low water and low ph
high water activity neutral ph
7ph
They all have a low pH, distilled water has a pH of around 7 and vinegar is an acid along with seawater making them below seven.
The optimum pH for catalase activity is around pH 7, which is neutral. Catalase works best at this pH level to break down hydrogen peroxide into water and oxygen.
Water
At low pH levels, enzymes can become denatured, meaning their structure and function can be disrupted. This can lead to a decrease in enzyme activity and effectiveness.
Generally the juice of vegetables is under 7.
pH levels vary among bacterial species. For example; acidophillic bacteria grow best at low pH. While alkalophiles grow better at alkaline (high) pH. Most bacteria grow best at high aw (>0.90). While few bacterial species such as xerophiles grow best at an aw of 0.6-0.7
Yes, gravy will go bad if not refrigerated. The pH and water activity are not low enough to make it shelf stable without a canning process.
Yes, you can drink water with a low pH, but it is recommended to consume water with a pH close to neutral (around 7) for optimal hydration and health. Water with a low pH may be slightly acidic, which may not be harmful in small amounts, but prolonged consumption of highly acidic water could potentially have negative effects on your teeth and digestive system.
Maybe the water has some CO2 dissolved in it.
Because water is a neutral and high pH values are basic and low pH values are asidic.