Effect of Kombucha on gut-microbiota in mouse having non-alcoholic fatty liver disease

Food Science and Biotechnology - Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver disorders. Possible links have been recently found between the gut-microbiota and the host...     

Preparation of a hydrophobic recycled jute-based nonwoven using a titanium dioxide/stearic acid coating

This work aims at developing a hydrophobic treatment for jute fiber-based nonwovens. Three solutions of titanium dioxide (TiO₂) nanoparticles were prepared through a sol–gel method by varying the molar ratio of the various constituents. The nonwoven was pretreated with these solutions before being impregnated with different concentrations of stearic acid. The TiO₂ nanoparticles synthesized are amorphous; their size varies with the concentration of ethanol used as a solvent in the sol–gel method. The nanoparticle coating produced on the jute fibers is uniform. The nonwoven wettability was evaluated by measuring its water contact angle and retention time; the nonwoven became hydrophobic at the lowest fatty acid concentration tested. An increase in the stability of the hydrophobicity was observed when the TiO₂ nanoparticle pretreatment was used compared to the application of the stearic acid treatment only. No detrimental effect of the hydrophobic treatment on the nonwoven mechanical performance and thermal stability was observed. These results demonstrate the potential of the TiO₂ nanoparticle/stearic acid treatment as a fast method to provide a stable hydrophobicity to recycled jute-based nonwovens.     

Correlation of In Vivo and In Vitro Assay Results for Assessment of Free Radical Scavenging Activity of Green Tea Nutraceuticals

Green tea (GT)‐derived catechins; epigallocatechin gallate (EGCG) in particular are commonly used nutraceuticals for their free‐radical scavenging activity (FRSA). The influence of photodegradation on the protective power of GT nutracenticals against oxidative stress was thoroughly explored. Photodegradation of GT extracts was carried out and monitored using orthogonal stability‐indicating testing protocol; in vitro and in vivo assays. Total polyphenol content (TPC) and FRSA were determined spectrophotometrically while EGCG was selectively monitored using SPE‐HPLC. In vivo assessment of photodegraded samples was investigated via measuring a number of biomarkers for hepatic oxidative stress and apoptosis (caspase‐3, inducible nitric oxide synthase, nitric oxide, mitogen‐activated protein kinase, glutathione, thiobarbituric acid reactive substances, nuclear factor kappa beta, and nuclear factor erythroid 2‐related factor) as well as liver damage (alanine transaminase and aspartate transaminase) in serum of rats previously subjected to oxidative stress. Results showed complete degradation of EGCG in photodegraded green tea samples with no correlation with either TPC or FRSA. On the other hand, in vivo assay results revealed not only loss of activity but formation of harmful pro‐oxidants. Photostability was found crucial for the protective effect of GT extract against lead acetate insult. Results confirmed that careful design of quality control protocols requires correlation of chemical assays to bioassays to verify efficacy, stability, and most importantly safety of nutraceuticals.     

Ultrasound‐based,in‐line monitoring of anaerobe yeast fermentation: model,sensor design and process application

In order to implement process analytical technology in beer manufacturing, an ultrasound‐based in‐line sensor was developed which is capable to determine sound velocity and density via the multiple reflection method. Based on a systematic study of the ternary system water–maltose–ethanol, two models were established to estimate the critical process parameters: sugar and ethanol mass fraction. The sound velocity‐based model showed unreasonable high errors although temperature variations and deviations due to dissolved CO₂ were corrected. In contrast, the sound velocity–density–temperature model provided an average root mean square error of 0.53%g/g sugar and 0.26%g/g ethanol content for the main fermentation. Method, sensor and model showed the capability to capture the process signature which may be related to product and process quality.     

The food preservative potential of essential oils: is lemongrass the answer?

Several essential oils of medicinal plants possess proven antimicrobial activity and are suitable for applications on the food industry. The oil from Cymbopogon citratus (lemongrass) has been reported to have a wide range of biological activities. However, there are few controlled studies confirming its antimicrobial activity. The aim of our study was to assess the antimicrobial potential of lemongrass oil against a wide spectrum of food spoilage and pathogenic bacteria and yeast in liquid and vapour phase. The chemical composition of the oil was analyzed by gas chromatography; 14 components were identified and geranial (28.93 %), neral (24.30 %) and myrcene (23.92 %) were the most abundant constituents. Lemongrass oil showed potent antimicrobial activity against Gram positive bacteria and exhibited the strongest antifungal effect against Candida albicans and C. parapsilosis. Minimum inhibitory concentration varied from 0.019 to 1.25 mg mL^?1 for Gram positive bacteria and yeasts, indicating Staphylococcus aureus, S. epidermidis and C. albicans as the most susceptible strains. Moreover, the diameter of inhibition zone (DIZ) increased with increasing essential oil (EO) volume. Considerably superior antimicrobial activity was observed in the vapour phase. The DIZ resulting from the exposure to EO vapour was significantly larger than that from the same volume in the liquid phase. The DIZ varied from 22 to 90 mm for Candida strains. There is growing evidence that EO in vapour phase are effective antimicrobial systems and that they do have advantages over the use of oil in liquid phase. Our results imply that lemongrass oil could be useful for the development of novel types of natural preservatives for food control.     

Determination of biogenic amines in selected Malaysian food

The biogenic amines tryptamine (TRP), putrescine (PUT), histamine (HIS), tyramine (TYR) and spermidine (SPD) were determined in 62 selected food items commonly consumed in Malaysia. This include the local appetisers “budu” and “cincalok”, canned fish, salt-cured fish, meat products, fruit juice, canned vegetables/fruits and soy bean products. After the aqueous extraction, the samples were derivatised with dansyl chloride before analysing using reversed phase HPLC with UV detection. Mean levels of TRP, PUT, HIS, TYR and SPD in eight budu samples were 82.7, 38.1, 187.7, 174.7 and 5.1 mg kg⁻¹, respectively. The main biogenic amines found in cincalok were PUT, HIS and TYR where the mean values were 330.7, 126.1 and 448.8 mg kg⁻¹, respectively. With the exception of “pekasam” and “belacan”, significantly lower levels of biogenic amines were found in canned fish and salt-cured fish samples. Non detectable or low levels of biogenic amines were found in meat, fruit juice and canned vegetables/fruit samples.     

Parameters Influencing Power Generation in Eco-friendly Microbial Fuel Cells

Pulp and papermaking industries generate high volumes of carbohydrate-rich effluents. Microbial fuel cell (MFC) technology is based on organic materials’ consumption?and efficient power production. Using a classical two-chamber lab-scale MFC design with an external resistance of 2000 W, we investigated the effects of anode chamber biofilm adaptation (ACBA) and cathode chamber redox solutions (CCRS) on the operation efficiency of MFC when treating wastewater. In ACBA studies, biofilm growth activation showed an increase in the power density to 20.48, 35.18, and 36.98 mW/m² when the acetate feeding concentrations were 3, 6, and 12 g/L, respectively. Improvement by biofilm adhesion on granular activated carbon (GAC) was examined by scanning electron microscopy (SEM). The obtained power density increased to 25.47, 33.42, and 40.39 mW/m² when the GAC particles concentrations were 0, 50, and 100 g/L, respectively. The generated power densities were 51.26 and 40.39 mW/m² as well as the obtained voltages were 0.41 and 0.72 V when the electrode area increased from 16 to 64 cm²², current density of 0.094 A/m², and voltage of 1.20 V with a successful organic removal efficiency of 86.0% after 264 h of operation.     

Preparation and Aqueous Properties of Starch‐grafted Polyacrylamide Copolymers

In the present work, starch‐grafted polyacrylamide copolymers were prepared and their rheological properties, either in water or in water‐based muds, were investigated. The advantages in using starches as substrates to prepare additives which are suited for improving stability and the rheological properties of water‐based muds, lie in their low cost, and their lower biodegradability than native starches. Thus, various copolymer series were prepared by free‐radically grafting acrylamide (AM) onto starch using ceric ammonium sulphate (CAS) as initiator. It is shown that the intrinsic viscosity and the molecular weight of the grafted starches are controlled by the initiator and monomer concentrations. Furthermore, to predict the behaviour of the samples under oil‐well conditions, the aqueous solution properties of the copolymers such as water solubility, viscosity, shear rate, were determined as function of temperature, salt concentration and type, and aging time. The knowledge of these properties is a prerequisite for the use of the copolymers in drilling fluids. The data indicate that starch‐grafted polyacrylamide copolymers as compared to the non‐modified starch, behave as shear‐thinning, are salt resistant, and their rheological properties are stable with time. The grafted starches as prepared above were also added to water‐based mud and the rheological properties of the resulting muds were determined under oil‐well conditions. Grafted starches, having high AM contents, are more efficient in decreasing the filtrate volume, and increasing the plastic viscosity of the muds, when compared to PAC‐L, a modified cellulosic polymer used in the filtration control of most water‐based muds. Such improvements in the rheological properties of the muds were found to result from the behaviour and/or properties of the grafted starches in water.