Aktuelle Themen

Aktuelle Themen

Aktuelle Themen


Asmaa Cherif Anntar, Mohamed Salih Barka, Ibrahim Benamar, Nahida Bendimered, Karima Boumediene, Baltasar Mayo, Ivan Leguirinel, Buomedine Moussa Boudjemaa
Assessment of the efficiency of cleaning and disinfection protocols against Enterococcus faecalis biofilms recovered from milk pipes
Bewertung der Wirksamkeit von Reinigungs- und Desinfektionsprotokollen gegen Enterococcus faecalis-Biofilme die Milchleitungen entnommen wurden

The formation of bacterial biofilm in dairy plant is the main source of milk and related dairy products contamination which is commonly related to improper Cleaning and ­Disinfection (C&D). Cleaning-In-Place (CIP) is the conventional process described to clean and remove on milk residues and bacterial contaminants from dairy processing lines. In this study, effectiveness of 3, 5 and 7 steps CIP protocols was evaluated against Enterococcus faecalis (E. faecalis) mature biofilms formed on stainless steel (SS) coupons. The results revealed that the most effective treatment was the 7 step protocol based on 2% sodium hydroxide (NaOH) cleaning combined with 3% enzyme mixture at 50°C for 20 minutes followed by 1% nitric acid (HNO3) at 55°C for 20 minutes and completed by 0.5% quaternary ammonium at 25°C for 20 minutes showed a significant difference in the number of recovered cells between untreated and treated coupons with a value of 5.32 log cfu/cm2 which was a very satisfying reduction level followed by CIP 2 with 4 log reduction value and CIP 1 presented by 3.14 log reduction. Even with 5 log reduction, a complete E. faecalis biofilm removal was not reached, showing persistence of mature biofilm to C&D protocols.

Ghazaleh Abdullahi Moghaddam Masouleh, Leila Nateghi, Masoumeh Moslemi
Comparison of antioxidant potency, pectin methyl esterase activity, and microbial contamination in red grape juice samples pasteurized by ultrasonication and thermal process
Vergleich der antioxidativen Wirkung, der Pektin-Methylesterase-Aktivität und der mikrobiellen Kontamination in roten Traubensaftproben, die mit Ultraschall und thermischen Verfahren pasteurisiert wurden

Today, people tend to consume products with high nutritional value. Ultrasound-assisted pasteurization is one of alternative methods for thermal pasteurization. In this study, red grape juice samples were treated by ultrasonication at different powers (10, 105, and 200 W), temperatures (0, 30, and 60 °C), and times (2, 6, and 10 min). After optimization by response surface methodology (Box-Behnken method), antioxidant potency, pectin methyl esterase activity, and microbial contamination (total count of microorganisms, coliforms, molds, and yeasts) of the red grape juice treated by the optimized ultrasonication were compared to those achieved by thermal pasteurization (at 90 °C for 30 sec) as control. By increasing power from 10 to 200 W, temperature from 0 to 60 °C, and time from 2 to 10 min, antioxidant potency, activity of pectin methyl esterase, and microbial population decreased in the samples, significantly. The optimum condition of ultrasonication to achieve the least microbial growth (non-detectable), and the highest antioxidant potency (IC50 of 62.3062 µl/ml) and pectin methyl esterase activity (0.0568 PEU/ml) was predicted at 180 W, 42 °C, and 8 min. After optimization, there was no significant difference between microbial contamination in the sample treated by ultra­sonication and the thermally pasteurized red grape juice, but higher antioxidant potency and pectin methyl esterase activity was observed in the ultrasound-treated sample than control. Therefore, grape juice can be pasteurized by ultrasonication instead of thermal process, through which bioactive compounds are better preserved without safety concern in term of microbial contamination.

Ellagitannins loaded maltodextrin and ­lecithin nanoparticles: antioxidant, anti­microbial, antidiabetic activity, and bio­accessibility under in-vitro digestion
Mit Ellagitanninen beladene Maltodextrin- und Lecithin-Nanopartikel: ­Antioxidative, antimikrobielle und antidiabetische Aktivität sowie Bio­verfügbarkeit bei in-vitro-Verdauung

In recent years, the evaluation of by-products from agricultural and food processing has become very important. However, the biological activity of these components decreases as a result of the losses that occur during the applied processes and metabolism activities. In this study, antioxidant, and antimicrobial activity, antidiabetic properties, and bioaccessibilities of pomegranate peel ellagitannins nanoencapsulated with maltodextrin and soy lecithin were investigated. Results showed that significant increases were obtained in the solubility in pH 6.8 phosphate buffer. There was a decrease in the total phenolic content, antimicrobial and antioxidant activity values of the nanoparticles compared to the core material due to the nanoencapsulation process. In addition, all samples showed higher antidiabetic activity compared to acarbose. As a result, the nanoparticles have the potential to be a natural resource that can be used in the pharmacology, food, and cosmetics industries with their high ellagic acid (EA) bioaccessibility, antidiabetic activities, and increased solubility.