Optimization of pectinase extraction from mango (Mangifera indica cv. Chokanan) peel using response surface methodology

Today pectinases (EC 3.2.1.15) have become an integral part of the food and feed industry and plant peel could be a potential source of pectinase. Thus, the main objective of the study was the optimization of pectinase extraction from mango (Mangifera indica cv. Chokanan) peel. For this purpose, response surface methodology (RSM) was employed to optimize the extraction conditions and the effect of independent variables, namely temperature (-25 to +25°C), mixing time (2–10 min) and pH of buffer (1–8), on specific activity, storage stability, temperature stability and surfactant agent stability of pectinase from mango peel was investigated. The study demonstrated that using optimum temperature, mixing time and pH of buffer, protected pectinase during extraction, as indicated by low activity and low stability loss. It was found that the interaction effect of mixing time and buffer content improved the pectinase stability, and pH of buffer had the most significant effect on specific activity of the pectinase. The ideal condition of 2.5°C temperature, 6 min mixing time at pH 4.5 was established for pectinase extraction from mango peel. The result indicated that the optimized extraction of pectinase from mango peel provides high activity and stability of pectinase in harsh conditions, which makes the enzyme suitable for use in various types of industry and biotechnological applications. Furthermore, there was not any significant (p>0.05) difference between the experimental and predicted values. This ensured that the response surface models used to indicate property changes of pectinase as a function of enzyme extraction conditions were sufficient

Probiotics your friendly gut bacteria

The functional food concept has in recent years, moved progressively towards the development of dietary supplements that may stimulate gut microbial composition and activities. The rationale behind these advances is consequent to the realization that gut microflora has profound influence on the host’s health. The human gastrointestinal tract (GIT) represents an ecosystem of the highest complexity and is very dynamic in composition. The micro biota exists in a commensal, symbiotic or an antagonist microbial relationship. Among more than 400 species of bacteria present in the GIT of an adult human being, bifidobacteria and lactobacillus are considered to be the most beneficial to human health. Members of these genera are thought to enhance digestion, adsorption of nutrients, prevention of colonization by pathogens, decreasing serum cholesterol and stimulation of immune responses. The ability of these bifidobacteria and lactobacilli to ferment non-digestible oligosaccharides may be an important characteristic which enables them to establish themselves in the colon. Studies were undertaken by researchers in our laboratory to elucidate the probiotic characteristics and effects of the bifidobacteria species isolated from the human GIT and to propose screening, cultivation and preservation and delivery techniques for this bacterium

Probiotic: your friendly gut bacteria

The functional food concept has in recent years, moved progressively towards the development of dietary supplements that may stimulate gut microbial composition and activities. The rationale behind these advances is consequent to the realization that gut microflora has profound influence on the host’s health. The human gastrointestinal tract (GIT) represents an ecosystem of the highest complexity and is very dynamic in composition. The micro biota exists in a commensal, symbiotic or an antagonist microbial relationship. Among more than 400 species of bacteria present in the GIT of an adult human being, bifidobacteria and lactobacillus are considered to be the most beneficial to human health. Members of these genera are thought to enhance digestion, adsorption of nutrients, prevention of colonization by pathogens, decreasing serum cholesterol and stimulation of immune responses. The ability of these bifidobacteria and lactobacilli to ferment non-digestible oligosaccharides may be an important characteristic which enables them to establish themselves in the colon. Studies were undertaken by researchers in our laboratory to elucidate the probiotic characteristics and effects of the bifidobacteria species isolated from the human GIT and to propose screening, cultivation and preservation and delivery techniques for this bacterium

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

Purification of serine proteases from mango (Mangifera indica cv. Chokanan) peel using expanded bed adsorption: optimisation using response surface methodology

Proteolytic enzymes or proteases are a class of proteins ubiquitously found in all organisms; they act as catalysts and perform diverse vital functions. In plants, proteases of plant origin play a vital function from the mobilisation of storage proteins during germination to the initiation of cell death and senescence. Proteases derived from plants are extensively employed in food industries because of the wide range of good solubility, substrate specificity, activity over a wide pH and temperature range and high stability in extreme conditions. Plant peel could be a potential source of proteases due to the easy purification methods, low levels of interfering substances during purification, and good yield of proteases. An expanded bed adsorption (EBA) technique was used to purify serine proteases from mango peel. Response surface methodology (RSM) with a central composite design was employed to optimise the EBA technique. Analysis of independent factors as a function of flow rate, temperature, pH of buffer and salt revealed different effects of these four factors on the studied parameters (total protein, total activity, specific activity, purification factor, yield, storage, thermal and pH stability). It was demonstrated that the serine protease could be recovered with a yield of 82% and a purification factor of 11.3 after a single step elution with 1.0 M NaCl. No significant (p>0.05) difference was found between the experimental and predicted values, thus ensuring the adequacy of the RSM employed for describing the changes in the properties of the serine protease as a function of operating conditions using EBA

Effects of low temperature storage and thermisation on the quality of raw and heat treated milk

ON-FARM MILK QUALITY STUDIES 1.0 Three surveys were conducted approximately at three months apart to evaluate the quality of raw milk produced from dairy farms in the south-west of Scotland. The farms assinged to the study were within the scheduled route of the three road tankers supplied by the local bulk milk haulage contractor of the Scottish Milk Marketing Board. The sequence of milk collection by each road tanker during the first survey was noted and the sequence was repeated in the subsequent surveys. SIMULATED BULK MILK SILO STUDIES 2.0 A simulated study was conducted to measure the effects of blending and subsequent storage of raw milk at low temperatures on the quality of pasteurised milk made from it. EFFECTS OF THERMISATION ON MILK QUALITY 3.0 Two preliminary trials were conducted to compare the effects of a range of thermisation heat treatments on bacterial counts and alkaline phosphatase content of milk. THE EFFECTS OF EXTENDED RAW MILK STORAGE ON THE EFFECTIVENESS OF THERMISATION AND THE EFFECTS OF DOUBLE HEAT TREATMENTS ON PASTEURISED MILK QUALITY 4.0 Three trials were conducted to measure the effects of extended storage of raw milk for 2, 4 and 7 days at

Recovery of amylase from mango (Mangifera indica L. cv. Chokanan) waste using organic solvent/salt aqueous two-phase system: a potential low cost source of enzyme and purification method

Amylases, which constitute approximately 25-33% of the world enzyme market, are in second place after protease enzymes and have great significance due to their extensive biotechnological applications in food, detergent, pharmaceutical, textile and paper industries. Currently, conventional methods of purification, such as precipitation, chromatography and electrophoresis, are employed to isolate and purify the amylase. These methods are multistep, discontinuous, time and labour consuming. Aqueous two-phase system by integrating of concentration, clarification and initial purification has become a desirable method for the recovery of many biological products. Therefore, in this study, amylase as valuable components for the first time was recovered from mango (Mangifera indica cv. Chokanan) waste using organic solvent aqueous two-phase system. The effectiveness of different parameters, such as type and concentration of alcohol (1-propanol, 2-propanol and ethanol), type of salt (sodium phosphate and ammonium sulphate, sodium citrate), pH and NaCl on the partitioning behaviour of amylase were investigated. The selectivity (S), purification factor (P) and yield (Y%) were investigated in this study as important parameters for the evaluation of the enzyme recovery. The highest partition coefficient (101.2) and selectivity (303.4) for amylase purification value were achieved in an ATPS of 19% (w/w) ethanol, 25% (w/w) sodium phosphate and 5% (w/v) NaCl at pH 7.0. It was demonstrated that amylase from mango peel could be recovered with a yield of 88.4% and a purification factor of 13.3. Therefore, this study proves that alcohol salt aqueous two-phase system can be an inexpensive and effective method for recovery of amylase from plant source

Characterization of novel amylase enzyme from mango (Mangifera indica cv. Chokanan) peel

Amylase is one of the important industrial enzymes used in different types of industries such as food, detergent, pharmaceutical, pulp and paper. Mango peel could be a potential source of amylase, which has been extracted and purified from mango (Mangifera indica cv. Chokanan) peel using alcohol/salt, aqueous two phase system. In this study, the effect of temperature, pH, metal ions, inhibitors and surfactant agents on amylase activity and stability were investigated. In addition, purity and molecular weight of amylase was determined using sodium dodecyl sulphate gel electrophoresis. Amylase showed the highest activity and stability at 50°C for 20 min after enzyme incubation at different temperatures (20 to 90°C) in interval time. Amylase from mango peel is thermostable because more than 85% of enzyme activity was retained at temperatures of 20-55°C for 20 min. The amylase was incubated at pH 3-10 and the highest enzyme activity was obtained at pH 7.0. The enzyme activity was significantly decreased at pH 3.0 and 10 because of protein denaturation. Molecular weight of amylase from Mangifera indica L. cv. Chokanan was 42 kDa. Activity of amylase was significantly (p < 0.05) increased in presence of Ca2+ but Zn2+ and Cu2+ reduced the enzyme activity due to replacing of calcium cation from the binding site of amylase. In addition, the effect on amylase activity was investigated at a concentration of 5 mM. The enzyme was completely deactivated in presence of carbodimine and p-chloromercuribenzoic acid whereas iodoacetamide did not show any significant (p <0.05) effect on amylase activity. Thus, amylase from mango peel with this unique characteristic has potential application in various kind of industries such as food, detergent, pharmaceutical and biotechnological applications

Purification and characterisation of a novel amylase enzyme from red pitaya (Hylocereus polyrhizus) peel

An amylase enzyme from pitaya peel was purified 234.2-folds with 72.1% recovery using ammonium sulphate precipitation, gel filtration and ion exchange chromatography. Gel filtration chromatography and SDS–PAGE revealed that the enzyme is monomeric with a molecular weight of 42.1 kDa. The apparent Km and Vmax of the amylase were 2.7 mg/ml and 34.30 u/min/mg of protein, respectively. The enzyme was highly active and stable over a wide pH range from pH 3 to pH 11.0, with optimum activity being observed at pH 5.0. The enzyme was highly selective for soluble starch, amylopectin, glycogen and pulullan. The purified amylase did not require calcium and displayed extreme stability with regard to surfactants and oxidising agents. EDTA, a powerful chelating agent, did not have any significant effect on the stability of the enzyme. Such characteristics have not been previously reported for this type of enzyme from fruit peel. This enzyme, which possesses unique properties, could be widely used in different types of industries, especially in food and biotechnological applications

Storage stability of clarified banana juice fortified with inulin and oligofructose.

Clarified banana juice fortified with inulin and oligofructose were stored for 8 weeks at 4, 25 and 35C. Changes in physicochemical characteristics (pH, total soluble solids [TSS], titratable acidity, sucrose, reducing sugars and turbidity), microbial count and sensory quality were determined. No differences were observed for pH and titratable acidity for all the stored juice samples. However, increase in turbidity was observed in all the juice samples, whereas juice samples stored at 35C recorded highest increases. Increase in reducing sugars (glucose and fructose) was also observed during storage, particularly at 25 and 35C. TSS values were observed fluctuating for all the samples. No microbial growth was recorded for all the juice samples stored at three different temperatures. Sensory results for taste, flavor and odor revealed no difference until the seventh week of storage; however, the overall acceptability of the juice stored at 4C was rated highest as compared with juice samples stored at 25 and 35C. Overall, the quality of juice stored at 4C was rated highest not only for all the sensory characteristics but also less turbidity problem compared with juices stored at 25 and 35C