1,721,053 research outputs found
Production of cheeses enriched with by-products from the food industry: focus on sheep’s milk cheeses processed with the addition of grape pomace in Sicily
No full textCheese production is a very ancient activity. Recently, producers and consumers found a growing need for diversification of dairy products. Furthermore, the current regulations for the disposal of by-products and the increasing awareness for the sustainability of food productions have stimulated innovation in the dairy sector that mainly led to the development of cheeses enriched with functional ingredients. However, the innovation mainly involved the transformation of cow’s milk. Regarding sheep’s milk transformation, some products have been made using by-products of the food industries. This mini-review reports on dairy products made in Sicily with the use of by-products deriving from wineries. In addition to process and product innovation, this article also focuses on the sensory characteristics and antioxidant properties of the novel cheeses
Effect of three different aloe vera gel-based edible coatings on the quality of fresh-cut “Hayward” kiwifruits
Full text linkIn recent years, the market for minimally processed fruit has increased. Fresh-cut fruits are characterized by a short shelf life due to the processing phases that accelerate the ripening courses. The aim of this work is to analyze the effect on the quality of fresh-cut Hayward kiwis of three different edible coatings based on (1) Aloe vera gel, (2) Aloe vera gel + hydroxypropyl methylcellulose and (3) Aloe vera gel + lemon essential oil. Fruit firmness, weight loss, color, soluble solids content, titratable acidity, microbial load and sensory analysis were evaluated as fresh after 2, 4, 7 and 10 days. Aloe vera gel and Aloe vera gel + lemon essential oil maintained the best values, as they acted as a barrier to gas exchange and further reduced the microbial load. These results were confirmed by sensory analysis: Aloe vera gel + hydroxypropyl methylcellulose does not alter the natural taste of kiwi slices, Aloe vera gel + lemon essential oil gives the characteristic taste of lemon essential oil and Aloe vera gel gives an herbaceous taste. The Aloe vera gel, in combination with these additives, maintains the ability to preserve the quality of fresh-cut kiwifruit
Trasmissione dei geni di antibiotico-resistenza durante la produzione di pane a lievitazione naturale
No full textThis study reports on data from a research aimed at monitoring the transfer of antibiotic resistance genes along the sourdough bread production chain. Specifically, raw materials
such as durum wheat semolina and wheat flour, doughs at the end of fermentation and finished products were analysed. Microbiological analyses were conducted using a polyphasic approach, including culture-dependent and culture-independent analyses. Both methods resulted in the detection of significant levels of lactic acid bacteria in all samples under investigation. The search for genes associated with resistance to the main antibiotics commonly used to treat bacterial infections in farm animals revealed that no transfer of genes associated with penicillins, chloramphenicol and macrolides occurred. However, three semolina samples and only one bread sample demonstrated the presence of tetracycline resistance-related amplicons. This work demonstrated that in traditional bread production, although at low levels, raw materials may be responsible for the dissemination of antibiotic resistance genes
Alimenti arricchiti: caratterizzazione chimica di formaggio ovino a pasta pressata addizionato con diverse percentuali di polvere di Moringa oleifera
No full textLa Moringa oleifera è una pianta distribuita in molti paesi tropicali e subtropicali, e rappresenta una preziosa fonte di molecole bioattive con numerosi benefici per la salute. L'obiettivo di questo lavoro è stato quello di utilizzare diverse percentuali di polvere di moringa (1%, 2% p/p) per la produzione di formaggi funzionali, al fine di valutare l'effetto sulle caratteristiche chimiche e l’attività antiossidante del prodotto finito. Le analisi microbiologiche hanno evidenziato l’assenza dei principali patogeni di interesse lattiero-caseario e la dominanza dei lattococchi aggiunti come colture starter. Le analisi chimiche effettuate sui formaggi fortificati hanno mostrato valori promettenti di attività antiossidante, con un range di valori pari a 0.82 – 1.35 mmol TEAC/100g per il test ABTS e 0.99 – 1.21 mmol TEAC/100g per il test DPPH, altamente superiori al formaggio controllo (0.11 – 0.06 mmol TEAC/100g, rispettivamente). Anche i valori riguardanti il contenuto fenolico totale (TPC) sono risultati essere interessanti, con valori pari a 2.01 e 2.72 mgGAE/g per il formaggio fortificato all’1% e al 2%, rispettivamente. Dalle analisi GC/MS è stato riscontrato un maggior contenuto in acidi grassi monoinsaturi, tra cui il principale è risultato essere l’acido oleico. Le analisi UHPLC-ESI MS/MS hanno mostrato un aumento di polifenoli nel formaggio sottoposto a fortificazione, soprattutto quercitrina, quercetina e acido ferulico. Questa fortificazione rappresenta quindi una strategia ottimale per valorizzare il latte ovino Siciliano mediante la produzione di prodotti lattiero-caseari innovativi, ricchi in molecole bioattive e con una maggiore shelf-life grazie alla presenza di composti antiossidanti
Aggiunta di Moringa oleifera in polvere per la funzionalizzazione di un formaggio ovino a pasta pressata
No full textLa Moringa oleifera è una pianta distribuita in molti paesi tropicali e subtropicali, con numerosi benefici per la salute ed un alto valore nutrizionale. L'idea di utilizzare questa pianta come integratore o come costituente nella preparazione e nella fortificazione alimentare è data dal fatto che questa rappresenta una preziosa fonte di molecole bioattive.
Nel presente lavoro, una polvere commerciale ottenuta dalle foglie di Moringa oleifera è stata utilizzata per la produzione di un formaggio ovino fresco a pasta pressata. Le caseificazioni sperimentali sono state condotte a livello industriale utilizzando latte ovino crudo e due ceppi di Lactococcus lactis (CAG4 e PON36) come agenti fermentanti. Il piano sperimentale ha previsto la realizzazione di una produzione controllo e due produzioni sperimentali. Quest’ultime sono state ottenute aggiungendo alla cagliata la polvere di Moringa o. a una percentuale dell’1% e del 2% (p/p). Sia le cagliate controllo che sperimentali, dopo la formatura, sono state stufate, salate in salamoia satura e infine stagionate per due mesi. I prodotti finiti sono stati sottoposti a caratterizzazioni chimiche quali-quantitative sul profilo lipidico, fenolico, microbiologico e sensoriale.
Inoltre, su queste matrici è stata indagata l’attività antiossidante espressa in mmol Trolox Equivalent Antioxidant Capacity (TEAC)/100g utilizzando i test DPPH e ABTS, il contenuto fenolico totale (TPC) mediante metodo Folin-Ciocalteau, espresso in mg Acido Gallico Equivalenti (GAE)/g, il profilo fenolico mediante analisi UHPLC-ESI/MS-MS e il profilo degli acidi grassi effettuato mediante analisi GC- MS.
Le analisi effettuate sui formaggi fortificati hanno mostrato valori promettenti di attività antiossidante, con un range di valori pari a 0.67 – 0.91 mmol TEAC / 100g. L’aggiunta di Moringa ha quindi aumentato la capacità scavenger anti-radicalica. Le analisi svolte sui formaggi sperimentali hanno inoltre evidenziato valori interessanti del contenuto fenolico totale, con un range di valori pari a 1.33 – 2.72 mg GAE/g. Data l’elevata potenzialità in termini di contenuto fenolico totale, nei formaggi fortificati è stata anche effettuata una valutazione quali-quantitativa del profilo dei singoli polifenoli mediante analisi UHPLC-ESI/QTOF-MS, che ha mostrato una maggiore presenza di flavonoidi (apigenina, quercetina, luteolina, miricetina, kaempferolo), lignani (secoisolariciresinolo, isolariciresinolo, medioresinolo, epipinoresinolo glicosidi) e acidi fenolcarbossilici e loro derivati (acidi cumaroilchinico, caffeilchinico, feruloilchinico).
Sugli stessi campioni è stato studiato anche il profilo dei principali acidi grassi ottenuti dall’idrolisi basica dei trigliceridi; dalle analisi è stato riscontrato un maggior contenuto in acidi grassi monoinsaturi, con un elevato rapporto acidi grassi monoinsaturi/saturi (MUFA/SFA), tra cui il principale è risultato essere l’acido oleico.
Le analisi microbiologiche condotte con un approccio coltura dipendente hanno evidenziato l’assenza dei principali patogeni di interesse lattiero-caseario e la dominanza dei lattococchi aggiunti come colture starter, confermando che la fortificazione con polvere di moringa non esercita nessun effetto inibente sul processo fermentativo.L’aggiunta di polvere di moringa sebbene abbia influenzato i tratti sensoriali dei formaggi non ha inciso negativamente sul grado di apprezzamento complessivo dei giudici.
L'aggiunta delle foglie di moringa al formaggio rappresenta quindi una strategia ottimale per valorizzare il latte ovino Siciliano mediante la produzione di prodotti lattiero-caseari innovativi ricchi in molecole bioattive e con una maggiore shelf-life grazie alla presenza di composti antiossidanti
Selection of starter lactic acid bacteria capable of forming biofilms on wooden vat prototypes for their future application in traditional Sicilian goat's milk cheese making
Full text linkIn this study, 327 presumptive lactic acid bacteria (LAB) were isolated from goats' milk acid curds produced at a Sicilian dairy farm with the aim to identify potential starter cultures for traditional cheeses. All isolates were first processed by randomly amplified polymorphic DNA (RAPD)-PCR analysis. This approach identified 63 distinct strains which were evaluated for their acidifying capacity. Only 15 strains specifically stood out for their acidification capacity and were identified through 16S rRNA gene sequencing as Lactococcus lactis (11 strains) Enterococcus faecalis (three strains), and Ligilactobacillus animalis (one strain). Notably, all 15 LAB isolates produced bacteriocin-like inhibitory substances and anti-biofilm compounds, against both planktonic and biofilm forms of Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli, and Staphylococcus aureus, albeit at varying levels. Among these 15 LAB, En. faecalis RGM25 and Lc. lactis RGM55, susceptible to five antibiotics tested, were put in contact with wooden vat prototypes, because all equipment used in traditional cheese production in Sicily are made of wood. Scanning electron microscopy and bacterial plate counts of the wooden vat prototypes showed the development of biofilms at levels of approximately 6.0 log CFU/cm2. Overall, this study contributes to establishing a custom-made LAB starter cultures with bio-preservatives properties for Sicilian cheese productions
Survey of antibiotic resistance of Pseudomonas isolated from fresh cut red chicory (Cichorium intybus L., Asteraceae)
Full text linkThe present work was carried out to investigate the safety
aspects of minimally processed red chicory (Cichorium
intybus L., family Asteraceae) regarding the antibiotic resistance
of Pseudomonas Migula, 1894 populations (Bacteria
Pseudomonadaceae). The Pseudomonas strains
tested for their characteristics were previously isolated
from experimental monovarietal salads prepared with two
different processes, a classic ready-to-eat (RTE) process
and a process with entire leaves, and stored under refrigeration
(4 °C) up to 15 days from production. Due to their
dominance over the microbial community, Pseudomonas
strains were better characterised for their undesirable features
that might be exerted on the health of consumers.
To this purpose, the 21 dominant Pseudomonas strains
were subjected to the antimicrobial resistance test, applying
the antibiotics commonly administered to combat intestinal
bacteria responsible for human infections. The
results revealed a certain sensibility to almost all the antibiotics
diffused among these bacteria, with the exception
of ampicillin, amoxicillin, and chloramphenicol. If, on
one hand, this study has found that, generally,
Pseudomonas are not related to the dissemination of the
majority of antibiotics used for hospitalized patients, on
the other hand, it poses the attention to this microbial
group regarding ampicillin and amoxicillin
Sviluppi e potenzialità della trasformazione del latte ovino in Sicilia
Full text linkInnovation is crucial across various economic sectors, with dairy products playing a significant role in the food market. In the Euro-Mediterranean regions, Sicily particularly emphasizes the processing of ewe’s milk, owing to its extensive range of ovine products. Nevertheless, the small ruminant dairy sector encounters substantial organizational challenges. Despite these hurdles, innovation remains vital for the economic sustainability of small dairy farms in the region. This paper aims to explore the potential for enhancing and revitalizing the ewe’s milk processing sector in Sicily. Scientific literature indicates that innovation in the primary sector can positively influence rural development, local economies, and environmental preservation, especially in marginal areas. Consequently, ovine cheese can become a symbol of gastronomic culture and cultural identity, contributing to the sustainable development of the area
Microbiological and physicochemical profile of sugar added ewe’s Ricotta during storage
No full textThe microbiological and physicochemical traits of fresh ewe’s Ricotta made with (40% w/w) and without sucrose were investigated. Sugar added Ricotta (SAR) andcontrol Ricotta (CTR) were packaged and stored at 4°C for 90 d. Salmonella spp., Listeria monocytogenes,Escherichia coli, coagulase positive staphylococci, Enterobacteriaceae, total coliforms, Pseudomonas, yeasts, moulds and clostridia were undetectable during the entire monitoring. Total mesophilic and psychrotrophic microorganisms and mesophilic cocci lactic acid bacteria increased over time,but their development was limited in SAR production. The acidificationwas observed only for CTR.
Water activity was consistently low(0.897 on average) in SAR that were also characterized by the highest percentage of dry matter (45.27 – 47.36%). Fat, protein and salt contents were in the range
typical for ewe’s Ricotta. The results provided evidences on a 40-d shelf life for SAR product
Reduction of Pericarp Browning and Microbial Spoilage on Litchi Fruits in Modified Atmosphere Packaging
Full text linkThe pericarp browning and postharvest microbiological decay of litchi fruit (Litchi chinensis Sonn cv Kwai Mai) significantly reduce its commercial potential in the fresh market. In this study, different combinations of modified atmosphere packaging (MAP) were applied at 5 ± 1 °C based on the use of natural gases that are innocuous to human health and an alternative to commercially adopted sulfur dioxide (SO2) treatment. The results showed that control fruits, after 6 days of storage, begin to show the first symptoms of decay, revealed by the appearance of lesions and microbial infections determined by total mesophilic microorganisms and molds. This is not the case in the MAP-treated fruits and the MAP 3-treated (5% O2 + 20% CO2 + 75% N2) fruits that show the best results. The control fruits, moreover, turned completely brown by the end of the storage period. The MAP 3 treatment was the most effective in preventing browning and the loss of the red pericarp color and vitamin content and in maintaining acceptable SSC/TA levels and flavor. In addition, a microbiological analysis revealed that all the MAP-treated litchi fruits did not harbor undesirable microorganisms during the entire cold storage period. In conclusion, the MAP 3 conditions delayed pericarp browning and maintained the better organoleptic quality of litchi fruits
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