Packaging materials and technologies for microwave applications: a review¹

Abstract

Packaging materials for microwave application should be generally designed based on products properties and processing conditions such as microwavability, susceptibility, processing condition, barrier properties, mechanical properties, storage condition, sustainability, convenience, and so on. Ready-to-eat products are packed in materials that can sustain thermal processing in an industrial oven and warming process in a household oven. In this context, high barrier polymers are versatile microwave packaging materials due to the microwave transparency (unlike metalized film) and high barrier. Additionally, microwave packaging materials used for ready-to-cook are intended to facilitate the microwave heating of the products in a domestic oven. The introduction of a functional feather to microwave packaging tends to improve the microwaving efficiency such as susceptor and shielding in the household oven or self-venting microwave packaging to safely release the internal steam. Furthermore, microwave-assisted thermal processing intends to control microbial contamination, requiring materials with adequate stability during processing and storage. The features of these materials are addressed in this review along with details on the basic requirements and advanced technologies for microwave packaging, microwave processing of prepackaged food, and migration testing. The prospects of microwave packaging materials in the near future are also discussed.

Keywords:

• Microwave packaging
• smart materials
• self-venting materials
• food packaging

Disclosure statement

The authors declare no conflict of interest.

Notes

1 Polyethylene, PE; Polypropylene, PP; Polyethylene terephthalate, PET; Ready to cook, RTC; Ready to eat, RTE; Crystallized PET, CPET; Polypropylene-graft-maleic anhydride, PP-g-MA; Modified atmosphere packaging, MAP; Vertical form fill seal, VFFS; Oxygen transmission rate, OTR; Water vapor transmission rate, WVTR; Glass transition temperature, T_g; Melting point, Tm; Poly(N-isopropylacrylamide), Poly(NIPAAm); Methacrylic acid, MAA; Poly(ether-block-amide), PEBAX; Polyethylene glycol, PEG; Microwave-assisted thermal sterilization, MATS; Ethylene vinyl alcohol, EVOH; Food and drug administration, FDA; Good manufacturing practices, GMP; Code of federal regulations, CFR; European committee for standardization, CEN; Phase change material, PCM; Poly(lactic acid), PLA; Polyhydroxy butyrate, PHB; Poly(butylene adipate terephthalate), PBAT.

2 Ωs/q is the unit of metal deposition, indicating a measure of resistance of thin films that are nominally uniform in thickness.

Additional information

Funding

This work was supported by the National Research Foundation of Korea (NRF) and the Korean government (MSIP) (grant number 2020R1A2B5B01001797).