177,428 research outputs found
I batteri lattici delle cariossidi del grano: influenza geografica, varietale e del periodo di invecchiamento
No full textIl presente articolo riporta i dati di alcune ricerche volte a risalire all’origine dei batteri lattici degli impasti acidi. A tal proposito, i batteri lattici del frumento di quattro varietà moderne sono stati monitorati a partire dalle spighe. Le cariossidi ospitavano livelli di microrganismi inferiori rispetto a quelli rilevati sulle spighe e queste ultime livelli inferiori rispetto alle semole. La minore biodiversità lattica è stata riscontrata sulle cariossidi, mentre le semole hanno mostrato la maggiore ricchezza di specie e ceppi. Al fine di valutare la resistenza dei batteri lattici del grano durante l’invecchiamento, le cariossidi di due varietà antiche e due moderne di grani duri siciliani fino a 3 anni dalla raccolta sono state molite per rilevare la biodiversità lattica delle semole risultanti. Lattobacilli e enterococchi hanno superato le condizioni di stress subite durante la conservazione meglio di altri batteri lattici comunemente associati alle cariossidi di frumento.This article shows research data to retrieve the origin of lactic bacteria in sourdoughs. To this purpose, wheat lactic acid bacteria from four modern varieties were monitored starting from the ears. In general, kernels harboured lower levels of microorganisms than ears and ears than semolinas. The lowest lactic acid bacteria complexity was found on kernels, while a richer biodiversity in terms of species and strains was observed in semolinas. In order to assess the resistance of wheat lactic acid bacteria during aging, the kernels of two old landraces and two modern genotypes of Sicilian durum wheat up to 3 years after harvest were milled to detect the biodiversity of the resulting semolinas. Lactobacilli and enterococci were able to overcome the stressing conditions represented by cereal storage better than other lactic acid bacteria genera commonly found associated to wheat kernels after harvest
“RAIN was planting the seeds”: An Interview with Tom Bender, co-editor of RAIN: Journal of Appropriate Technology
No full textFrom 1974 through 1980, RAIN: Journal of Appropriate Technology was the foremost “print tool” of the Appropriate Technology, or AT, Movement in the United States. During that period, the Rainmakers, led by Steve Johnson, Lee Johnson, Land de Moll, and Tom Bender, constructed a visionary ecotopia on the pages of their journal, supplying readers with the philosophical grounding, real-world advice, and political conviction to pursue AT projects within their own communities. This article is an abridged transcript of an interview conducted by architectural historian, Meredith Gaglio, with one of RAIN’s co-editors, the late Tom Bender, at his home in Manzanita, Oregon, in April, 2016. In the interview, Bender recollects his introduction to Appropriate Technology, through the work of Ernst Friedrich Schumacher and R. Buckminster Fuller, discusses the foundations of RAIN: Journal of Appropriate Technology, and shares his thoughts on how sustainable change is made.De 1974 à 1980, RAIN: Journal of Appropriate Technology a été le principal "outil imprimé" du mouvement de la technologie appropriée (AT) aux États-Unis. Pendant cette période, les Rainmakers, menés par Steve Johnson, Lee Johnson, Land de Moll et Tom Bender, ont construit une écotopie visionnaire dans les pages de leur journal, fournissant aux lecteurs les bases philosophiques, les conseils pratiques et la conviction politique nécessaires à la mise en œuvre de projets AT au sein de leurs propres communautés. Cet article est une transcription abrégée d’un entretien mené par l’historienne de l’architecture Meredith Gaglio avec l’un des coéditeurs de RAIN, le regretté Tom Bender, à son domicile de Manzanita, dans l’Oregon, en avril 2016. Dans cet entretien, Bender se souvient de son introduction à la technologie appropriée, à travers les travaux d’Ernst Friedrich Schumacher et de R. Buckminster Fuller, discute des fondements de RAIN: Journal of Appropriate Technology, et partage ses réflexions sur la façon dont le changement durable est réalisé
Activation of wooden vats with selected lactic acid bacteria for the year-round production of traditional Vastedda-like cheese
No full textVastedda is a pasta filata cheese made from raw ewes’ milk without the addition of starter cultures. Cheese production is carried out in wooden vats characterized by microbial biofilms hosting lactic acid bacteria (LAB) responsible for the acidification of the curds. Vastedda cheese was traditionally produced during the summer season, but it is currently produced throughout the year. In order to minimize production variability, several LAB were isolated from Vastedda PDO cheeses, characterized for their technological potential (Gaglio et al., 2014a) and selected to obtain the best strain combination for the production (Gaglio et al., 2014b). In this study, the multiple strain culture composed of Lactococcus lactis subsp. cremoris PON36, PON153 and PON203 was applied during production carried out at large scale level in a dairy factory with bulk milk from different farms using new chestnut wooden vats [commercial production (CMP)]. The same trials were also carried out in controlled conditions at an experimental dairy factory using milk from only one farm [controlled production (CNP)]. In both CMP and CNP productions were used two new vats, one activated with a whey containing the lactococci selected and one traditionally activated with the whey. In the experimental trials, conducted in the vats activated with the lactococci, the same lactococci were also used as starter culture, while the control productions were performed without the addition of starter. Productions were performed every day for the first 5 d and at 5 d intervals for a month. Microbiological counts and strain recognition performed by randomly amplified polymorphic DNA (RAPD)-PCR demonstrated the ability of the triple Lactococcus combination to form a stable biofilm in the active vats. Cheeses analysed at T0 (soon after production) and after 15 days of refrigerated storage showed the persistence and dominance of the inoculated LAB
Il vino e la fermentazione alcolica
No full textIl consumo di bevande alcoliche ha da sempre accompagnato la storia dell’uomo, riscontrandosi in tutte le civiltà, dalle meno evolute a quelle più progredite. Le scoperte scientifiche del XV secolo hanno messo in luce come tutti i popoli abbiano ampiamente sfruttato il fenomeno della fermentazione di cereali per produrre bevande. Lo stesso vino, inoltre, aveva assunto fin dai tempi più antichi
un valore liturgico presso tutte le civiltà che si erano affacciate al Mediterraneo. Anche oggi, e in misura maggiore rispetto al passato, si fa largo uso di bevande alcoliche ottenute sia da fermentazione che da distillazione di liquidi zuccherini. Le bevande alcoliche fermentate sono caratterizzate dalla presenza di concentrazioni variabili di alcol, ottenute da frutta, semi di cereali e tuberi, mediante la fermentazione di soluzioni zuccherine. Nelle bevande alcoliche fermentate, la presenza di alcol etilico è dovuta ad un processo naturale denominato “fermentazione alcolica”, operato da lieviti, mediante il quale le sostanze zuccherine si trasformano in alcol etilico e anidride carbonica. Per la legislazione italiana (D.P.R. n. 162), può essere denominato “vino” esclusivamente il prodotto ottenuto attraverso la fermentazione alcolica spontanea, totale o parziale, dell’uva fresca, dell’uva ammostata o del mosto d’uva con gradazione alcolica non inferiore ai
tre quinti della gradazione complessiva. Pertanto, con il termine “vino” si indica il prodotto finale di una lunga catena biotecnologica articolata nelle fasi di preparazione del mosto, di fermentazione, di maturazione e di invecchiamento. Ciascuna delle fasi appena menzionate investe fenomeni chimici, chimico-fisici e biologici che si cerca di regolare con tecniche atte a conservare i caratteri
della materia prima e a migliorare la qualità dei vini che ne derivano, anche in considerazione della crescente domanda e del maggiore interesse dei consumatori per un vino di qualità. Sicuramente, la svolta microbiologica ha rappresentato una delle innovazioni tecniche più importanti nella storia dell’enologia, insieme alle osservazioni sugli effetti dell’ossigeno, sui costituenti fenolici e dell’aroma, grazie alla capacità di incidere sul processo di fermentazione. I principali agenti responsabili della fermentazione alcolica sono i lieviti appartenenti al genere Saccharomyces (in particolare Saccharomyces cerevisiae), mentre i batteri lattici sono determinanti per la fermentazione malolattica. Tali microrganismi guidano la vinificazione del succo d’uva e, per questa ragione, osservare e comprendere il loro comportamento in ambiente enologico è di elevata importanza per l’ottenimento di prodotti finiti con caratteristiche organolettiche ottimali. Le interazioni microbiche, infatti, sono di notevole rilevanza in quanto lo sviluppo di microrganismi indesiderati può generare alterazioni e difetti di natura organolettica
Evaluation of curd cooking on microbiological characteristics of “Grana” type pressed cheeses processed from raw ewes’ milk
No full textThis work was carried out to pursue a double objective: to improve the hygienic safety of cheeses produced from raw ewes’ milk; and to produce a new typology of cheese through the application of “Grana” technology.
With this in mind, raw milk from an individual farm was transformed under controlled condition at a pilot dairy plant. The production technology included the partial skimming of the evening and morning milk mixture by cream surfacing, the addition of a natural whey starter cultures (NWSC) prepared with four selected Streptococcus thermophilus strains (PON6, PON244, PON261 e PON413) isolated from raw ewes’ cheese productions (Gaglio et al., 2014), milk clotting at 38°C, curd cooking at 56°C, cheese moulding at room temperature, immersion salting and ripening for 9 months.
In this study, 10 microbial groups were investigated from raw milk until ripened cheeses. Lactic acid bacteria (LAB) were in the range 104 - 105 CFU/ml before NWSC addition. After curdling, these bacteria increased to 3 Log cycles and were counted at 106 CFU/ml after curd cooking. A rapid pH drop (to 6.05) was registered after almost 3 h from NWSC addition. The levels of members of the Enterobacteriaceae family were at about 103 CFU/ml in raw milk and decreased after curd cooking to 1 Log cycle. A similar behavior was shown by the other undesired microbial group till the complete disappearance of staphylococci. The microbiological counts of 9-month ripened cheeses showed the dominance of LAB and undetectable levels of undesired bacteria. Next Generation Sequence analyses are in progress to evaluate the total microbial composition of the final cheeses.
On the basis of the results, the main hypothesis of the work was accepted since the undesired microbial groups were reduced in number in comparison with uncooked hard pressed technology
Improvement of raw milk cheese hygiene through the selection of starter and non-starter lactic acid bacteria: The successful case of pdo pecorino siciliano cheese
No full textThis review article focuses on the technological aspects and microbiological critical points of pressed-cooked cheeses processed from raw ewe’s milk without the inoculation of starter cultures, in particular “Pecorino” cheese typology produced in Italy. After showing the composition of the biofilms adhering to the surface of the traditional dairy equipment (mainly wooden vat used to collect milk) and the microbiological characteristics of PDO Pecorino Siciliano cheese manufactured throughout Sicily, this cheese is taken as a case study to develop a strategy to improve its hygienic and safety characteristics. Basically, the natural lactic acid bacterial populations of fresh and ripened cheeses were characterized to select an autochthonous starter and non-starter cultures to stabilize the microbial community of PDO Pecorino Siciliano cheese. These bacteria were applied at a small scale level to prove their in situ efficacy, and finally introduced within the consortium for protection and promotion of this cheese to disseminate their performances to all dairy factories. The innovation in PDO Pecorino Siciliano cheese production was proven to be respectful of the traditional protocol, the final cheeses preserved their typicality, and the general cheese safety was improved. An overview of the future research prospects is also reported
Modern advances in cheese making: Biopreservation, functionalization, and reusing agri-food by-products
No full textInnovation is essential across various economic sectors, and dairy products hold a significant place in the food market. Innovation in this sector is vital for the economic sustainability of dairy farms. This review explores recent technological advancements in cheese production, including the selection of probiotic cultures, the incorporation of by-products containing polyphenolic compounds, and the use of natural preservatives with antimicrobial properties. Functionalizing dairy products is crucial since they are often unjustly deemed unhealthy. Biopreservation strategies are needed to reinforce the natural image of these foods. Scientific literature indicates that innovation in the primary sector can positively affect rural development and local economies, especially in marginal areas. For instance, cheese can symbolize gastronomic culture and cultural identity, boosting tourism. Modern consumers increasingly appreciate the authenticity and genuine connection that cheese represents. Future perspectives aim to enhance the effectiveness of bioactive compounds in cheese, as well as substances deemed "waste" by other supply chains. This involves evaluating whether these changes are beneficial or restrictive
Biotecnologie applicate alla valorizzazione della “Pagnotta di Piana degli Albanesi”
No full textIl presente articolo riassume il progetto di valorizzazione della Pagnotta di Piana degli Albanesi attraverso lo sviluppo di un impasto acido ottenuto da batteri lattici selezionati dalle materie prime, al fine di legare la produzione al territorio e permettere di recuperare le note di tipicità. Le farine e le semole rappresentano dei veri e propri habitat microbici, la cui composizione può variare in funzione dell’area geografica e delle condizioni di conservazione. Trattandosi di materie prime che non possono essere trattate termicamente prima della trasformazione, esse trasferiscono i loro microrganismi al prodotto in lavorazione.
Pertanto, qualora tali microorganismi esprimano proprietà panarie rappresentano degli utili strumenti per l’esaltazione delle note aromatiche desiderate. Il contributo scientifico riporta le popolazioni lattiche delle materie prime siciliane impiegate nella produzione di pani tipici, la selezione dei batteri lattici e lo scaleup della loro applicazione
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