Spray-dried porcine blood as nutritional and functional ingredient: stabilization strategies, characterization and application in bologna-type sausages

Abstract

Porcine blood is a by-product with high nutritional and technological potential, but its use as a food ingredient is limited by the susceptibility of heme proteins to oxidation and color changes during processing and storage. This study aimed to evaluate the effects of pretreatment of porcine blood with sodium nitrite and S-nitroso-N-acetylcysteine (NAC-SNO), prior to spray drying, on the characteristics and stability of the resulting blood powder and its application as an ingredient in a meat product. Initially, different pretreatment conditions were evaluated, and those resulting in greater nitrosyl pigment formation were selected. Untreated blood and blood pretreated with sodium nitrite or NAC-SNO were spray-dried and characterized regarding their physicochemical, nutritional, and technological properties, pigment formation, and oxidative and color stability during storage. Subsequently, the resulting powders were incorporated into bologna-type sausages as partial or total replacements for soy protein isolate, and their technological, nutritional, and physicochemical properties, as well as their stability during refrigerated storage, were evaluated. The blood powders had a protein content above 85%, and the pretreatments increased nitrosyl pigment formation (P < 0.05), increasing its conversion from 0.29% in the control to 39.50% and 46.93% in the sodium nitrite and NAC-SNO treatments, respectively. NAC-SNO showed greater preservation of sulfhydryl groups, Snitrosothiols, and nitrosyl pigments during storage, particularly in the absence of light (P < 0.05). In the application in bologna-type sausages, replacement of soy protein isolate with blood powder did not compromise emulsion stability or texture properties and increased the iron content of the products (P < 0.05). Pretreatment with sodium nitrite and NAC-SNO reduced lipid oxidation compared with untreated blood (P < 0.05), without affecting residual nitrite content or microbiological stability. Thus, pretreatment of porcine blood prior to spray drying altered the properties of the ingredient and enabled its application as a source of protein and iron in bologna-type sausages, contributing to the utilization of porcine blood as a by-product of the meat industry.