Optimization of phospholipase A[1] immobilization on plasma surface modified chitosan nanofibrous Mat

Phospholipase A! is known as an effective catalyst for hydrolysis of various phospholipids in enzymatic vegetable oil degumming. Immobilization is one of the most efficient strategies to improve its activity, recovery and functional properties

In this study, chitosan-co-polyethylene oxide [90:10] nanofibrous mat was successfully fabricated and modified with atmospheric plasma at different times [2, 6 and 10 min] to interact with enzyme molecules. Scanning electron microscopy images revealed that the membranes retained uniform nanofibrous and open porous structures before and after the treatment. PLA[1] was successfully immobilized onto the membrane surfaces via covalent bonds with the functional groups of chitosan nanofibrous mat. Response surface methodology was used to optimize the immobilization conditions for reaching the maximum immobilization efficiency

Enzyme concentration, pH, and immobilization time were found to be significant key factors. Under optimum conditions [5.03 h, pH 5.63, and enzyme dosage 654.36 UI], the atmospheric plasma surface modified chitosan nanofibers reached the highest immobilization efficiency [78.50%]

Fourier transform infrared spectroscopy of the control and plasma surface-modified chitosan nanofibers revealed the functional groups of nanofibers and their reaction with the enzyme

The results indicated that surface modification by atmospheric plasma induced an increase in PLA[1] loading on the membrane surfaces

Utilization of membrane systems in beer processing

Beer is the most consumed beverage after tea, carbonates, milk and coffee in the world and it continues to be a popular drink. One of the important reason for its popularity is that beer is a drink with a pleasant flavor, an attractive color and also because of its clarity. So, Membrane separation technology has become widely used in the food processing industryto attain these characteristics.As advantages of membrane filtration are included maintainingdissolved macromolecules that give the beer its flavor and functional properties while causes removal of yeast cells and turbidity colloids and also, reducing the components that cause turbidity of the bottled beer.Because of the potential of cross-flow microfiltration as a separation method for brewery, it has been investigated in the many of recent studies. Clarification of rough beer [RB] and pasteurization of clarified beer [CB] are as an application of cross-flow microfiltration [CFMF] in brewery. An important limitation in the performance of membrane processes is the fouling mechanism and the general effect of these phenomena, known as concentration polarization have described briefly in this review article. Moreover, the influence of important parameters in the filtration process such as temperature, pressure,type of membrane, pore size and the use of stamped membrane have been discussed

Effect of Storage in the Fortified Probiotic Corn Flakes Prepared by L. plantarum and L. reuteri

Nowadays corn flakes are the most common form of breakfast cereals; however, their vitamins are declined during the baking process. In this research, production of fortified corn flakes by Lactobacillus plantarum and L. reuteri, as well as incorporation of oat and malt fiber as prebiotics have been studied. Plackett-Burman statistical design was used to evaluate the impact of eleven-process variables on the viability of both probiotics. The highest survival rate of L. plantarum [340 ×10[6] CFU.g[-1]] was obtained by 2.5% w/w inoculation of a 24 h inoculum in a medium containing 10% w/v oat extract to enrich corn flakes [10% w/w malt fiber], packed in aluminum foil and kept at 20 [degree]C in anaerobic conditions for 2 weeks. Also the highest survival rate of L. reuteri [123 ×10[6] CFU.g[-1]] was achieved when the 48 h cultured bacteria grown in a medium containing 5% w/v malt extract and MRS broth was inoculated [2.5% w/w] to the flakes enriched by 20% w/w malt fiber, and kept in anaerobic conditions inside the polypropylene cover packaging at 20 [degree]C for 2 weeks. Sensory evaluation showed no significant difference between the treatments in terms of taste, odor and overall acceptability as compared to the control

Antifungal and anti-bacterial synergistic effects of mixture of honey and herbal extracts

By increasing resistance of several bacterial and fungal species to many kinds of antibiotics, applications of natural base compounds e.g. honey and medicinal herbs have been more attractive. The aim of present research is evaluation of anti-bacterial and anticandida effects of three kinds of honey of Iran together with alcoholic extract of mint and zataria, as well as extract and starch of ginger on Staphylococcus aureus, Pseudomonas aueoginosa, Escherichia coli and Candida albicans, as pathogens of human body. Minimum inhibitory concentration [MIC] and minimum additive inhibitory concentration [MAIC] were determined by the agar diffusion method by dilution method in Sabouraud agar. By inoculation of 10 micro L from suspension and appearance of colorless vesicles, MIC was determined. Growth inhibition was calculated by ANOVA, Mann-Whitney U and t-student tests. All experiments were conducted three times. MIC for three variety of honey on Staphylococcus aureus [32, 30, 29% v/v], Pseudomonas aeroginosa, [70, 67, 71% v/v], Escherichia coli [40, 35, 39% v/v] and Candida albicans [45, 48, 50% v/v] are reported. While, the MAIC for the growth inhibition of honeys together with extract of mint and zataria, as well as extract and starch of ginger were reduced. The results show that ginger extract has more significant impact on microorganism growth with respect to others. Pseudomonas aeroginosa was the most susceptible microorganisms to ginger extract. Growth inhibitory effect of ginger extract was more significant than ginger starch. Addition of herbal extract increases antibacterial and anticandida properties of honey thus letting hope for a honey benefit and would constitute an alternative way against the resistance to bacteria

Production and purification of a protease from an alkalophilic Bacillus sp. 2-5 strain isolated from soil

This research has focused on isolation and characterization of a strain of Bacillus sp. from alkaline soil, which was able to produce extracellular alkaline protease at pHs ranging from 8 to 11 and temperatures of 20 to 50§C. Also the impact of different carbon and nitrogen sources were investigated. The yield and fold of enzyme purification was 24% and 50 times, respectively. Molecular weight of purified enzyme was measured by SDS-PAGE as 24.7 kDa. The alkaline protease produced by Bacillus sp. 2 - 5 showed the most caseinolytic activity [without any gelatinolytic activity] at pH>10