Storage and thermal stability of novel heme-based pigments prepared from porcine hemoglobin

The stability of novel meat pigments derived from heme-enriched extract obtained from porcine hemoglobin was assessed. Four different ligands (sodium nitrite, 4-methylimidazole, methyl nicotinate, and pyrazine) were used to produce spray-dried, microencapsulated heme-ligand complexes. The storage and thermal stabilities of the produced pigments were assessed, over a 6-months storage period and across a temperature range of 25-75 degrees C. Color measurements and evaluation were made on the dissolved pigments by ultraviolet-visible absorbance spectroscopy and CIELAB color space. All heme-ligand complexes exhibited a stable red color across the storage period, except for the heme-methyl nicotinate adduct, which color faded to brown after 30days of storage. For thermal stability, only the heme-4-methylimidazole complex did not retain its red color beyond 55 degrees C. The redness of the heme-pyrazine complex showed improvement upon heating, which is proposed to be due to the degradation of polymeric heme-pyrazine structure formed during the ligation process. Practical applicationsDue to the global effort to reduce nitrite addition in food product, there is an important interest to replace it in processed meat products, wholly or in part. Additionally, the perspective of optimizing the usage of an under-utilized blood fraction is attractive for the meat industry. The development of a heme pigment derived from porcine blood thus presents a good commercial potential. Two important aspects of such product would be its stability upon storage, or during heat treatment to levels similar to what is used in processed, cooked meat products. This study presents the behavior for those two aspects of different heme-ligand complexes, and compares the results obtained with a heme pigment produced from the traditionally used nitrite.