Combined Effect of Citric Acid and Polyphenol-Rich Grape Seed Extract towards Bioactive Smart Food Packaging Systems

Alginate films (2% w·v−1) were prepared with varying concentrations (5–20% w/w) of citric acid and aqueous grape seed extract (GSE) filtrate (11.66 ± 1.32 g GAE/L) using the solvent-evaporation method. Crosslinking alginate via ester bonds (FTIR analysis) with citric acid up to 10% (w/w) led to a 33% increase in tensile strength, a 34% reduction in water vapor transmission rate (WVTR), and had no impact on elongation at break. Crosslinking alginate with citric acid in the presence of GSE increased the tensile strength by 17%, decreased WVTR by 21%, and significantly improved DPPH scavenging activity. Moreover, after incubation for 24 h at 37 °C, the film-forming solutions exhibited increased antimicrobial activity, resulting in 0.5- and 2.5-log reductions for Escherichia coli and Staphylococcus aureus, respectively, compared to the values obtained without the addition of GSE. The stronger inhibitory effect observed against Gram-positive bacteria can be attributed to the unique composition and structure of their cell walls, which creates a barrier that restricts the penetration of polyphenols into the cells. The pH adjustment of the GSE film-forming solution from 2.0 to 10.0 shifted the UV/VIS absorption spectra, resulting in a colour change from yellow to red. The findings of this study have showcased the potential of combining GSE and citric acid to enhance the functionality and bioactivity of alginate films for applications in smart food packaging.publishedVersio

Susceptibility and transcriptomic response to plasma-activated water of Listeria monocytogenes planktonic and sessile cells

[EN] Plasma-Activated Water (PAW) was generated from tap water using a surface dielectric barrier discharge at different discharge power (26 and 36 W) and activation time (5 and 30 min). The inactivation of a three-strain Listeria monocytogenes cocktail in planktonic and biofilm state was evaluated. PAW generated at 36 W-30 min showed the lowest pH and the highest hydrogen peroxide, nitrates, nitrites contents and effectiveness against cells on planktonic state, resulting in 4.6 log reductions after a 15-min treatment. Although the antimicrobial activity in biofilms formed on stainless steel and on polystyrene was lower, increasing the exposure time to 30 min allowed an inactivation >4.5 log cycles. The mechanisms of action of PAW were investigated using chemical solutions that mimic its physico-chemical characteristics and also RNA-seq analysis. The main transcriptomic changes affected carbon metabolism, virulence and general stress response genes, with several overexpressed genes belonging to the cobalamin-dependent gene cluster.S

Understanding how micro-organisms respond to acid pH is central to their control and successful exploitation

Microbes from the three domains of life, bacteria, archaea and eukarya, share the need to sense and respond to changes in the external and internal concentrations of protons. When the proton concentration is high, acidic conditions prevail and cells must respond appropriately to ensure that macromolecules and metabolic processes are sufficiently protected to sustain life. While we have learned much in recent decades about the mechanisms that microbes use to cope with acid, including the unique challenges presented by organic acids, there is still much to learn and much to be gained from developing a deeper understanding of the effects and responses to acid in microbes. In this perspective article, we survey the key molecular mechanisms that are known to be important for microbial survival during acid stress. We discuss the research approaches that have been taken to investigate the problem and highlight promising new avenues. We highlight the importance of understanding acid stress in controlling spoilage and pathogenic microbes in the food chain. We discuss the influence of acid on pathogens during the course of infections and highlight the potential of using organic acids in treatments for some types of infection. We explore the influence of acid stress on photosynthetic microbes, and on biotechnological and industrial processes, including those needed to produce organic acids. Finally, we invite colleagues with an interest in microbial responses to low pH to participate in the EU-funded COST Action project called EuroMicropH and contribute to a comprehensive database of literature on this topic that we are making publicly available

Safety of Beta‐lactoglobulin as a Novel food pursuant to Regulation (EU) 2015/2283

[EN] Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on beta-lactoglobulin (BLG) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF (≥ 90% w/w dry matter protein) consists of BLG as primary component (≥ 90% of total protein), which is equivalent to BLG present in bovine milk and whey protein isolate (WPI). The NF is produced from bovine whey by crystallisation under acidic or neutral conditions. The NF is proposed to be used as a food ingredient in isotonic and sport drinks, whey powder and milk-based drinks and similar products, and in food for special medical purposes as defined in Regulation (EU) No 609/2013. The target population is the general population. The highest daily intake of the NF was estimated for children of 3 to < 10 years of age as 667 mg/kg body weight (bw) per day. The NF presents proximate composition and content of essential amino acids similar to those in WPI. The Panel notes that the highest mean and highest 95th percentile daily protein intakes from the NF are below the protein population reference intakes for all population groups. Although a tolerable upper intake level has not been derived for protein, the protein intake from the NF may nevertheless further contribute to an already high dietary protein intake in Europe. The exposure to the reported minerals does not raise concerns. The Panel considers that the consumption of the NF is not nutritionally disadvantageous. No genotoxic concerns were identified from the standard in vitro test battery. No adverse effects were observed in the subchronic toxicity study, up to the highest dose tested, i.e. 1,000 mg NF/kg bw per day. The Panel concludes that the NF is safe under the proposed conditions of use.SIThe Panel wishes to thank EFSA Staff Reinhard Ackerl, Paolo Colombo, Céline Dumas, Wolfgang Gelbmann and Emanuela Turla for the support provided to this scientific output

Safety of the extension of use of 2’‐fucosyllactose/difucosyllactose (2’‐FL/DFL) mixture and lacto‐N‐tetraose (LNT) as novel foods in food supplements for infants pursuant to Regulation (EU) 2015/2283

© 2022 European Food Safety Authority. EFSA Journal Published by Wiley-VCH GmbH on behalf of European Food Safety Authority[EN] Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of the extensions of use of the authorised novel foods (NFs) 2’-fucosyllactose/difucosyllactose (2’-FL/DFL) mixture and lacto-N-tetraose (LNT) in food supplements (FS) for infants pursuant to Regulation (EU) 2015/2283. The NFs are produced by fermentation with genetically modified strains of Escherichia coli K-12 DH1 and already included in the EU list of NF. The applicant stated that no changes in the production process or the identity of the NFs occurred. The applicant proposes an extension of use of the NF containing 2’-FL/DFL mixture in FS intended for infants ( 6 months. The applicant also proposes an extension of use of LNT in FS intended for infants ( 6 months. The intake per kg body weight of 2’-FL/DFL and LNT from the proposed maximum use levels of the respective NFs in FS for infants does not exceed the lowest estimated mean intake of naturally occurring 2’-FL/DFL and it is similar to the highest estimated mean intake of LNT by breastfed infants. In addition, the Panel notes that the proposed uses of the NFs in FS for infants result in lower maximum daily intakes than those from the already authorised uses of the NFs for the same population group. The Panel concludes that the uses of the NFs containing either 2’-FL/DFL or LNT in FS for infants are safe under the proposed conditions of use.S

Safety of 6'-sialyllactose (6'-SL) sodium salt produced by derivative strains of Escherichia coli BL21 (DE3) as a novel food pursuant to Regulation (EU) 2015/2283.

Requestor: European Commission Question number: EFSA-Q-2020-00623 Correspondence: nif@efsa. europa.euPeer reviewedPublisher PD

Safety of 2'-fucosyllactose (2'-FL) produced by a derivative strain (APC199) of Corynebacterium glutamicumATCC 13032 as a novel food pursuant to Regulation (EU) 2015/2283.

Requestor: European Commission Question number: EFSA-Q-2020-00500 Correspondence: [email protected] reviewedPublisher PD

Safety of 3'-sialyllactose (3'-SL) sodium salt produced by derivative strains of Escherichia coli BL21 (DE3) as a Novel Food pursuant to Regulation (EU) 2015/2283.

Requestor: European Commission Question number: EFSA-Q-2020-00625 Correspondence: [email protected] reviewedPublisher PD

Safety of 3-fucosyllactose (3-FL) produced by a derivative strain of Escherichia coli BL21 (DE3) as a Novel Food pursuant to Regulation (EU) 2015/2283.

Requestor: European Commission Question number: EFSA-Q-2020-00309 Correspondence: [email protected] reviewedPublisher PD

Safety of 2'-fucosyllactose (2'-FL) produced by a derivative strain (Escherichia coli SGR5) of E. coli W (ATCC 9637) as a Novel Food pursuant to Regulation (EU) 2015/2283.

Peer reviewe