When avocados are cut, the pulp's PPO and a group of antioxidants known as phenolic compounds are exposed to oxygen. The phenols subsequently change into quinones, which are compounds that produce color.

Quinones and their byproducts then undergo a number of reactions to produce the brown pigment. In other words, PPO, phenolic compounds, and oxygen are the only three factors that may initiate the enzymatic browning reaction. By taking away the oxygen from the cut surface, it may be avoided. Therefore, limiting oxygen exposure and delaying browning may be done by wrapping a cut avocado in plastic wrap or storing it in an airtight container. However, if you take the avocado out of the container and re-expose it to oxygen, browning will start to occur again.

A helpful alternative to oxygen for preventing the browning of avocados is pH level modification. Targeting other factors that have an impact on PPO's activity because PPO is essential for regulating browning may also help avoid it.

Since PPO is active between pH 6 and 7.5 and inactive below pH 3, one way to affect PPO is by adding acidulants, which are chemical compounds that help lower pH levels. Avocados' pH is lowered by acidulants such as citric and ascorbic acid, which may be found in lemon juice, and their enzyme activity is reduced, preventing browning. Furthermore, strong antioxidants found in citrus fruits work against oxygen to prevent some foods from spoiling or turning brown. Squeezing some lemon or lime juice over the flesh of sliced avocados before storing them in an airtight container should prevent browning for about a day.

In addition to adding flavor to guacamole, onions are an avocado's BFF or Brown-Fighting Friend. According to evidence, onion extract may stop enzymatic browning by preventing PPO activity.

According to researchers, because PPO is an enzyme that has copper, the sulfuric compounds and derivatives found in onions may interact with copper at the enzyme's active site and reduce its activity. In fact, up to 33% of PPO-induced browning can be disrupted by compounds containing a sulfhydryl group. As a result, storing your cut avocado with a sliced onion may also prevent it from browning without affecting its flavor, just make sure the onion only comes into touch with the avocado's skin and not the flesh.

Submerging your avocado in coconut water is another technique to prevent it from turning brown. In addition to minimizing oxygen exposure, the antioxidant component of coconut water appears to contribute to the delay of the enzymatic reaction of PPO.

To avoid losing its firmness and turning mushy, you might not want to soak your avocado in water for a long period of time. When you just need to keep an avocado overnight, this method could be helpful. Or much easier, avocados can be soaked in water and stored in a refrigerator. If you have a lot of avocados to use quickly or are leaving brand-new avocados behind while you're away for a week, this will help keep them fresh.

The ability of pineapple shell extract (PSE) and its ultrafiltered fractions to inhibit banana polyphenol oxidase (PPO) and keep fresh-cut banana slices from browning was tested. The result is similar when compared to avocado.

Pineapple juice can help prevent the browning of your avocado, much like lemon juice does. In fact, there are two possible explanations for how pineapple juice affects PPO. On the other hand, evidence suggests that pineapple juice is comparable to sulfite, a commonly used anti-browning substance that prevents enzymatic browning. On the other hand, the browning-preventative properties of pineapple juice may be brought on by the concentration of antioxidants in the juice. Therefore, brushing a little juice on your avocado's exposed pulp may prevent browning.