Oxygen scavenging system

Abstract

The oxygen scavenging system of the subject invention contemplates a composition, system and appurtenant methodology for substantially eliminating elemental oxygen from packaged oxygen sensitive products. The composition or scavenging agent includes an oxidoreductase enzyme, a suitable energy source or substrate for the enzyme, and a buffer. The composition binds oxygen when exposed to moisture, thereby reducing the level of oxygen in a closed (e.g., sealed) space such as a food package or the like. More particularly and preferably, the composition includes glucose oxidase in an amount of between 1 and 100 activity units (U) per gram, catalase in an amount of between 1 and 300 activity units (U) per gram, dextrose in an amount of between about 20 and 99 percent by weight, and sodium bicarbonate in an amount of between about 1 and 80 percent by weight.

Description

[0001] This is a regular application filed under 35 U.S.C. §111(a) claiming priority under 35 U.S.C. §119(e)(1), of provisional application Ser. No. 60 / 389,246 having a filing date of Jun. 17, 2002 and filed under 35 U.S.C. §111(b).TECHNICAL FIELD [0002] The present invention relates generally to oxygen scavenging (i.e., targeting and reduction / elimination) for oxygen sensitive products, more particularly to a composition, system, and attendant methodology for removing oxygen from stored oxygen sensitive products such as food, pharmaceuticals, etc. BACKGROUND OF INVENTION [0003] The quality and character of products, whether they be consumables, intermediates, etc., remain of utmost importance. Furthermore, it is well known that freshness and shelf life can be key or determinative considerations in one's selection calculus. Although degradation is a natural phenomenon and can in fact be desirable, it more often than not is a condition sought to be controlled, more particularly elimi...

AI Technical Summary

Benefits of technology

[0011] The subject oxygen scavenging system is generally directed to the elimination of oxygen from packaged oxygen sensitive products where moisture is present of may become present. An oxygen scavenging composition of the subject invention includes an enzyme system (e.g., an oxidoreductase enzyme), a suitable energy source for the enzyme system, and a buffer. The composition, which enhances the shelf-life of a packaged product, is suitable for direct application to the product of the packaged product with no consumer detectable change in product character. The composition binds oxygen when exposed to moisture, thereby reducing the level of oxygen in a closed (e.g., sealed) space such as a food package or the like. The system of the subject invention contemplates the scavenging composition in combination with a discrete water permeable “housing” within which the composition is contained, or as an integral element or component of a perishable storage container or the like. More specific features and advantages will become apparent with reference to the DETAILED DESCRIPTION OF THE INVENTION, and appended claims.

Problems solved by technology

Oxygen is known to cause oxidative damage to many products, particularly, but not limited too, fats and oils.

Removal of oxygen from packages of products where gas is trapped within the product (e.g. bread or pasta) is especially difficult.

Furthermore, most packaging materials are not impervious to oxygen penetration (i.e., package ingress: over time, oxygen leaks through the packaging material, and into the package).

However, BHA is regarded as moderately toxic by ingestion, and even though BHT is considered to have low toxicity, the use in foods of either of these compounds is limited.

Drawbacks associated with such approach have included, but are not limited to, careful sealed storage of the sealed package so as to prevent activation upon exposure to oxygen, the expense of such system, and the fact that iron oxide creates heat as it binds oxygen, a less than desirable outcome.

Peroxide may have detrimental effects on the product in the package and its presence may limit the further binding of oxygen by the glucose oxidase.

This works acceptably in many systems where the glucose oxidase / catalase mixture is spread over a surface, and the packaged product acts as a pH buffer, maintaining an acceptable pH range where the oxygen binding reaction proceeds, however, efforts to use such enzymatic formulations in a dispersed or contained form on iron rich products have been unsuccessful because of discoloration of the product.

It is believed that the lack of success with such enzymatic formulations is most likely due to the oxygen binding reaction being self-limited by the change in pH within the bag or sachet (see generally Enzyme Technology, Chaplin & Bucke, Cambridge University Press, 1990).

Thus, in combination, the variability of the charges with pH (i.e., the charges being a function of pH) affect the activity, structural stability and solubility of the enzyme, and have thus been limitations upon this form of oxygen scavenging system.

Although the use of a buffer to stabilize a liquid glucose oxidase system during storage is described in European patent EP0418940, it does not address oxygen removal or buffering of the system during enzyme activity.

Be this as it may, there are practical limitations on the amount of glucose oxidase that can be applied to food wrappers / containers utilizing heretofore known techniques.