Water Vapor Transmission Rate ($WVTR$) of flexible polymeric food packaging films is defined as the quantity of water vapor passing through:
Options:
(A) Unit area of film per unit time under specified conditions of temperature and relative humidity
(B) Unit thickness of film per unit temperature gradient
(C) Total package volume per year
(D) Per unit mass of food product
Answer Key:
A
Step-by-Step Solution & Explanation
$WVTR$ (or $MVTR$) measures the barrier property of a packaging film, defined as the mass of water vapor transmitted per unit film area per unit time (typically $\text{g/(m}^2\cdot\text{day)}$) under defined temperature ($38^\circ\text{C}$) and relative humidity differential ($90\%\text{ vs. }0\%$).