Correct answer: (4) Green tea

Green tea is typically produced by minimal oxidation and no true microbial fermentation, whereas the other listed products involve clear microbial fermentation steps.

Option analysis

• (1) Cheese
  Cheese production relies on lactic acid bacteria (and often secondary molds or surface bacteria) to ferment lactose into lactic acid, develop flavor and texture, and lower pH for preservation. This is a classic food fermentation product.

• (2) Black tea
  Black tea leaves undergo an enzymatic and often microbially assisted fermentation/oxidation step after rolling, during which polyphenols are oxidized and complex flavor compounds form. In tea technology this step is traditionally called “fermentation,” so black tea is considered a fermented tea.

• (3) Kombucha
  Kombucha is a fermented beverage made by a symbiotic culture of bacteria and yeast (SCOBY) that converts sugared tea into a mildly acidic, carbonated drink containing organic acids and trace ethanol. It is unequivocally a fermentation product.

• (4) Green tea
  Green tea is produced by rapid heating or steaming of fresh leaves to inactivate oxidizing enzymes and prevent fermentation/oxidation of catechins. Because this preserves the leaf in a near-fresh, unfermented state, green tea is not typically classified as a fermentation product.