Sobrevivência da levedura probiótica Komagataella phaffii cepa X-33 livre e microencapsulada aplicada em uma matriz alimentar não láctea

Abstract

Yeasts have been considered important probiotics in the human and animal microbiome, and some studies have demonstrated their probiotic potential in non-dairy food matrices. The demand for non-dairy-based products has increased in recent years, offering an option for people with intolerance and/or allergies to dairy components, as well as those who, by choice, do not consume animal-based products. The yeast Komagataella phaffii (K. phaffii, previously described as Pichia pastoris) has been shown to have probiotic effects by some researchers, promoting benefits such as growth stimulation, immunity enhancement, and addressing potential nutritional deficiencies in animals. This study aimed to evaluate the survival of free and microencapsulated K. phaffii strain X-33 during passage through a simulated gastrointestinal tract, storage at different temperatures, and resistance to heat treatment, as well as when applied to a non-dairy food matrix during refrigerated storage. For this, K. phaffii and S. boulardii yeasts were cultivated in a bioreactor in YPD medium with sucrose and then added to encapsulating materials, inulin, and rice protein. The microcapsules produced by spray drying showed viability for K. phaffii of 11,1 log CFU.g-1 and 11,0 log CFU.g-1 for S. boulardii, with an encapsulation efficiency of 95,7% for both yeasts. Viable cells of free and microencapsulated yeasts remained stable for 60 days of storage (> 8.0 log CFU.g-1) at different temperatures analyzed (-20°C, 4°C, and 25°C), but the microcapsules with S. boulardii were no longer viable after 60 days, and the free forms of both yeasts showed higher survival rates. The free forms of K. phaffii and S. boulardii also showed higher survival rates under gastrointestinal conditions compared to the microcapsules, and even after passing through gastric conditions, with viable cell concentrations higher than under intestinal conditions, the free yeasts survived at concentrations above 10 log CFU.g-1 under intestinal conditions. In the heat resistance evaluation, microencapsulation protected only S. boulardii, and free K. phaffii had significantly greater survival than microencapsulated yeasts, while free S. boulardii did not survive. The yeasts showed potential for application in food, as free K. phaffii maintained an adequate survival rate up to 28 days (9.8 log CFU.g−1) in cashew milk, as did S. boulardii. Thus, it can be understood that free K. phaffii showed higher survival rates than S. boulardii and its encapsulated forms, maintaining concentrations above 6 log CFU.g−1, showing potential for the development of a non-dairy probiotic or functional product, regardless of microencapsulation. Further studies can be conducted on the application of K. phaffii in foods and microencapsulation.