0000000000121337
AUTHOR
E. Poznanski
L'aroma del Puzzone
A factory-scale application of secondary adjunct cultures selected from lactin acid becteria during Puzzone di Moena cheese ripening
The lactic acid populations of 2 seasonal Puzzone di Moena cheeses made from winter and summer raw cow's milk were characterized at different ripening times. Lactic acid bacteria (LAB) were isolated on selective media and subjected to genetic typing and identification. The species most frequently found during ripening were Lactobacillus paracasei ssp. paracasei, Lactobacillus plantarum, and Pediococcus pentosaceus. The different strains recognized by random amplification of polymorphic DNA-PCR were characterized for their acidifying and proteolytic activities to select nonstarter LAB to be used as secondary adjunct cultures (SAC). For each of the 3 above species, a strain showing weak acidi…
Mantenere la tipicità in un mondo che cambia
Temperatura e modalità di conferimento del latte al caseificio: effetti sulla tecnologia di lavorazione
La tecnologia di lavorazione del Grana Trentino che prevede la raccolta doppia giornaliera del latte è stata messa a confronto con un’altra che prevede la conservazione a bassa temperatura, in stalla, del latte munto la mattina, e la sua unione con il latte munto alla sera. Il conferimento al caseificio del latte di un’intera giornata avviene una sola volta, la sera. Si sono impostate due temperature di conservazione del latte in stalla, 8°C e 12°C, per il sistema di raccolta unica, che è stato messo a confronto con il latte conferito due volte al giorno, che è stato conservato a 18 °C (il cosiddetto “raffrescato”), o trasportato senza refrigerazione in bidoni da 50 litri. I confronti sono …
The spatial distribution of bacteria in Grana-cheese during ripening.
The microbial composition and its spatial distribution of Grana Trentino, a hard Parmesan-like cheese, was determined, from vat milk to cheese. After cutting along the vertical axis of the cheese wheels, three layers were sampled diagonally across the cheese: under the cheese rind, an intermediate section and the cheese core. After two different ripening periods (9 and 18 months), the cheese samples were analysed using traditional culture dependent and culture independent methods. Milk samples were dominated by mesophilic and psychrophilic bacterial counts. Thermophilic bacteria (Lactobacillus helveticus) were found in high amounts in cooked whey and natural whey starter cultures. After 9 m…
Microbiological characteristics of Trentingrana cheese after nine months of ripening
Microbial analysis of raw cows' milk used for cheese-making: influence of storage treatments on microbial composition and other technological traits
Raw milk used to produce Grana cheese was subjected to several treatment regimes, including varying temperatures and storage times. Milk from morning and evening milking were transferred to a dairy factory sepa- rately (double delivery) or together (single delivery), after storage at the farm for 12 h; in the former case, milk was stored at 12 or 8°C, whereas, in the latter, it was kept at ambient temperature or 18°C. Values of pH of the vat milk were lower for milk samples kept at room temperature, while other physico-chemical parameters and rheological characteristics tested did not show significant differ- ences linked to the different storage temperatures of milk used for ‘‘Grana Trenti…
Extension of Tosela cheese shelf-life using non-starter lactic acid bacteria
Six strains of non-starter lactic acid bacteria (NSLAB) were used to extend the shelf-life of the fresh cheese Tosèla manufactured with pasteurised cows’ milk. The acidification kinetics of three Lactobacillus paracasei, one Lactobacillus rhamnosus and two Streptococcus macedonicus were studied in synthetic milk medium. Lb. paracasei NdP78 and NdP88 and S. macedonicus NdP1 and PB14-1 showed an interesting acidifying capacity and were further characterised for growth in UHT milk and production of antimicrobial compounds. Lb. paracasei NdP78 and S. macedonicus NdP1 grew more than 2 log cycles in 6 h. Lb. paracasei NdP78 was also found to produce a bacteriocin-like inhibitory substance (BLIS) …
Biodiversity and technological potential of wild lactic acid bacteria from raw cows' milk
To study lactic acid bacteria (LAB) biodiversity and to evaluate their potential for use in dairy applications, eight raw cows' milk batches were sampled from five dairy factories located in different areas of the Trentino region during winter and summer milkings. A total of 370 (Gram-positive and catalase-negative) isolates were first molecularly analysed by means of randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). After strain differentiation (124 profiles), LAB were genetically identified at species level. The most frequently isolated LAB were lactococci, enterococci and streptococci. Lactobacilli, leuconostocs and pediococci were found at low levels. All strains …