Utjecaj autolize bakterija mliječno-kiselog vrenja na senzorske značajke fermentiranih namirnica

Lactic acid bacteria autolysis is due to intracellular hydrolytic enzymes that act on specific parts of the cell wall causing the release of biologically active compounds, in particular enzymes, to the medium. Consequently, the role of lactic acid bacteria in the transformation of foodstuffs does not involve merely the fermentation stage but also the later maturation and aging stage thanks to the compounds released to the medium that combine in order to change the sensorial profile of the product. This phenomenon is particularly important for cheese types subjected to very long aging, for salami ripening and for red aged wines.Autoliza bakterija mliječno-kiselog vrenja nastaje djelovanjem intracelularnih hidrolitičkih enzima koji u reakciji sa specifičnim dijelovima staničnog zida uzrokuju izlazak biološki aktivnih spojeva, osobito enzima, u podlogu. Stoga utjecaj tih bakterija na promjene u namirnicama nije ograničen samo na fermentaciju već i na vrijeme zrenja i starenja zbog spojeva koji su iz stanica ušli u medij, što dovodi do promjena senzorskih značajki proizvoda. Taj je proces posebno važan za vrste sira koje dugo sazrijevaju, za zrenje salame i za proizvodnju odležanih crvenih vina

Whey starter addition during maturation of evening milk: effects on some characteristics of cheese milk and Parmigiano–Reggiano cheese

International audienceAbstractCheese milk “maturation” during natural creaming in large flat vat is a critical step in the production of Parmigiano–Reggiano cheese. Thanks to an improved management, during the last years, a generalized reduction of mesophilic microbial counts has occurred, which did not favour an adequate increase in milk acidity during natural creaming. For this reason, some cheesemakers have introduced the practice to add a rate of natural whey starter in active fermentation in the evening milk to favourize its “maturation”. The aim of this work was to verify the effects of this practice on the characteristics of Parmigiano–Reggiano milk and on some chemical, microbiological and sensory properties of the ripened cheese. Thirty-six cheesemaking trials were carried out in a dairy: 12 with 0.2% of young whey starter addition, 12 with 0.4% and 12 as control. The addition of young whey starter improved the coagulation properties of the cheese milk and did not affect the normal succession of thermophilic and mesophilic lactic acid bacteria during the cheese ripening. The chemical composition of the ripened cheeses was not affected by the practice of whey starter addition. From the sensory point of view, the addition of natural whey starter improved the compliance scores and decreased the defects, as eyes and cracks. This work confirmed the empirical observations of some cheesemakers. The adoption of this technique has considerable technological importance, improving the coagulation properties of the milk and the sensory characteristics of the cheese

Effects of Lactic Acid Bacteria Autolysis on Sensorial Characteristics of Fermented Foods

Lactic acid bacteria autolysis is due to intracellular hydrolytic enzymes that act on specific parts of the cell wall causing the release of biologically active compounds, in particular enzymes, to the medium. Consequently, the role of lactic acid bacteria in the transformation of foodstuffs does not involve merely the fermentation stage but also the later maturation and aging stage thanks to the compounds released to the medium that combine in order to change the sensorial profile of the product. This phenomenon is particularly important for cheese types subjected to very long aging, for salami ripening and for red aged wines

A procedure for the sensory evaluation of Salama da sugo, a typical fermented sausage produced in the Emilia Romagna Region, Italy

BACKGROUND: Salama da sugo is a fermented sausage fromthe Ferrara tradition (Italy, Emilia-Romagna region), subjected to a long ripening period (4–6 months) and characterised by a high content of wine and spices in the mixture. It can be consumed after cooking and it is served with its sugo, i.e. the liquid extracted by cooking process. The aim of this work was to set up a method for the sensory profile of Salama da sugo as a request for Protected Geographical Indication (PGI) has been made to the European Commission. RESULTS: A system of sample preparation that provides for the precooking in an autoclave and cooking in boiling water was set up. A specific sheet for sensory evaluation of Salama da sugo has been created and reports 23 descriptors identified during the lexicon development. The differences in sensory profile of four samples were evaluated and principal component analysis highlighted themore discriminant parameters, i.e. odour intensity, wine odour, spicy aroma, fat/lean connection, sweet, bitter, juiciness, chewiness and pricking. CONCLUSIONS: The proposed method allows the standardisation of sensory profiling of Salama da sugo, and is also to verify compliance with the specification PGI

Detection and identification of yeasts in natural whey starter for Parmigiano Reggiano cheese-making

The yeast populations of natural whey starter (NWS) samples from dairies of PDO Parmigiano Reggiano cheese production area were enumerated and characterised. Yeasts were detected with an average value higher than 3 log cfu mL−1 and in a case study we highlighted the correlation between the yeast growth and incorrect management of NWS fermentation. Isolated strains showed the typical Kluyveromyces marxianus PCR-RFLP pattern and D1/D2 sequences obtained displayed similarity values ranging from 99% to 100% for the same species. RAPD-PCR fingerprinting revealed 14 biotypes. The ability of several strains to grow at 52 °C demonstrates that the yeasts may be perfectly integrated into the ecosystem of NWS. This work confirms that yeasts are part of the NWS secondary microbiota, composed by wild strains with relevant biotechnological interest