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Layer by Layer Assembly of a Biocatalytic Packaging Film: Lactase covalently Bound to Low‐Density Polyethylene
Author(s) -
Wong Dana E.,
Talbert Joey N.,
Goddard Julie M.
Publication year - 2013
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/1750-3841.12134
Subject(s) - lactase , low density polyethylene , chemistry , substrate (aquarium) , active packaging , layer (electronics) , polyethylene , glutaraldehyde , lactose , chromatography , chemical engineering , food science , organic chemistry , food packaging , biology , ecology , engineering
Active packaging is utilized to overcome limitations of traditional processing to enhance the health, safety, economics, and shelf life of foods. Active packaging employs active components to interact with food constituents to give a desired effect. Herein we describe the development of an active package in which lactase is covalently attached to low‐density polyethylene (LDPE) for in‐package production of lactose‐free dairy products. The specific goal of this work is to increase the total protein content loading onto LDPE using layer by layer (LbL) deposition, alternating polyethylenimine, glutaraldehyde (GL), and lactase, to enhance the overall activity of covalently attached lactase. The films were successfully oxidized via ultraviolet light, functionalized with polyethylenimine and glutaraldehyde, and layered with immobilized purified lactase. The total protein content increased with each additional layer of conjugated lactase, the 5‐layer sample reaching up to 1.3 μg/cm 2 . However, the increase in total protein did not lend to an increase in overall lactase activity. Calculated apparent K m indicated the affinity of immobilized lactase to substrate remains unchanged when compared to free lactase. Calculated apparent turnover numbers ( k cat ) showed with each layer of attached lactase, a decrease in substrate turnover was experienced when compared to free lactase; with a decrease from 128.43 to 4.76 s −1 for a 5‐layer conjugation. Our results indicate that while LbL attachment of lactase to LDPE successfully increases total protein mass of the bulk material, the adverse impact in enzyme efficiency may limit the application of LbL immobilization chemistry for bioactive packaging use.