Log CFU Research Articles

A comprehensive study on the autochthonous microbiota, volatilome, physico-chemical, and morpho-textural features of Montenegrin Njeguški cheese

The present study aims to deepen the knowledge of the microbiota, gross composition, physico-chemical and morpho-textural features, biogenic amines content and volatilome of Njeguški cheese, one of the most popular indigenous cheeses produced in Montenegro. Cheese samples were collected in duplicate from three different batches produced by three Montenegrin artisan producers. For the first time, the microbiota of Njeguški cheese was investigated using both culture-dependent techniques and metagenomic analysis. Coagulase positive staphylococci viable counts were below the detection limit of the analysis (<1 log cfu g−1). Salmonella spp., Listeria monocytogenes and staphylococcal enterotoxins were absent. However, relatively high viable counts of Enterobacteriaceae, Escherichia coli, Pseudomonadaceae and eumycetes were detected. Metataxonomic analysis revealed a core microbiome composed of Lactococcus lactis, Streptococcus thermophilus, Debaryomyces hansenii, and Kluyveromyces marxianus. Furthermore, the detection of opportunistic pathogenic yeasts such as Magnusiomyces capitatus and Wickerhamiella pararugosa, along with the variable content of biogenic amines, suggests the need for increased attention to hygienic conditions during Njeguški cheese production. Significant variability was observed in humidity (ranging from 38.37 to 45.58 %), salt content (ranging from 0.70 to 1.78 %), proteins content (ranging from 21.42 to 25.08 %), ash content (ranging from 2.97 to 4.05 %), hardness, springiness, and color among samples from different producers. Gas chromatography-mass spectrometry analysis showed a well-defined and complex volatilome profile of the Njeguški cheese, with alcohols (ethanol, isoamyl alcohol, phenetyl alcol), esters and acetates (ethyl acetate, ethyl butanoate, isoamyl acetate), ketones (acetoin, 2-butanone), and acids (acetic, butanoic, hexanoic acids) being the main chemical groups involved in aroma formation. This research will provide new insights into the still poorly explored identity of Njeguški cheese, thus serving as a first baseline for future studies aimed at protecting its tradition.

Dry biofilms on polystyrene surfaces: the role of oxidative treatments for their mitigation

Candida auris and Staphylococcus aureus are associated with a wide range of infections, as they exhibit multidrug resistance – a growing health concern. In this study, gaseous ozone, and ultraviolet-C (UVC) radiation are applied as infection control measures to inactivate dry biofilms of these organisms on polystyrene surfaces. The dosages utilised herein are 1000 and 3000 ppm.min for ozone and 2864 and 11592 mJ.cm−2 for UVC. Both organisms showed an increased sensitivity to UVC relative to ozone exposure in a bespoke decontamination chamber. While complete inactivation of both organisms (>7.5 CFU log) was realized after 60 mins of UVC application, this could not be achieved with ozonation for the same duration. However, a combined application of ozone and UVC yielded complete inactivation in only 20 mins. For both treatment methods, it was observed that dry biofilms of S. aureus were more difficult to inactivate than dry biofilms of C. auris. Compared to dry biofilms of C. auris, micrographs of wet C. auris biofilms revealed the presence of an abundance of extracellular material after treatments. Interestingly, wet biofilms were more difficult to inactivate than dry biofilms. These insights are crucial to preventing recalcitrant and recurrent infections via contact with contaminated polymeric surfaces.

Unveiling the effects of ZnO nanoparticle incorporated chitosan coating on postharvest quality of eggplant (Solanum melongena L.)

Due to rapid moisture loss, eggplant (Solanum melongena L.), a significant economic product, has a short postharvest shelf life. This study examined at 4 °C for 20 days at the effects of chitosan (CH) 1% and CH with micro ZnO (0.25 g/L) on eggplant quality. After 0, 5, 10, 15, and 20 days, coating effects on parameters (weight loss, pH, respiration rate, total acidity, soluble solids, firmness, total anthocyanin, antioxidant, phenolic, antioxidant enzymes superoxide dismutase, peroxidase and malondialdehyde activity), as well as microbiological count (total bacteria and yeast), were examined. When compared to the control, the coatings significantly affected the quality parameters, eggplant fruit coatings with CH (1 %) + nano ZnO (0.25 g/L) had the significantly least respiratory rate, weight loss, firmness, TAC, TPC, TAA and enzyme activity (P < 0.05). The microbial load during fruit preservation was suppressed by nano ZnO treatments (total bacterial and fungal count in control and eggplant treated with nano ZnO were 4.46, 4.33 and 3.96, 3.17 log CFU g−1 respectively). Treatments had little effect on fruit's flavour or aroma, but ZnO-treated fruit had improved texture, colour, and acceptance overall compared to control fruit. Finally, nano ZnO may offer a chance to preserve quality and limit deterioration during extended storage.

Impact of pulsed light treatment on achieving microbial safety, enzymatic stability, and shelf life extension of dragon fruit juice

AbstractDue to microbial and enzymatic spoilage, dragon fruit juice has a limited shelf life. This study examines the shelf life of dragon fruit juice treated with thermal and pulsed light (PL) processing and stored at 4°C. The thermal treatment at 95°C/3 min and PL treatment at 1.4 J cm−2 produce a microbially safe juice. Both thermal and PL‐treated juice samples were packed in ethylene vinyl alcohol pouches and stored at refrigerated conditions (4°C). The juice's microbial, enzymatic, and biochemical attributes were analyzed over 30 days of refrigerated storage. There is no significant influence (p &lt; 0.05) on total soluble solids, pH, and titratable acidity. The thermally treated juice loses 36% of the total phenols and 22% of antioxidants. The loss of bioactive compounds is higher in thermal than in PL treatment. The shelf life of PL‐treated juice is 25 days, and thermal treatment juice is 30 days, based on the microbial analysis (6 log10 CFU mL−1). The study affirms the potential of PL treatment as an alternative technique for preserving dragon fruit juice.

Administration of Lacticaseibacillus casei CSL3 in Swiss Mice with Immunosuppression Induced by Cyclophosphamide: Effects on Immunological, Biochemical, Oxidative Stress, and Histological Parameters.

The study aimed to evaluate the effects of supplementation with Lacticaseibacillus casei CSL3 in Swiss mice immunosuppressed with cyclophosphamide on immunological, biochemical, oxidative stress, and histological parameters. The animals were distributed into four groups (control, CSL3, cyclophosphamide, and CSL3 + cyclophosphamide), where two groups were treated with L. casei CSL3 (10 log CFU mL-1) for 30days, and two groups received chemotherapy (days 27 and 30-total dose of 250mgkg-1). Counts of lactic acid bacteria (LAB) and bile-resistant LAB in stool samples; blood count (erythrogram, leukogram, and platelets); serum total cholesterol levels; catalase enzyme activity; and thiobarbituric acid reactive substances (TBARS) levels in liver, kidney, and brain; IL-4 expression; IL-23, TNF-α, NF-κβ in the spleen; and histological changes in the liver, kidneys, and intestine were evaluated. The CSL3 + cyclophosphamide group showed a significant increase in bile-resistant LAB counts in feces (p = 0.0001), leukocyte counts, and expression of IL-23, TNF-α, and NF-κβ (p < 0.05) significantly reduced total cholesterol levels (p = 0.001) and protected liver damage of supplemented animals. For oxidative stress damage, the bacterium did not influence the results. It is concluded that the bacterium is safe at a concentration of 10 log CFU mL-1 and has probiotic potential due to its positive influence on the immune response and lipid metabolism.

Effects of adding autochthonous Lacticaseibacillus paracasei culture on the characteristics of Minas Frescal goat cheese and its survival under simulated gastrointestinal conditions

A freeze-dried lactic acid culture was prepared with an autochthonous strain of Lacticaseibacillus paracasei TRA061676 (Lp-TRA061676), cultivated in skimmed goat milk and its technological suitability in the production of Minas Frescal Goat Cheese (MFGC) was investigated. The viability of the freeze-dried culture was greater than 8.92 Log CFU g−1 during 360 days of storage at −22 °C. Lp-TRA061676 incorporated into MFGC showed remarkable survival, with populations of 9.65 Log CFU g−1 and a survival rate under in vitro gastrointestinal tract conditions of 96.90% for 28 days at 4 °C. Lp-TRA061676 did not modify the proximate composition of MFGC, but it affected the physicochemical characteristics and instrumental color, and improved the product's texture. These results demonstrate the suitability of Lp-TRA061676 for producing MFGC and the potential of this cheese to be used as an effective matrix to protect the strain from gastrointestinal conditions.

Fermented plant-based beverage supplemented with uvaia (Eugenia pyriformis) pulp: an innovative and pioneering approach to diversify plant-based diet product market

Over the years, there has been an increase in demand for plant-based foods as alternatives. In line with this, this work explores the production and in vitro digestion of a fermented plant-based beverage (FPBB) produced with pea and rice proteins and 0% (FPBB-C), 5% (FPBB-5), and 10% (FPBB-10) uvaia pulp through lactic fermentation with Lacticaseibacillus rhamnosus GG. The in vitro gastrointestinal digestion process was conducted to assess the bioaccessibility of L. rhamnosus GG, total phenolic content (TPC), and antioxidant activity before and after simulating the gastrointestinal conditions. After 48 h of digestion, highly viable L. rhamnosus GG cells remained throughout the gastrointestinal system. FPBB-C (106.89%) and FPBB-5 (109.38%) exhibited higher survival rates than FPBB-10 (102.20%), indicating that these beverages have a higher prebiotic action potential. Compared with the non-digested samples, after 48 h of digestion, all samples exhibited a significant increase in TPC. The same behavior occurs for the antioxidant activity of FPBB-C, FPBB-5, and FPBB-10 by DPPH (4.06, 3.96, and 8.44 mg TEAC mL−1), ABTS (10.28, 11.06, 11.97 mg TEAC mL−1), and FRAP method (917.02, 863.87, and 1983.23 mg TEAC mL−1). Thirteen compounds were identified and quantified in uvaia pulp by HPLC-DAD-ESI-MS, particularly epigallocatechin gallate, quercetin-3-rhamnose, and quercetin-3-glucoside. Isorhamnetin was the main phenolic compound detected in the colon, assumably due to the conversion of quercetin-3-glucoside by the probiotic cells. In conclusion, as all counts were above 9 log CFU g−1, the FPBB formulations containing pea, rice protein, and uvaia pulp become a promising vehicle for carrying L. rhamnosus GG.

CONTROL OF LISTERIA MONOCYTOGENES AND STAPHYLOCOCCUS AUREUS IN MEAT AND MEAT PRODUCTS BY CELL-FREE SUPERNATANT OF BREVIBACILLUS LATEROSPORUS BGSP7 AND BGSP9

The presence of pathogens in food has increased awareness of food safety, but it also causes large economic losses. Fresh meat and meat products contain a sufficient quantity of proteins, lipids, water, and a favorable pH that stimulates the growth of various microorganisms, including pathogens. The aim of this study was to investigate the efficacy of Brevibacillus laterosporus BGSP7 (CFS-BGSP7) and BGSP9 (CFS-BGSP9) cell-free supernatants in the control of Listeria monocytogenes and Staphylococcus aureus in raw meat and meat products. Raw meat and meat products were sliced and then aseptically treated by immersion for 2 minutes into solutions containing: i) CFS-BGSP7; ii) CFS-BGSP9; iii) no treatment. The samples were then artificially contaminated with: Group I – L. monocytogenes (~4 log cfu g-1); Group II – S. aureus LMM322 (~4 log cfu g-1). Each sample was individually aseptically vacuum-packed and stored at 4°C for 8 weeks. The number of surviving bacteria in the samples were analyzed immediately after contamination with L. monocytogenes and S. aureus and at regular time-intervals: after 1, 3, 5 and 8 weeks of storage at 4°C. Meat samples treated with CFS-BGSP7 and CFS-SP9 showed a significant decrease in the cell counts of L. monocytogenes and S. aureus. When meat samples treated with CFS-BGSP7 and CFS-BGSP9 are compared, the results show a more intense reduction rate of both L. monocytogenes and S. aureus in all samples treated with CFS-BGSP7.

Bacterial Inactivation Studies in Shrimp Pond Water by using Different Disinfectant Agents

Abstract Background Aquaculture water plays an important role in the dissemination of antibiotic-resistant bacteria during harvest of shrimps. Mitigation of bacteria through discharge is essential to prevent dissemination downstream. Chemical disinfection of culture water is feasible compared to other methods of bacterial inactivation. Objective To study the effect of different disinfectant agent’s viz., chlorine, Fenton’s reagent, and hydrogen peroxide (H2O2) on inactivation of bacteria from shrimp pond water Methods The water samples were subjected to treatment with various concentrations of chlorine (0.0, 1.0, 2.5, 5.0 and 10.0 mg L−1), Fenton’s reagent (1:10 mM ratio of Fe2+:H2O2; 2:20, 3:30, 4:40, 5:50) and H2O2 (20, 30, 40 and 50 mM) for different time durations (5 min, 15 min, 30 min and 60 min). Results The results indicated that all the disinfecting agents inactivated both the total heterotrophic bacteria and tetracycline-resistant bacteria with increased concentrations and time. At the end of 60 min treatment with chlorination (2.5 mg Cl2 L−1), Fenton’s reagent (2 mM Fe2+ + 20 mM H2O2) and H2O2 (50 mM H2O2), the total heterotrophic bacterial count in the water samples gradually decreased by 2.35, 2.65, and 1.38 log10 CFU mL−1, and tetracycline-resistant bacteria count reduced by 1.57, 1.66, and 1.43 log10 CFU mL−1, respectively from initial bacterial load. Conclusions The study revealed that disinfection agents can be successfully employed in the inactivation of antibiotic-resistant bacteria discharged through aquaculture water. Among three disinfection agents, Fenton’s reagent has been found effective in inhibiting both heterotrophic bacteria and tetracycline-resistant bacteria from water samples. Highlights Bacterial inactivation studies were carried with Chlorination, Fenton’s reagent, and Hydrogen peroxide. The highest decrease in HPC (2.65 log) and tetracycline-resistant bacterial (1.66 log) was noticed in the water samples treated with Fenton’s reagent. The use of disinfection agents effectively mitigates antibiotic-resistant bacteria from aquaculture wastewater.

In Vitro evaluation of probiotic properties of lactic acid bacteria strains isolated from juçara fruit native to the Atlantic Forest

Lactic acid bacteria (LAB) are the microorganisms most commonly used as probiotics. Since probiotic benefits are strain-dependent, there is a continuous need for research into new cultures with probiotic properties. Fruits such as juçara (Euterpe edulis Martius), a palm species from the Atlantic Forest threatened with extinction, are rich niches for microorganisms, including LAB. This study investigated the probiotic properties of Lactococcus lactis J7 and Leuconostoc pseudomesenteroides JF17 strains isolated from juçara fruits native to the Atlantic Forest. Probiotic characteristics, such as tolerance to simulated gastrointestinal fluids or juices, hydrophobicity, autoaggregation, coaggregation properties, inhibition of pathogenic microorganisms, and technological properties were evaluated. The survival rate of L. lactis J7 and L. pseudomesenteroides JF17 decreased after exposure to simulated gastrointestinal conditions; however, L. lactis J7 was more resistant, maintaining viability at the end of the enteric phase of 6.07 ± 0.16 log CFU mL-1. The J7 strain also exhibited the highest values in hydrophobicity (12.55 ± 0.52%), autoaggregation (25.63 ± 0.75%), and coaggregation capacity with E. coli ATCC 25922 (21.52 ± 0.98%) and S. Enteritidis ATCC 13076 (22.68 ± 1.01%). Both J7 and JF17 strains demonstrated antimicrobial activity, confirmed by the multilayer agar plate system. Additionally, the growth of the strains was temperature-dependent, and they were able to thrive in high concentrations of sodium chloride (6%). Thus, L. lactis J7 is a promising probiotic candidate for the development of functional products. Nevertheless, further studies using animal models are necessary to explore the properties of these probiotic bacteria. Novel strains isolated from fruits should be studied to broaden the application of probiotic microorganisms in the development of foods and medicines.

Cooling Uncovered Foods at a Depth of ∼5.1 cm (2 in.) or Less Poses Little Risk of Pathogen Growth

The U.S. Food and Drug Administration has guidelines for cooling cooked foods in retail operations. Data on foodborne illness risk factors in restaurants indicate that cooling is often out of compliance with these guidelines. We sought to identify factors under the control of the operator that had a significant effect on the cooling rates of cooked foods. Minneapolis Minnesota Health Inspectors were trained in standardized operating procedures for cooling data collection. Data loggers set to appropriate time intervals and calibrated to ±0.5 °C (∼1°F) were used in data collection. Analysis was performed using the R statistical computing language version 4.2.2. Preexisting pathogen models were used to predict Log CFU increases of Clostridium perfringens or Bacillus cereus. Data from 224 recipes were recorded by inspectors between October 2018 and October 2019. Food depth had a highly significant effect (p = 8.90E−08) on cooling rate. The use of an ice bath or ice wand was also significant (p < 0.005). There was a significant correlation between container material (metal or plastic) and food depth because foods with a greater depth are often being cooled in plastic containers. Foods at a depth greater than 5.1 cm (2 in.) that cooled faster than 0.23 log(°C)/h were often wholly or partially cooled in blast chillers or freezers, cooled using an ice bath or ice wand (or both), or were composed of protein pieces (e.g., chicken wings) that facilitated more rapid cooling due to air gaps in the food. Foods in shallow containers at a food depth of less than or equal to ∼5.1 cm (2 in.) that cooled more slowly than 0.23 log(°C)/h were being cooled at temperatures greater than 5 °C (41°F) or were partially or wholly covered. These foods also showed little evidence of pathogen growth from predictive models. Our analysis shows that cooling foods in shallow containers at a food depth of less than or equal to ∼5.1 cm (2 in.) poses little risk of significant pathogen growth.

Antibacterial evaluation of garlic extracts on chitosan/starch packaging film using response surface methodology and its application for shelf-life extension of bell peppers (Capsicum annuum).

In this study, garlic extract (GE) was assessed as a potential additive in chitosan/starch (Ch/De) coatings, focusing on phenolic and flavonoid content analyses and antibacterial properties. Using response surface methodology approach, an optimization method was employed to achieve the optimal antibacterial formulation, with Ch, De, and GE identified as key variables in the Design of Experiment. Fourier transform infrared spectroscopy and X-ray diffraction analyses elucidated interactions among these primary components within the films, while thermogravimetric analysis confirmed the enhanced thermal stability of GE-coated film formulations (Ch/De/GE). The Ch/De/GE exhibited antibacterial efficacy against Escherichia coli (ATCC 25922) with an inhibition zone of 7.2mm at optimized concentrations of 2% w/v Ch, 1.5% w/v starch, and 0.5% v/v GE. In silico molecular docking studies provided insights into GE's inhibitory role as an antibacterial agent. Evaluation of green and yellow bell peppers (Capsicum annuum) over 18 days showed that coated peppers maintained better visual appearance and mass stability, with a weight loss decrease of 40.54%-48.96%, compared to uncoated ones. Additionally, the Ch/De/GE coating effectively inhibited bacterial growth, reducing it by 1-1.23 log CFU, during the storage period. In conclusion, the Ch/De/GE coating effectively extends the shelf-life of bell peppers and maintains their quality, demonstrating its potential for use in food packaging to preserve perishable items. PRACTICAL APPLICATION: The optimized chitosan/starch/garlic extract (Ch/De/GE) film developed in this study shows promising potential for application in the food packaging industry, particularly in extending the shelf life of perishable items like bell peppers. Its enhanced antibacterial properties, along with its ability to maintain visual appearance and reduce weight loss, make it an effective natural preservative that could replace synthetic additives in food packaging. By incorporating this biodegradable film into packaging solutions, producers can offer safer, more sustainable products that meet consumer demand for natural and environmentally friendly options.

HPLC-DAD method validation for quantification of dehydroabietic acid and abietic acid in oral spray containing Pinus merkusii heartwood extract and its antibacterial effects on clinically isolated Streptococcus mutans

AbstractPinus merkusii Jungh &amp; De Vries. has become increasingly gathered more attention from researchers because the plant has a range of folk medicinal uses. Heartwood plant is the major source of dehydroabietic acid (DHAA) and abietic acid (AA), which possesses several medicinal properties, such as antiviral, antimicrobial, antiobesity and anti-inflammatory. The research proposed herein a low-cost, fast, specific, uncomplicated, sensitive, precise reverse-phase high-performance liquid chromatography (RP-HPLC). This method was conducted and validated for evaluating an amount of DHAA and AA in ethanol extract and oral spray containing P. merkusii heartwood extract. Additionally, stability and antimicrobial activities against clinically isolated Streptococcus mutans of the oral spray were determined. The separation was achieved on Pursuit 200Å PFP column, 150 × 4.6 mm, particles of 3 µm with a flow rate of 1.0 mL min−1. Methanol and water (70:30 v/v) were used as eluent with an isocratic mode and sample analysis volume was set at 10 µL, at a detection wavelength of 210 and 245 nm. The developed HPLC method for analysis of DHAA and AA showed good linearity with correlation coefficients equal to 1. Moreover, other validation parameters, comprised of accuracy, precision, specificity and detection and quantitation limits of this method displayed excellent reliability, validity and sensitivity. This method could be an interesting alternative for quantitative measurement of P. merkusii heartwood extract, oral spray formulation and other P. merkusii heartwood extract preparations. The result from antibacterial tests suggested that the oral spray containing P. merkusii heartwood extract is able to inhibit the oral pathogens causing dental caries. The oral spray decreased S. mutans population size by about 0.5–2 Log CFU mL−1 at 1–4 h and complete elimination of all bacteria strains within 24 h. This study provides validity for using P. merkusii heartwood extract as an alternative for preventing and treating oral infectious diseases.

Combination of bacteriophages and vancomycin in a co-delivery hydrogel for localized treatment of fracture-related infections

Fracture-related infections (FRIs), particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA), are challenging to treat. This study designed and evaluated a hydrogel loaded with a cocktail of bacteriophages and vancomycin (1.2 mg/mL). The co-delivery hydrogel showed 99.72% reduction in MRSA biofilm in vitro. The hydrogel released 54% of phages and 82% of vancomycin within 72 h and maintained activity for eight days, in vivo the co-delivery hydrogel with systemic antibiotic significantly reduced bacterial load by 0.99 log10 CFU compared to controls, with active phages detected in tissues at euthanasia (2 × 103 PFU/mL). No phage resistance was detected in the phage treatment groups, and serum neutralization resulted in only a 20% reduction in phage count. In this work, we show that a phage-antibiotic co-delivery system via CMC hydrogel is a promising adjunct to systemic antibiotic therapy for MRSA-induced FRI, highlighting its potential for localized, sustained delivery and improved treatment outcomes.

Effect of propolis extract-loaded films made of apple pomace pectin and grass pea protein on the shelf life extension of black mulberry

The main aim of this study was to investigate the effect of different concentrations of propolis extract (PE) (0, 3, 6, and 12% v/w) on edible films, containing 3% w/v apple pomace pectin and 5% w/v grass peas protein. The structural and morphological properties of the films were characterized using FT-IR, XRD, and SEM analysis, showing higher PE levels led to a more homogeneous and compact structure. Moreover, incorporating PE into the film samples developed their mechanical properties, hydrophobicity, antioxidant, and antimicrobial attributes, particularly against Escherichia coli, Bacillus cereus, and Botrytis cinerea. In addition, the 12% PE film exhibited the highest water vapor and oxygen barrier abilities of 3.57 × 10−10 g m−1 s−1 Pa−1 and 1.43 meq/Kg, respectively. Furthermore, the film solutions with the same PE concentrations were applied as coatings to extend black mulberry shelf life. Results revealed that PE-enriched coatings decreased the weight loss and fungal contamination of the fruits during the storage. Specifically, the 12% PE-coated samples showed ABTS radical scavenging activity of 90.22%, total yeast and mold count of 3.11 log CFU g−1, and superior sensorial properties after 18 days of storage. Accordingly, the 12% PE coating was identified as the most effective, preserving postharvest attributes of fruits and prolonging their shelf life until 18 days at 4 °C. Overall, these results suggested that the apple pomace pectin, grass pea protein, and PE can be efficiently used as a promising natural substitute for food packaging to develop the antioxidant and antimicrobial properties of films and coatings with various applications in food products.

Modification of Fungicide Treatment Needs and Antioxidant Content as a Result of Real-Time Ozonation of Raspberry Plants.

Raspberry plants need intensive anti-fungal protection. A solution to this problem could be the application of an ozonation process. For this purpose, a technical solution was proposed and implemented in raspberry plant production. The proposal suggests replacing 25% of standard fungicide treatments with ozonation. It was demonstrated that the use of ozone under the proposed conditions made it possible to maintain stable parameters of chlorophyll content and fluorescence (no significant differences), but the intensity of gas exchange was increased. The greatest differences were observed in the second measurement period (T2), when the plants were in the stage of most active development. Additionally, the content and profile of low-molecular-weight antioxidants and the microbial load were determined in the collected fruits. In periods T2 and T3, the proposed method caused a reduction reaching ~2 log cfu g-1 in the microbial content of raspberry fruits. It was shown that ozone treatment intensified the biosynthesis of low-molecular-weight antioxidants in fruit (increasing the total polyphenol content by more than 20%). The proposed scheme allows a 25% reduction in standard fungicide treatments while maintaining the health of cultivated raspberry plants. The reduction in fungicide use aligns with the EU regulations and produces fruit with better quality.

Lacticaseibacillus casei as Anti-blowing Agents: Impact on the Evolution of Ripening and Sensory Profile of Montasio Cheese

AbstractRecently, the Lacticaseibacillus casei group strains have been gaining growing interest due to their potential to be used as secondary adjunct cultures in cheese. This work aimed to test autochthonous Lb. casei strains as anti-blowing agents and to evaluate their impact on the evolution of the ripening and the sensory profile of Montasio cheese. The cheesemaking trial included a control production without lysozyme (C1), a control with lysozyme (C2), and four experimental productions, each containing a different pool of autochthonous Lb. casei strains (EX1-4). Samples were taken during ripening, and physicochemical, microbiological, and sensory analyses were carried out. Lb. casei counts indicate that the selected strains survived the cheesemaking and maintained their viability of about 9 log cfu g−1 at the end of the ripening. Only EX3 showed a significant slowdown of the proteolytic index compared to controls over time. Furthermore, from the principal component analysis, it emerged that at the end of the 120-day-long ripening, C2 and the experimental samples were characterized by similar profiles of volatile compounds. The late-blowing defect (LBD) was observed exclusively in C1, whereas it was not detected in the control sample with lysozyme or in any experimental samples. These findings not only confirmed the efficacy of lysozyme in preventing LBD but also supported the effectiveness of the selected Lb. casei strains as anti-blowing agents with the ability to contribute to the final volatile profile without compromising the typicality of the product.

Functional Cyperus esculentus L. Cookies Enriched with the Probiotic Strain Lacticaseibacillus rhamnosus SL42.

This study presents for the first time functional cookies for diabetics made with 100% organic Cyperus esculentus L. flour, either plain or enhanced with 5% polyfloral honey syrup containing the probiotic strain Lacticaseibacillus rhamnosus SL42. The flour's chemical composition and rheological and functional properties were analyzed, and 33 diabetic and semi-naive panelists assessed the cookies' sensory properties. MRS-cys agar cultures and SEM analysis evaluated SL42 survival and adhesion capacity over 21 days at 25 °C. Results showed that the flour and its extracts are rich in polyphenols and flavonoids, indicating strong antioxidant and antibacterial properties. Both cookie types met international standards when compared to commercial cookies and had similar physical properties. Sensory evaluation on day 1 revealed higher quality indicators for honey syrup-enriched cookies, but after 15 days, control cookies were preferred. The CIE LAB analysis confirmed the dietetic flour's typical dark color, with honey syrup-enriched cookies being darker. Despite textural differences, both cookies maintained detectable crispness over storage. Honey syrup-enriched cookies effectively carried L. rhamnosus SL42, remaining viable at 6.43 Log CFU per cookie after 21 days and adhering to the cookie's surface, as confirmed by SEM analysis. Further research is recommended to better understand the therapeutic value of these cookies.

Co‐digestion of xanthan gum/Lactobacillus plantarum 75‐coated cantaloupes with Natal plum (Carissa macrocarpa) fruits or beetroot (Beta vulgaris L.) leaves on the bioaccessibility of anthocyanins and carotenoid components

SummaryCo‐digestion of cantaloupe (C) melon fresh cuts (FC) coated with probiotics [Lactiplantibacillus plantarum 75/xanthan gum with Natal plum (NP)] or beetroot leaves (BL) was evaluated to determine their bioaccessibility of individual anthocyanins (cyanidin‐3‐glucoside, cyanidin‐3‐O‐sambubioside) and carotenoids (lutein, trans‐β‐carotene and cis‐β‐carotene). Co‐digestion of probiotic‐coated C‐melon‐FC with NP increased the percentage (%) bioaccessibility of cyanidin‐3‐glucoside (11.18%) and cyanidin‐3‐O‐sambubioside (8.89%) compared to single digestion of Natal plum. Bioaccessibility of lutein (18.2%), trans‐β‐carotene (36.92%) and cis‐β‐carotene (16.74%) increased when co‐digestion of probiotic‐coated C‐melon‐FC with BL compared to the single digestion of uncoated C‐melon. Co‐digestion of C‐melon‐FC‐L75 with BL showed the highest antioxidant activity. L. plantarum had the highest LAB survival at the intestinal phase (6.01–6.26 Log CFU mL−1) during single and co‐digestion showing probiotic potential. C‐melon‐FC‐L75, Natal plum and beetroot leaves could be recommended as functional ingredients in meal preparation.

Production of set-type probiotic and prebiotic yogurt-like products using Enterococcus faecium and Enterococcus faecalis strains in combination with pumpkin waste

This study investigated the effect of pumpkin powder (2 %, 4 %, and 6 %) and Enterococcus faecium and Enterococcus faecalis probiotics on the physicochemical, microbiological, and sensory properties of yogurt samples during 28 days of storage at 4 °C. The prebiotic effect of pumpkin powder (Cucurbita pepo) and the probiotic effect of Enterococcus faecium and E. faecalis were determined. Adding pumpkin powder to yogurt did not significantly alter the pH, acidity, fat, protein, and ash content (p > 0.05). Water holding was not changed during the storage time in the samples of probiotic yogurts, but as the pumpkin powder content increased, the water holding capacity also increased (p < 0.05). This situation did lead to a reduction in syneresis (p < 0.05). The lowest gumminess value at the end of storage was found in the D2 sample (p < 0.05), and the highest adhesiveness value was found in the D4 sample (p < 0.05). Furthermore, throughout the 28-day storage period, E. faecium and E. faecalis maintained a live cell count of ≥6 log CFU g-1 in the probiotic product. As a result of the statistical evaluation, there was a decrease in E. faecium in the D4, S2, and S4 samples, and then it increased again (p > 0.05) during the storage time. As a result of the statistical evaluation, it was determined that the smell, consistency in the spoon, consistency in the mouth, flavor, and acidity changes during the storage were not substantial (p > 0.05). In conclusion, it was found that pumpkin, a byproduct of the pumpkin seed industry, has the potential to act as a prebiotic and improve the properties of dairy products. Additionally, the study suggests that E. faecium and E. faecalis strains could be suitable for probiotic yogurts.