0000000000370207
AUTHOR
A. Cavazza
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…
Temperatura e modalità di conferimento del latte al caseificio: effetti sulla carica psicotrofa e non solo
Obiettivo di questo lavoro era lo studio dell´evoluzione della carica microbica totale e psicrotrofa indesiderata nel latte per produzione di Grana Trentino al variare del sistema di raccolta del latte. Il conferimento due volte al giorno del latte raccolto in bidoni senza refrigerazione o in cisterna refrigerata a 18°C è stato confrontato con il conferimento una volta al giorno del latte raffreddato alla stalla a 8 o 12°C. I latti sono stati seguiti dalla stalla alla caldaia, i campioni di latte e panna sono stati analizzati tramite tecniche classiche e molecolari per la definizione del quadro microbico. La composizione microbica del latte intero non differiva nelle 4 tesi: in tutti i camp…
Mantenere la tipicità in un mondo che cambia
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…
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…
L’evoluzione del microbioma durante la caseificazione e la stagionatura: il caso del Grana Trentino.
La composizione microbica del Grana Trentino e del suo siero-innesto è stata studiata non solo in relazione alla differente tecnologia di raccolta e conservazione del latte ma anche in relazione al tempo di stagionatura e alla zona di campionamento. Per una serie di lavorazioni si è determinata la composizione microbica di latte, siero e di due forme gemelle, aperte dopo 9 e 18 mesi. Queste sono state tagliate lungo l’asse verticale e sono state campionate tre diverse zone lungo la diagonale: sotto la crosta, al centro e in posizione mediana. I campioni sono stati analizzati tramite metodi coltura-dipendenti e coltura-indipendenti (DGGE e 454 pyrosequencing) e i risultati sono stati messi i…
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 …