The Effect of Plasma-Activated Water Combined with Rosemary Extract (Rosmarinus officinalis L.) on the Physicochemical Properties of Frankfurter Sausage during Storage.

This study investigated the impact of plasma-activated water (PAW) and rosemary extract on the bacterial inactivation and quality attributes of Frankfurter sausages during a 6-day storage period. The antibacterial activity, total phenol content (TPC), and total flavonoid content (TFC) of the rosemary extract were evaluated. The TPC of the rosemary extract was 89.45 mg gallic acid/g dry weight, while the TFC was 102.3 mg QE/g dry weight. Even at low concentrations, the rosemary extract effectively inhibited the growth of all the tested pathogens using the Well Diffusion Agar method (WDA). The sausages were treated with different concentrations of PAW and rosemary extract and stored for 1 and 6 days. Sample B (100% rosemary extract + PAW treatment) showed the greatest reduction in microbial load and was selected for further analysis. Throughout the storage period, Sample B exhibited no significant changes in pH, moisture content, textural parameters, or sensory evaluation compared to the control group. However, the hardness and color parameters (L*, a*) of Sample B decreased, while the TBARS value increased after 6 days of storage. The combination of PAW and rosemary extract, particularly Sample B, effectively inhibited bacterial growth in the Frankfurter sausages without compromising most quality attributes. Some changes in hardness, color, and lipid oxidation were observed over the extended storage period.

Characterization of antioxidant active biopolymer bilayer film based on gelatin-frankincense incorporated with ascorbic acid and Hyssopus officinalis essential oil.

In this study, a bio-based bilayer edible film based on gelatin/frankincense, with the incorporation of different concentrations of Ascorbic acid (AA) (0, 1, 2%) into the inner layer (gelatin) and Hyssopus officinalis (HO) (0, 0.75, 1.5%) essential oil in the outer layer (frankincense) was prepared. A significant increase (p < 0.05) in b* and a remarkable decrease in whiteness and lightness of the films were seen via increasing the HO ascribed to the Total Phenolic Content of HO and non-enzymatic browning. Although there was a significant decrease (p < 0.05) in Tensile Strength with the addition of HO, Elongation at Break was increased significantly as a function of HO, which is correlated with a dense and compact network in SEM images. The maximum thickness of film emulsified with 1.5%HO + 2%AA ascribed to the accumulation of solid content. The improvement in Water Contact Angle (℃) and a reduction in Water Vapor Permeability (gr/s mPa) have occurred due to the hydrophobic nature of HO.

Optimization of gamma-aminobutyric acid production by Lactobacillus brevis PML1 in dairy sludge-based culture medium through response surface methodology.

Gamma-aminobutyric acid (GABA) is a pharmaceutical, bioactive amino acid that can produce by some species of Lactic Acid Bacteria (LAB). For the first time, we evaluated the production of GABA by Lactobacillus brevis PML1 in the medium that contain the contaminant food bio-product like dairy sludge and soybean meal. GABA production was analyzed by chromatography (TLC, HPLC) and the features of fermented extract which contains this amino acid were evaluated. The results of Response Surface Methodology (RSM) of Central Composite Design (CCD) at p < .05 showed 300 ppm of GABA production in optimal treatment including 14.77% dairy sludge powder, 6.27% soybean meal, and 0.49% ammonium sulfate (32°C for 120 hr fermentation). The results of fermented extract also showed the acceptable antimicrobial, antioxidant, and toxicity (against cancer cell) properties. Also, L. brevis PML1has not shown any hemolytic or DNase activity which confirm its safety aspects. According to the results, this new culture can be used as a cheap substrate to biological production of GABA, by L. brevis PML1 in various food and pharmaceutical formulations.

Control of microbial growth and lipid oxidation in beef using a Lepidium perfoliatum seed mucilage edible coating incorporated with chicory essential oil.

In this study, chicory essential oil (CEO) was obtained by hydrodistillation-based extraction method and it was rich in camphor (31.3%) and phenolic compounds with outstanding antioxidant and antimicrobial properties. The CEO was then incorporated into Lepidium perfoliatum seed mucilage (LPSM) based aqueous solution to prepare an active CEO-loaded LPSM edible coating. The effect of the edible coating was then investigated on the quality and shelf life of beef slices during 7 days storage at 4°C. The results revealed that beef slice coated with CEO-loaded LPSM edible coating had a significant inhibitory effect on its lipid oxidation and microbial growth. The CEO-LPSM coating also inhibited the weight and texture losses of beef slices during display more efficiently compared with the control and CEO-free LPSM coating. Besides, the beef slices coated with CEO-LPSM were the preferred samples in terms of sensory scores throughout the storage. Thus, using CEO-rich LPSM edible coating might inhibit decay and significantly improve the shelf life of fresh beef.

Probiotic characterization of Pediococcus strains isolated from Iranian cereal-dairy fermented product: Interaction with pathogenic bacteria and the enteric cell line Caco-2.

In present study, we investigated the probiotic potential of three Pediococcus spp. isolated from Iranian traditional fermented cereal-dairy product, Tarkhineh. These 3 strains were identified as Pediococcus acidilactici VKU2, P. acidilactici IAH-5 and P. pentosaceus DHR005 by 16S rRNA gene sequencing. All the strain were found tolerate to pH 3 and 0.3% oxall for 3 h as well as simulated gastric and intestinal juice. P. acidilactici IAH-5 showed the highest cholesterol removal (67.52%), hydroxyl radical scavenging activity (58.32%), hydrophobicity (40.3%) and auto-aggregation (48%). Pediococcus spp. inhibited the growth of tested pathogens (Escherichia coli ATCC 25922, Pseudomonas aeruginosa PTCC 1707, Salmonella typhimurium PTCC 1609, and Staphylococcus aureus ATCC 25923) which the most susceptible strain was S. aureus. In competition assay, P. acidilactici IAH-5 was able to inhibited adhesion of 67.3% of S. typhimurium and in inhibition assay 45.8% of the pathogenic adhesion to Caco-2 cells were decreased. P. acidilactici VKU2 and P. acidilactici IAH-5 showed 16.32 and 12.25% adhesion to simulated epithelial cell line which were also confirmed by scanning electron microscopy. Pediococcus spp. did not showed DNase production or hemolytic activity which confirm its safety aspects. Our findings suggested that the P. acidilactici IAH-5 has the best properties with probiotic features and cholesterol assimilation for its application as novel bio-therapeutic and bio-preservation agents.

Chemical Composition and Antioxidant, Antimicrobial, and Antiproliferative Activities of Cinnamomum zeylanicum Bark Essential Oil.

This study examines the chemical constituents, antioxidant potential, antibacterial mechanism, and antiproliferative activity of Cinnamomum zeylanicum bark essential oil. The compositions of the oil were analyzed by GC-MS, and the major constituents were found to be (E)-cinnamaldehyde (71.50%), linalool (7.00%), ß-caryophyllene (6.40%), eucalyptol (5.40%), and eugenol (4.60%). C. zeylanicum essential oil contained remarkable levels of phenolic and bioactive compounds with outstanding ability to scavenge free radicals and inhibit ß-carotene oxidation. The growth of pathogenic and spoilage bacteria, especially Gram-positive ones (i.e. Listeria innocua, Staphylococcus aureus, and Bacillus cereus), was highly inhibited by the oil, compared to the Gram-negative pairs (i.e. Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi). The cells of L. innocua and E. coli (as the most sensitive and resistant strains to the oil, respectively) treated with C. zeylanicum essential oil were observed by scanning electron microscopy to unravel structural changes. It was observed that the essential oil quickly exerted its antibacterial activity through disrupting cell envelope and facilitating the leakage of intracellular compounds. The essential oil had also a dose-dependent antiproliferative effect on adipose-derived mesenchymal stem cells (AT-MSCs), and the cell proliferation could be induced by low concentrations of the oil. The present study indicated that C. zeylanicum essential oil with remarkable antioxidant and antimicrobial properties could be applied to develop novel natural preservatives for food and medicinal purposes.

Study of Lactic Acid Bacteria Community From Raw Milk of Iranian One Humped Camel and Evaluation of Their Probiotic Properties.

BACKGROUND: Camel milk is amongst valuable food sources in Iran. On the other hand, due to the presence of probiotic bacteria and bacteriocin producers in camel milk, probiotic bacteria can be isolated and identified from this food product. OBJECTIVES: The objectives of the present research were the isolation and molecular identification of lactic acid bacteria from camel milk and evaluation of their probiotic properties. MATERIALS AND METHODS: A total of ten samples of camel milk were collected from the Golestan province of Iran under aseptic conditions. Bacteria were isolated by culturing the samples on selective medium. Isolates were identified by amplification of the 16S rDNA and Internal Transcribed Spacer (ITS) region between the 16S and 23S rRNA genes by Polymerase Chain Reaction (PCR) and were then screened and grouped by the Amplified Ribosomal DNA Restriction Analysis (ARDRA) method. To evaluate probiotic properties, representative isolates of different ARDRA profiles were analyzed. The antimicrobial activity of Lactic Acid Bacteria (LAB) against Pediococcus pentosaceus, Escherichia coli and Bacillus cereus was examined by the agar diffusion assay. Acid and bile tolerance of isolates were evaluated. RESULTS: A total of 64 isolates were analyzed based on biochemical tests and morphological characteristics. The most frequently isolated LAB was Enterococci. Weissella, Leuconostoc, Lactobacilli and Pediococci were less frequently found. Based on restriction analysis of the ITS, the isolates were grouped into nine different ARDRA patterns that were identified by ribosomal DNA sequencing as P. pentosaceus, Enterococcus faecium strain Y-2, E. faecium strain JZ1-1, E. faecium strain E6, E. durans, E. lactis, Leuconostoc mesenteroides, Lactobacillus casei and Weissella cibaria. The results showed that antimicrobial activity of the tested isolates was remarkable and P. pentosaceus showed the most antibacterial activity. In addition, E. durans, E. lactis, L. casei and P. pentosaceus were selected as probiotic bacteria. CONCLUSIONS: This study revealed the presence of bacteriocin-producing bacteria and probiotic bacteria in camel milk from the Golestan province of Iran.