supply H+ ions or OH- ions, the buffer solution's pH remains fairly constant, despite the addition of limited quantities of strong acids or bases. By reducing large shifts in pH, buffers can provide improved stability of flavor, color, gelation rate and subsequent gel strength, and pH-sensitive sweeteners. Flavor characteristics can vary at different pH values (similar to the way colors can shift in different pH ranges). Also, the products can degrade and/or be lost at a pH level outside of the "optimum range." For example, the optimum pH for aspartame is 4.2. And in some instances, buffers can directly influence flavor. At a given pH, a buffer will have a more- or less-sour taste impact.