Functional properties of probiotic strained yoghurt enriched with phenol-rich pennyroyal powder

The current investigation aimed to improve the functional properties of probiotic yoghurt containing ۰.۱ g/L of B. bifidum, via enrichment with polyphenols extracted from pennyroyal. The polyphenols extracted from the pennyroyal plant were applied as free (FPP) and encapsulated using polymeric whey protein (EPP). The prepared FPP and EPP were incorporated into strained probiotic yoghurts at different concentrations (۰.۰۴ and ۰.۰۸ wt%). Additionally, the effect of freeze-drying (FD) and storage for ۱۵ days on the yoghurts' properties was also examined. Non-FD and FD yoghurt samples were subjected to physicochemical, nutritional, microbiological, textural, rheological, colorimetric, and sensory properties on days ۱ and ۱۵ of refrigerated storage. Yoghurts fortified by FPP had higher acidity (۰.۹۵%), on the other hand, samples containing EPP had larger total solid content (۲۸.۶۶±۰.۵۶-۳۱.۶۷±۰.۶۱%) and showed better water holding capacity, hardness, and viscosity. Furthermore, the viability of probiotic bacteria (۶.۹۳ log CFU/G), and sensory perception in yoghurt enriched with EPP were significantly (P<۰.۰۵) larger than in yoghurts enriched with FPP. The FD-samples obtained a lower sensory score by evaluators. Additionally, the acidity, syneresis, hardness, cohesiveness, viscosity, and general acceptance of polyphenols-enriched probiotic yoghurt gradually elevated during the refrigerated storage. These results proved that fortifying probiotic yoghurts with ۰.۰۸% EPP yielded the highest probiotic retention and sensory perception after ۱۵ days of refrigerated storage. As the first study, the inclusion of polyphenol-rich pennyroyal in yoghurt formulation, as a health-promoting ingredient, domestically or at the laboratory scale can offer a great horizon for implementing novel functional ingredients in formulating probiotic yoghurt.

کلیدواژه ها:

Functional yoghurt ، Probiotics ، Polyphenols of pennyroyal ، Encapsulation ، Freeze drying