1,721,056 research outputs found
Potential of high pressure homogenisation on probiotic Caciotta cheese quality and functionality
Full text linkThe probiotic Lactobacillus paracasei A13, treated at 50 MPa sub-lethal high pressure homogenisation (HPH), was used as adjunct for producing Caciotta cheese. The cell HPH treatment was used because it has been proven to increase the in vitro strain functionality. The starters and Lb. paracasei A13 viability, the cheese hydrolytic patterns and organoleptic profiles were monitored. After cheesemaking and during ripening, the Lb. paracasei A13 gastric acid resistance in cheese and the ability of the cheese, containing HPH-treated or untreated cells, to modulate the gut mucosal immune system in mice were evaluated. Traditional Caciotta was used as controls. The HPH-treated probiotic strain maintained high viability for 14 days whilst the physico-chemical analyses on Caciotta cheese containing HPH-treated cells showed a faster ripening, compared to other cheeses. For functional properties, the 50 MPa treatment increased the Lb. paracasei gastric resistance in Caciotta, maintaining high strain viability, but IL-10 producing capacity was lost by HPH-treatment whilst IgA production was not modified.Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Patrignani, Francesca. Universidad de Bologna; ItaliaFil: Tabanelli, Giulia. Universidad de Bologna; ItaliaFil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Siroli, Lorenzo. Universidad de Bologna; ItaliaFil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Gardini, Fausto. Universidad de Bologna; ItaliaFil: Lanciotti, Rosalba. Universidad de Bologna; Itali
POTENTIAL OF HIGH PRESSURE HOMOGENIZATION AND FUNCTIONAL STRAINS FOR NOVEL FUNCTIONAL DAIRY FOODS
No full textFunctional foods are one of the fastest increasing fields in the global food industry since they are positively perceived by the consumers as dietary strategy to reduce the incidence of illness in the humankind. Actually, the use of biotechnological strategies, based on the use of functional and specific strains and sustainable technologies, such as high pressure homogenization, can be a great chance to create innovation in dairy field. Critical discussion on the actual scenario will be the main topic of this chapter
Contribution of Two Different Packaging Material to Microbial Contamination of Peaches: Implications in Their Microbiological Quality
Full text linkAim: Aim of this work was understanding the microbial transfer dynamics from packaging to packed peaches in relation to the packaging used. Method and Results: A challenge test was performed, inoculating Escherichia coli, Pseudomonas spp. and Saccharomyces cerevisiae on cardboards and RPC (Reusable Plastic Containers), and monitoring their cell loads on fruits according to a probabilistic model and a Response Surface Methodology (RSM) in relation to several independent variables (number of fruit lesions, fruit temperature storage and commercialization time). The data recorded on packed peaches for Pseudomonas and S. cerevisiae were modeled to fit the second order model to study the main, interactive and quadratic effects of the independent variables on the cell loads of target microorganisms as well as on the shelf-life of the fruits in relation to packaging material used. The data collected for E. coli were codified as presence (1) or absence (0) and modeled with a logistic regression analysis to assess the probability of E. coli transferring from packaging to fruits in relation to the adopted variables. The data showed a higher contamination frequency of the fruits packed in plastic than in cardboard. Increasing the storage temperature and the number of lesions, the probability of transferring of E. coli from packaging materials to fruits increased, independently on commercialization time or packaging used. For Pseudomonas, the contamination levels detected on fruits packaged in plastic were significantly higher compared to those found on fruits packed in cardboard, independently on the considered variables. The polynomial equations showed the S. cerevisiae cell loads of fruits stored in plastic was positively affected by the quadratic term of temperature. Conclusions: the use of cardboard, compared to plastic, can significantly reduce the potential of microbial transferring from packaging to fruits. The probabilistic and kinetic models used showed a higher microbiological qualities of peaches stored in cardboard boxes, independently on the independent variables considered. The best performances of cardboard, compared to plastic, was probably due to its capability to entrap microbial cells. Significance and Impact: cardboard reduces fruit contamination and increases their shelf-life with positive fallouts on fruit shelf-life and all the logistic and distribution chain
Effects of sub-lethal concentrations of thyme and oregano essential oils, carvacrol, thymol, citral and trans-2-hexenal on membrane fatty acid composition and volatile molecule profile of Listeria monocytogenes, Escherichia coli and Salmonella enteritidis
Full text linkThe aim of this work was to investigate the modifications of cell membrane fatty acid composition and
volatile molecule profiles of Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, during growth
in the presence of different sub-lethal concentrations of thyme and oregano essential oils as well as carvacrol,
thymol, trans-2-hexenal and citral. The results evidenced that the tested molecules induced
noticeable modifications of membrane fatty acid profiles and volatile compounds produced during the
growth. Although specific differences in relation to the species considered were identified, the tested
compounds induced a marked increase of some membrane associated fatty acids, particularly unsaturated
fatty acids, trans-isomers, and specific released free fatty acids. These findings can contribute to the
comprehension of the stress response mechanisms used by different pathogenic microorganisms often
involved in food-borne diseases in relation to the exposure to sub-lethal concentrations of natural
antimicrobials
Bacterial Cellulose Production by Komagataeibacter spp. in Agrifood By-Products
No full textBackground: Bacterial cellulose (BC) is produced by certain acetic acid bacteria (AAB)
and has gained increasing interest due to its versatility and possible applications in various industrial sectors including biomedical, cosmetic and food packaging. However, the high production cost and low BC yield remain an issue. Therefore, it is necessary to develop novel strategies for effective and inexpensive BC production.
Methods: The aim of this study was to assess the capability of five different strains of AAB belonging to the species Komagataeibacter xylinus, Komagataeibacter rhaeticus, and Komagataeibacter hansenii to grow and produce BC on various agri-food by-products: beet molasses, brewery spent grains and cheese whey. The assessment of growth and BC production by the selected strains was done during the incubation of the samples at 28 °C for 10 days.
Results: The results indicated that all the AAB strains were able to grow on all the natural substrates although different growth kinetics was observed. The ability to produce BC was dependent on the AAB strain and the agrifood by-product. Brewery spent grains showed good BC yields by all the strains considered. Conversely, on beet molasses, the highest BC yields were obtained with the strain K. xylinus DSM 2004, reaching 3 g/L of dried pellicle. Whey and molasses were the most selective substrates regarding BC yields; indeed, only the strains K. xylinus DSM 2004, K. rhaeticus LM4, and K. rhaeticus SM1 were able to produce significant amounts of BC. Generally, the BC yield gradually increased with the increase of incubation time, but the rate of BC yield remained almost constant after 7 days in all the substrates considered.
Conclusions: This work allowed to identify the strains capable of producing the
highest quantities of bacterial cellulose in relation to the agri-food by-product used as substrate; however, certain growth variables could be modulated in order to potentially increase and optimize the yields of bacterial cellulose
Lactic acid bacteria and natural antimicrobials to improve the safety and shelf-life of minimally processed sliced apples and lamb's lettuce
No full textOutbreaks of food-borne disease associated with the consumption of fresh and minimally processed fruits and vegetables have increased dramatically over the last few years. Traditional chemical sanitizers are unable to completely eradicate or kill the microorganisms on fresh produce. These conditions have stimulated research to alternative methods for increasing food safety. The use of protective cultures, particularly lactic acid bacteria (LAB), has been proposed for minimally processed products. However, the application of bioprotective cultures has been limited at the industrial level. From this perspective, the main aims of this study were to select LAB from minimally processed fruits and vegetables to be used as biocontrol agents and then to evaluate the effects of the selected strains, alone or in combination with natural antimicrobials (2-(E)-hexenal/hexanal, 2-(E)-hexenal/citral for apples and thyme for lamb's lettuce), on the shelf-life and safety characteristics of minimally processed apples and lamb's lettuce. The results indicated that applying the Lactobacillus plantarum strains CIT3 and V7B3 to apples and lettuce, respectively, increased both the safety and shelf-life. Moreover, combining the selected strains with natural antimicrobials produced a further increase in the shelf-life of these products without detrimental effects on the organoleptic qualities
Innovative strategies based on the use of bio-control agents to improve the safety, shelf-life and quality of minimally processed fruits and vegetables
Full text linkThe consumption of minimally processed fruits and vegetables has increased in recent years. Currently,
the use chemical preservatives is unable to guarantee the safety of minimally processed fruits and
vegetables. These conditions have stimulated research into alternative methods for increasing their
safety and shelf-life. The use of protective cultures, particularly lactic acid bacteria, microorganisms from
indigenous microflora and their antimicrobial products, has been proposed for minimally processed
products. However, the application of bioprotective cultures has been limited at the industrial level. In
this perspective, the aim of this review was to summarize the state-of-the-art application of biocontrol
agents in minimally process
Innovative strategies based on the use of essential oils and their components to improve safety, shelf-life and quality of minimally processed fruits and vegetables
Full text linkMinimally processed fruits and vegetables are one of the major growing sector in food industry. Although important for their nutritional values and convenience, their composition and physicochemical properties affect their microbiological shelf life and overall quality. On the other hand, processing steps as washing, if well performed, can partially reduce the occurring microflora and the use of sanitizers are perceived negatively by the consumers. For this reasons, researchers have proposed some alternatives to the use of traditional sanitizers, such as essential oils which are complex mixtures of volatile compounds, characterized by a strong sensorial impact and produced by many plants as secondary metabolites. In this perspective, this review discusses the growing importance of minimally processed fruits and vegetables and the potential application of essential oils and their components as natural antimicrobial. Finally, the mechanisms of action of these molecules have being reviewed taking into account their use in food systems
Functional and biochemical characterization of pre-fermented ingredients obtained by the fermentation of durum wheat by-products
Full text linkThis work was aimed to characterize functional and biochemical parameters of a bakery ingredient prepared with durum wheat by-products (micronized bran and middling) fermented by a selected microbial consortium composed of yeasts and lactic acid bacteria. The unfermented milling by-products mixture and the mixture fermented by a baker’s yeast were used as reference. The innovative ingredient showed more stable colour indexes compared to the references, a more complex profile in volatile molecules characterized by a higher presence of alcohols, ketones and acids compared to the references. A significant increase in the content of peptides, short chain fatty acids, total phenols, antioxidant activity and prebiotic activity together with a reduction in phytic acid content was observed in the samples fermented by the selected microbial consortium compared to the references. This work provides information on the impact of lactic acid bacteria and yeasts on functional and biochemical characteristics of fermented milling by-product
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