Produção e caracterização de iogurte incorporado com Spirulina sp

Abstract

Yogurt is an ancient, fermented drink, which dates to prehistoric times, illustrating the possibility of producing the drink using low budgets and few technologies. Despite this, the food industry is increasingly seeking techniques to optimize processes and the nutritional qualities of food, as the consumer market becomes constantly more demanding. Linked to this, we can see an evolution in the consumption of functional foods, that is, those with high nutritional content. In this sense, the present work aims to produce a yogurt incorporated with cyanobacterium of the genus Spirulina, evaluating its fermentation kinetics and the final proximate composition of the fermented product. To this end, pasteurized whole milk was fermented with different concentrations of cyanobacteria (Spirulina platensis) between 0.5-4% (w/v) with commercial lactic yeast (sufficient concentration to obtain an initial concentration of 104-105 CFU /mL). Fermentation occurred at 40ºC for 5h (part in which the kinetics were directly evaluated), being cooled to 4ºC for 28 days for stabilization and proximate (or physical-chemical) characterization of the final product in terms of moisture, ash, proteins, lipids and carbohydrates. During the fermentation process it was noticed that a higher concentration of algal biomass resulted in a lower growth of lactic acid bacteria, going from 1.108(0.5% Spirulina) to 3.107 (4% Spirulina) CFU/mL. However, there was an equivalent consumption of sugar (except for the yogurt incorporated with 0.5% Spirulina, which consumed more sugar than the others), as well as acid production, obtaining a final acidity between 1.9-2.2%. In relation to the proximate composition, the protein, lipid, and ash contents increased proportionally with the incorporation of Spirulina, going from 4.12 ± 0.19 to 5.49 ± 0.22, 8.42 ± 0.05 to 8. 89 ± 0.02 and 0.77 ± 0.01 to 0.97 ± 0.01, respectively, varying the incorporation from 0.5% to 4% of Spirulina. It was noticed that it was possible to obtain a product with characteristic acidity with good development of lactic acid bacteria, despite their growth decreasing with the increase in the incorporation of Spirulina biomass. Furthermore, there was a greater increase in proteins and ash in the final product, mainly. However, it is known that there are still many studies to be carried out before a commercial product can be developed, such as rheological and sensorial studies.