pH-sensitive nanoparticles for detecting and preventing food spoilage

Patent metadata

Field	Value
Publication number	US-11435333-B2
Application number	US-201815863463-A
Country	US
Kind code	B2
Filing date	Jan 5, 2018
Priority date	Jul 6, 2015
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

Nanoparticles and compositions thereof are provided for detecting and/or preventing food spoilage. Methods of making the nanoparticles and compositions, and methods of using the nanoparticles and compositions, e.g. in food packaging, are also provided. The nanoparticles can have a hydrophobic core containing a hydrophobic active agent, e.g. a hydrophobic dye and/or an antimicrobial agent, for detecting and/or preventing food spoilage. The nanoparticles can also have a copolymer of a hydrophobic polymer repeat unit, e.g. styrene or lactic acid, and a pH responsive dendrimer repeat unit. The pH responsive dendrimer repeat unit can have a pH responsive amine core having a plurality of branched acrylate arms extending therefrom. The nanoparticles can be chemically stable at neutral pH, and then release the hydrophobic active agent at a pH range indicative of food spoilage. By releasing the hydrophobic dye and/or antimicrobial agent, the nanoparticles can detect and/or inhibit food spoilage.

First claim

We claim:

1. A nanoparticle for the detection of food spoilage, the nanoparticle comprising:
a hydrophobic core comprising a hydrophobic dye; and
a copolymer of a hydrophobic polymer repeat unit and a pH responsive dendrimer repeat unit,
wherein the pH responsive dendrimer repeat unit has a structure according to the following formula or a derivative thereof,

wherein each occurrence of X is independently a branched acrylate arm having a structure according to the following formula

wherein each occurrence of B is a substituted or unsubstituted, linear or branched alkyl, heteroalkyl, alkenyl, alkynyl, carbocyclic, or heterocyclic group,
wherein m is an integer of 2 to 8,
wherein the pH responsive dendrimer repeat unit is present at an amount from about 5 wt % to 20 wt % based upon the weight of the copolymer,
wherein the nanoparticle is chemically stable and has a diameter of about 50 nm to 200 nm at neutral pH, and
wherein the nanoparticle releases the hydrophobic dye at a pH range of about 4.5 to 6.7 to indicate the food spoilage.

2. The nanoparticle according to claim 1 , wherein the pH responsive dendrimer repeat unit has a structure according to the following formula

3. The nanoparticle according to claim 1 , wherein the pH responsive dendrimer repeat unit has a structure according to the following formula

4. The nanoparticle of claim 1 , wherein the nanoparticle has a diameter of 50 nm to 250 nm.

5. The nanoparticle of claim 1 , wherein the hydrophobic polymer repeat unit is selected from the group consisting of a fluorocarbon, a tetrafluoroethylene, a vinylfluoride, a siloxane, a dimethylsiloxane, butadiene, a methacrylate, ethylene, an olefin, styrene, propylene, and an oligomer thereof.

6. A packaged food product comprising:
a food product;
a packaging containing the food product; and
a composition comprising a plurality of the nanoparticles according to claim 1 .

7. The packaged food product according to claim 6 , wherein the pH responsive dendrimer repeat unit has a structure according to the following formula

8. The packaged food product according to claim 6 , wherein the pH responsive dendrimer repeat unit has a structure according to the following formula

9. The packaged food product of claim 6 , wherein the food product is selected from the group consisting of beef, pork, poultry, and fish.

10. The packaged food product of claim 6 , wherein the packaged food product is a ready-to-eat food product.

11. The packaged food product of claim 6 , wherein the composition is part of the packaging and is in contact with the food product inside the packaging; and
wherein a release of the hydrophobic active agent indicates the food has spoiled, inhibits or prevents the growth of a food spoilage microorganism, or both.

Assignees

• Univ Florida

Inventors

• Tong Zhaohui
• Jairam Suguna

Classifications

• G01N21/78

  producing a change of colour · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• B65D81/34

  for packaging foodstuffs {or other articles} intended to be cooked or heated within the package · CPC title

• C09B67/009

  polymeric dispersing agent · CPC title

• C09B67/0013

  with polymeric coatings · CPC title