Atlanta,
GA 1998
MOISTURE SHELF LIFE STUDY OF
PACKAGED MILK
K. Tanprasert and R.J. Hernandez
Michigan State University, School Of
Packaging, East Lansing, MI 48824, USA
Non-fat dry milk, widely used as an ingredient in many foods,
is a moisture sensitive product. The increase in moisture
content shortens its shelf life by affecting flavor, composition,
appearance, and flow properties. There is an industry interest
in evaluating the application of shelf life models for selecting
diverse packaging materials like plastic coated or laminated
on f-flute corrugated board.
The objective of this work was to evaluate
the shelf life of non-fat milk powder packaged in one-kg boxes
made from corrugated composite material and two glue patters.
Calculated and experimental shelf life values are compared.
Parameters of GAB sorption isotherm
equation for non-fat dry milk were determined at 20, 30, and
40°C. Permeance of the packaging materials were determined
at 25, 30, and 40°C and values were fitted by Arrhenius
equation. Boxes made with the material having the lowest permeance
were hot-melt sealed using two different glue patterns (Bellow
and FOL). Computer modeling was employed to calculate the
system’s shelf life at two isothermal storage conditions
based on the dry milk sorption isotherm and the packaging
material permeance data. Polypropylene laminated (double face)
f-flute corrugated board had the lowest permeance among the
tested material, and the longest shelf life value. There was
no significant difference between the glue patterns so the
simplest design, FOL, was selected. Final calculated and experimental
shelf life values will be presented.
This study provides a method to design
food packages for extending shelf life for a moisture sensitive
dry powder using new corrugated package materials
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