Estimating the Prevalence of Foodborne Pathogen Campylobacter jejuni in Chicken and Its Control via Sorghum Extracts.

Campylobacter jejuni is a Gram-negative bacterium which is considered as the most reported cause of foodborne infection, especially for poultry species. The object of this work is to evaluate the occurrence of C. jejuni in chicken meat as well its control via three types of sorghum extracts (white sorghum (WS), yellow sorghum (YS), and red sorghum (RS)); antibacterial activity, antioxidant power, and cytotoxicity of sorghum extracts were also assessed. It was found that C. jejuni is very abundant in chicken meat, especially breast and thigh. WS extract showed more effectiveness than both yellow and red ones. Lyophilized WS extract offered high total phenolic compounds (TPCs) and total flavonoid compounds (TFCs) of 64.2 ± 0.8 mg gallic acid equivalent (GAE/g) and 33.9 ± 0.4 mg catechol equivalent (CE)/g, respectively. Concerning the antibacterial and antioxidant activities, WS showed high and significant antibacterial activity (p < 0.001); hence, WS displayed a minimum inhibitory concentration (MIC) of 6.25%, and revealed an inhibition zone of 7.8 ± 0.3 mm; it also showed an IC50 at a concentration of 34.6 µg/mL. In our study, different samples of chicken fillet were collected and inoculated with pathogenic C. jejuni and stored at 4 °C. Inoculated samples were treated with lyophilized WS extract at (2%, 4%, and 6%), the 2% treatment showed a full reduction in C. jejuni on the 10th day, the 4% treatment showed a full reduction in C. jejuni on the 8th day, while the 6% treatment showed a full reduction in C. jejuni on the 6th day. Additionally, 2%, 4%, and 6% WS extracts were applied on un-inoculated grilled chicken fillet, which enhanced its sensory attributes. In sum, WS extract is a promising natural preservative for chicken meat with accepted sensory evaluation results thanks to its high antibacterial and antioxidant potentials.

Complementary spectroscopy studies and potential activities of levan-type fructan produced by Bacillus paralicheniformis ND2.

This study aimed at the production of marine bacterial exopolysaccharides (EPS) as biodegradable and nontoxic biopolymers, competing the synthetic derivatives, with detailed structural and conformational analyses using spectroscopy techniques. Twelve marine bacterial bacilli were isolated from the seawater of Mediterranean Sea, Egypt, then screened for EPS production. The most potent isolate was identified genetically as Bacillus paralicheniformis ND2 by16S rRNA gene sequence of ~99 % similarity. Plackett-Burman (PB) design identified the optimization conditions of EPS production, which yielded the maximum EPS (14.57 g L-1) with 1.26-fold increase when compared to the basal conditions. Two purified EPSs namely NRF1 and NRF2 with average molecular weights (Mw¯) of 15.98 and 9.70 kDa, respectively, were obtained and subjected for subsequent analyses. FTIR and UV-Vis reflected their purity and high carbohydrate contents while EDX emphasized their neutral type. NMR identified the EPSs as levan-type fructan composed of ß-(2-6)-glycosidic linkage as a main backbone, and HPLC explained that the EPSs composed of fructose. Circular dichroism (CD) suggested that NRF1 and NRF2 had identical structuration with a little variation from the EPS-NR. The EPS-NR showed antibacterial activity with the maximum inhibition against S. aureus ATCC 25923. Furthermore, all the EPSs revealed a proinflammatory action through dose-dependent increment of expression of proinflammatory cytokine mRNAs, IL-6, IL-1ß and TNFα.

Evaluation of the Adsorption Efficacy of Bentonite on Aflatoxin M1 Levels in Contaminated Milk.

The existence of aflatoxin M1 (AFM1) in raw milk results in economic losses and public health risks. This research aims to examine the capability of bentonite to adsorb and/or eliminate AFM1 from various raw milk types. In addition, the effects of numerous bentonites (HAFR 1, 2, 3 and 4) on the nutritional characteristics of the milk were studied. Our findings revealed that goat milk had the highest value of AFM1 (490.30 ng/L) in comparison to other milks. AFM1 adsorption was influenced by applying bentonite (0.5 and 1 g) in a concentration-dependent manner for different time intervals (from 0 to 12 h). The percentage of AFM1 reached the maximum adsorption level after 12 h to 100, 98.5 and 98% for bentonites HAFR 3, 1 and 2, respectively. HAFR 3 (1 g bentonite) presented higher adsorption efficiency than other bentonites used in the phosphate buffer saline (PBS) and milk. Residual levels of AFM1 reached their lowest values of 0 and 1.5 ng/L while using HAFR 3 in PBS and milk, respectively. With regard to the influence of bentonite on the nutritional characteristics of milk, there was an increase in fat, protein and solid non-fat ratio while using HAFR 3 and 4, yet decreased lactose in comparison with the control. Scanning Electron Microscopy and Fourier Transform-Infrared Spectroscopy both identified bentonites as superior AFM1 binders. The results demonstrated that bentonite, particularly HAFR 3, was the most effective adsorbent and could thus be a promising candidate for the decontamination of AFM1 in milk.