Novel freshness indicators were developed using a starch-polyvinyl alcohol matrix incorporating pomegranate juice as a natural source of anthocyanins. To ensure a sustainable production process, the anthocyanins were not isolated from the juice, thus avoiding the use of organic solvents and energy-intensive extraction processes. The resulting smart indicators were characterised in terms of their optical properties, microstructure, infrared spectrum, water affinity, color response across a range of pH values, reactivity to volatile amines (ammonia, trimethylamine and dimethylamine), and color reversibility. The smart indicators were tested in fish fillet packaging systems under controlled temperature conditions (2.8 degrees C), where their performance was evaluated over time. An artificial intelligence tool was employed to classify the visual appearance of the films during storage. Microstructure analysis revealed satisfactory microstructural integrity and compatibility between the pomegranate juice and the biopolymer carrier. The incorporation of pomegranate juice enhanced the hydrophilicity of the membranes. The color sensitivity test demonstrated that the smart films responded effectively to increases in pH and volatile amine concentrations. A perceptible color shift from red to purple-green was observed from the early stages of spoilage (day 4-5), with intensity increasing as degradation advanced. The indicator response aligned with changes in headspace gas composition and was consistent with microbiological and chemical quality indicators of fish flesh, highlighting their potential as effective tools for real-time monitoring of fish freshness and spoilage.

The selection of adequate plasticizers to synthesize biopolymer biodegradable and edible films for food packaging is crucial to develop materials with appropriate barriers, mechanical and physicochemical properties. The aim of the study was to develop hydroxypropyl methyl cellulose (HPMC) based films with hydrophilic and hydrophobic plasticizers and evaluate their effectiveness as green packaging materials for gilthead seabream fillets. Mechanical properties, water barrier, surface hydrophobicity, optical and UV–visible barrier properties were determined. The films produced were transparent with excellent optical appearance and good preventive ability against UV radiation. HPMC based films with glycerol as plasticizer were more compact and had lower thickness (45.43±3.33 μm) and higher young’s modulus, indicating stiffer, less flexible films (1613.22±492.88 MPa). In contrast, films plasticized with oleic acid had the highest elongation at break (30.35±4.21 %), indicating greater flexibility. The films with glycerol were hydrophilic (contact angle equal to 81.47±6.65°) while the films with fatty acids (oleic and linoleic acid) were hydrophobic (contact angle > 90°). The hydrophobic films had also better water barriers compared to films with glycerol. All tested packaging materials resulted in similar preservative effect on packed gilthead seabream fillets, leading in shelf life 7–8 days at 2 °C. The results of the study show the potential of the developed biodegradable films to replace the conventional synthetic petroleum based materials in fresh fish packaging.

Novel smart packaging systems demonstrate great potential in addressing challenges related to cold chain management and in reducing food waste. This study focused on the development of smart indicators composed of polyvinyl alcohol and starch, infused with anthocyanins extracted from winery residues. The extract held an adequate amount of anthocyanins (similar to 339 mg/L cyanidin-3-glucoside equivalents) and showed increased pH sensitivity. Similarly, the obtained smart indicators exhibited high pH responsivity (Delta Epsilon = 39.37) and exhibited sensitivity to volatile amines, as tested with trimethylamine (Delta Epsilon reached 53.34), dimethylamine (Delta Epsilon reached 54.71) and ammonia vapour solutions (Delta Epsilon reached 57.69). Based on microstructure and infrared spectra, the incorporation of anthocyanins slightly enhanced the miscibility of the polymers. Water solubility, swelling index and wettability values did not show significant variations between the control indicators and the smart indicators. The films were also evaluated for water adsorption, water solubility, wettability and colour stability over a 45-day storage period under three different temperatures (5 degrees C, 15 degrees C and 25 degrees C) and five distinct relative humidity (33%, 56%, 75%, 90% and 98%) environments. Increased temperature and relative humidity conditions compromised the functional properties of the films. Subsequently, the smart indicators were incorporated into sealed packages of gilthead sea bream to monitor fish freshness under constant and variable temperature conditions. Fish spoilage was verified using microbiological (total viable counts, Pseudomonas spp. and Enterobacteriaceae) as well as physicochemical (pH, total volatile basic nitrogen) indices. The colour change (from pinkish-red to pale green-blue) of the smart indicators, along with the total colour difference (Delta Epsilon reached 23.5 at constant and 35.7 at variable temperature conditions), indicated that the fabricated smart labels were capable of reflecting temperature fluctuations during fish storage and providing insights into the spoilage level of the packaged fish.

In the seafish sector, industrial processing and by-catch currently lead to the waste of over 36 % of global fish production by weight. This is largely due to insufficient revalorization of by-products and the underdevelopment of sustainable practices to manage these discarded volumes, which are often disposed of or released into the environment, contributing to pollution. In this study, antimicrobial proteins were extracted from fish by-products for incorporation into biopolymer formulations. Specifically, the focus was on lysozyme, which was targeted using a molecular-proteomic approach. Protein extractions were conducted at various pH levels from Gilthead seabream (Sparus aurata) tissues (skin with scales and mucus, liver, and intestine) normally discarded during processing, to assess recovery of proteins from the selected tissues. The extracted proteins were separated using mild ion-exchange chromatography, followed by quantification and qualitative analysis via SDS-PAGE. The expression levels of lysozyme types -g and -c were quantified through Real-Time qPCR. The antimicrobial activity of the extracted proteins was assessed against Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) bacteria using a Minimal Inhibitory Concentration (MIC) assay. The proteins were subsequently incorporated into biodegradable film-forming solutions based on hydroxypropyl methylcellulose/chitosan and hydroxypropyl methylcellulose/guar gum mixtures. These films were further tested against the same human pathogens. The results demonstrate the feasibility of extracting proteins from fish by-products using a non-targeted buffer pH extraction approach, which, even without further chromatographic purification, exhibited promising intrinsic antimicrobial activity for potential applications in the food industry.

The rising packaging industry together with global demand for sustainable production has increased the interest in developing biodegradable packaging materials. The aim of the study was to develop edible films based on pectin, gelatin, and hydroxypropyl methylcellulose and evaluate their applicability as biodegradable packaging materials for gilthead seabream fillets. Mechanical properties, water barriers, wettability of the films through contact angle measurement, optical, and UV–Vis barrier properties were evaluated for food packaging applications. The effective blend of polysaccharide and protein film-forming solutions was confirmed by the produced films with excellent optical properties, acceptable mechanical properties and adequate barriers to water vapor. The contact angle for pectin based and gelatin based films were higher than 90° indicating the hydrophobic films, while HPMC based films had contact angle lower than 90°. The produced films were tested as alternative and environmentally friendly packaging materials for gilthead seabream fillets during refrigerated storage. All tested packaging conditions resulted in similar shelf-life in packed gilthead seabream fillets (i.e. 7–8 days at 2 °C). The results showed that the developed films may reduce the use of conventional petroleum-based food packaging materials without affecting the shelf-life of fish.

Background: Food technology has played a crucial role since the beginning of human civilization. Throughout the centuries, the evolution of food processing has led to an increase of food safety and quality, enhancing the overall quality of human life. Lately, academic research and industries have gained awareness about the impact of conventional preservation technologies like heat sterilization and chemical preservatives on environment and economy, besides the detrimental effects on the organoleptic and nutritional quality of foods. This consciousness oriented the efforts towards more sustainable techniques, paving the way to a new "green era" of food technology.Scope and approach: This work explores seven non-thermal technologies, describing their theoretical principles, mechanism of action, effect on microorganisms, advantages, and limitations. Besides, the concept of hurdle technology to overcome the criticisms related to single processing techniques is highlighted.Key findings and conclusions: Non-thermal technologies have the potential to substitute conventional techniques for microbial inactivation, improving the safety and quality of food. The efficiency of each technique strongly relies on the process parameters (treatment intensity; exposure time), equipment (geometry; conformation), product (physical state; composition; viscosity; geometry), and microorganism characteristics (strain; concentration; growth phase; resistance mechanisms). In this sense, the hurdle approach allows to overcome the limitations related to the single technologies, broadening their efficiency and application range, and minimizing their impact on food quality. Further studies are recommended to better understand the mechanisms of mutual interaction among these techniques when combined together in specific conditions, in view of their scaling-up for commercial applications.

Recently, academic research and industries have gained awareness about the economic, environmental, and social impacts of conventional plastic packaging and its disposal. This consciousness has oriented efforts towards more sustainable materials such as biopolymers, paving the way for the “green era” of food packaging. This review provides a schematic overview about polymers and blends of them, which are emerging as promising alternatives to conventional plastics. Focus was dedicated to biopolymers from renewable sources and their applications to produce sustainable, active packaging with antimicrobial and antioxidant properties. In particular, the incorporation of plant extracts, food-waste derivatives, and nano-sized materials to produce bio-based active packaging with enhanced technical performances was investigated. According to recent studies, bio-based active packaging enriched with natural-based compounds has the potential to replace petroleum-derived materials. Based on molecular composition, the natural compounds can diversely interact with the native structure of the packaging materials, modulating their barriers, optical and mechanical performances, and conferring them antioxidant and antimicrobial properties. Overall, the recent academic findings could lead to a breakthrough in the field of food packaging, opening the gates to a new generation of packaging solutions which will be sustainable, customised, and green.

This study evaluated the effectiveness of a novel pectin-based edible coating (PBEC), alone or added with the antagonistic yeast Wickerhamomyces anomalus BS91 (PBECY), in reducing postharvest rots of Tarocco orange fruit. Their antifungal efficacy was assessed in vitro and in vivo, as well as their ability to preserve fruit quality under refrigerated conditions on three different cultivars, comparing a commercial wax amended with a fungicide. For all the treatments, the decay incidence, physiological disorders, weight loss and physical-chemical parameters were evaluated. The in vivo test results indicated that PBECY enhanced the antifungal effect compared to PBEC, given the significant reduction (p < 0.01) of Penicillium digitatum (PD) decay incidence (up to 90%). After 30 d of cold storage, both PBEC and PBECY reduced fruit decay (p < 0.05) in all cultivars, with values between 0 and 1.2%, relatively to the untreated control (up to 10%). Pectin-coated fruit showed a cultivar-dependent weight loss, with values comparable or higher to the other treatments, respectively for T. Lempso and T. Messina, whereas weight loss in T. Sciara was higher only when coated with PBEC. Fruit physical and chemical parameters were preserved until 30 d of storage, thus demonstrating the potential of this edible coating for future industrial application.

Cold storage coupled with gaseous ozone represents a potential strategy to reduce or inhibit the presence of pathogenic and spoilage bacteria in a food storage cold chamber. This study aims to evaluate the impact of gaseous ozone treatment (0.05 ppm at exposure times of 30 and 60 min) on the bacterial contamination of internal surface and air in a cold chamber (3 degrees C) intended for food storage. The bacterial load of internal surfaces was reduced by 0.99 +/- 0.24 and 1.35 +/- 0.27 log after 30 and 60 min ozone treatment, respectively. Airborne bacterial load was reduced by 0.93 +/- 0.24 log after 30 min ozone treatment and became non-detectable after 60 min. Gaseous ozone treatments (0.05 ppm at exposure times of 1, 2, 6, 24, 30, and 48 hr) of the cold chamber were investigated to evaluate the effectiveness of this technology against Escherichia coli, Listeria monocytogenes, Salmonella enterica Typhimurium, Campylobacter jejuni, and Pseudomonas fluorescens cultured in broth cultures. Ozone treatment was effective against C. jejuni since the population at the highest concentration of inoculum (3.34 log CFU/plate) was reduced by 2.23 log after 1 hr and it was completely undetectable after 2 hr. S. enterica and E. coli showed the highest resistance to short ozone treatment since 6 hr treatment did not show antibacterial activity whereas after 24 hr treatment around 2 log reduction was observed for both pathogens. Short ozone treatment did not affect L. monocytogenes viability. P. fluorescens showed high sensitivity to short treatments, with 0.75-1.32 log reductions after 1 hr and further 0.22-0.53 log reductions after 6 hr.

Sourdoughs represent an awesome example of ecosystem in which yeasts and lactic acid bacteria (LAB) interact with each other, defining the characteristics of the final product in terms of composition, texture, taste and flavor. Therefore, the identification of dominant yeasts and LAB involved in the fermentation process can lead to the selection of starters with suitable fermentation aptitude and capable of producing desired aromas and/or aromatic precursors. In this work, two sourdoughs samples (A and B) for Panettone production were collected from an artisan bakery. Yeasts and bacteria were isolated at different fermentation steps on selective agar media. A total of 120 isolates were obtained and firstly characterized by conventional microbiological methods. Afterward, genomic DNA was extracted from the cultures, and (GTG)5-PCR fingerprinting analysis was carried out to reduce the redundance among the isolates. Representative yeasts and LAB strains, having a unique profile, were identified by sequencing the D1/D2 domain of the 26S rRNA and the 16S rRNA genes, respectively. The results highlighted the occurrence of Kazachstania humilis and Fructilactobacillus sanfranciscensis in both sourdoughs. Among LAB, also some other strains belonging to Lactobacillus genus were found. Moreover, Saccharomyces cerevisiae and Staphylococcus spp. strains were detected in sample B. In this study, a pool of yeasts and LAB strains for producing starter cultures with specific technological traits for sourdoughs production was obtained.

Practical applications This study highlights the potential application of pectin-alginate blend (PA) and pectin-alginate-LAE blend (PAL) coatings to eliminate Salmonella enteriditis 10,118 cross-contamination without changing the shelf-life of fresh eggs and their physico-chemical properties during storage at 7 degrees C for 42 days. Egg shells were dipped in a solution of Salmonella enteritidis 10,118 with a concentration of 7 x 10(6) cfu/ml to assess Salmonella cross-contamination. PA and PAL coatings did not have a significant effect on shelf-life based on physico-chemical properties. The egg shells treated with PA and PAL coatings had a significantly lower microbial population compared to the uncoated egg shells. PA and PAL coatings effectively inhibited the growth of Salmonella after 1 and 7 days of storage, respectively. In addition, no outgrowth was observed up to 42 days. This study highlights the results of coating applications on eggs to enhance food safety. In the food industry, the only technology applied to eggs is brushing, however, this technique does not eliminate the safety risks such as Salmonella and other pathogenic bacteria. The coating enhances the shelf-life of eggs and their safety in terms of human consumption, by blocking the horizontal cross-contamination. Our results can be integrated with other studies to bring this technology from the lab to the egg industry.

This study compared the faecal microbial composition of formula‐fed infants who did and did not have colic.

This study compared the faecal microbial composition of formula-fed infants who did and did not have colic. Faecal samples from formula-fed infants under 16 weeks of age with (n = 38) and without (n = 39) colic were collected at Department of Pediatrics in Turin, Italy, between February 2014 and October 2015. The pH and faecal ammonia were determined and total bacteria, bifidobacteria , lactic acid bacteria and coliforms were quantified by fluorescent in situ hybridisation (FISH). Faecal ammonia was significantly higher in the colicky infants than in the controls (483 vs. 216 μ g/g, p < 0.05). The FISH counts of total bacteria were lower in colicky infants (1.8E10 ± 1.5E10) than in the controls (3.4E10 ± 3.0E10) (p < 0.05). The relative abundance of coliform bacteria was significantly higher in colicky infants (p < 0.05). No differences were observed for the bifidobacteria and lactic acid bacteria counts between the two groups. Our comparison of formula-fed infants with and without colic revealed significant differences in total bacteria, Enterobacteriaceae and faecal ammonia. This study provides the stimulus for further studies of the gut microbiome, using new methods of analysis such as 16S metagenomics sequencing in order to lead to more tailored dietary approaches.

Parmigiano Reggiano (PR) is a raw-milk, hard cooked, long-ripened cheese of high quality and nutritional value. Long ripening times allow for extensive proteolysis of milk proteins to yield a number of peptides, some of which have potential healthy bioactive properties. This study aimed to: i) determine the peptide profile of PR cheese subjected to simulated gastrointestinal transit; ii) evaluate in vitro whether the peptides could support growth of beneficial microbial groups of the gut microbiota. PR samples were subjected to in vitro digestion, simulating oral, gastric, and duodenal transit. Liquid chromatography coupled with tandem mass spectrometry revealed that digestion caused the disappearance of the serum proteins and most of the original peptides, while 71 new peptides were found, all ranging from 2 to 24 residues. The digests were given as sole nitrogen source to pure cultures of Bifidobacterium (27 strains) and Lactobacillus (30 strains), and to bioreactor batch cultures of human gut microbiota. Most of bifidobacteria and lactobacilli grew more abundantly on PR digests than on the control peptone, and exhibited strain- or species-specific peptide preferences, as evidenced by principal component analysis. Bifidobacteria generally consumed a greater amount of peptides than lactobacilli, in terms of both the mean peptide consumption and the number of peptides consumed. For bifidobacteria, peptide preferences were very diverse, but a core of 10 peptides with 4 or 5 residues were consumed by all the strains. Lactobacilli behaved more homogenously and consumed nearly only the same 6 peptides, mostly dipeptides. The peptide preferences of the different groups of bifidobacteria and lactobacilli could not be ascribed to features such as the length of the peptide or the abundance of residues with peculiar properties (hydrophobicity, polarity, charge) and likely depend on specific proteases and/or peptide transporters preferentially recognizing specific sequence motifs. The cultures of human colonic microbiota confirmed that PR digest promoted the growth of commensal bifidobacteria. This study demonstrated that peptides derived from simulated gastrointestinal digestion of PR supported the growth of most lactobacilli and bifidobacteria.

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.

Conjugated linoleic acids (CLA) are positional and geometric isomers of linoleic acid involved in a number of health aspects. In humans, CLA production is performed by gut microbiota, including some species of potential probiotic bifidobacteria. 128 strains of 31 Bifidobacterium species were screened with a spectrophotometric assay to identify novel CLA producers. Most species were nonproducers, while producers belonged to B. breve and B. pseudocatenulatum. GC-MS revealed that CLA producer strains yielded 9cis,11trans-CLA and 9trans,11trans-CLA, without any production of other isomers. Hydroxylated forms of LA were absent in producer strains, suggesting that the myosin-cross-reactive antigen (MCRA) protein that exerts hydratase activity is not involved in LA isomerization. Moreover, both CLA producer and nonproducer species bear a MCRA homologue. The strain B. breve WC 0421 was the best CLA producer, converting LA into 68.8% 9cis,11trans-CLA and 25.1% 9trans,11trans-CLA. Production occurred mostly during the lag and the exponential phase. For the first time, production and incorporation of CLA in biomass were assessed. B. breve WC 0421 stored CLA in the form of free fatty acids, without changing the composition of the esterified fatty acids, which mainly occurred in the plasmatic membrane.

SCOPE:This study aimed to improve the knowledge of secoisolariciresinol diglucoside (SDG) transformation by human gut microbiota.METHODS AND RESULTS:SDG-supplemented microbiota cultures were inoculated with the feces of five subjects. The same volunteers received a flaxseed supplement for 7 days. SDG metabolites in cultures, feces, and urine were monitored by LC-ESI-QTOF and LC-DAD. In all cultures, SDG was deglycosylated to secoisolariciresinol (SECO) within 12 h. SECO underwent successive dehydroxylations and demethylations yielding enterodiol (4-18% conversion) and enterolactone (0.2-6%) after 24 h. Novel intermediates related to SECO, matairesinol (MATA), and anhydrosecoisolariciresinol (AHS) were identified in fecal cultures. These metabolites were also found after flaxseed consumption in feces and urine (in approximate amounts between 0.01-47.03 μg/g and 0.01-13.49 μg/mL, respectively) in their native form and/or modified by phase II human enzymes (glucuronide, sulfate and sulfoglucuronide conjugates).CONCLUSIONS:Derivatives of MATA and AHS are described for the first time as intermediates of SDG biotransformation by intestinal bacteria, providing a more comprehensive knowledge of lignan intestinal metabolism. The transformations observed in vitro seem to occur in vivo as well. The detection in urine of SDG intermediates indicates their gut absorption, opening new perspectives on the study of their systemic biological effects.

Cereal fibres such as wheat bran are considered to offer human health benefits via their impact on the intestinal microbiota. We show here by 16S rRNA gene-based community analysis that providing amylase-pretreated wheat bran as the sole added energy source to human intestinal microbial communities in anaerobic fermentors leads to the selective and progressive enrichment of a small number of bacterial species. In particular, OTUs corresponding to uncultured Lachnospiraceae (Firmicutes) related to Eubacterium xylanophilum and Butyrivibrio spp. were strongly enriched (by five to 160 fold) over 48 h in four independent experiments performed with different faecal inocula, while nine other Firmicutes OTUs showed >5-fold enrichment in at least one experiment. Ferulic acid was released from the wheat bran during degradation but was rapidly converted to phenylpropionic acid derivatives via hydrogenation, demethylation and dehydroxylation to give metabolites that are detected in human faecal samples. Pure culture work using bacterial isolates related to the enriched OTUs, including several butyrate-producers, demonstrated that the strains caused substrate weight loss and released ferulic acid, but with limited further conversion. We conclude that breakdown of wheat bran involves specialist primary degraders while the conversion of released ferulic acid is likely to involve a multi-species pathway.

Different culture-dependent and independent methods were applied to investigate the population of bifidobacteria and lactobacilli in the feces of five healthy subjects. Bacteria were isolated on MRS, a complex medium supporting growth of lactobacilli and bifidobacteria, and on three selective media for bifidobacteria and two for lactobacilli. Taxonomic characterization of the isolates was carried out by RAPD-PCR and partial 16S sequencing. The selectivity of genus-specific media was also investigated by challenging colonies from MRS plates to grow onto each medium. In parallel, a quantitative and qualitative description of bifidobacteria and lactic acid bacteria was obtained by FISH, qPCR, TRFLP, and 16S rRNA gene sequencing. Bifidobacteria did not fail to grow on their specific media and were easily isolated and enumerated, showing comparable quantitative data among culture-dependent and -independent techniques. The Bifidobacterium species identified on plates and those extracted from TRFLP and 16S rRNA gene sequencing were mostly overlapping. Selective media for lactobacilli gave unsuitable results, being too stringent or too permissive. The quantification of lactobacilli through selective plates, qPCR, FISH, and 16S rRNA gene sequencing gave unreliable results. Therefore, unlike bifidobacteria, intestinal lactobacilli are still problematic in terms of quantification and accurate profiling at level of species and possibly of strains by both culture-dependent and culture-independent techniques.