303 research outputs found

    Raw meat shel life increasing by antimicrobial edible coating

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    The aim of this work is show how the integration of antimicrobial and edible pectin films from food waste could increase the shelf life of different kind of meat[1]. Chicken and beef raw meat are the two type of meat considered; in two different form: hamburger and sliced meat. To obtain this edible film are used low methoxyl (LM) pectin esterification degree 30-36% and amidation degree 14-20%, in addition with glycerol as plasticizers[2]. The antimicrobial activity are improved with LAE (Ethyl-N-lauryl-L-arginine), 1,6 mg/ml[3]. To observe the real activity of LAE and the migration of that from the coating, all kind of meat are wrapped with different coating: • Pectin film without LAE • Reticulated Pectin film without LAE • Pectin Film with LAE • Reticulated Pectin film with LAE To reticulate the film Calcium D-Pantothenate are added by spraying techniques. All the samples are wrapped in the antimicrobial coating, put inside a Styrofoam tray, closed with polyethylene film, and stored at 4°C. The test consist to check the microbial growth during the storage periods with classic microbiological protocol. 10 grams of sample is mixed with 90 ml of sterile physiological water with a stomacher, the solution formed after serial dilution is inoculated inside Plate count agar media. The bacterial colonies in Petri dish, after 24 hour of incubation at 30°C, are counted to determinate Ufc/g so to establish when meat are not more safe for human health[4]. The final goal of this work is show how the integration of not polluting coating, produced from food waste, had a synergic activity with classic packaging to increase shelf life and safety of high perishable food. The point above means a longer life of the plastic packaging too, then a less production of plastic waste and a better health of environment

    Evaluation of the antimicrobial activity of a blend of monoglycerides against Escherichia coli and Enterococci with multiple drug resistance

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    Bacterial antibiotic resistance is a natural phenomenon, seriously affecting the treatment of infections. The biggest danger is that current antibiotics are not able to eradicate the resistant strains. In recent years, alternative antibacterial substances are being sought, which can help in these cases. Fatty acids and monoglycerides are known among the natural substances for their antimicrobial properties and, important detail, bacteria do not develop resistance to them. In this work, we studied the antimicrobial effects of a monoglyceride blend against some multi-resistant Enterococci and Escherichia coli strains. Based on literature data, a blend of fatty acids and their monoglycerides was created and its antimicrobial activity was evaluated against 37 strains of E. coli and 17 Enterococci presenting resistance to at least two antibiotics. A different behavior was observed in the two groups of bacteria, proving that alternative substances can be considerate for the potential treatment of multidrug-resistant strains

    Dessert freddi: criteri per la loro classificazione [Cold dessert: criteria for their classification]

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    The expression “cold desserts” names a heterogeneous group of sweet products, which includes gelati, ice cream, pudding, mousse and more. The present work develop an inventory of all the sweet products falling under the definition of “cold desserts”. To reach this aim, several databases (Mintel GNPD), pastry’s books, industrial, as well as artisanal, products are going to be consulted. Moreover, the research has the objective to advance a rational organization of the sweet products comprised by the “cold dessert”’s definition. Thanks to such a logical organization, it will be possible to develop homogenous groupings of products, according to their characteristics. The variables with the greatest discriminating and grouping power employed in this research are: the product’s temperature of consumption, its structure, and the modalities through which it incorporates the air. The main difference between industrial and artisanal gelato is indeed in the modalities through which the air is incorporated in the products and in their consequently different rheological properties

    Elimination of Salmonella cross-contamination on eggs using antimicrobial coating

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    Gastro-intestinal infections caused by Salmonella strains, together with Campylobacter, are among the most common food-borne diseases in Italy (EFSA journal 2016). Therefore, it is important to avoid the spreading of bacterial colonization on different type of foods. A common vector of Salmonella are eggs, which can be contaminated by the laying hen (vertical or horizontal infection) or by contact with contaminated eggs of food (cross-contamination). At the moment, the Italian prevention practices to control Salmonella spreading are bacterial controls on laying hens and their environment and eggs brushing before packaging. Other countries allow eggs washing, but this process decreases the shelf-life of the product. This study investigates the efficiency of an antimicrobial coating to avoid Salmonella cross-contamination on eggs. Coating the eggs with a pectin-alginate polymer drastically improves their food safety and reduces the recovery of Salmonella colonies from the egg surface. Therefore, the occurrence of cross-contamination would be highly reduced as well. The positive effect of the coating itself showed to be highly effective even without the addition of antibacterial agents such as LAE. This active packaging could guarantee higher safety for eggs and opens the possibility to test this procedure on other food matrices common carriers of potentially pathogenic bacteria

    Exploring the Role of Interdisciplinarity in Physics: Success, Talent and Luck

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    Although interdisciplinarity is often touted as a necessity for modern research, the evidence on the relative impact of sectorial versus to interdisciplinary science is qualitative at best. In this paper we leverage the bibliographic data set of the American Physical Society to quantify the role of interdisciplinarity in physics, and that of talent and luck in achieving success in scientific careers. We analyze a period of 30 years (1980-2009) tagging papers and their authors by means of the Physics and Astronomy Classification Scheme (PACS), to show that some degree of interdisciplinarity is quite helpful to reach success, measured as a proxy of either the number of articles or the citations score. We also propose an agent-based model of the publication-reputation-citation dynamics reproduces the trends observed in the APS data set. On the one hand, the results highlight the crucial role of randomness and serendipity in real scientific research; on the other, they shed light on a counter-intuitive effect indicating that the most talented authors are not necessarily the most successful ones.Comment: 21 pages, 19 figure

    Assessment of the secondary shelf life of Bolognese sauce based on domestic use simulation

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    Household food waste contributes significantly to global food waste throughout the food supply chain, resulting in a substantial waste of resources. The inability of consumers to utilize food before it spoils generally leads to its disposal, thus representing one of the causes of food waste. The secondary shelf life (SSL) is the period a product should be consumed within once open, specified in the label, which sometimes is extremely short and may lead to a significant amount of discarded food. This study focuses on evaluating the SSL of Bolognese sauce through domestic use simulation and monitoring its microbiological and sensory quality, to explore the potential extension of the SSL, allowing consumers more time to consume the product. Results show that, even under harsh usage conditions, Bolognese sauce can have a SSL longer than 13 days, 2–3 times longer than the current SSL. The results highlight the influence of consumer behavior in determining the SSL, suggesting that improved food management could further reduce household food wast

    Properties of poly(vinyl alcohol) films as determined by thermal curing and addition of polyfunctional organic acids

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    The aim of the study was to assess the effect of the addition of citric and malic acid and heat curing on the mechanical, physical and optical properties of poly(vinyl alcohol) (PVOH) films. The addition of the organic acids without successive thermal treatments has a mere plasticising effect, while their application with heat curing has a combined crosslinking and plasticising effect. While conventional plasticizers and crosslinkers improve either extensibility or tensile strength of films, respectively, the addition of citric and malic acid coupled with heat curing determined good tensile strength and extensibility. Hydrophilicity was significantly reduced by thermal curing and even further reduced with the organic acids addition. The high transparency of the PVOH films was not affected either by heat-curing, acid addition and their combination, while the use of high curing temperature coupled with acid addition caused a slight yellowing of the films. The use of citric and malic acid in combination with thermal curing is a viable strategy for tailoring the performances of PVOH films thus broadening their spectrum of application

    Improving the post-harvest quality of fruits during storage through edible packaging based on guar gum and hydroxypropyl methylcellulose

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    Fruits are particularly susceptible to post-harvest decay. In this context, bio-based coatings could be a useful andsustainable approach to overcome this problem. The EU Commission is very restrictive about food additives andmaterials in contact with food, regulated respectively by Reg. UE (CE) 1333/2008 and Reg. UE (CE) 10/2011. Inthis research, different percentages of hydroxypropyl methylcellulose (H)-guar gum (G) (1–2% w/v) and po-tassium sorbate (PS) (0–2% w/v) were used to produce coatings to be applied on tomatoes (Solanum lycopersi-cum) and oranges (Citrus sinensis). The efficacy of the coatings was firstly evaluated through an accelerated test(28 ◦C 90% RH, 20 days) on artificially wounded fruits, and then under storage conditions (8 ◦C 95% RH, 6weeks). The physical and chemical parameters of the fruits were periodically analyzed and used to evaluate theeffect of the coatings on the fruit quality through a multivariate approach (PCA). All coatings were effective inpreserving fruits under refrigeration against Penicillium spp. and Alternaria spp., but PS led to significant fruitweight loss despite its strong fungistatic activity. Biopolymers showed potential for preserving fruit freshness, butalternative antifungal agents without adverse weight effects should be explored using a similar statisticalapproach. (16) (PDF) Improving the post-harvest quality of fruits during storage through edible packaging based on guar gum and hydroxypropyl methylcellulose. Available from: https://www.researchgate.net/publication/374295352_Improving_the_post-harvest_quality_of_fruits_during_storage_through_edible_packaging_based_on_guar_gum_and_hydroxypropyl_methylcellulose#fullTextFileContent [accessed Oct 06 2023]

    Metodi molecolari per l’identificazione di lieviti isolati dalle paste acide siciliane

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    Le paste acide sono impasti fermentati grazie alla presenza di una ricca floramicrobica costituita da batteri lattici e lieviti. Questi ultimi rivestono un ruolomolto importante, in quanto i prodotti primari del loro metabolismo energetico,anidride carbonica ed etanolo, determinano l’aumento di volume dell’impasto ela formazione della struttura porosa e alveolata della pasta, mentre alcuniprodotti secondari contribuiscono a determinare l’aroma tipico del pane. Lepaste acide sono costituite da farina, acqua e “lievito naturale”. Quest’ultimo èl’impasto della lavorazione precedente opportunamente rinnovato da impiegarecome coltura starter. Originariamente il lievito naturale era ottenutodall’acidificazione spontanea dell’impasto, dovuta alla contaminazione dellematerie prime e dagli attrezzi utilizzati. Il tempo necessario alla maturazionedegli impasti varia da qualche ora a tutta la notte precedente la lavorazionevera e propria. Invece con il termine “lievito madre” si intende la frazione diimpasto conservata in forma disidratata o congelata da impiegare come inoculoper la produzione di lievito naturale.In questo lavoro sono stati identificati, impiegando tecniche molecolari, ilieviti che caratterizzano gli impasti acidi siciliani. L’elettroforesi in campopulsato (PFGE), la PCR/RFLP delle regioni NTS2 (Non-Transcribed spacer2) eITS (Internal Transcribed Spacer) contenute nel DNA ribosomale (rDNA) edancora il parziale sequenziamento della subunità 26S del rDNA sono statiimpiegati per l’identificazione dei ceppi in esame. I risultati, di seguito esposti,mostrano la presenza di ceppi di lievito appartenenti alle specie Saccharomycescerevisiae, Saccharomyces anamensis, Issatchenkia orientalis, Candida milleri
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