William E Porter

US Patent:

42538483, Mar 3, 1981

Filed:

Jan 21, 1980

Appl. No.:

6/114033

Inventors:

William L. Porter - Cambridge MA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G01N 3106
G01N 3302

US Classification:

23230HC

Abstract:

A method for rapid, dry, non-destructive assay of the oxidative status of unsaturated lipids in whole foods, fats or oils and a method for prediction of the storage life of such lipids are disclosed. A method for evaluating the effectiveness of natural or synthetic antioxidants in dry, thin layers of lipid supported on polypeptide is also disclosed. All of these methods depend on the fluorescence of compounds formed by the reaction of volatiles from oxidizing lipids and a polymerized epsilon-caprolactam.

US Patent:

54588960, Oct 17, 1995

Filed:

Oct 22, 1993

Appl. No.:

8/147239

Inventors:

William L. Porter - Natick MA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G01N 3303

US Classification:

426232

Abstract:

A non-destructive technique for examining the oxidative status of packaged, dry or intermediate moisture foods. In a preferred embodiment, the technique involves packaging the foods in an assembly comprising a container or pouch formed from a pair of sheets heat-sealed to one another along their peripheries. The sheets may each be a trilaminate comprising a polyethylene terephthalate outer layer, an aluminum foil middle layer and a polyolefin inner layer. One of the sheets is provided with a cut-out portion which serves as a light transmissive window. A device comprising a strip of polyethylene terephthalate which is coated on one side with a polyamide coating is mounted across the light transmissive window, with the polyamide coating facing in towards the interior of the pouch. The food within the pouch is stored within about 2 cm of the polyamide coating during oxidation. To test the oxidative status of the food, a beam of about 420 nm light is used to illuminate the polyamide coating through strip of polyethylene terephthalate, and the resultant fluorescence is observed through the strip of polyethylene terephthalate at a wavelength of approximately 464 nm.

US Patent:

42577764, Mar 24, 1981

Filed:

Jan 21, 1980

Appl. No.:

6/114035

Inventors:

William L. Porter - Cambridge MA
Roslyn E. Kramer - Boston MA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G01N 3106
G01N 3108

US Classification:

23230M

Abstract:

Method of screening a mixture of organic compounds to detect the presence of an antioxidant material wherein the organic mixture is first chromatographically separated on a polyamide coated plate and then coated with linoleic acid. The plate is heated until the linoleic acid oxidation products react with the free amine groups on the polyamide material to produce a color change. Antioxidant compounds separated on the plate inhibit the color change and can be visually detected.