Purification of pectinase from mango (Mangifera indica L. cv. Chokanan) waste using an aqueous organic phase system: a potential low cost source of the enzyme

As a novel method of purification, an aqueous organic phase system (AOPS) was employed to purify pectinase from mango waste. The effect of different parameters, such as the alcohol concentration (ethanol, 1-propanol, and 2-propanol), the salt type and concentration (ammonium sulfate, potassium phosphate and sodium citrate), the feed stock crude load, the aqueous phase pH and NaCl concentration, were investigated in the recovery of pectinase from mango peel. The partition coefficient (K), selectivity (S), purification factor (PF) and yield (Y, %) were investigated in this study as important parameters for the evaluation of enzyme recovery. The desirable partition efficiency for pectinase purification was achieved in an AOPS of 19% (w/w) ethanol and 22% (w/w) potassium phosphate in the presence of 5% (w/w) NaCl at pH 7.0. Based on the system, the purification factor of pectinase was enhanced 11.7, with a high yield of 97.1%

Characterization of polyphenol oxidase from mango (Mangifera indica L. cv. Chokanan) peel

Plant polyphenol oxidase showed positive effect in the production of coca, black tea and flavonoid-derived colorants and antioxidants. High activity and stability in a wide range of pH and temperature of plant enzyme make it suitable and also inexpensive for use in industry. For these reasons, there is growing interest in seeking more plant sources of polyphenol oxidase. Mango (Mangifera indica L. cv. Chokanan) peel can be a potential source of polyphenol oxidase, which has been extracted and purified from peel of mango using the aqueous two-phase system (ATPS). In the present study, the effects of different temperatures, pH, inhibitors and metal ions on the stability and activity of polyphenol oxidase from mango peel were investigated. In addition, the molecular weight of this enzyme was estimated at 133 kDa by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The highest enzyme activity of polyphenol oxidase to catalyze catechol in sodium phosphate buffer was achieved at 55°C at pH 5.5. Furthermore, the enzyme was stable at temperatures of 10 to 60°C and pH 3 to 6. Beta-mercaptoethanol, ascorbic acid, l-cysteine and pyrogallol were effective inhibitors of the enzyme. Also, activity of polyphenol oxidase was increased in the presence of some metal ions such as Ca2+, Mg2+ and Cu2+ which implies that the enzyme involved metal ions. Therefore, polyphenol oxidase extracted from mango (Mangifera indica L. cv. Chokanan) peel has potential applications in various industries because it is thermostable under high temperatures in either acidic medium, or when there is the presence of metal ions

Characterization of pectinase from mango (Mangifera indica Cv. chokanan) peel

Today, pectinase has emerged as an integral part of the food and feed industries. Plant peel could be a potential source of pectinase, which has been extracted and purified from mango (Mangifera indica cv. Chokanan) peel using the aqueous two-phase system (ATPS). In the present study, the effects of temperature, pH and metal ions on the stability and activity of pectinase were investigated. In addition, the molecular weight of this enzyme was determined as 31 kDa with SDS-PAGE. Pectinase showed the highest enzyme activity at 60ºC for 30 min after incubation at different temperatures (20 to 80ºC). Also, this enzyme has been shown to be thermostable because more than 90% of residual enzyme activity was retained at temperatures of 20 to 60ºC for 30 min. Pectinase was incubated in different pH from 3 to 9 and the highest enzyme activity was achieved at pH 8. Furthermore, the enzyme was stable at pH 5 to 9 after enzyme incubation at different pH for 24 h at 4ºC. Activity of the enzyme was significantly decreased at pH 3 and 9 due to the protein denaturation. Pectinase activated by Ca2+ showed that this cation has an important effect on activity and stability of the enzyme; but Li+, Na+ and K+ had no effect on its activity. Also, the reduction in the activity of pectinase was observed in the presence of Fe2+, Cu2+, Mn2+, Zn2+ and Al3+. Therefore, pectinase extracted from mango peel has potential applications in various industries like food and feed because it is thermostable under high temperatures in either alkaline medium or when there is the presence of metal ions

Purification of a novel protease enzyme from kesinai plant (Streblus asper) leaves using a surfactant–salt aqueous micellar two-phase system: a potential low cost source of enzyme and purification method

Serine protease from kesinai leaves was purified for the first time by a surfactant–polymer aqueous micellar two-phase system. The effectiveness of different types and concentrations of non-ionic surfactants (Pluronic series and X-114) on the partitioning behaviour of the protease was evaluated. The results showed that the enzyme preferentially partitioned into the bottom surfactant-rich phase, while the hydrophilic amino acid preferred the top aqueous phase. This distribution of the enzyme is due to the hydrophobic interaction of the serine protease with the hydrophobic lid of the micelle core in the bottom phase. The influence of different types of salts (K2SO4, KH2PO4, KCl and KNO3) on the purification and selectivity of the enzyme was determined. The protease partitioning in the bottom phase increased in the presence of KNO3, which confirmed that the salt was able to improve the protein solubility in bottom phase and increase the hydrophobic interaction between the two phases. In addition, the protease from the bottom phase was re-extracted to a new aqueous phase solution to remove and recycle the surfactant. Addition of potassium thiocyanate led to the partitioning of the enzyme in top aqueous phase due to high ionic strength of SCN−, which forced the lighter micellar phase toward the upper position of the system. A high purification factor (10.3) and yield of 92 % of the enzyme were achieved in a solution of 31 % of Pluronic L61 using 0.3 % KNO3 and 50 % crude feedstock at pH 7.0

Characterization of headspace volatile flavor compounds formed during kefir production : application of solid phase microextraction.

Headspace volatile flavor compounds of kefir were monitored using headspace solid phase microextraction (HS-SPME) method during fermentation of milk with kefir starter culture. Among all flavor compounds, forty volatile compounds were initially detected using gas chromatography coupled to time-of-flight mass spectrometer (GC-TOFMS). Consequently, eight volatile flavor compounds, namely ethanol, ethyl acetate, ethyl butyrate, 2-butanone, acetone, 3-hydroxy-2-butanone (acetoin), 2,3-butanedione (diacetyl) and acetaldehyde were considered as the representative of the alcohol, ketone, ester and aldehyde compounds in kefir. Moreover, in term of quantitative analysis, more than 97% of total flavor compounds composed of the proposed volatile flavor compounds. The results indicated that the concentration of 2-butanone released into headspace of kefir was found to be stable during fermentation. The release content of other volatile flavor compounds increased throughout the fermentation process. However, the headspace concentration of acetoin significantly (P < 0.05) decreased between pH 5.2 and 4.6

Compression and encryption for ECG biomedical signal in healthcare system

The ECG data needs large memory storage device due to continuous heart rate logs and vital parameter storage. Thus, efficient compression schemes are applied to it before sending it to the telemedicine center for monitoring and analysis. Proper compression mechanisms can not only improve the storage efficiency but also help in faster porting of data from one device to another due to its compact size. Also, the collected ECG signals are processed through various filtering techniques to remove unnecessary noise and then compressed. In our scheme, we propose use of buffer blocks, which is quite novel in this field. Usage of highly efficient methods for peak detection, noise removal, compression and encryption enable seamless and secure transmission of ECG signal from sensor to the monitor. This work further makes use of AES 256 CBC mode, which is barely used in embedded devices, proves to be very strong and efficient in ciphering of the information. The PRD outcome of proposed work comes as 0.41% and CR as 0.35%, which is quite better than existing schemes. Experimental results prove the efficiency of proposed schemes on five distinct signal records from MIT-BIH arrhythmia datasets

Effect of alginate and chitosan on viability and release behavior of Bifidobacterium pseudocatenulatum G4 in simulated gastrointestinal fluid

The main aim of this study was to investigate the effect of different coating materials (i.e. Na-alginate and chitosan) on the viability and release behavior of Bifidobacterium pseudocatenulatum G4 in the simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). This study reports the viability of encapsulated B. pseudocatenulatum G4 coated using different alginate (2–4 g/100 mL) and chitosan (0.2–0.8 g/100 mL) concentrations. The results indicated that the highest concentration of alginate (4.4142 g/100 mL) along with 0.5578 g/100 mL chitosan resulted in the highest viability of B. pseudocatenulatum G4. The release behavior of the encapsulated probiotics in SGF (pH 1.5) in 2 h followed by 4 h in SIF (pH 7.4) was also assessed. The resistance rate of alginate–chitosan capsule in SGF was higher than SIF. The alginate–chitosan encapsulated cells had also more resistance than alginate capsules. The current study revealed that alginate encapsulated B. Pseudocatenulatum G4 exhibited longer survival than its free cells (control)

Development of alginate – gum arabic beads for targeted delivery of protein

Controlled release beads were prepared by using the combination of alginate and gum Arabic through ionotropic gelation method. Bovine serum albumin was used as model protein for in vitro assessments. The effect of amount of sodium alginate and gum Arabic as the factor affecting protein encapsulation efficiency and protein release were optimized and analyzed by using RSM-FCCD. It was observed that protein encapsulation efficiency was increased and protein release was decreased with the increase of both of the amount of sodium alginate and gum Arabic, used as polymer blend. The optimized beads showed high encapsulation efficiency (87.5 ± 3.65%) with suitable protein release (100% protein release after almost 4 hrs). The swelling of beads were highly influenced by pH of dissolution medium. These beads were also characterized by FT-IR spectroscopy, SEM and TA for protein-excipients interaction, beads surface morphology and beads strength, respectively. These calcium alginate/gum Arabic beads have good potential to be used as delivery vehicle for protein drugs

Molecular identification of Lactobacillus spp. isolated from the honey comb of the honey bee (Apis dorsata) by 16S rRNA gene sequencing

The objective of this study was to isolate and identify novel potential probiotic Lactobacillus using a culture method and Polymerase Chain Reaction (PCR) amplification of the 16S rRNA gene. Seventeen Lactobacillus strains were isolated from a full honey comb of the honey bee Apis dorsata using selective media. The 16S rRNA genes from the extracted DNA of bacterial colonies were amplified with PCR using universal bacteria primers. All bacterial 16S rRNA genes were sequenced, aligned and the distant bacteria were deposited in GenBank. The lactobacilli strains were identified as Lactobacillus spp. related-sequences (64.15%) with other abundant sequences being related to Lactobacillus kunkeei (34.85%). The findings revealed that Apis dorsata honey comb has potential to be a source of new bacteria with probiotic activities in honey bee or as natural food preservatives for the food industry