Question Statement:
Which of the following environmental factors increase the thermal resistance ($D$-value) of bacterial endospores during food processing?
Options:
- (A) Reduced water activity ($a_w$) in the heating medium (e.g., high lipid or sugar content)
- (B) Neutral pH ($pH = 6.5\text{--}7.2$) compared to acidic conditions ($pH < 4.5$)
- (C) Presence of high concentrations of soluble proteins and fats providing protective micro-capsulation
- (D) Addition of organic acids lowering pH below 4.0