Physicochemical, textural properties, and lactic acid bacteria counts of Peruvian fresh cheese with added probiotic cultures

Abstract The present study aims to evaluate the impact of incorporating commercial probiotic lactic acid bacteria cultures on the physicochemical and textural characteristics of fresh cheese, as well as their viability. The probiotic strains Lactobacillus acidophilus and Lacticaseibacillus rhamnosus were assessed at two different incorporation times — before the renneting and salting stages — using a factorial treatment design. Over a refrigerated storage period of 21 days (4 °C to 5 °C), the total lactic acid bacteria count, acidity, pH, and syneresis were monitored at intervals of 0, 1, 7, 14, and 21 days. Texture profile analysis was conducted at the 21-day mark to assess instrumental texture parameters of the cheese treatments. After the storage period, fresh cheeses supplemented with L. rhamnosus added before the renneting process exhibited similar acidity values (0.18% lactic acid), pH (5.36), and percentage of syneresis (4.71%), when compared to the control cheeses without probiotics. Except for the adhesiveness, no significant differences were observed regarding the texture profile parameters of the evaluated cheeses. Furthermore, the fresh cheese supplemented with L. rhamnosus added before renneting maintained a microorganism count exceeding 6 logarithmic cycles per gram throughout the storage period. The findings of this study suggest that Peruvian fresh cheese presents a promising matrix for delivering probiotic microorganisms, particularly the L. rhamnosus.