Antioxidant Properties

A major preventive measure of lipid oxidation is the use of synthetic or natural antioxidants that function either by scavenging chain-carrying peroxyl radicals or by diminishing the formation of initiating lipid radicals. Synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) have long been used to control oxidation of lipids and vitamins in the feed, but recent concern over their use has created a need and prompted research for alternative antioxidants.

In the last few years, a range of naturally occurring antioxidants including extracts of herbs and spices have been studied for their potential to protect lipids and vitamins in feed from the process of peroxidation. Herbs of the Labiatae family were found to exhibit substantial antioxidant activity and might be useful in animal diets.

According to Joseph Mercola, who reported his findings in the Journal of Agricultural and Food Chemistry in November 2001, the herbs with the highest antioxidant activity belonged to those from the Labiatae family, and these have three to 20 times higher antioxidant activity than all the other herbs studied.

On a per-gram fresh weight basis, they ranked even higher in antioxidant activity than fruits and vegetables, which are known to be high in antioxidants. In comparison to the antioxidant activities of a few select fruits and vegetables, this particular herb has 42 times more antioxidant activity than apples, 30 times more than potatoes, 12 times more than oranges and four times more than blueberries. The antioxidant properties of Orego-Stim® are due to its phenolic compounds, carvacrol and thymol. Carvacrol and thymol are bioflavonoids that act as powerful antioxidants, which help to combat free radical damage and help prevent the process of peroxidation. So Orego-Stim helps protect the lipids and vitamins such as A, D and E in the feed.

The ability of Orego-Stim to replace synthetic antioxidants can be observed and self-experimented in feed mills. If the feed mills could measure the level of vitamins in the final feed with and without the inclusion of Orego-Stim, they would be able to see a difference. Based on this difference, the levels of synthetic antioxidants such as BHT and BHA used in the feed could be reduced by using Orego-Stim. Orego-Stim also helps reduce spoilage in the long-term storage of feed.

Antifungal Properties

Essential oils derived from various plants are known to possess antifungal activities (Thompson, 1989). The antifungal properties of essential oils from medicinal as well as other edible plants have been recognized since ancient times (Hitokoto et al., 1980; Beuchat&& Golden, 1989; Farag et al., 1989b; Zambonelli et al., 1996; Adam et al., 1997; Daferera et al., 2000). One of such essential oils possesses a broad spectrum of antifungal activities attributed to the high content of its phenolic derivatives, carvacrol and thymol (Knobloch et al., 1989; Laredo et al., 1995; Leung et al., 1996). Earlier studies have demonstrated its ability to retard and inhibit the growth of various food spoiling organisms including the species of Aspergillus, which is a type of mycotoxicogenic filamentous fungi and Hansenula, which are industrial yeasts (Tantaoui-Elaraki et al., 1994; Lis-Balchin & Deans, 1997; Barrata et al., 1998a; Barrata et al., 1998b).

In a study conducted by Stiles et al. (1995), its antifungal properties were examined against three different strains of the yeast, Candida albicans, using agar diffusion and serial broth methods. The minimum inhibitory concentration (MIC) was found to be at less than 0.2µg per ml against each of the Candida strains studied. Manohar et al. in 2001 have shown that it effectively inhibits the in vitro growth of C. albicans by directly inhibit its germination and pseudomycelial phase. Sokovic et al. have demonstrated that the high percentage of carvacrol in the essential oil contributes to its high antifungal affinity. It was postulated that carvacrol may interfere with some cell wall enzymes like chitin synthase or chitinase as well as α- and β-glucanases of the fungus (Adams et al., 1996).

Various studies have demonstrated its anti-aflatoxicogenic properties on the mycotoxin-producers Aspergillus species (Farag et al., 1989b; Karapinar, 1990; Mahmoud, 1994), and also in the biosynthesis of ochratoxin A (Basilico & Basilico, 1999), but the understanding of the modulatory actions of such essential oil on the mycotoxins production is still underway. However, many reports showed a direct relationship between inhibitory effects of essential oils on fungal growth and toxin formation (Karapinar, 1990; Mahmoud, 1994; Velluti et al., 2003)

The essential oils mentioned are contained within Orego-Stim. Orego-Stim possesses a broad spectrum of antifungal activities attributed to the high content of its phenolic derivatives, carvacrol and thymol. In a study conducted by Stiles et al in 1995, its antifungal properties were examined against three different strains of the yeast Candida albicans using agar diffusion and serial broth methods. The minimum inhibitory concentration (MIC) was found to be at less than 0.2µg per ml against each of the Candida strains studied. In a separate study, the MIC of Orego-Stim was tested against Candida albicans (strain reference R3251) at the Veterinary Laboratories Agency (VLA) in the United Kingdom, and it was found to be only 0.195µg per ml.

Orego-Stim kills or inhibits the growth of virtually any fungus. It is known that Orego-Stim acts as a mould inhibitor at inclusion rates as low as 40g per tonne. Therefore, when Orego-Stim is used at recommended inclusion rates, there would be mould inhibiting properties in the feed. However, Orego-Stim should not be mistaken as a toxin binder, as it cannot bind to toxins. There will always be a need for toxin binders once the toxins are produced by fungus which grows in the grain.

June 2011