It could be produced under a wide range of pHs.

它可以在很宽的 pH 值范围内生产。

For example, a study published in 2001 is often touted as showing that special diets can tweak internal pHs but even it didn't actually find much of an effect.

比如说，2001 年发表的一项研究常被鼓吹为证明了特殊饮食可以扭转体内酸碱值，但是并没有发现什么效果。