Emine Dinçer

Tarhana is a traditional fermented cereal–yogurt food widely consumed in Türkiye. It is often described as a low-glycemic index (GI) food, but this belief is based mostly on secondary sources, and direct evidence is limited. This study aimed to evaluate the in vitro GI of different tarhana varieties produced in Türkiye. Seven types—Konya flour, Beyşehir crisp, Maraş, Elbistan, grape, cornelian cherry, and Muğla Göce tarhana—were analyzed using the Englyst hydrolysis method with white bread as the reference. Hydrolysis index (HI) values were calculated and converted to GI using established equations. GI values ranged from 57.25 ± 2.22 to 95.09 ± 0.70, showing clear variation among samples. Konya flour tarhana was classified as low GI, cornelian cherry tarhana as medium GI, and the other five varieties, including grape, Elbistan, and Maraş tarhana, as high GI. These findings challenge the common belief that tarhana is always a low-GI food. They also show that its glycemic response depends strongly on ingredients and processing methods. Although tarhana is nutritionally valuable, some types may impose a high glycemic load. This is especially important for individuals who need to control blood glucose, such as those with diabetes or metabolic syndrome. Because this study was conducted in vitro, further in vivo research is required to confirm the results and guide dietary recommendations.

The search for alternative, cost‐effective, and side‐effect‐free therapies for hyperlipidemia remains a priority. This study evaluated the effects of probiotic Lacticaseibacillus casei ATCC 393, prebiotic d ‐tagatose, and their synbiotic combination on hyperlipidemia induced in BALB/c mice via a high‐fat, high‐cholesterol diet over 12 weeks. During the final 4 weeks, different groups received the respective treatments. Compared to the positive control (PC) group, synbiotic administration (SYN group) significantly reduced serum glucose by 32.8%, total cholesterol by 20.2%, HDL‐C by 28.0%, and triglycerides by 42.5% ( p < 0.05). Although serum albumin, alanine aminotransferase, and aspartate aminotransferase levels decreased by 3.9%, 5.2%, and 16%, respectively, these changes were not statistically significant ( p > 0.05), suggesting preserved liver function without adverse effects. Histological evaluation revealed a significant reduction in microvesicular steatosis and IL‐6 immunoreactivity scores exclusively in the synbiotic group, indicating alleviated hepatic lipid accumulation and inflammation. Although synbiotic treatment did not alter overall gut microbiota diversity or species richness, it selectively enriched certain taxa, resulting in dominance of Coprococcus, Parabacteroides, and Bacteroides genera as identified by LEfSe analysis (LDA score ≥ 4, p < 0.05). Conversely, Streptococcus and [Ruminococcus] abundances significantly declined from 3.59% to 1.1% and 7.25% to 0.75%, respectively ( p < 0.05). Collectively, these findings demonstrate that synbiotic supplementation effectively improves lipid profiles and mitigates hepatic lipid accumulation and inflammation without compromising liver function. The modulation of specific gut microbiota taxa further supports its therapeutic potential. Therefore, the synbiotic formulation investigated herein represents a promising alternative biotherapeutic approach for managing hyperlipidemia.

In this study, ethanol extracts of some wild mushroom species, in the phylum Basidiomycota, [Armillaria mellea (Vahl) P. Kumm., Infundibulicybe geotropa (Bull.) Harmaja, Leucopaxillus gentianeus (Quél.) Kotl. and Trametes versicolor (L.) Lloyd] were tested for their antioxidant, antimicrobial, antibiofilm, and cytotoxic activities. Mushroom samples showed low antimicrobial activity on Enterococcus faecalis and Staphylococcus aureus, while biofilm inhibitory activity on test microorganisms ranging from 24.6% to 80.5%. At the end of the antioxidant activity studies A. mellea was the mushroom sample having the highest DPPH radical scavenging capacity (0.105±0.001 mg/mL) whereas T. versicolor was the one having the highest iron (III) ion reducing power (40.709±0.003 µg TE/100g). The highest polyphenol content was observed in T. versicolor (29.916±0.002 mg GAE/100g) samples, and the lowest in A. mellea (9.5±0.006 mg GAE/100g) samples. The cytotoxic effects of the samples were tested on MCF-7 and MDA-MB-231 (breast cancer) and L929 (mouse fibroblast) cell lines using the MTT method. As a result, it was observed that A. mellea and T. versicolor samples were more effective on MCF-7 cell line, A. mellea on MDA-MB-231 cell line.

Listeria monocytogenes is one of the most important foodborne pathogens, causing listeriosis, a disease characterized by high mortality rates. This microorganism, commonly found in food production environments and transmitted to humans by consuming contaminated food, has the ability to form biofilms by attaching to a wide variety of surfaces. Traditional hygiene and sanitation procedures are not effective enough to completely remove L. monocytogenes biofilms from food-contact surfaces, which makes them a persistent threat to food safety. Alternative approaches to combating Listeria biofilms are needed, and the use of lactic acid bacteria (LAB) and their antimicrobial compounds shows promise. The present study investigated the effect of Lactobacillus strains, previously isolated from various foods and known to possess antimicrobial properties, on the biofilm formation of L. monocytogenes on three different food-contact surfaces. To study L. monocytogenes IVb ATCC 19115 type, culture was preferred to represent serotype IVb, which is responsible for the vast majority of listeriosis cases. The results demonstrated that cell-free supernatants (CFS_s) of LAB strains inhibited biofilm formation by up to 51.57% on polystyrene, 60.96% on stainless steel, and 30.99% on glass surfaces. Moreover, these CFS_s were effective in eradicating mature biofilms, with reductions of up to 78.86% on polystyrene, 73.12% on stainless steel, and 72.63% on glass surfaces. The strong inhibition rates of one strain of L. curvatus (P3X) and two strains of L. sakei (8.P1, 28.P2) used in the present study imply that they may provide an alternate technique for managing Listeria biofilms in food production environments.

Objectives: Due to the presence of various bioactive compounds including polyphenols and saponins, tea exhibits antimicrobial activity against microorganisms. The aim of this study is to investigate the antimicrobial activity of black, white, green, and oolong tea against some foodborne pathogens. Materials and Methods: For the extraction of tea samples, the Soxhlet method was chosen, and MIC values were determined using the broth micro-dilution method for the evaluation of antimicrobial activity. The selection of tea varieties used in the study was determined based on their consumption frequencies and popularity. Escherichia coli ATCC 25922, Proteus vulgaris ATCC 7829, Staphylococcus aureus ATCC 292123, and 3 Listeria monocytogenes (L. monocytogenes ATCC 19111, L. monocytogenes ATCC 7644, and L. monocytogenes 4b ATCC 19115) strains were used as indicator microorganisms in the study. Results: The highest antimicrobial activity was observed against L. monocytogenes strains in white tea, with an MIC value of 0.256 mg/mL. The comparison of antimicrobial activity of different tea types revealed that black tea exhibited lower antimicrobial activity compared to other tea varieties. Conclusion: The findings of the current study indicate that non-fermented tea types, such as white and green tea, which are known to be more effective in terms of healthy nutrition, exhibit higher antimicrobial activity. Therefore, it is believed that non-fermented tea varieties would be more effective in combating pathogenic microorganisms.

Emine Dincer. J. Microbiol. Biotechnol. 2024;34:349-57. https://doi.org/10.4014/jmb.2308.08043

In the present work, a novel electrochemical DNA sensor was designed to detect L. monocytogenes. Two different gene fragments were selected for the sensor design. One is a 702 bp long fragment of the hlyA gene, encoding the synthesis of listeriolysin O toxin, which is unique only to pathogenic strains of L. monocytogenes and is essential for pathogenicity. The other is a 209 bp long fragment of the 16 S RNA gene found in all species of the Listeria genus. As the working electrode, the pencil graphite electrode was modified in various ways (activated or covered with polypyrrole), and six different combinations were constituted using three types of the modified working electrode and two different gene fragments. The developed system is based on differential pulse voltammetric transduction of guanine oxidation after hybridization between the selected gene fragment (38 µg/mL) and the selected fragment-specific inosine-modified probe (1.8 µmol/L) immobilized on a pencil graphite electrode surface. The comparison of all combinations demonstrates that the best results are obtained with the combination formed from a polypyrrole-coated pencil graphite electrode (prepared at 2 scans) and 702 bp fragment of the hlyA gene. The analysis time is less than 1 hour, and the necessary DNA concentrations for the analysis have been determined as 8.2 × 10⁻¹¹ M DNA and 2.7 × 10⁻¹⁰ M DNA respectively, for the hlyA gene and 16 S RNA gene.

Objective: The aim of the authors of this study was to determine the reference values for the Adductor Pollicis Muscle Thickness (APMT) in individuals belonging to a healthy population and to compare these values with other anthropometric measurements. Materials and Methods: In this cross-sectional study, the APMT in the dominant and non-dominant hands of 385 healthy individuals categorized according to age and gender variables were measured with a caliper. Individuals in the “A” category according to the Subjective Global Assessment (SGA) test were included in the study, and anthropometric measurements. Results: In the study, 193 women and 192 men were included, and various anthropometric measurements were taken. The mean APMT values of the dominant and non-dominant hands were 20.87 ± 3.23 mm and 19.28 ± 2.93 mm in men and 16.78 ± 3.10 mm and 15.43 ± 2.92 mm in women, respectively, which indicates that there were significant differences between the members of the two genders and between the members of the same gender (p<0.001). There was a high level of positive correlation between the mean APMT values of the dominant hand and the mid-upper arm circumference (p<0.001). Conclusion: In this study, a high-level and positive correlation was found between APMT values and mid-upper arm circumference (MUAC), mid-upper arm muscle circumference (MUAMC) and mid-upper arm muscle area (AMA) values. APMT measurement emerges as a useful and new anthropometric measurement method in the assessment of the nutritional status of a person.