Lactic acid bacteria, potentially probiotic, in whole-grain pet biscuits: survival and technological potential of millet-based formulations (Pennisetum glaucum)

Abstract The relationship between humans and pets has driven the development of functional foods. This study aimed to develop pet biscuits containing Lacticaseibacillus paracasei GV17 and Lactococcus lactis GV103 and to evaluate the effects of wheat flour, millet flour, and a combination of both on the stability of lactic acid bacteria (LAB), resistance to simulated gastrointestinal tract (GIT) conditions, technological characteristics, and viability during storage. Three formulations were prepared using wheat flour (WF), millet flour (MF), and a mixture of flours (WMF), in which the GV17 and GV103 strains, as well as their combined culture (GV17.103), were incorporated into the biscuit cavities. The type of flour significantly influenced the physicochemical and technological characteristics of the formulations. A higher luminosity value was observed in the WF formulation (76.31), while the WMF showed greater hardness (46.18 N), indicating greater resistance to breakage. The MF presented higher lipid (24.80%) and fiber (5.76%) contents, WMF higher moisture (12.49%), and WF higher carbohydrate (55.95%). All formulations recover LAB counts to values above 7.0 log CFU/mL at the end of simulated digestion. WF103, MF103, and MF17.103 stood out for their storage stability. These results demonstrate that the tested matrices are suitable for the development of pet biscuits containing potentially probiotic LAB strains.