Biopreservation of Fior di Latte cheese

Abstract In this study a new biopreservation system consisting of an active sodium alginate coating containing Lactobacillus reuteri applied to Fior di Latte cheese was studied. The final aim was to extend cheese shelf life by the in situ production of reuterin. Experimental trials were carried out with and without glycerol. How the fermentation time could improve the production of reuterin, enabling Fior di Latte shelf life, was also assessed. To this aim, the experimental analyses were conducted in 2 different trials, using 2 different production batches of samples. In the first one, Fior di Latte samples were dipped into the active sodium alginate solution prepared on the same day of their production, whereas in the second trial, samples were dipped into the active solution prepared 48h before their production to allow a proper fermentation of the inoculated microorganism. Microbiological and sensory quality indices were monitored to prove the effectiveness of biopreservation on product quality during storage. In the first trial, the combination of the probiotic microorganism with glycerol improved the microbial quality by 1 d compared with the same active solution without glycerol, whereas the 48-h-fermented active alginate solution (second trial) showed a further improved microbial quality. The application of an active coating enriched with L. reuteri and glycerol to Fior di Latte cheese is an optimal and innovative way to preserve the product and at the same time, with a combination of an optimal fermentation time, to prolong its microbial quality and thus its shelf life

Evaluation of bovine beta casein polymorphism in two dairy farms located in northern Italy

Bovine beta casein A1 is one of the most common variants in dairy cattle breeds; it is considered a risk factor in milk intolerance and in other important human diseases, because of the bioactive peptide beta casomorphin-7 (BCM7) produced by raw or processed A1-milk, but not by A2-milk, during digestion. The aim of this study was to perform a cheap and rapid method to investigate beta casein polymorphism in copious animals. The study included 2 dairy farms with a totally of 1230 cows. Beta casein genotypes were estimated evaluating Exon 7 region of bovine beta casein gene (CSN2) by sequences analysis. In the population included in the study 5 variants (A1, A2, B, F, I) and 13 genotypes (A1A1, A1A2, A1B, A1F, A1I, A2A2, A2B, A2F, A2I, BB, BF, BI, FI) were detected. The method showed high sensibility and specificity, resulted low-cost and few time consuming

Combined effect of active coating and modified atmosphere packaging on prolonging the shelf life of low-moisture Mozzarella cheese

Abstract In this work, the effect of active coating on the shelf life of low-moisture Mozzarella cheese packaged in air and modified atmosphere (MAP) was studied. The active coating was based on sodium alginate (2%, wt/vol) and potassium sorbate (1%, wt/vol). The MAP was made up of 75% CO 2 and 25% N 2 (MAP1), 25% CO 2 and 75% N 2 (MAP2), or 50% CO 2 and 50% N 2 (MAP3). The product quality decay was assessed by monitoring microbiological and sensory changes during storage at 4, 8, and 14°C. Results showed that the combination of active coating and MAP was able to improve the preservation of low-moisture Mozzarella cheese. Specifically, the shelf life increased up to 160 d for samples stored at 4°C, and 40 and 11 d for those at 8 and 14°C, respectively. A faster quality decay for untreated samples packaged in air was observed. In particular, the Pseudomonas spp. growth and the appearance of molds were responsible for product unacceptability. The combination of active coating and MAP represents a strategic solution to prolong the shelf life of low-moisture Mozzarella cheese and to ensure the safety of the product under thermal abuse conditions

Strain Diversity of Pseudomonas fluorescens Group with Potential Blue Pigment Phenotype Isolated from Dairy Products

The blue discoloration in Mozzarella cheese comes from bacterial spoilage due to contamination with Pseudomonas. Fourteen Pseudomonas fluorescens strains from international collections and 55 new isolates of dominant bacterial populations from spoiled fresh cheese samples were examined to assess genotypic and phenotypic strain diversity. Isolates were identified by 16S rRNA gene sequencing and tested for the production of the blue pigment at various temperatures on Mascarpone agar and in Mozzarella preserving fluid (the salty water in which the cheese is conserved, which becomes enriched by cheese minerals and peptides during storage). Pulsed-field gel electrophoresis analysis after treatment with the endonuclease SpeI separated the isolates into 42 genotypes at a similarity level of 80%. Based on the pulsotype clustering, 12 representative strains producing the blue discoloration were chosen for the multilocus sequence typing targeting the gyrB, glnS, ileS, nuoD, recA, rpoB, and rpoD genes. Four new sequence typing profiles were discovered, and the concatenated sequences of the investigated loci grouped the tested strains into the so-called ''blue branch'' of the P. fluorescens phylogenetic tree, confirming the linkage between pigment production and a specific genomic cluster. Growth temperature affected pigment production; the blue discoloration appeared at 4 and 14°C but not at 30°C. Similarly, the carbon source influenced the phenomenon; the blue phenotype was generated in the presence of glucose but not in the presence of galactose, sodium succinate, sodium citrate, or sodium lactate

Microbial Community Dynamics in Mother’s Milk and Infant’s Mouth and Gut in Moderately Preterm Infants

Mother’s own milk represents the optimal source for preterm infant nutrition, as it promotes immune defenses and gastrointestinal function, protects against necrotizing enterocolitis, improves long-term clinical outcome and is hypothesized to drive gut microbiota assembly. Preterm infants at birth usually do not receive their mother’s milk directly from the breast, because active suckling and coordination between suckling, swallowing and breathing do not develop until 32–34 weeks gestational age, but actual breastfeeding is usually possible as they grow older. Here, we enrolled moderately preterm infants (gestational age 32–34 weeks) to longitudinally characterize mothers’ milk and infants’ gut and oral microbiomes, up to more than 200 days after birth, through 16S rRNA sequencing. This peculiar population offers the chance to disentangle the differential contribution of human milk feeding per se vs. actual breastfeeding in the development of infant microbiomes, that have both been acknowledged as crucial contributors to short and long-term infant health status. In this cohort, the milk microbiome composition seemed to change following the infant’s latching to the mother’s breast, shifting toward a more diverse microbial community dominated by typical oral microbes, i.e., Streptococcus and Rothia. Even if all infants in the present study were fed human milk, features typical of healthy, full term, exclusively breastfed infants, i.e., high percentages of Bifidobacterium and low abundances of Pseudomonas in fecal and oral samples, respectively, were detected in samples taken after actual breastfeeding started. These findings underline the importance of encouraging not only human milk feeding, but also an early start of actual breastfeeding in preterm infants, since the infant’s latching to the mother’s breast might constitute an independent factor helping the health-promoting assembly of the infant gut microbiome

Relationship between Food Waste Probability and Shelf Life

Obiettivo dello studio L’allungamento della shelf life dei prodotti alimentari è un tema particolarmente sentito dal sistema agroindustriale italiano ed in particolare dall’industria lattiero-casearia a fronte della crescente richiesta da parte dei consumatori di prodotti freschi ed ultrafreschi. Il presente studio si pone come obiettivo primario valutare l’esistenza o meno di una correlazione fra estensione della durabilità dei prodotti alimentari, ed in particolare dei latticini freschi prendendo a modello la mozzarella Fior di Latte, e riduzione dello spreco alimentare. Si eseguirà a tal scopo studio statistico di dati di mercato per cercare di correlare, nel comparto lattiero-caseario, la shelf life dei prodotti con lo spreco alimentare, adottando come parametro principale di valutazione la percentuale di prodotto reso da mercato sul prodotto venduto. Si pone inoltre come ulteriori obiettivi lo studio sperimentale di strategie per l’allungamento della durabilità della mozzarella Fior di Latte (FdL). Materiali e Metodi Lo studio statistico è stato condotto utilizzando dati cortesemente messi a disposizione da una grande industria alimentare italiana, relativi a 640 diverse referenze di prodotti lattiero-caseari, che sono stati suddivisi in 17 classi in funzione della shelf life loro assegnata. Come variabili sono state utilizzate il valore di shelf life e la percentuale di reso da mercato (reso/venduto). I dati sono stati sottoposti dapprima ad analisi ANOVA per valutare eventuali differenze fra le 17 classi e il reso% e quindi a modellizzazione per analizzare la correlazione esistente fra le due variabili. Tutte le analisi statistiche sono state condotte con il pacchetto statistico IBM SPSS 20. Diverse strategie di packaging e le loro relative combinazioni sono state utilizzate per valutare il loro impatto sulla durabilità della mozzarella Fior di Latte mantenuta alla temperatura costante di + 8°C (la temperature media dei frigoriferi domestici in Italia). In particolare si sono utilizzati coating attivi e confezionamento in atmosfera modificata (MAP) per valutarne l’effetto combinato. Ad intervalli regolari di tempo si sono prelevate unità campionarie che sono state valutate per la composizione del gas presente nello spazio di testa della confezione, per il pH del prodotto e del liquido di governo, per I contenuti microbici (conta microbica totale, conta dei batteri lattici e delle pseudomonadacee), nonchè per le caratteristiche sensoriali. Definiti i limiti di accettabilità microbica e sensoriale (MAL and SAL) rispettivamente a 10exp6 ufc/g per le pseudomonadacee e a punteggio 4,0 per la qualità globale dell’analisi sensoriale, è stato possibile calcolare la shelf life della mozzarella Fior di Latte sulla base del minimo valore ottenuto di MAL e SAL. Risultati principali dello studio All’analisi ANOVA il parametro reso% non mostra, per i prodotti freschi con shelf life inferiore o uguale a 30 giorni, differenze significative delle medie. Al contrario, per i prodotti aventi shelf life superiore a 30 giorni, le differenze fra i valori medi del reso% appaiono significative. L’ulteriore indagine condotta con un approccio di modellizzazione ha portato ad un modello esponenziale che spiega la correlazione fra shelf-life e reso% da mercato. Dal lato della sperimentazione di tecniche protettive per l’estensione della shelf life si è evidenziato che la semplice ricopertura della mozzarella Fior di Latte con un strato di alginato polimerizzato in loco protegge solo relativamente il prodotto dallo sviluppo microbico. Il confezionamento in atmosfera modificata (MAP), specialmente ad alte proporzioni di CO2, risulta invece efficace nell’inibizione dei microorganismi alteranti ma impatta negativamente la superficie del formaggio, ciò che non avviene se il formaggio è protetto dalla copertura di alginato. Caricando la copertura di alginato con composti ad azione antimicrobica (active coating) aumenta l’efficacia del sistema: i risultati sperimentali confermano che accoppiando MAP ed active coating (es. potassio sorbato o nanoparticelle di argento) si ottiene un sistema efficace nell’allungamento della shelf life della mozzarella Fior di Latte. Parimenti l’inclusione di cellule di L. reuteri e di glicerolo a formare un coating bioattivo migliora significativamente la shelf life del prodotto in liquido di governo se accoppiato a MAP. Conclusioni L’analisi statistica mostra una correlazione di tipo esponenziale fra percentuale di reso da mercato, uno degli indicatori di spreco alimentare, e shelf life assegnata ai prodotti quando questa è superiore a 30 giorni. La differenza fra le medie del reso% in funzione della shelf life non appare invece significativa per i prodotti freschi ed ultrafreschi (DLC < 30 gg). Il dato statistico sembra non concordare con quanto osservato sul campo dagli operatori alimentari, che rilevano benefici, a parità delle altre variabili, in termini di reso da mercato a seguito di allungamento della shelf life. Il confezionamento in MAP ad elevate proporzioni di CO2 è in grado di controllare lo sviluppo di Pseudomonads spp., il principale agente di alterazione di Fior di Latte e mozzarelle fresche in liquido di governo, ma altera le caratteristiche organolettiche del prodotto, in particolare degradandone la superficie. La presenza di una copertura di alginato protegge la superficie del formaggio dai danni causati dall’acidità del liquido di governo. L’utilizzo combinato di un coating attivo e del confezionamento in atmosfera modificata risulta in grado di allungare la shelf life del prodotto, confermando che è necessario un approccio ad ostacoli multipli per ottenere i risultati attesi

Advances in Dairy Products

Advances in Dairy Product Science & Technology offers a comprehensive review of the most innovative scientific knowledge in the dairy food sector. Edited and authored by noted experts from academic and industry backgrounds, this book shows how the knowledge from strategic and applied research can be utilized by the commercial innovation of dairy product manufacture and distribution. Topics explored include recent advances in the dairy sector, such as raw materials and milk processing, environmental impact, economic concerns and consumer acceptance. The book includes various emerging technologies applied to milk and starter cultures sources, strategic options for their use, their characterization, requirements, starter growth and delivery and other ingredients used in the dairy industry. The text also outlines a framework on consumer behavior that can help to determine quality perception of food products and decision-making. Consumer insight techniques can help support the identification of market opportunities and represent a useful mean to test product prototypes before final launch. This comprehensive resource: Assesses the most innovative scientific knowledge in the dairy food sectorReviews the latest technological developments relevant for dairy companiesCovers new advances across a range of topics including raw material processing, starter cultures for fermented products, processing and packagingExamines consumer research innovations in the dairy industry Written for dairy scientists, other dairy industry professionals, government agencies, educators and students, Advances in Dairy Product Science & Technologyincludes vital information on the most up-to-date and scientifically sound research in the field

Technological Strategies to Preserve Burrata Cheese Quality

Burrata cheese is a very perishable product due to microbial proliferation and undesirable sensory changes. In this work, a step-by-step optimization approach was used to design proper processing and packaging conditions for burrata in brine. In particular, four different steps were carried out to extend its shelf life. Different headspace gas compositions (MAP-1 30:70 CO2:N2; MAP-2 50:50 CO2:N2 and MAP-3 65:35 CO2:N2) were firstly tested. To further promote product preservation, a coating was also optimized. Then, antimicrobial compounds in the filling of the burrata cheese (lysozyme and Na2-EDTA) and later in the coating (enzymatic complex and silver nanoparticles) were analyzed. To evaluate the quality of the samples, in each step headspace gas composition, microbial population, and pH and sensory attributes were monitored during storage at 8 ± 1 °C. The results highlight that the antimicrobial compounds in the stracciatella, coating with silver nanoparticles, and packaging under MAP-3 represent effective conditions to guarantee product preservation, moving burrata shelf life from three days (control sample) to ten days

Evaluation of bovine beta casein polymorphism in two dairy farms located in northern Italy

Bovine beta casein A1 is one of the most common variants in dairy cattle breeds; it is considered a risk factor in milk intolerance and in other important human diseases, because of the bioactive peptide beta casomorphin-7 (BCM7) produced by raw or processed A1-milk, but not by A2- milk, during digestion. The aim of this study was to perform a cheap and rapid method to investigate beta casein polymorphism in copious animals. The study included 2 dairy farms with a totally of 1230 cows. Beta casein genotypes were estimated evaluating Exon 7 region of bovine beta casein gene (CSN2) by sequences analysis. In the population included in the study 5 variants (A1, A2, B, F, I) and 13 genotypes (A1A1, A1A2, A1B, A1F, A1I, A2A2, A2B, A2F, A2I, BB, BF, BI, FI) were detected. The method showed high sensibility and specificity, resulted low-cost and few time consuming