Publications by authors named "M Gabriella Brasca"

84 Publications

High biodiversity in a limited mountain area revealed in the traditional production of Historic Rebel cheese by an integrated microbiota-lipidomic approach.

Sci Rep 2021 May 14;11(1):10374. Epub 2021 May 14.

Institute of Agricultural Biology and Biotechnology, National Research Council, via Einstein, 26900, Lodi, Italy.

Historic Rebel (HR) cheese is an Italian heritage cheese, produced from raw milk during the summer grazing period in the Alps. The aim of this work was (i) to characterize the cheese microbiota, by 16S rRNA gene amplicons sequencing, and the volatile and non-volatile lipophilic fraction, by Gas Chromatography and Dynamic Headspace Extraction-Gas Chromatography-Mass Spectrometry, and (ii) to evaluate their respective associations. HR cheese was dominated by Firmicutes phylum (99% of the entire abundance). The core microbiota was formed by Streptococcus, Lactobacillus, Lactococcus, Leuconostoc and Pediococcus genera together representing 87.2-99.6% of the total abundance. The polyunsaturated fatty acids composition showed a high PUFA n-3, PUFA n-6 and CLA content, two fold higher than typical plain cheeses, positively correlated with pasture altitude. A complex volatilome was detected, dominated in terms of abundance by ketones, fatty acids and alcohols. Total terpene levels increased at higher altitudes, being the main terpenes compounds α-pinene, camphene and β-pinene. The HR cheese showed a great diversity of bacterial taxa and lipophilic fractions among producers, despite belonging to a small alpine area, revealing a scarce cheese standardization and a chemical fingerprint of a typical mountain cheese produced during the grazing period. A deeper knowledge of the variability of HR cheese due to its composition in microbial community and volatile compounds will be appreciated, in particular, by elite consumers looking for niche products, adding economic value to farming in these alpine areas.
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http://dx.doi.org/10.1038/s41598-021-89959-xDOI Listing
May 2021

Proteolytic Traits of Psychrotrophic Bacteria Potentially Causative of Sterilized Milk Instability: Genotypic, Phenotypic and Peptidomic Insight.

Foods 2021 Apr 24;10(5). Epub 2021 Apr 24.

National Research Council, Institute of Sciences of Food Production, Via G. Celoria 2, 20133 Milan, Italy.

The proteolytic traits of the psychrotrophic strains Pseudomonas poae LP5, Pseudomonas fluorescens LPF3, Chryseobacterium joostei LPR1, Pseudomonas fulva PS1, Citrobacter freundii PS37, Hafnia alvei PS46, and Serratia marcescens PS92 were initially investigated by phenotypic and genotypic approaches. Six strains elicited extracellular proteolytic activity, and five expressed the thermostable AprX or (likely) Ser1 enzymes. Then, the strains were inoculated (10 CFU/mL) in microfiltered pasteurized milk and kept at 4 °C for five days. All of the strains reached 10 CFU/mL at the end of storage and five produced thermostable extracellular proteolytic enzymes. The freshly inoculated samples and the corresponding samples at 10 CFU/mL were batch-sterilized (131 °C, 30 s) and kept at 45 °C up to 100 days. The former samples did not gel until the end of incubation, whereas the latter, containing , , , , and gelled within a few days of incubation. The thermostable proteolytic activity of strains affected the peptidomic profile, and specific proteolyzed zones of β-CN were recognized in the gelled samples. Overall, the results confirm some proteolytic traits of psychrotrophic Pseudomonas spp. strains and provide additional insights on the proteolytic activity of psychrotrophic bacteria potentially responsible for sterilized milk destabilization.
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http://dx.doi.org/10.3390/foods10050934DOI Listing
April 2021

Paraprobiotics: A New Perspective for Functional Foods and Nutraceuticals.

Nutrients 2021 Apr 8;13(4). Epub 2021 Apr 8.

Institute of Sciences of Food Production, National Research Council (CNR-ISPA), Via G. Celoria 2, 20133 Milan, Italy.

Probiotics are live microorganisms that confer health benefits on the host. However, in recent years, several concerns on their use have been raised. In particular, industrial processing and storage of probiotic products are still technological challenges as these could severely impair cell viability. On the other hand, safety of live microorganisms should be taken into account, especially when administered to vulnerable people, such as the elderly and immunodeficient individuals. These drawbacks have enhanced the interest toward new products based on non-viable probiotics such as paraprobiotics and postbiotics. In particular, paraprobiotics, defined as "inactivated microbial cells (non-viable) that confer a health benefit to the consumer," hold the ability to regulate the adaptive and innate immune systems, exhibit anti-inflammatory, antiproliferative and antioxidant properties and exert antagonistic effect against pathogens. Moreover, paraprobiotics can exhibit enhanced safety, assure technological and practical benefits and can also be used in products suitable for people with weak immunity and the elderly. These features offer an important opportunity to prompt the market with novel functional foods or nutraceuticals that are safer and more stable. This review provides an overview of central issues on paraprobiotics and highlights the urgent need for further studies aimed at assessing safety and efficacy of these products and their mechanisms of action in order to support decisions of regulatory authorities. Finally, a definition is proposed that unambiguously distinguishes paraprobiotics from postbiotics.
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http://dx.doi.org/10.3390/nu13041225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8068161PMC
April 2021

Assessment of Possible Application of an Atmospheric Pressure Plasma Jet for Shelf Life Extension of Fresh-Cut Salad.

Foods 2021 Mar 1;10(3). Epub 2021 Mar 1.

National Research Council, Institute of Sciences of Food Production, Via G. Celoria 2, 20133 Milan, Italy.

Ready-to-eat salads are very perishable with quality losses within 6-7 days, and the extension of their shelf life is still a challenge. In this work, an atmospheric pressure plasma jet (APPJ) was applied for the surface decontamination of fresh-cut lettuce baby leaves. The APPJ antimicrobial efficiency on the natural microbiota and its impact on some physicochemical attributes of lettuce were evaluated as a function of the treatment duration (0-30 s). Then, the influence of plasma treatment on the salad shelf life was studied, following the growth of aerobic mesophilic bacteria in both untreated and plasma-treated samples during 9 days of storage at 4 °C, together with the plasma-induced changes in physicochemical parameters of lettuce leaves. The APPJ induced a fast (15 s) microbial decontamination (1.3 log CFU/g) of the salad surface. Exposure time and salad-plasma plume distance were the parameters that substantially affected the microbial inactivation. APPJ treatment retarded bacterial growth during the refrigerated storage, as plasma-treated samples were noticeably less contaminated than the non-treated ones in the first 3-4 days. No significant effect were observed on electrolyte leakage, pH, and dry matter content in both the set up phase and the shelf life study.
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http://dx.doi.org/10.3390/foods10030513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8001164PMC
March 2021

Effect of Different Farming Practices on Lactic Acid Bacteria Content in Cow Milk.

Animals (Basel) 2021 Feb 17;11(2). Epub 2021 Feb 17.

National Research Council, Institute of Sciences of Food Production, via Celoria 2, 20133 Milan, Italy.

The natural load of lactic acid bacteria (LAB) in milk is the basis of the production of raw milk cheeses, such as Grana Padano PDO. In the last decades, improvements in livestock hygiene management resulted in bulk cow milk with less than 20,000 colony forming units (CFU) of bacterial count, unable to ensure a sufficient supply of LAB, with a negative impact on cheese quality. This study investigated the relations between farm management practices and prevalence of different groups of bacteria in cow milk. Sixty-two intensive dairy farms located in Lombardy (Italy) where involved, most of them destined as milk for the production of Grana Padano. Season had no significant effect on the content of most of the bacterial groups, except for coliforms. A strong relation among standard plate count (SPC) and other bacterial groups was evidenced. Cluster analysis showed that the most productive farms applied a complete milking routine and produced milk with the lowest value of SPC, the lowest count of the other bacteria, including LAB, but the highest LAB/SPC. The study suggests that complexity of farming practices can affect the microbial population of milk.
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http://dx.doi.org/10.3390/ani11020522DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7922825PMC
February 2021