The aims of this study were to characterize postbiotics, and to evaluate their antibacterial effects in-vitro and on chicken drumsticks. Postbiotics Pediococcus. acidilactici (PA), Latilactobacillus ...sakei/Staphylococcus xylosus (LS) exhibited strong antioxidant activity, and their total phenolic contents were found as 2952.78 ± 0.4 and 1819.44 ± 0.39 mg GAE/L, respectively (P < 0.05). A total of 19 different phenolic and flavonoids were determined in the postbiotics. The results of the study revealed that 5% and 10% postbiotics + EDTA decreased the number of L. monocytogenes nearly 5.0 log10 in 6 h in TSB. S. Typhimurium count in the chicken drumstick decontaminated with 10% PA was found as 2.1 log10 lower than the control group on day 0. L. monocytogenes counts in the chicken drumstick decontaminated with 10% Postbiotics+1% LA groups were found to be 1.1 log10 lower than the control group (P < 0.05). The lowest total mesophilic aerobic bacteria counts in the chicken drumsticks were found in the 10% Postbiotics+1% LA samples, and postbiotics did not change the color properties of the drumstick samples on day 0 (P > 0.05). In conclusion, postbiotics and their combinations with natural preservatives may be an alternative approach to reduce the food-borne pathogens and to extend the shelf-life of poultry meat and meat products.
•A total of 19 different phenolic compounds were determined in postbiotics.•10% postbiotics+0.02 M EDTA decreased L. monocytogenes counts 5.0 log in 6 h in TSB.•10% postbiotics reduced S. Typhimurium count as 2.1 log in chicken drumstick.•Postbiotics did not change the L*, a* and b* values of chicken drumstick samples.
The objective of the study was to carry out characterization of postbiotics from Pediococcus acidilactici and to assess their efficacy (50% and 100%) in combination with chitosan (0.5 and 1%) against ...Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes on frankfurters during refrigerated storage for 35 days. High amounts of total phenolic content (1708.15 ± 93.28 mg GAE/L) and carboxylic acids, which comprised 74.89% of the total volatiles, were found in the postbiotics. On day 0, the postbiotic-chitosan combinations decreased the E. coli O157:H7, L. monocytogenes and S. Typhimurium counts ranging from 1.58 to 3.21 log10 compared to the control in frankfurters (P < 0.05). Total viable count and number of lactic acid bacteria were effectively reduced in all treatment groups (P < 0.05), and postbiotic and chitosan treatments did not cause any changes in pH and color of the frankfurters. In conclusion, postbiotic-chitosan combinations can be used to reduce the risks that might be associated with E. coli O157:H7, L. monocytogenes, and S. Typhimurium in frankfurters.
The current study aimed to characterize homemade fermented pickle juice and evaluate its efficacy as a marinade on physicochemical, microbiological, textural properties, microstructure, and sensory ...attributes of the strip loins. Organic acids, phenolics, flavonoids, volatiles, total phenolic content (TPC), and in-vitro antioxidant capacity (ABTS and FRAP) analyses were carried out. Furthermore, minimum inhibitory concentration (MIC), and the diameter of inhibition zones of the pickle juice were determined against Escherichia coli O157:H7, Salmonella Typhimurium, S. enteritidis, and Listeria monocytogenes. The strip loins were marinated with five different concentrations (10%, 25%, 50%, 75%, and 100%) of pickle juice at 4 °C for 24 h. A total of 4 organic acids, 23 phenolic and flavonoid compounds, and 69 volatiles were identified in the pickle juice. The TPC, ABTS, and FRAP values of the pickle juice were found to be 184.24 ± 33.28 GAE/L, 44.48 ± 0.41 mg TEAC/L, and 2.79 ± 0.01 mM FE/L, respectively. The MIC and inhibition zones were recorded between 7.81 and 12.50% and 8.25-13.80 mm against pathogenic bacteria, respectively. The textural properties of the strip loins marinated with 100% pickle were improved compared to the control (P < 0.05). Moreover, this concentration decreased the number of pathogens in strip loins, ranging between 1.07 and 2.77 log
CFU/g (P < 0.05). Regarding sensory attributes, the strip loins marinated with 50% and 100% pickle juice had higher scores compared to the non-marinated samples. The results of this study indicated that pickle juice can be evaluated as a marinade to improve the microbiological quality and textural properties of strip loins.
Hepatitis A is transferred via fecal-oral route, direct contact from person to person or with ingestion of contaminated food. Foods like, raspberries, strawberries and blueberries are important ...source of hepatitis A virus (HAV). Frozen retail packaged raspberries are analyzed in this study. Frozen raspberry samples have were obtained from local supermarkets monthly between January and December 2015 in Ankara province, Turkey. The samples were evaluated for HAV contamination using ISO/TS 15216-1:2013 in duplicate and Mengovirus was used for process control. Samples that found to be contaminated with HAV were further analyzed for Enterobacteriaceae Coliform and Escherichia coli. Totally 240 samples were analyzed and 20 (8.33%) were found to be contaminated with HAV. The highest HAV prevalence was on 6th month (25%). On the contrary no HAV was found on 3rd, 4th and 10th months of analyzes. The highest Enterobacteriaceae, Coliform and E. coli counts were found on 2nd month 4.90, 4.84 and, 3.48 log10 cfu/g, respectively. The results indicate that even the food relies with the microbiological criteria, there is no guarantee for viral contamination. Additionally, high cost of virus analyzes is another barrier for routine control which has a direct impact on public health. Additional measures like HACCP, GHP and GMP should be applied strictly from farm to fork to avoid contamination with HAV.
Hepatit A virüsü (HAV), genellikle fekal-oral yolla, kişiden kişiye direkt temas veya kontamine gıda ve suyun alınmasıyla bulaşmaktadır. Dondurulmuş ahududu, çilek ve yabanmersini gibi üzümsü meyveler kategorisinde yer alan ürünler, HAV kontaminasyonu açısından önemli kaynaklar arasında yer almaktadır. Bu çalışmada piyasada paketli olarak satılan dondurulmuş ahududu örnekleri kullanılmıştır. Dondurulmuş ahududu örnekleri, 2015 yılında Ankara’da bulunan marketlerden Ocak-Aralık ayları arasında her ay 20 tane olacak şekilde toplanmıştır. Çalışma konusunu oluşturan ahududu örneklerinde HAV analizi ISO/TS 15216-1:2013 uygun olacak şekilde iki paralel olarak yapılmıştır ve proses kontrolü için Mengovirüs kullanılmıştır. HAV pozitif bulunan örneklerde Enterobacteriaceae, Koliform bakteri ve E. coli sayımları gerçekleştirilmiştir. Toplam 240 adet ahududu örneğinin 20 adetinin (%8,33) HAV pozitif olduğu tespit edilmiştir. En yüksek prevalansın 6. ayda (%25) olduğu tespit edilirken, 3, 4 ve 10. aylarda alınan örneklerde ise HAV bulunmamıştır. En yüksek Enterobacteriaceae, koliform ve E. coli sayılarının 2. ayda olduğu ve bu ayda sırasıyla 4,90, 4,84 ve 3,48 log10 kob/g bakteri olduğu tespit edilmiştir. Bu sonuçlar gıdaların mikrobiyolojik kriterlere göre bakteriyel ajanlar bakımından yeterli koşulları sağlıyor olduğunu gösteriyor olmasına rağmen, viral etkenler bakımından herhangi bir garanti sağlamadığını göstermektedir. Ayrıca yüksek maliyetli virüs analizleri, halk sağlığı üzerinde doğrudan etkisi olan rutin kontrollerin yapılması için bir engel oluşturmaktadır. HACCP, GHP ve GMP gibi ilave önlemler, HAV ile bulaşmayı önlemek için kesinlikle çiftlikten çatala kadar uygulanmalıdır
This study was carried out to characterize antioxidant activity, total phenolic content, and the phenolic and flavonoids profile of postbiotic of Pediococcus acidilactici and to evaluate the effects ...of postbiotics (10% and 50%) alone and in combination with chitosan coating (1%) on the microbial and chemical quality of chicken breast fillets during storage at 4 °C. Antioxidant activity and total phenolic content of the postbiotics were found to be 1291.02 ± 1.5 mg/L TEAC and 2336.11 ± 2.36 mg/L GAE, respectively. The most abundant phenolic was vanillic acid, followed by t-caffeic, gallic, and caftaric acids. The postbiotic-chitosan (50% + 1%) combination decreased L. monocytogenes and S. Typhimurium counts by 1.5 and 2.1 log10 CFU/g, respectively, compared to the control (P < 0.05). This combination decreased the total viable count (TVC), lactic acid bacteria (LAB), and psychrotrophic bacteria count compared to the control (P < 0.05). No differences were found in thiobarbituric acid (TBA) values among the samples during storage (P > 0.05). Postbiotic treatment did not significantly change the pH values and color properties of the breast fillets (P > 0.05). Postbiotic-chitosan combinations extended the shelf-life by up to 12 days compared to the control. In conclusion, the postbiotic-chitosan combination can be used to preserve and improve the microbial quality of chicken meat products.
In the current study, it was hypothesized to evaluate the potential effects of hawthorn vinegar-based marinade at 3 different concentrations (25%, 50%, and 100%) and marination duration (2, 6, and ...24 h) on the physicochemical, microbiological, textural properties, microstructure, and sensory attributes of tenderloins. It was also aimed to identify and quantify the bioactive compounds present in the hawthorn vinegar that contribute to the aforementioned properties of tenderloins. The levels of organic acids, individual phenolic and flavonoid compounds, volatiles, in-vitro antioxidant capacity (DPPH, ABTS, and FRAP) of the hawthorn vinegar were analyzed. In addition, minimum inhibitory concentration (MIC), and inhibition zones were determined against Escherichia coli O157:H7, Salmonella Typhimurium, S. Enteritidis, and Listeria monocytogenes strains. A total of five organic acids, 21 phenolic and flavonoid compounds and 51 volatiles were determined in the hawthorn vinegar, and displayed strong antioxidant capacity determined by DPPH (470.93 ± 28.55 mg TEAC/L), ABTS (706.03 ± 4.88 mg TEAC/L) and FRAP (59.15 ± 0.50 mM FE/L) tests. The MIC and inhibition zones of the hawthorn vinegar ranged between 5.21 and 6.25%, and 9.41–11.43 mm against tested pathogens, respectively. In the tenderloin experiment, all marination treatments significantly changed the physicochemical and textural properties, microbiological status, and microstructure of the tenderloins (P < 0.05). Among them, the most effective treatment was the marination with 100% hawthorn vinegar for 24 h. In this treatment, the hardness, chewiness, springiness, and gummines values of the tenderloins were found lower than untreated tenderloins (P < 0.05). Furthermore, this treatment provided a high reduction in the number of pathogens ranging between 3.08 and 3.82 log10 CFU/g (P < 0.05) compared to the control. Although no differences were found among the groups (P > 0.05), flavor, odor, appearance, texture, and color scores of the tenderloins marinated with 100% hawthorn vinegar for 24 h were found higher than the non-marinated samples. The results of this study revealed that hawthorn vinegar contains certain levels of bioactive compounds which can help to improve the microbiological quality and textural properties of the meat parts.
Abstract In this study, biodegradable active films were designed by adding ZnO-NPs to the quince seed mucilage/chitosan matrix. The films were investigated for characterization and in vitro ...bioactivity. According to the results, a significant decrease in moisture content, water holding capacity and light (L*) occurred with the addition of ZnO-NP. ( p < 0.05). FT-IR spectra showed the interaction between ZnO-NPs and N-H quince seed mucilage and chitosan groups. Nanocomposite films containing ZnO-NP showed improved thermal stability. The developed bionanocomposite films were easily buried in soil and subjected to degradation. The minimum degradation of the film in soil after 20 days was 62.02%. The maximum cell viability (%) of C/ZnO-NP and C/QSM/ZnO-NP films were determined as 86.81% and 91.22%, respectively, and the films were found to be non-toxic. Moreover, while the quince seed mucilage film did not show antibacterial performance, chitosan and ZnO NPs showed antibacterial effects against the tested bacteria Listeria monocytogenes (ATCC 7644) and Escherichia coli O157:H7 (ATCC 35,150). In this context, the design bionanocomposite films can be used as an active food packaging material for food preservation by controlling food-borne pathogens. In addition, the developed films do not pose a threat to the environment and therefore have great potential for the sustainable food packaging industry.
The current research was designed to compare the physicochemical and antimicrobial properties of cell-free supernatant (CFS) and whole-cell postbiotic (WCP) and reveal the efficacy of WCP in ...combination with chitosan and thymol for extending the shelf life and inhibiting emerging foodborne pathogens in chicken breast fillets during storage at 4 °C. For this purpose, pH, organic acids, titratable acidity, antioxidant capacity assays (FRAP, ABTS, and DPPH), free amino acids (FAA), free fatty acids (FFA), total phenolic content, individual phenolics, color properties, and volatiles of CFS and WCP were compared. The levels of some organic acids, FAA, titratable acidity, and total phenolic content (TPC) of WCP were higher than CFS (
P
< 0.05). Almost similar inhibition zones (7.82 to 10.43 mm) were recorded between the CFS and WCP against some pathogenic bacteria including
S.
Typhimurium,
E. coli
O157:H7, and
L. monocytogenes
. In chicken breast fillets, the total viable count of the control group reached the upper limit (7.0 log
10
) on the 6th day, while WCP (50%) + thymol (0.5%) + chitosan (0.5%) treatment provided a shelf life extension of 9 days (
P
< 0.05). Additionally, this treatment provided 2.35, 2.35, and 1.96 log
10
CFU/g reductions in
S.
Typhimurium,
E. coli
O157:H7, and
L. monocytogenes
counts on the initial day, respectively (
P
< 0.05). The result of this study revealed that WCPs can be easily prepared without any changes in antibacterial efficacy and used in food matrices to control major foodborne pathogens and extended the shelf life by retarding microbial and chemical deteriorations.
The aim of this study was to determine the single and combined effect of chitosan and Pediococcus acidilactici (B-LC-20) on Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes ...in meatballs. After spiking the samples with pathogens, meatball mixture was divided into 4 groups as control, chitosan, B-LC-20 and chitosan + B-LC-20. Subsequently, chitosan (0.4%) and P. acidilactici (6.73 log10) was added into the treatment groups. P. acidilactici effectively decreased the numbers of E. coli O157:H7 in B-LC-20 group in 10 days (P < 0.05). The differences in L. monocytogenes count on day 0, between the control (6.8 log10) and chitosan + B-LC-20 (5.3 log10) groups were found to be significant (P < 0.05). During the storage period; total mesophilic aerobic bacteria (TMAB), Lactobacillus-Leuconostoc-Pediococcus (LLP) and yeast-mold counts in control group were higher than the chitosan and chitosan + B-LC-20 (P < 0.05). Briefly, chitosan was found to be effective on E. coli O157:H7 and L. monocytogenes. In addition, P. acidilacitici showed an inhibitory effect on E. coli O157:H7. The combination of chitosan and P. acidilactici exhibited a slight inhibitory effect on E. coli O157:H7 and L. monocytogenes. It is concluded that the studies on bio-protective cultures combined with chitosan, could be optimized and used for food safety.
•Meat and meat products carry various microorganisms include pathogens and saprophytes.•The demand for natural preservatives instead of synthetic chemicals is increasing.•Bio-protective culture and chitosan have been widely used for food safety.•The combination chitosan and P. acidilactici showed a slightly inhibitory effect.
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