Why does onion juice contain more reducing sugars than potato juice?

Onion juice generally does not contain more reducing sugars than potato juice. In fact, potato juice typically contains a higher concentration of reducing sugars compared to onion juice.

Reducing sugars are sugars that can react with oxidizing agents, such as Benedict's reagent or Fehling's reagent, to produce a color change. The most common reducing sugars are glucose, fructose, and maltose.

The content of reducing sugars in fruits, vegetables, and other plant-based foods can vary depending on factors such as the type of plant, the maturity of the plant, and the storage conditions. In general, fruits and vegetables that are high in starch, such as potatoes, tend to have higher levels of reducing sugars as starch is broken down into simple sugars during ripening and storage. Onions, on the other hand, are typically lower in starch and may have lower levels of reducing sugars compared to potatoes.

However, it is important to note that the specific sugar content of any food item can vary and it's always best to refer to reliable sources or conduct specific tests to determine the exact composition.