Effect of replacing sodium nitrite by nanocapsules carrying astaxanthin from Haematococcus pluvialis in common sausage formulation on the growth and proliferation of pathogenic and spoilage microorganisms

The purpose of present study was to use nanocapsules carrying astaxanthin pigment in common sausage formulation as a substitute for sodium nitrite and search for pathogenic and spoilage microorganisms in the product. For this purpose, after extracting astaxanthin from Haematococcus pluvialis microalgae and producing nanocapsules carrying pigment with maltodextrin-sodium caseinate combined coating, five treatments using different proportions of sodium nitrite and nanocapsules carrying astaxanthin along with control were designed and evaluated in term of the presence of Clostridium perfringens, Staphylococcus aureus, coliform, salmonella, Escherichia coli, Clostridium botulinum, lacticacid bacteria bacteria, yeasts and molds during 28 days of storage at refrigerator temperature. The results showed that in the treatment with the permissible limit of sodium nitrite or 120 mg/kg (treatment A) and also the treatments that this limit was replaced by 30 mg/kg (treatment C) and 60 mg/kg (treatment D) of nanocapsules carrying astaxanthin, the counts of Clostridium perfringens, Staphylococcus aureus, and coliform bacteria were within the standard limit and recorded less than 10 cfu/gr. In treatments containing only 120 mg/kg nanocapsules carrying astaxanthin and also containing 30 mg/kg sodium nitrite and 90 mg/kg nanocapsules carrying astaxanthin (treatment E), only on day 28, the counts of three mentioned bacteria were more than 10 CFU/gr. Further, it was found that none of the research treatments contain Salmonella, Escherichia coli and Clostridium botulinum bacteria. Also, all five formulated treatments were within the standard range in terms of lactic acid bacteria during storage time. The results of counting molds and yeasts showed that this treatments, unlike the control sample, did not have any mold and yeast colonies in the whole of storage period. According to the findings of this research if 50% of permissible sodium nitrite limit using nanocapsules carrying astaxanthin is replaced, it is possible to produce a product free of health-threatening microorganisms.