In part one of this series, it was explained that a bright-colored egg or a well-pigmented chicken always comes from a healthy bird. It was also explained that the pigmentation depends on several factors but that a key one is the source and feed stability of the carotenoids used for the process. Carotenoids by nature are susceptible to degradation by light, heat, humidity and oxidative agents. Storage, milling, premixing, feed processing and feed storage present multiple opportunities to reduce the number of active particles per gram of final product. Technology has therefore been developed to protect them throughout the entire feed manufacturing process.
DSM uses a beadlet technology containing apo-ester in a corn-starch-coated matrix of lignosulfonate. Butylated hydroxytoluene (BHT) is added as an antioxidant. The aim is to have the best-performing and most stable yellow carotenoid in the animal nutrition market. In order to verify the process, DSM’s Nutrition Innovation Center in Kaiseraugst, Switzerland, carried out an experiment involving the most important brands of yellow carotenoids. Samples were received from different markets, analyzed for initial content verification, and stored at 4 °C until they were ready to be tested. They were then subjected to three different processes in order to evaluate their stability across the whole feed production cycle.
1. Stability As-Is:
Samples were stored at 30 °C with 65% relative humidity (rH) in polyethylene (PE) pouches, and the apo-ester content was measured after 0, 1, 3 and 6 months.
2. Stability in premix:
Samples were incorporated in a vitamin/mineral premix containing 3.8% of choline chloride and 2.5% of trace minerals. After incorporation, the samples were stored at 25°C with 60% rH, and the apo-ester content was evaluated after 1, 3 and 6 months of storage.
3. Stability in feed:
Feed containing 64% wheat and 28% soybean meal was prepared at the feed mill of the Nutrition Research Center in Village-Neuf, France. After mixing, it was processed at 90°C and stored in polyethylene (PE) bags at an ambient temperature (20–25°C, with 30–60% rH). The apo-ester content was measured in feed samples after 0, 1 and 3 months. Feed was analyzed either in mash or pelleted form.
After the three processes were completed a calculation of total stability was performed, considering Carophyll® yellow 10% as the standard. Analysis was performed in duplicate at DSM’s Analytical Research Center in Kaiseraugst, Switzerland
Initial content and participant products are presented in Table 1. A total of four different samples were analyzed from three different producers of apo-ester. All samples were above the declared levels. Differences in initial content can be attributed to time after production, packaging, formulation, storage conditions and coating technology. All products are showing a satisfactory apo-ester content, which is one of the main characteristics that is reviewed by feed companies across the world. Graph 1 shows the results of the recovery trial for the product As Is.
Differences in the degradation rate of the carotenoid across different products are a direct consequence of different formulation technologies – packaging, storage conditions and timing all being equal. In this particular data set, the initial content differed across the four different samples. However, similar content was found after 1, 3 and 6 months of storage. Under these conditions, all the sources of apo-ester lost more than 30% of their initial content, highlighting the need to keep all the products at the recommended room temperatures and as far as possible in the original package so as to avoid carotenoid degradation. In the case of Carophyll® Yellow, it is recommended to keep this product below 15°C, and in the unopened original container. Once opened, the contents should be used quickly.