• Assertion (A) is True: In thermal food processing, High-Temperature Short-Time (HTST) and Ultra-High Temperature (UHT) processes preserve heat-sensitive nutrients (thiamine, vitamin C) and sensory qualities (flavor, color) far better than conventional long-duration canning.
• Reason (R) is True and Explains (A):
• The temperature dependence of reaction rates is quantified by the $z$-value (temperature change required for a tenfold change in decimal reduction time $D$):
• Microbial vegetative cells and bacterial spores have low $z$-values ($z = 8 - 10^{\circ}\text{C}$).
• Chemical degradation of vitamins, natural pigments, and aroma compounds has high $z$-values ($z = 25 - 45^{\circ}\text{C}$).
• Consequently, elevating processing temperature accelerates microbial destruction by several orders of magnitude more than it accelerates nutrient/pigment destruction, making short exposure at high heat superior.
• Conclusion: Both (A) and (R) are true, and (R) is the correct explanation of (A) (Option 1).

Correct option: (1) Both (A) and (R) are true and (R) is the correct explanation of (A)