Three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes

Identification, rapid screening, docking mechanism and in vitro digestion stability of novel DPP-4 inhibitory peptides from wheat gluten with ginger protease

To better understand the hypoglycemic potential of wheat gluten (WG), we screened dipeptidyl peptidase IV (DPP-4) inhibitory active peptides from WG hydrolysates. WG hydrolysates prepared by ginger protease were found to have the highest DPP-4 inhibitory activity among the five enzymatic hydrolysates, from which a 1-3 kDa fraction was isolated by ultrafiltration. Further characterization of the fraction with nano-HPLC-MS/MS revealed 1133 peptides. Among them, peptides with P'2 (the second position of the N-terminal) and P2 (the second position of the C-terminal) as proline residues (Pro) accounted for 12.44% and 43.69%, respectively. The peptides including Pro-Pro-Phe-Ser (PPFS), Ala-Pro-Phe-Gly-Leu (APFGL), and Pro-Pro-Phe-Trp (PPFW) exhibited the most potent DPP-4 inhibitory activity with IC50 values of 56.63, 79.45, and 199.82 μM, respectively. The high inhibitory activity of PPFS, APFGL, and PPFW could be mainly attributed to their interaction with the S2 pocket (Glu205 and Glu206) and the catalytic triad (Ser630 and His740) of DPP-4, which adopted competitive, mixed, and mixed inhibitory modes, respectively. After comparative analysis of PPFS, PPFW, and PPF, Ser was found to be more conducive to enhancing the DPP-4 inhibitory activity. Interestingly, peptides with P2 as Pro also exhibited good DPP-4 inhibitory activity. Meanwhile, DPP-4 inhibitory peptides from WG showed excellent stability, suggesting a potential application in type 2 diabetes (T2DM) therapy or in the food industry as functional components.

Efficient three phase partitioning of actinidin from kiwifruit (Actinidia deliciosa) and its characterization

Three phase partitioning (TPP) method was effectively utilized for the extraction and purification of milk clotting protease (actinidin) from the kiwifruit pulp. The different purification parameters of TPP such as ammonium sulfate saturation, ratio of the crude kiwifruit extract to tert-butanol, and the pH value of extract were optimized. The 40% (w/v) salt saturation having 1.0:0.75 (v/v) ratio of crude kiwifruit extract to tert-butanol at 6.0 pH value exhibited 3.14 purification fold along with 142.27% recovery, and the protease was concentrated exclusively at intermediate phase (IP). This fraction showed milk-clotting activity (MCA), but there was no such activity in lower aqueous phase (AP). The enzyme molecular weight was found to be 24 kDa from Tricine SDS-PAGE analysis. Recovered protease demonstrated greater stability at pH 7.0 and temperature 50 °C. The Vmax and Km values were 121.9 U/ml and 3.2 mg/ml respectively. Its cysteine nature was demonstrated by inhibition studies. This study highlighted that the TPP is an economic and effective method for extraction and purification of actinidin from kiwifruit, and it could be used as a vegetable coagulant for cheesemaking.

Plant-derived rennet: research progress, novel strategies for their isolation, identification, mechanism, bioactive peptide generation, and application in cheese manufacturing

Rennet, an aspartate protease found in the stomach of unweaned calves, effectively cuts the peptide bond between Phe105-Met106 in κ-casein, hydrolyzing the casein micelles to coagulate the milk and is a crucial additive in cheese production. Rennet is one of the most used enzymes of animal origin in cheese making. However, using rennet al.one is insufficient to meet the increasing demand for cheese production worldwide. Numerous studies have shown that plant rennet can be an alternative to bovine rennet and exhibit a good renneting effect. Therefore, it is crucial and urgent to find a reliable plant rennet. Based on our team's research on rennet enzymes of plant origin, such as from Dregea sinensis Hemsl. and Moringa oleifer Lam., for more than ten years, this paper reviews the relevant literature on rennet sources, isolation, identification, rennet mechanism, functional active peptide screening, and application in cheese production. In addition, it proposes the various techniques for targeted isolation and identification of rennet and efficient screening of functionally active peptides, which show excellent prospects for development.

A comprehensive review on Ginger (Zingiber officinale) as a potential source of nutraceuticals for food formulations: Towards the polishing of gingerol and other present biomolecules

Currently, ginger is one the most consumed plants when dealing with the treatments of various illnesses. So far, it is known that various biologically active molecules, such as gingerols, shogaols and zingerone, among others, are the main responsible for specific biological activities, opening a new window for its utilization as a nutraceutical in foods. In pioneering extraction processes, solvent extraction has been initially used for these applications; however, the drawbacks of this typical extraction method compared with other emergent separation techniques make it possible for the exploration of new extraction pathways, including microwave, ultrasound, supercritical, subcritical and pressurized-assisted extraction, along with three phase partitioning, high-speed counter current chromatography and magnetic solid phase extraction. To the best of our knowledge, there is no report documenting the recent studies and cases of study in this field. Therefore, we comprehensively review the progress and the latest findings (over the last five years) on research developments, including patents and emerging extraction methods, aiming at the purification of biologically active molecules (gingerols, shogaols and zingerone) contained in ginger. Over the course of this review, particular emphasis is devoted to breakthrough strategies and meaningful outcomes in ginger components extraction. Finally, dosage and safety concerns related to ginger extracts are also documented.

New Coagulant Proteases for Cheesemaking from Leaves and Latex of the Spontaneous Plant Pergularia tomentosa: Biochemical Characterization of Coagulants and Sensorial Evaluation of Cheese

The purpose of this study was to evaluate the caseinolytic and milk-clotting activities of aqueous crude extracts from leaves and latex of the Pergularia tomentosa, to determine their suitability as a rennet substitute. These extracts were subjected to a series of biochemical tests before being used in the production of cheese. The results showed that the enzymatic latex extract had a higher coagulant activity than the leaf extract. However, under different clotting conditions (pH, temperature, and CaCl₂ concentration), both coagulants behaved similarly in the coagulation of Berridge substrate. The SDS-PAGE and zymographic analysis revealed identical protein bands with a single active zone in both extracts, corresponding to a molecular weight of 26.98 kDa and 26.03 kDa in the extract of leaf and latex, respectively. Both extracts were stable to different effectors but strongly inhibited by iodoacetamide and Hg, suggesting it to be a cysteine protease. Both extracts were able to hydrolyze casein and generate peptides of 14 kDa, with excessive hydrolysis of the other casein fractions. The physicochemical parameters of cheese made from latex and leaf extract evolved similarly to control cheese. According to the sensory evaluation, cheese made with latex had a mildly bitter flavor but showed a high acceptance rate (>80%).

Application of Plant Proteases in Meat Tenderization: Recent Trends and Future Prospects

Papain, bromelain, and ficin are commonly used plant proteases used for meat tenderization. Other plant proteases explored for meat tenderization are actinidin, zingibain, and cucumin. The application of plant crude extracts or powders containing higher levels of compounds exerting tenderizing effects is also gaining popularity due to lower cost, improved sensory attributes of meat, and the presence of bioactive compounds exerting additional benefits in addition to tenderization, such as antioxidants and antimicrobial effects. The uncontrolled plant protease action could cause excessive tenderization (mushy texture) and poor quality due to an indiscriminate breakdown of proteins. The higher cost of separation and the purification of enzymes, unstable structure, and poor stability of these enzymes due to autolysis are some major challenges faced by the food industry. The meat industry is targeting the recycling of enzymes and improving their stability and shelf-life by immobilization, encapsulation, protein engineering, medium engineering, and stabilization during tenderization. The present review critically analyzed recent trends and the prospects of the application of plant proteases in meat tenderization.

Current Understanding of the Molecular Basis of Spices for the Development of Potential Antimicrobial Medicine

Antimicrobial resistance increases day by day around the world. To overcome this situation new antimicrobial agents are needed. Spices such as clove, ginger, coriander, garlic, and turmeric have the potential to fight resistant microbes. Due to their therapeutic properties, medicinal herbs and spices have been utilized as herbal medicines since antiquity. They are important sources of organic antibacterial substances that are employed in treating infectious disorders caused by pathogens such as bacteria. The main focus of the study is the bioactivity of the active ingredients present in different kinds of naturally available spices. We conducted a thorough search of PubMed, Google Scholar, and Research Gate for this review. We have read many kinds of available literature, and in this paper, we conclude that many different kinds of naturally available spices perform some form of bioactivity. After reading several papers, we found that some spices have good antimicrobial and antifungal properties, which may help in controlling the emerging antimicrobial resistance and improving human health. Spices have many phytochemicals, which show good antimicrobial and antifungal effects. This review of the literature concludes that the natural bioactivate compounds present in spices can be used as a drug to overcome antimicrobial resistance in human beings.

Improving tenderness and quality of M. biceps femoris from older cows through concentrate feeding, zingibain protease and sous vide cooking

The study investigated the effect of zingibain protease and sous vide cooking on tenderness and water-holding capacity of M. biceps femoris (BF) from 30 older Angus cows (6-7 years) fed concentrates for 0, 28, 42 or 56 days. BF were cooked for 1, 8, and 18 h at 65 °C and 75 °C, without any pre-treatment, after they have been injected with water only or after they have been injected with either 1 g/L or 2 g/L ginger powder solution (containing zingibain). Samples were tested for cooking loss, total water content, Warner-Bratzler shear force (WBSF), collagen content, and myofibrillar fragmentation index (MFI). Results revealed the significant interactions between concentrate feeding, ginger powder injection, cooking temperature, and time on quality traits. WBSF was reduced (P < 0.001) by increasing zingibain concentration at 65 °C but a gradual decrease was noted at 75 °C. Collagen solubility and MFI increased (P < 0.05) with increasing zingibain concentration. Injecting zingibain along with sous vide cooking demonstrated the weakening of myofibrillar and connective tissue proteins contributing to enhanced collagen solubility and tenderness in BF.

Proteomics analysis of the bio-functions of Dregea sinensis stems provides insights regarding milk-clotting enzyme

Dregea sinensis (D. sinensis) stems have traditionally been used as milk coagulant in Dali of Yunnan Province, China. In this study, proteomics was used to investigate the bio-functions of D. sinensis stem proteins, leading to the purification and identification of the milk-clotting enzyme. A total of 205 proteins mainly involved in the catalytic and metabolic processes were identified, of which 28 proteins exhibited hydrolase activity. Among the 28 proteins, we focused on two enzymes (M9QMC9 and B7VF65). Based on proteomics, a cysteine protease (M9QMC9) with a molecular weight of 25.8 kDa and milk-clotting activity was purified from D. sinensis stems using double ammonium sulfate precipitation and was confirmed using liquid chromatography-mass spectrometry (LC-MS/MS). The milk-clotting temperature using the purified enzyme was around 80 °C (specific activity at 314.38 U/mg), and it was found to be stable in the pH range of 6-9 in NaCl concentration of <0.8 mol/L. These findings indicated that the enzyme isolated from D. sinensis stems has potential in the dairy and food sectors, especially in the cheese-making industry.

Cohnella 1759 cysteine protease shows significant long term half-life and impressive increased activity in presence of some chemical reagents

Thermostability and substrate specificity of proteases are major factors in their industrial applications. rEla is a novel recombinant cysteine protease obtained from a thermophilic bacterium, Cohnella sp.A01 (PTCC No: 1921). Herein, we were interested in recombinant production and characterization of the enzyme and finding the novel features in comparison with other well-studied cysteine proteases. The bioinformatics analysis showed that rEla is allosteric cysteine protease from DJ-1/ThiJ/PfpI superfamily. The enzyme was heterologously expressed and characterized and the recombinant enzyme molecular mass was 19.38 kD which seems to be smaller than most of the cysteine proteases. rEla exhibited acceptable activity in broad pH and temperature ranges. The optimum activity was observed at 50℃ and pH 8 and the enzyme showed remarkable stability by keeping 50% of residual activity after 100 days storage at room temperature. The enzyme Km and Vmax values were 21.93 mM, 8 U/ml, respectively. To the best of our knowledge, in comparison with the other characterized cysteine proteases, rEla is the only reported cysteine protease with collagen specificity. The enzymes activity increases up to 1.4 times in the presence of calcium ion (2 mM) suggesting it as the enzyme's co-factor. When exposed to surfactants including Tween20, Tween80, Triton X-100 and SDS (1% and 4% v/v) the enzyme activity surprisingly increased up to 5 times.

Protein function analysis of germinated Moringa oleifera seeds, and purification and characterization of their milk-clotting peptidase

The present study aimed to investigate the biological functions of germinated M. oleifera seed proteins and to identify the identity of milk-clotting proteases. A total of 963 proteins were identified, and those with molecular weights between 10 and 30 kDa were most abundant. The identified proteins were mainly involved in energy-associated catalytic activity and metabolic processes, and carbohydrate and protein metabolisms. The numbers of proteins associated with the hydrolytic and catalytic activities were higher than the matured dry M. oleifera seeds reported previously. Of the identified proteins, proteases were mainly involved in the milk-clotting activity. Especially, a cysteine peptidase with a molecular mass of 17.727 kDa exhibiting hydrolase and peptidase activities was purified and identified. The identified cysteine peptidase was hydrophilic, and its secondary structure consisted of 27.60% alpha helix, 9.20% beta fold, and 63.20% irregular curl; its tertiary structure was also constructed using M. oleifera seed 2S protein as the protein template. The optimal pH and temperature of the purified protease were pH 4.0 and 60 °C, respectively. The protease had high acidic stability and good thermostability, thus could potentially be applied in the dairy industry.

Application of three-phase partitioning to the purification and characterization of polyphenol oxidase from antioxidant rosemary (Rosmarinus officinalis L.)

Polyphenol oxidase (PPO) has been purified from the rosemary plant (Rosmarinus officinalis L.) through three-phase partitioning (TPP) and has been biochemically characterized. The optimized TPP consisted of 50% (w/v) ammonium sulfate and equal volumes of crude extract and tert-butanol prepared at pH 6.5 and room temperature. Using this system, PPO was purified 14-fold, with 230% recovery of activity from the middle phase. The partitioned enzyme had a molecular mass of 53 kDa. The highest enzyme activity was detected at 30 °C and pH 7.0 against catechol. In substrate specificity tests, the enzyme displayed activity towards catechol, 4-methylcatechol, caffeic acid, hydroquinone, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), pyrogallol, syringaldezine, and 3,4-dihydroxy-L-phenylalanine but no activity towards L-tyrosine. The enzyme was inhibited by the common PPO inhibitors; salicylhydroxamic acid (SHAM), cetyltrimethylammonium bromide (CTAB), polyvinylpyrrolidone (PVP), and the organic solvent dimethyl sulfoxide (DMSO). Enzyme activity increased in the presence of the organic solvents acetone, ethanol, and methanol.

Development of low-cost paper-based biosensor of polyphenol oxidase for detection of phenolic contaminants in water and clinical samples

In the present work, polyphenol oxidase (PPO) enzyme was purified from potato peel using three-phase partitioning (TPP). In this method, ammonium sulfate and t-butanol were added to precipitate the protein/enzyme from the crude aqueous extract. The PPO enzyme precipitated as an interfacial layer between the upper organic solvent phase and lower aqueous phase. Different purification parameters such as crude extract to t-butanol ratio, ammonium sulfate concentration, temperature, and pH were optimized for TPP. About 69% PPO enzyme activity was recovered in a single step of TPP with 9.2-fold purification. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile of partially purified PPO enzyme showed molecular weight in the range of about 30-40 kDa. The PPO enzyme was then investigated for the fabrication of a portable, cost-effective, and disposable colorimetric paper biosensor or colorimetric "test strips" for detection of phenolic contaminants. PPO and a chromophore reagent (3-methyl-2-benzothiazolinone hydrazine) generated a range of color in the presence of phenolic compounds (catechol, phenol, p-cresol, 4-methyl catechol) within 15 min, and limit of detection was found to be 0.5 μM. The biosensor worked in a broad range of pH from 3 to 11 and showed good storage stability at 25 °C and 4 °C for 30 days with no significant loss of activity. The biosensor was also applied on environmental water and urine sample to show reliability of biosensor.

Three phase partitioning as a rapid and efficient method for purification of plant-esterase from wheat flour

Three-phase partitioning (TPP) was used to purify plant-esterase from wheat flour. Effect of various process parameters has been evaluated and plant-esterase was purified to 11.35-fold by optimized single step TPP system (50%, (w/v) (NH4)2SO4 saturation, 1:1 (v/v) ratio of crude extract: t-butanol at pH 4).The enzyme was found to be exclusively partitioned in the aqueous phase. Using TPP system, plant-esterase quickly purified to homogeneity with very high purity and activity. On the basis of single factor research, purification process was optimized by using response surface method, established a new type of high efficient purification plant-esterase method. To the best of our knowledge, this is the first report for purification and characterization of plant-esterase by using three phase partitioning (TPP). The results indicated that, TPP is a simple, quick, economical and very attractive process for purification of plant-esterase compared to conventional chromatographic protocols.

Management of Fruit Industrial By-Products-A Case Study on Circular Economy Approach

The management of industrial fruit by-products is important not only to decrease the volume of food waste accumulated in the landfills but also to develop strategies through reuse with the purpose to valorise and add economic value. The disposal of food waste leads to different global issues in different sectors, such as social, environmental and economical. These by-products represent a rich source of valuable compounds (polyphenols) with high antioxidant activity, which can be extracted through biotechnological methodologies for future industrial applications. In this context, the management of fruit by-products is challenged to move from a linear economy to a circular economy. Therefore, the purpose of this review is to provide a critical view of an integrated valorisation of fruit by-products to overcome a global issue, via the production of antioxidant extracts with high economic value. A case study of pineapple processing industrialization in a circular economy is explored and discussed.

One-step recovery of latex papain from Carica papaya using three phase partitioning and its use as milk-clotting and meat-tenderizing agent

Three Phase Partitioning (TPP) system as an elegant non-chromatographic and bulk separation method was successfully applied for the extraction and recovery of papain from the latex of Carica papaya. The optimized parameters of TPP allowed achieving a purification fold of 11.45 and activity recovery of 134% with 40% (NH₄)₂SO₄, 1.0:0.75 ratio of crude extract: t-BuOH at pH and temperature of 6.0 and 25 °C, respectively. The recovered papain had a molecular weight of 23.2 kDa and revealed maximum activity at pH 6.0 and temperature of 50 °C. The maximum values of Km and Vmax parameters were 10.83 mg mL^-1 and 33.33 U mL^-1, respectively. The protease with 4 isoforms was stable at 40-80 °C and a pH range of 6.0-7.5 against numerous metal ions and none of them inactivated the recovered protease. Moreover, 10 mM Ca²⁺ improved 2-folds the activity and half-life of the protease at temperatures from 30 to 50 °C. The milk-clotting activity tests revealed high stability of latex papain at storage, namely at -20 °C compared to 4 °C and 25 °C for up than 5 weeks. As a meat tenderizing agent, it showed promising role under different treatments by improving the texture of tough meat. The findings indicated that one-step TPP system is a simple, quick, economical and very attractive process for fast recovery of latex papain compared to other proposed protocols.

Three phase partitioning to concentrate milk clotting proteases from Wrightia tinctoria R. Br and its characterization

Wrightia tinctoria stem proteases were partially purified for the first time through a non-chromatographic technique, three phase partitioning (TPP), to concentrate the milk clotting proteases. Various parameters like salt and solvent concentration that affect the partitioning of the protease were examined. Maximum recovery and purification fold of the protease activity were found in the interfacial phase (IP) with 60% ammonium sulphate and 1:1 crude enzyme to t-butanol. Optimum pH and temperature of the enzyme fraction were found to be 7.5 and 50 °C respectively. Inhibition studies revealed its serine nature. Non-denaturing PAGE, Zymography and 2D PAGE of IP revealed presence of three different caseinolytic proteases of molecular weights 95.62 kDa, 91.11 kDa and 83.23 kDa with pI 3.89, 5.45 and 5.43 respectively. Both aqueous and lyophilized form of IP were remarkably stable retaining complete activity at 4 °C for 3 weeks. Electrophoretic analysis of casein hydrolysate by IP at different incubation time indicated a time dependent substrate subunit specificity with hydrolysis of κ-casein commencing after 10 min followed by α and β caseins. This pattern was found similar to that by commercial vegetable coagulant, Enzeco®. Study details the effectiveness of TPP concentrated W. tinctoria proteases as a vegetable coagulant alternative in cheese making.

Biochemical properties of a new thermo- and solvent-stable xylanase recovered using three phase partitioning from the extract of Bacillus oceanisediminis strain SJ3

The present study investigates the production and partial biochemical characterization of an extracellular thermostable xylanase from the Bacillus oceanisediminis strain SJ3 newly recovered from Algerian soil using three phase partitioning (TPP). The maximum xylanase activity recorded after 2 days of incubation at 37 °C was 20.24 U/ml in the presence of oat spelt xylan. The results indicated that the enzyme recovered in the middle phase of TPP system using the optimum parameters were determined as 50% ammonium sulfate saturation with 1.0:1.5 ratio of crude extract: t-butanol at pH and temperature of 8.0 and 10 °C, respectively. The xylanase was recovered with 3.48 purification fold and 107% activity recovery. The enzyme was optimally active at pH 7.0 and was stable over a broad pH range of 5.0–10. The optimum temperature for xylanase activity was 55 °C and the half-life time at this temperature was of 6 h. At this time point the enzyme retained 50% of its activity after incubation for 2 h at 95 °C. The crude enzyme resist to sodium dodecyl sulfate and β-mercaptoethanol, while all the tested ions do not affect the activity of the enzyme. The recovered enzyme is, at least, stable in tested organic solvents except in propanol where a reduction of 46.5% was observed. Further, the stability of the xylanase was higher in hydrophobic solvents where a maximum stability was observed with cyclohexane. These properties make this enzyme to be highly thermostable and may be suggested as a potential candidate for application in some industrial processes. To the best of our knowledge, this is the first report of xylanase activity and recoverey using three phase partitioning from B. oceanisediminis.

The proteolytic system of pineapple stems revisited: Purification and characterization of multiple catalytically active forms

Crude pineapple proteases extract (aka stem bromelain; EC 3.4.22.4) is an important proteolytic mixture that contains enzymes belonging to the cysteine proteases of the papain family. Numerous studies have been reported aiming at the fractionation and characterization of the many molecular species present in the extract, but more efforts are still required to obtain sufficient quantities of the various purified protease forms for detailed physicochemical, enzymatic and structural characterization. In this work, we describe an efficient strategy towards the purification of at least eight enzymatic forms. Thus, following rapid fractionation on a SP-Sepharose FF column, two sub-populations with proteolytic activity were obtained: the unbound (termed acidic) and bound (termed basic) bromelain fractions. Following reversible modification with monomethoxypolyethylene glycol (mPEG), both fractions were further separated on Q-Sepharose FF and SP-Sepharose FF, respectively. This procedure yielded highly purified molecular species, all titrating ca. 1 mol of thiol group per mole of enzyme, with distinct biochemical properties. N-terminal sequencing allowed identifying at least eight forms with proteolytic activity. The basic fraction contained previously identified species, i.e. basic bromelain forms 1 and 2, ananain forms 1 and 2, and comosain (MEROPS identifier: C01.027). Furthermore, a new proteolytic species, showing similarities with basic bomelain forms 1 and 2, was discovered and termed bromelain form 3. The two remaining species were found in the acidic bromelain fraction and were arbitrarily named acidic bromelain forms 1 and 2. Both, acidic bromelain forms 1, 2 and basic bromelain forms 1, 2 and 3 are glycosylated, while ananain forms 1 and 2, and comosain are not. The eight protease forms display different amidase activities against the various substrates tested, namely small synthetic chromogenic compounds (DL-BAPNA and Boc-Ala-Ala-Gly-pNA), fluorogenic compounds (like Boc-Gln-Ala-Arg-AMC, Z-Arg-Arg-AMC and Z-Phe-Arg-AMC), and proteins (azocasein and azoalbumin), suggesting a specific organization of their catalytic residues. All forms are completely inhibited by specific cysteine and cysteine/serine protease inhibitors, but not by specific serine and aspartic protease inhibitors, with the sole exception of pepstatin A that significantly affects acidic bromelain forms 1 and 2. For all eight protease forms, inhibition is also observed with 1,10-phenanthrolin, a metalloprotease inhibitor. Metal ions (i.e. Mn²⁺, Mg²⁺ and Ca²⁺) showed various effects depending on the protease under consideration, but all of them are totally inhibited in the presence of Zn²⁺. Mass spectrometry analyses revealed that all forms have a molecular mass of ca. 24 kDa, which is characteristic of enzymes belonging to the papain-like proteases family. Far-UV CD spectra analysis further supported this analysis. Interestingly, secondary structure calculation proves to be highly reproducible for all cysteine proteases of the papain family tested so far (this work; see also Azarkan et al., 2011; Baeyens-Volant et al., 2015) and thus can be used as a test for rapid identification of the classical papain fold.

Three phase partitioning, a scalable method for the purification and recovery of cucumisin, a milk-clotting enzyme, from the juice of Cucumis melo var. reticulatus

Cucumisin [EC 3.4.21.25] was first purified from Cucumis melo var. reticulatus juice by three-phase partitioning (TPP). Optimum purification parameters of the TPP system were determined as 60% ammonium sulfate saturation with 1.0:1.25 ratio of crude extract: t-butanol at pH and temperature of 8.0 and 20°C, respectively. Cucumisin was purified with 4.61 purification fold and 156% activity recovery. The molecular weight of the recovered cucumisin was determined as 68.4kDa and its isoelectric point is 8.7. Optimum pH and temperature of cucumisin were pH 9.0 and 60-70°C, respectively. The protease was very stable at 20-70°C and a pH range of 2.0-12.0. Km and Vmax constants were 2.24±0.22mgmL^-1 and 1048±25μ Mmin^-1, respectively. The enzyme was stable against numerous metal ions and its activity was highly enhanced by Ca²⁺, Mg²⁺, and Mn⁺². Cucumisin activity was 2.35-folds increased in the presence of 5mM of CaCl₂. It was inactivated by Co²⁺, Cd²⁺, Zn²⁺ and Fe²⁺ and dramatically by PMSF. Cucumisin milk-clotting activity was highly stable when stored under freezing (-20°C) compared at 4°C and 25°C. Finally, TPP revealed to be a useful strategy to concentrate and purify cucumisin for its use as a milk-clotting enzyme for cheese-making.

Improving Bread Quality with the Application of a Newly Purified Thermostable α-Amylase from Rhizopus oryzae FSIS4

A new thermostable α-amylase from Rhizopus oryzae FSIS4 was purified for first time and recovered in a single step using a three-phase partitioning (TPP) system. The fungal α-amylase, at a concentration of 1.936 U per kg of flour, was used in bread-making and compared to the commercial enzyme. The results showed a significant effect of the recovered α-amylase in the prepared bread and allowed us to improve the quality of the bread. The study indicated clearly that the recovered α-amylase is a potential candidate for future applications in the bread-making industry and in other food biotechnology applications.

Data in support of three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes

This paper describes data related to a research article titled “Three Phase Partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes” (Gagaoua et al., 2015) [1]. Zingibain (EC 3.4.22.67), is a coagulant cysteine protease and a meat tenderizer agent that have been reported to produce satisfactory final products in dairy and meat technology, respectively. Zingibains were exclusively purified using chromatographic techniques with very low yield purification. This paper includes data of the effect of temperature, usual salts and organic solvents on the efficiency of the three phase partitioning (TPP) system. Also it includes data of the kinetic activity characterization of the purified zingibain using TPP purification approach.