Effects of carrot incorporation and high hydrostatic pressure processing on fresh cheese: Antilisterial activity, carotenoid degradation, and sensory characteristics.

Abstract

This study was carried out to evaluate the antilisterial activity of carrot, and the impact of its incorporation on the carotenoid content in Minas Frescal cheese, combined or not with high hydrostatic pressure processing, as an alternative for the development of healthier fresh cheese free of synthetic preservatives. Cheeses were manufactured with milk added with carrot incorporation (0, 3, and 6%) and pressurized (0; 250 and 500 MPa/10 min). Total carotenoid content, α-carotene, β-carotene, lutein, consumer acceptance, and sensory characteristics were determined one day after the manufacture while Listeria innocua enumeration was evaluated up to 22 days of storage at 8 ℃. The results showed that although a decrease of over 7 log CFU g-1 in L. innocua counts was observed immediately after fresh cheese processing at 500 MPa/10 min, inactivation was not complete, as the growth of this nonpathogen surrogate during storage was observed. The addition of 6% carrot had a slight bacteriostatic effect, verified on the 15th day of storage, particularly in pressurized cheeses. On the other hand, high pressure treatment at 500 MPa/10 min increased carotenoids degradation in cheeses. Although pressurized cheeses were characterized as "rubbery," high hydrostatic pressure had no significant effect on consumer acceptance.