Stabilized heme group from blood as an ingredient for meat products

Research output: Book/ReportPh.D. thesisResearch

  • Sorivan Chhem Kieth
Blood is a by-product generated in great quantities by the meat industry, making blood derivatives an important part of a sound strategy for an optimized usage of animal products. Currently, whole blood is a low-value sidestream product, and is commonly fractionated in different parts with specific functional qualities. Through successive separation steps, a hemeenriched extract can be obtained. This part presents a good potential to be used as a natural red colorant for meat products. The objective of this PhD project was to develop a heme-based red pigment using compounds alternative to nitrite, which is commonly used to stabilize the desirable red color of cured meat products. However, due to its role in the formation of potentially carcinogenic compounds, the usage of nitrite is controversial, and there is a great interest in finding viable substitutes. Six compounds (methyl nicotinate, 4-methylimidazole, pyrazine, pyrrolidine, piperidine, ligand X) amongst a larger group of ligand candidates showed promising results in terms of color intensity and stability. Further experiments demonstrated the optimal concentration at which the different ligands could be added to heme to cause a durable red hue, and results were shown as a predictive model using spectroscopic absorbance measurements in the visible range. The following step was to produce technically viable products. Four ligand candidates (methyl nicotinate, 4-methylimidazole, pyrazine, ligand X) were produced as encapsulated, sprayed-dried pigments, and subsequently tested for their color integrity in long-term storage conditions, as well as for their resistance to increased temperatures in cooking conditions. The produced pigments were added to emulsion sausages to test their impact on an actual meat product. Those experiments led to selection of three colorant products (methyl nicotinate, 4-methylimidazole, ligand X) to be added in fermented-type sausages.T
The color development was assessed during a 4-month period trial and if no improvement of the red color could be observed when compared to a blank sample, neither could a visible darkening of the product. At the conclusion of this project, several viable nitrite alternatives could be identified, and their affinity with heme-enriched extract obtained from animal blood by-products could be determined. Some promising heme-based pigments could be produced. However, no conclusive data could be drawn from the final experimentation on processed meat products. Prior to industrial-scale production, a review of the legislative implications concerning the development of a food colorant containing novel additive is required.
Original languageEnglish
PublisherDepartment of Food Science, Faculty of Science, University of Copenhagen
Publication statusPublished - 2018

ID: 201302186