Annika Boulaaba, Martina Kiessling, Nathalie Egen, Günter Klein, Stefan Töpfl
Effect of pulsed electric fields on the endogenous microflora and physico-chemical properties of porcine blood plasma
Einfluss gepulster elektrischer Felder auf die endogene Mikroflora und physikalisch-chemische Parameter von Schweineblutplasma
Objective: Blood plasma is a quickly perishable product. The aim of this study was to determine the impact of pulsed electric fields (PEF) on the inactivation of the endogenous microflora and on physico-chemical parameters of porcine blood plasma.
Methods: PEF application was performed at an initial temperature of 30 °C, electric field strength of 12 kV/cm, a frequency of 169 Hz which corresponds to a specific energy input of 113 kJ/kg and for a total treatment time of 130 µs. To determine the initial amounts of bacteria in the raw material and to investigate the effect of PEF on the inactivation of the endogenous microflora, samples were taken before and after PEF treatment, as well as on storage days 4, 8 and 14.
Results: We found a 1.44 log10 CFU/mL reduction in total aerobic plate count (TPC; p<0.001). For Pseudomonas spp. and Enterobacteriaceae subsequent to PEF application, counts were below the detection limit (p<0.0001 and p<0.05, respectively). A storage experiment showed significantly lower TP (p<0.01), Pseudomonas spp. (p<0.01) and Enterobacteriaceae (p<0.001) counts in the PEF treated plasma after storage for 14 days at 3 °C. There was no difference between native and PEF treated blood plasma samples concerning values of protein, ash, pH, electrical conductivity and aw.
Conclusion: In conclusion, PEF application and low temperature storage at 3 °C resulted in a strongly retarded growth of microorganisms in the PEF treated plasma samples, extending its shelf-life to 14 days based on strictest criteria for microbiological acceptability (5 x 104 CFU/mL for TPC, 5 x 103 CFU/mL for Pseudomonas spp., 5 x 102 CFU/mL for Enterobacteriaceae, 5 x 102 CFU/mL for coagulase-positive staphylococci and 1 x 102 CFU/mL for sulphite-reducing anaerobic bacteria). Thus, PEF treatment may be considered as an appropriate method for reducing microorganisms in porcine blood plasma and for extending shelf life.
Semra Gürbüz, Oktay Keskin, Sevil Erdenliğ Gürbilek, Osman Yaşar Tel, Akın Yiğin, Mehmet Demirci, Cemil Demir, Hala Hassan
Presence of Staphylococcus aureus, staphylococcal enterotoxins and antimicrobial resistance in traditionally produced raw milk cheeses
Vorhandensein von Staphylococcus aureus, Staphylokokken Enterotoxinen und antimikrobielle Resistenzen in traditionell hergestelltem Rohmilchkäse
The objectives of this study was to investigate the presence of Staphylococcus aureus, distribution of classical staphylococcal enterotoxin (SE) SEA to SEE, relevant gene/s and antimicrobial resistance pattern of S. aureus isolated from traditionally produced raw milk cheeses. A total of 106 fresh white cheese samples were examined. The 25 (23.6 %) of 106 cheese samples were found to be contaminated with coagulase positive staphylococci (CPS). From 52 isolates identified as S. aureus, one or more SEs was detected in 38.4 % of the isolates by ELISA whereas one or more se genes were detected in 50 % of the isolates by RT PCR. SEE (75 %) and see gene (61.5 %) were detected most frequently, whereas SED and sed gene were not detected in any isolates. Overall, 63.5 % of isolates were resistant to antimicrobial agents with 59.6 %, 13.5 %, 5.8 %, 5.8 % and 3.8 % of the isolates were resistant to penicillin, erythromycin, tetracycline, cefoxitin and kanamycin, respectively. The results of this study have revealed that cheeses made from raw milk were highly contaminated with S. aureus, therefore, creates a risk for public health due to the presence of enterotoxins as well as resistant strains against antimicrobial agents.
Ozgur Golge, Osman Kılınççeker, Ahmet Koluman
Effects of different fibers on the quality of chicken meatballs
Auswirkungen verschiedener Nahrungsfasern auf die Qualität von Hähnchenfleischbällchen
The objective of this study was to determine the effects of pea fiber, orange fiber and inulin fiber on some quality properties of chicken meatballs. Samples were prepared with different formulations (3, 6 and 9 %) for each fiber. Analyzes of pH determination, thiobarbituric acid and color values of raw meatballs were evaluated during cold storage whereas color, yield, diameter reduction, moisture retention, fat absorption and sensory properties of fried meatballs were determined. As a results, it was observed that fibers had significant effect on quality of meatballs. Pea fiber increased pH, yield and moisture retention whereas decreased diameter reduction and fat absorption. Inulin fiber increased pH, diameter reduction and fat absorption. Additionally, orange fiber improved TBA, a and b values of samples, positively. In particular, it was found that 3, 6 and 9 % of pea fiber and 9 % of inulin fiber are more successful for chicken poultry production.
Moneeza Abbas, Fatima Younas, Tahira Mughal, Amina Abrar
Comparison of nickel content in broiler chickens and domestic chickens
Vergleich des Nickelgehalts von Masthühnern und Hühnern aus häuslicher Haltung
Heavy metals are persistent in the environment and are subject to bioaccumulation in food chains. The present study was done to investigate the concentrations of Nickel in different organs of broiler and domestic chickens. Various organs (kidneys, livers, muscles, hearts and gizzards) of broiler and domestic chickens were collected from different shops and villages near Lahore. The samples were analyzed for Nickel concentration by using analytical technique of Atomic Absorption Spectrophotometer. Mean Ni concentration was significantly higher in various organs (kidneys, livers, muscles, hearts and gizzards) of broiler chickens as compared to domestic chickens. Highest mean Ni concentration was found in kidney samples of broiler chicken i. e. 2.3 ± 0.68 mg/kg as compared to other organs of broiler chicken. It is concluded that a large amount of heavy metals are added in feed given to broiler chickens to enhance their growth in short time span. Ni accumulates in body and may pose serious impacts to health.