Influence of native lactic acid bacteria on the microbiological, biochemical and sensory profiles of Serra da Estrela cheese

Abstract

Cheesemaking from batches of raw ewe's milk was carried out via inoculation with wild strains of Lactococcus lactis subsp. lactis ESB110019 and Lactobacillus plantarum ESB5004 independently, or combined with each other. Those two strains had been isolated from the native microflora of typical Serra da Estrela cheese. One control batch was processed in parallel without addition of any starter. The evolution in viable counts of the main microorganisms (viz. lactic acid bacteria, Enterobacteriaceae, staphylococci and yeasts), as well as in secondary proteolysis (WSN, 2% TCASN, 12% TCASN and 5% PTASN), was monitored throughout ripening time (over a 63-day period) in cheeses from each batch. The sensory features of the fully ripened cheeses were also assessed. Cheeses manufactured with starter showed significantly lower levels of viable Enterobacteriaceae than those manufactured without starter; viable counts of enterococci and staphylococci did significantly increase after addition of L. lactis or Lb. plantarum, respectively. Proteolysis in terms of WSN and 5% PTASN was not significantly affected by the lactic acid bacteria tested when compared to the control, but L. lactis played a significant role toward increasing the 2% TCASN content of cheeses; both strains led to a statistically significant increase of the 12% TCASN. The scores for flavor and texture of the control cheeses were somewhat above those for the experimental cheeses manufactured with starter.

Effect of different salting technologies on the chemical and microbiological characteristics of PDO Pecorino Siciliano cheese

“…In fact, in comparison with other raw ewes' milk cheeses, our data showed higher levels of the unwanted bacteria, especially Enterobacteriaceae. A level in the range 10 5 -10 6 cfu/g is common for this kind of cheeses at around 2-3 months of ripening [36,40,45], but the concentration of Enterbacteriaceae greatly decreases after that period [11,29,38], since their growth is affected by the stressing cheese conditions. Even though pseudomonads, the most frequently psychrotrophic bacteria of raw milk [28], due to their intense proteolytic and lypolytic activities [10] are implicated with spoilage of milk and milk-derivates [44], they are not generally searched in ripened cheeses.…”

“…Several studies have been forwarded to the description of NSLAB communities in Italian raw milk ewes' cheeses [12,14,41,49]. However, some other microbial groups, such as Enterobacteriaceae, have been reported in different Mediterranean cheeses made from ewes' raw milk and subjected to a short time of ripening, [23,36]. The presence of Enterobacteriaceae is supposed to influence the final characteristics of cheese [7].…”

Chestnut and lemon balm based ingredients as natural preserving agents of the nutritional profile in matured “Serra da Estrela” cheese

“…It is only manufactured with raw ewe's milk, salt and milk thistle flower for coagulation, and it is preferentially consumed as a soft cheese, with an average maturation of 1 month, although some consumers prefer to consume it as a hard cheese after at least 6 months of storage. Despite some published studies on the ''Serra da Estrela" cheese, that focus mainly on the microbial flora in the cheese, as well as the changes in some nutrients during ripening (Dahl, Tavaria, & Malcata, 2000;Macedo, Tavares, & Malcata, 2004;Partidário, Barbosa, & Boas, 1998;Tavaria, Franco, Carballo, & Malcata, 2003;Tavaria, Reis, & Malcata, 2006), the present work evaluates the effects of natural additives (chestnut flowers, lemon balm dry material and their decoctions) on the nutritional properties of cheese during its maturation.…”

Identification of lactic acid bacteria isolated from artisanal Coalho cheese produced in the Brazilian Northeast

“…In particular, different organoleptic properties are found in the cheeses produced in the various states of the northeast. Moreover, the use of conventional lactic yeast in the manufacturing of Coalho cheese may cause unwanted alterations of their typical characteristics (Franciosi, Settanni, Cavazza, & Poznanski, 2009;Macedo, Tavares, & Malcata, 2004).…”