Oxidation Destruction Begins During Ingredient Manufacturing

Oxidation Destruction Begins During Ingredient Manufacturing PowerPoint PPT Presentation


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Understanding Oxidation. Oxidation is an irreversible reaction of oxygen with fats and vitamins that leads to their destructionFats: reduction in energyVitamins: degradationPrimary and secondary oxidation products can harm the animal and impact performanceReduction in feed intake Reduction in

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Oxidation Destruction Begins During Ingredient Manufacturing

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1. Oxidation Destruction Begins During Ingredient Manufacturing The oxidative destruction of dietary nutrients begins during ingredient manufacturing and continues until absorption occurs in the digestive tract of an animal. Therefore an effective antioxidant plays an essential role in any feed quality program to help stop the oxidation process as soon as possible..The oxidative destruction of dietary nutrients begins during ingredient manufacturing and continues until absorption occurs in the digestive tract of an animal. Therefore an effective antioxidant plays an essential role in any feed quality program to help stop the oxidation process as soon as possible..

2. Understanding Oxidation Oxidation is an irreversible reaction of oxygen with fats and vitamins that leads to their destruction Fats: reduction in energy Vitamins: degradation Primary and secondary oxidation products can harm the animal and impact performance Reduction in feed intake Reduction in BW and feed efficiency

3. Chemical Representation Here we have a chemical representation of oxidation. The symbol R-H represents a fatty acid molecule. The hydrogen atom of the fatty acid breaks off to form a free radical. Heat, light and metals accelerate this process. The free radical will then combine with oxygen to form a peroxyl radical, which will return to attack the fatty acid to yield a hydroperoxide. In addition to the hydroperoxide, the reaction regenerates the initial free radical. The hydroperoxide is the source of the problems in oxidation because it can break at the oxygen-oxygen bond to produce two free radicals, both with enough energy to attack the fatty acid. This process began with one free radical, which was regenerated. In addition, two more free radicals were formed. These two free radicals can then attack the starting material, and cause the generation of more free radicals and hydroperoxides. This step causes the oxidation process to accelerate very rapidly. So stopping the oxidation process early, through proper antioxidants use, makes a huge difference in the quality of finished feed and rendered products.Here we have a chemical representation of oxidation. The symbol R-H represents a fatty acid molecule. The hydrogen atom of the fatty acid breaks off to form a free radical. Heat, light and metals accelerate this process. The free radical will then combine with oxygen to form a peroxyl radical, which will return to attack the fatty acid to yield a hydroperoxide. In addition to the hydroperoxide, the reaction regenerates the initial free radical. The hydroperoxide is the source of the problems in oxidation because it can break at the oxygen-oxygen bond to produce two free radicals, both with enough energy to attack the fatty acid. This process began with one free radical, which was regenerated. In addition, two more free radicals were formed. These two free radicals can then attack the starting material, and cause the generation of more free radicals and hydroperoxides. This step causes the oxidation process to accelerate very rapidly. So stopping the oxidation process early, through proper antioxidants use, makes a huge difference in the quality of finished feed and rendered products.

5. Antioxidants How does an antioxidant work? Antioxidants stabilize free radicals by donating a hydrogen R* + H-N R-H + * R* + H-O R-H + * AO distributes the absorbed chemical energy throughout its large structure Energy sink Let’s start talking about antioxidants and how they work. In general, antioxidants stabilize free radicals by donating a hydrogen to them. A representation of this reaction is shown here. This example uses two antioxidant types. Antioxidants with nitrogen, like Santoquin and antioxidants with oxygen like BHT. The free radical is stabilized after receiving the hydrogen from the antioxidant. The resulting antioxidant radical is not reactive because it can distribute the absorbed chemical energy throughout its large structure. This process is known as energy sink. Let’s start talking about antioxidants and how they work. In general, antioxidants stabilize free radicals by donating a hydrogen to them. A representation of this reaction is shown here. This example uses two antioxidant types. Antioxidants with nitrogen, like Santoquin and antioxidants with oxygen like BHT. The free radical is stabilized after receiving the hydrogen from the antioxidant. The resulting antioxidant radical is not reactive because it can distribute the absorbed chemical energy throughout its large structure. This process is known as energy sink.

6. Antioxidants Several AO are commercially available: Ethoxyquin Final feeds and rendered products (fats and meals) BHT (butylated hydroxytoluene) Final feeds and rendered products (fats and meals) BHA (butylated hydroxyanisole) As a blend in final feeds and rendered products TBHQ (tert-butylhydroquinone) As a blend in final feed and rendered products Blends (EQ, BHA, BHT, TBHQ, Acids) Ex. = Endox, Oxistat, Oxicheck

7. How Do We Measure Ingredient Quality And Oxidative Stability?

8. Standard Oxidation Test Methods Four methods commonly used: Initial Peroxide Method (PV) Active Oxygen Method (AOM, 20 hr) Oxidative Stability Index (OSI) Rancimat

9. Initial Peroxide Method (PV) Measures concentration of hydroperoxides at a single point in time Downside of this analysis: Analysis does not tell if peroxide level is in the formation or termination phase of the oxidative reaction

10. Understanding Oxidation The graph on this slide illustrates the three phases of oxidation. Note that in the Initiation phase, peroxide levels grow very rapidly because formation is much faster than degradation. The plateau represents the Equilibrium, where peroxide formation and degradation occur at the same rate. In the Termination phase, peroxides will either polymerize or decompose into secondary products at a rate higher than formation. Understanding these three phases of oxidation is key for the proper interpretation of oxidation test analysis.The graph on this slide illustrates the three phases of oxidation. Note that in the Initiation phase, peroxide levels grow very rapidly because formation is much faster than degradation. The plateau represents the Equilibrium, where peroxide formation and degradation occur at the same rate. In the Termination phase, peroxides will either polymerize or decompose into secondary products at a rate higher than formation. Understanding these three phases of oxidation is key for the proper interpretation of oxidation test analysis.

11. Active Oxygen Method (AOM) Measures concentration of peroxides over time Accelerated stress test Air is bubbled through at 98 C Peroxide Values are measured at several time points Initial, 4, and 20 h IPV Fats with less than 20 meq/kg peroxides at 20 h are considered stable

12. Active Oxygen Method

13. Modified Active Oxygen Method Measures the number of hours it takes to reach 20 meq peroxides/kg fat The greater the number of hours it takes to get to 20 meq/kg fat the better the oxidative stability of the fat or the antioxidant

14. Oxidative Stability Index (OSI) Measures the “induction” time or time it takes until the production of stable tertiary oxidation by-products Volatile fatty acids Accelerated stress test Fat is saturated with air at elevated temperatures (110 C, air flow rate 2.5 ml/sec) Automated analysis Downside of this analysis: No industry standards exist to define a stable fat

15. Oxidative Stability Index

17. Rancimat Accelerated stress test Fat is saturated with air at elevated temperatures (110 C, air flow rate 5.6 ml/sec) Measures stable tertiary oxidative by-products Downside of this analysis: No industry standards exist

18. Need To Understand…………. Stability Test NOT all TEST’s are created equal Sensitivity Reproducibility Effects of time Initial conditions of the fat This goes for ANTIOXIDANTS as well!

19. Objective To determine if the effectiveness of five different antioxidants currently available on the Australian and New Zealand market are equal in their ability to stabilize two fat sources using four stability measurements (PV, AOM, OSI, Rancimat).

20. Materials and Methods Five antioxidants were chosen for comparison Santoquin, BHT, Endox, Oxistat and Oxicheck Each antioxidant was tested according to the manufacturers recommended usage rate for poultry fat and tallow Four stability measurements were run on each antioxidant Peroxide Value Method (PV), Oxidative Stability Index (OSI), Rancimat and the Active Oxygen Method (AOM)

21. Materials and Methods PV, AOM, Rancimat analysis were run at the analytical laboratories of Novus International, Inc. OSI conducted at an outside contract lab. Duplicate analysis were run only on the Rancimat data with statistical analysis done using the GLM procedure of SAS.

22. Results

23. Initial Peroxide Method (PV)

24. 20 h Active Oxygen Method (AOM)

25. Modified Active Oxygen Method

26. Rancimat “Induction Time”

27. Oil Stability Index “Induction Time”

28. OSI vs Rancimat “ time it takes until the production of tertiary oxidative by-products”

29. Summary Poultry fat and tallow had low IPV’s indicating “good initial fat quality” All methodologies used to determine the relative effectiveness of the five antioxidants resulted in similar ranking of products for both poultry fat and tallow. Rankings were similar despite the different “end products” being tested.

30. Summary Product E performed the best regardless of the methodology used. The control, with no added antioxidant, performed the worst, regardless of methodology used!

31. Conclusion The methodologies used to determine the effectiveness of the commercially available antioxidants demonstrate that these products differ in their ability to stabilize different fat sources.

32. Antioxidants THE BEST WAY TO PREVENT OXIDATION Add antioxidants as early as possible! Antioxidants are oxidized before the fats The oxidized antioxidants are stable

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