Desirable Functional Properties Research Articles

The Impact of Drying Method on the Functional and Antioxidant Properties of Whitecheek Shark(Carcharhinus dussumieri) Protein Hydrolysates

The functional and antioxidant properties, physical structure of freeze-dried (FD-WCPH) and spray-dried (SD-WCPH) whitecheek shark (Carcharhinus dussumieri) fillet protein hydrolysates were compared to the non-dried (ND-WCPH). The results showed that the solubility of FD-WCPH and ND-WCPH were higher than SD-WCPH at various pH values (P < 0.05). The highest bulk density (113 g/L), foam capacity (120%) and foam stability were observed with FD-WCPH (P < 0.05). Generally, kinematic viscosity was improved with both drying methods. SD-WCPH has the highest fat adsorption (2.64 mg/mg of sample), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, relative induction period (2.38 × an untreated oil control) and whiteness (95). The particle morphology of FD- and SD-WCPH was completely different with FD-WCPH having larger particles with a flake-like structure, while most SD-WCPH particles had a round-shape and a smooth surface without any cracks. In spite of antioxidant activity, the results indicated that freeze-drying might be suitable to dry hydrolysates with desirable functional properties. Practical Applications The effect of the drying method on the functional and antioxidant properties of whitecheek protein hydrolysate was investigated. Whitecheek shark protein hydrolysate showed high functional properties and antioxidant activities which are affected by drying method. Therefore, depending on the use of the final product, choosing the proper drying method is an important step when producing protein hydrolysates.

Evolution of phospholipid contents during the production of quark cheese from buttermilk

We report the evolution of phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) contents during the production of quark cheese from buttermilk by successive ultrafiltration concentration, enrichment with cream, concurrent homogenization and pasteurization, fermentative coagulation, and separation of quark from whey by further ultrafiltration. Buttermilk is richer than milk itself in phospholipids that afford desirable functional and technological properties, and is widely used in dairy products. To investigate how phospholipid content is affected by end-product production processes such as ultrafiltration, homogenization, pasteurization or coagulation, we measured the phospholipids at several stages of each of 5 industrial-scale quark cheese production runs. In each run, 10,000L of buttermilk was concentrated to half volume by ultrafiltration, enriched with cream, homogenized, pasteurized, inoculated with lactic acid bacteria, incubated to coagulation, and once more concentrated to half volume by ultrafiltration. Phospholipid contents were determined by HPLC with evaporative light scattering detection in the starting buttermilk, concentrated buttermilk, ultrafiltrate, cream-enriched concentrated buttermilk (both before and after concurrent homogenization and pasteurization), coagulate, and quark, and also in the rinsings obtained when the ultrafiltration equipment was washed following initial concentration. The average phospholipid content of buttermilk was approximately 5 times that of milk, and the phospholipid content of buttermilk fat 26 to 29 times that of milk fat. Although phospholipids did not cross ultrafiltration membranes, significant losses occurred during ultrafiltration (due to retention on the membranes) and during the homogenization and pasteurization process. During coagulation, however, phospholipid content rose, presumably as a consequence of the proliferation of the inoculated lactic acid bacteria. In spite of these changes in total phospholipid content, the relative proportions of the phospholipids studied remain fairly stable throughout quark production (PE>PC>SM>PS>PI) and similar to those found in the milk of the region, except that SM content was lower than in milk.

Structural computational modeling of RNA aptamers

RNA aptamers represent an emerging class of biologics that can be easily adapted for personalized and precision medicine. Several therapeutic aptamers with desirable binding and functional properties have been developed and evaluated in preclinical studies over the past 25years. However, for the majority of these aptamers, their clinical potential has yet to be realized. A significant hurdle to the clinical adoption of this novel class of biologicals is the limited information on their secondary and tertiary structure. Knowledge of the RNA’s structure would greatly facilitate and expedite the post-selection optimization steps required for translation, including truncation (to reduce costs of manufacturing), chemical modification (to enhance stability and improve safety) and chemical conjugation (to improve drug properties for combinatorial therapy). Here we describe a structural computational modeling methodology that when coupled to a standard functional assay, can be used to determine key sequence and structural motifs of an RNA aptamer. We applied this methodology to enable the truncation of an aptamer to prostate specific membrane antigen (PSMA) with great potential for targeted therapy that had failed previous truncation attempts. This methodology can be easily applied to optimize other aptamers with therapeutic potential.

Advanced Synthesis &amp; Catalysisafter 15 Years: Challenges and New Opportunities for Synthetic Science

1 I am honored and excited to assume the role of Chairman of the Editorial Board for Advanced Synthesis and Catalysis. Professor Noyori’s legacy, not only with respect to this journal but to the fields for which it is named, is both overwhelming and greatly inspirational. My colleagues and I on the Editorial Board are deeply grateful to Prof. Noyori for his leadership on ASC, and we look forward to his continued guidance in his role as Chairman emeritus. The fields of synthetic chemistry and catalysis have certainly advanced in the 15 years since this journal has been in existence, in some ways more easily foreseen than others. This period has been marked by breakthroughs in established areas such as cross-coupling chemistry, olefin metathesis, biocatalysis, and enantioselective catalysis. Other areas exploded in importance from what had been highly specialized corners of the field. These include CH functionalization, gold catalysis, cascade reactions, organocatalysis, flow chemistry, and photocatalysis. The often-jolting progress in these arenas has been documented to a significant extent in the pages of ASC. At their very core, the fields encompassed by this journal span fundamental science and the practical world. The major changes in both the chemical and pharmaceutical industries in the last 15 years have been driven in part by advances in science and technology, but also by business and societal pressures that can seem to run in direct opposition to scientific progress. Through the many upheavals, it is clear that the importance of discovering unique molecules with desirable functional properties remains critical. Indeed, long-standing challenges in synthetic chemistry receive new urgency as society changes and new technologies emerge. The advent of automated high-throughput screening methods has created new opportunities and demands for chemists to invent methods for generating large numbers of new and diverse functional compounds. Chemistry plays a critical role in how our societies will contend with global climate change and the future of energy; I doubt if there is a reader of this journal that has not been inspired to spend some time recently thinking about the synthetic and catalytic chemistry of CO2. And the pressing need to minimize the environmental impact of the chemical enterprise is certain to influence the design and implementation of chemical reactions as never before. It is exciting to speculate about what areas might blossom during the next decade or two, and ASC will continue to strive to present the very best work in the field.

Extraction and Functional Properties of Proteins from Pre-roasted and Enzyme Treated Poppyseed (Papaver somniferum L.) Press Cakes.

In this study, proteins of the defatted meals obtained from cold-pressed poppyseed previously treated (pre-roasting and enzyme against control) were extracted and their compositional and functional properties were determined. Saline-alkaline extraction (pH 11-12, and 0.2-0.6 M NaCI) and isoelectric point (pH 4.0-5.5) precipitation technique showed that seed pre-roasting enhances protein yield while enzyme treatment reduces it. There were 7 bands on SDS-PAGE, and enzyme treated samples were weaker than control. While enzyme treatment decreased denaturation temperatures (T(d)), roasting enhanced the enthalpy change (ΔH) values. Pre-treatments caused a decrease in protein least gelling concentration (LGC) values. Water and oil holding capacities (WHC and OHC) were found lower in enzyme treated and higher in preroasted samples. Similar effects were also determined for emulsifying activity (EA) and emulsion stability (ES) values. While foaming capacity (FC) in treated samples decreased, foam stability (FS) increased oppositely. In conclusion, poppyseed meals can be nutritionally good source for diet protein, and a limited pre-roasting can be very beneficial for enhanced protein extraction yield and desirable functional properties.

Functional properties of composite material from recycled tires and polyurethane binder in water medium

The present research is as a continuation of the authors’ previous research of composite material and practical application of composite material largely connected with water. The aim of present study was to esablish certain functional properties of the material in water medium. Water permeability, absorption and swelling of the composite material after being exposed to water for certain period were determined. Water absorption, permeability and swelling of the composite material showed close correlation with polymer reactivity. Molding pressure, temperature and the distribution of rubber particle sizes also demonstrate a direct influence on the water absorption and permeability of the composite material. The obtained results are useful for the practical application of selected composite material with desirable and predictable functional properties.

Approach to graft bioactive polymers on titanium implants by UV irradiations

Event Abstract Back to Event Approach to graft bioactive polymers on titanium implants by UV irradiations Hamza Chouirfa1, Céline Falentin-Daudré1 and Véronique Migonney1 1 LBPS-CSPBAT UMR CNRS 7244, Université Paris 13, France Introduction: Titanium is widely used in orthopedic implants for its excellent resistance to corrosion and its biocompatibility. Nevertheless and despite the prevention rules, 1.5 to 2 % of implanted prostheses are still subject to bacterial infections, threatening their benefit on a long-term basis. That’s the reason why chemical modification of titanium surfaces to confer desirable functional properties is required. In order to prevent bacteria and improve the long-term osteointegration of titanium, bioactive polymers bearing ionic groups (sulfonate) were covalently grafted onto titanium surfaces. Classically, the grafting used the heat to create radicals and lasted more than half day[1]-[6]. We have elaborated a new approach to create radicals (UVs) in only one hour[7]. Methods: Grafting procedure (Figure 1): Titanium surface were cleaned by successive 10 min ultrasound treatments in a bath of distilled water. After drying, samples were oxidized in a solution containing the same volume of pure H2SO4 and H2O2 (30%). After oxidation, samples were rinsed thoroughly in distilled water and then placed directly into a mechanically stirred solution of the monomers. After UV initiation of the radical polymerization, samples were rinsed thoroughly in distilled water and dried. Results and Discussion: Ionic groups (sulfonate) were covalently attached to the titanium surfaces by radical polymerization of sodium styrene sulfonate (NaSS) initiated by radicals issued from titanium peroxide. Immersion of titanium samples in a mixture of pure sulphuric acid and hydrogen peroxide produces on its surface titanium hydroxide and titanium peroxide. The decomposition of titanium peroxide in radicals was been produced by UV irradiations. Amounts of grafted polymers were measured by colorimetric method. Other techniques were used to check the presence of the bioactive polymers at the surface of titanium samples: XPS analysis, IR-ATR, Contact angle analysis. The grafting by UV way showed same results than thermal way, yet the UV way is the fastest (15 times faster). Conclusion: In the last decade, many studies have been devoted to improving the bone cell-implant interaction, with the goal of improving the osseointegration of devices for dental and orthopaedic applications. There are various ways to modify surface implants, and our strategy is to graft polymer model at their surface in using the UVs. The advantage of our method is that the coating is linked by a covalent bond to the titanium substrates. Surface characterization techniques have shown that the UV grafting of bioactive polymers at the surface of titanium reaches 5 µg.cm-2 like by thermal grafting. Our approach is interesting from an industrial point of view because it also needs few time and few quantity of monomers to obtain a high yield of polymer grafting. Excellent biological results were been obtained by thermal grafting and we would like to check biologically the UV grafting. Figure 1: Grafting of bioactive polymers on titanium surfaces.

Modification of structural and functional properties of sunflower 11S globulin hydrolysates

The structural and functional properties such as solubility, emulsifying properties, foaming properties, oil binding capacity, and surface hydrophobicity of sunflower 11S globulin hydrolysates generated by Alcalase at hydrolysis time of 30, 60, 90, and 120 min were evaluated. Circular dichroism analysis showed the hydrolysates possessed a decreased α-helix and β-structure. The hydrolysates exhibited lower surface hydrophobicity. Hydrolysates with shorter hydrolysis time showed the higher emulsifying activity index, but the same emulsion stability and oil binding capacity compared to the original 11S globulin. The longer hydrolysis resulted in lower foaming and emulsion stability. Thus it was demonstrated that by controlling the hydrolysis time of sunflower 11S globulin, hydrolysate with a desirable functional properties can be obtained.

Enzymatic Hydrolysis Does Not Reduce the Biological Reactivity of Soybean Proteins for All Allergic Subjects.

Many soybean protein products are processed by enzymatic hydrolysis to attain desirable functional food properties or in some cases to reduce allergenicity. However, few studies have investigated the effects of enzymatic hydrolysis on the allergenicity of soybean products. In this study the allergenicity of soybean protein isolates (SPI) hydrolyzed by Alcalase, trypsin, chymotrypsin, bromelain, or papain was evaluated by IgE immunoblots using eight soybean-allergic patient sera. The biological relevance of IgE binding was evaluated by a functional assay using a humanized rat basophilic leukemia (hRBL) cell line and serum from one subject. Results indicated that hydrolysis of SPI by the enzymes did not reduce the allergenicity, and hydrolysis by chymotrypsin or bromelain has the potential to increase the allergenicity of SPI. Two-dimensional (2D) immunoblot and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of the chymotrypsin-hydrolyzed samples indicated fragments of β-conglycinin protein are responsible for the apparent higher allergenic potential of digested SPI.

Abstract 2464: DART® molecules with enhanced DR5 agonistic activity for improved cancer cell cytotoxicity

Abstract Introduction: Death Receptor 5 (DR5) belongs to the tumor necrosis factor receptor superfamily. The target and its associated signaling pathway are preferentially active on cancer cells. DR5 elicits pro-apoptotic signal through receptor oligomerization upon binding of TRAIL or an agonistic mAb. Chemotherapy and radiation also can synergize with the DR5 pathway. Various therapeutics targeting DR5 have been generated but clinical outcomes have been generally disappointing. Here we describe optimization of the agonistic activity of anti-DR5 mAbs by enabling multivalent target engagement via engineering into DARTs; covalently-linked Fv-based diabodies optimized for manufacturability and stability (1) whose modular nature facilitates tailoring avidity and PK properties to the specific needs of the application. Methods: Anti-DR5 mAbs were selected from a panel of mAbs generated from cancer cell immunizations and characterized for binding properties. DARTs with varying anti-DR5 specificities, valency and incorporation of either a wild type IgG1 Fc or an Fc mutated to eliminate FcγR binding, were expressed in CHO cells and purified to homogeneity. DR5 DARTs and mAbs were characterized across a panel of cell lines including those derived from colorectal, lung, pancreatic, breast and prostate cancer and by IHC on normal and tumor tissue specimens. Results: mAbs from whole cancer cell immunizations displaying differential expression on both normal and cancer tissues were subjected to antigen identification and identified a subset with reactivity to DR5. Binding analyses revealed DR5 mAbs recognizing non-overlapping epitopes that do not block the TRAIL-DR5 interaction. Upon secondary cross-linking or when combined, the DR5 mAbs induced apoptosis across multiple cancer cell lines. Further potency enhancement independent of secondary cross-linking was obtained by the engineered multivalent DR5-targeting DARTs. Dose-dependent growth inhibition assay demonstrated that the DR5-targeting DARTs delivered significantly greater potency than TRAIL (≥100-fold) across a broad range of cancer cell lines. Furthermore, the DR5-targeting DARTs maintained the exquisite tumor/normal differential reactivity displayed by the parental DR5 mAbs from which they were derived. Combination of an HDAC inhibitor with DR5-targeting DARTs revealed maintenance of synergistic activity and potential to overcome pathway resistance. Conclusion: Whole cancer cell immunizations yielded DR5 mAb candidates with desirable binding and functional properties. Through incorporation of the anti-DR5 mAb specificities into multivalent DART molecules, we have generated a new class of therapeutics that may overcome the limitations of existing DR5-based therapeutics. The data support the use of DR5-targeting DARTs to target this apoptotic pathway in multiple cancer cells. Reference: (1) Johnson et al. 2010. J Mol Bio. 399:436-49 Citation Format: Jonathan C. Li, Kalpana Shah, Jill Rillema, Francine Chen, Doug Smith, Steve Burke, Valentina Ciccarone, Sergey Gorlatov, Ralph Alderson, James Tamura, Ezio Bonvini, Syd Johnson, Paul A. Moore. DART® molecules with enhanced DR5 agonistic activity for improved cancer cell cytotoxicity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2464. doi:10.1158/1538-7445.AM2015-2464

ChemInform Abstract: Beta‐lactoglobulin‐Based Encapsulating Systems as Emerging Bioavailability Enhancers for Nutraceuticals: A Review

AbstractReview: 113 refs.

Optimizing Functional Properties of Bambara Bean Protein Concentrate by Enzymatic Hydrolysis Using Pancreatin

Enzymatic hydrolysis of Bambara bean protein concentrate was investigated with the view to produce hydrolysates with desirable functional properties. A Box–Behnken design was used for experiments and models capable of predicting functional properties depending on hydrolysis conditions were developed. These models were then used to determine optimum hydrolysis conditions. It was found that hydrolysis parameters had significant influence on the functional properties. Nitrogen solubility and oil-holding capacity of Bambara bean protein hydrolysates were improved, while a slight increase in foaming capacity and decrease in emulsifying activity were observed. The optimum hydrolysis conditions were: time 97.5 min, solid-to-liquid ratio 6/75 (w/v) and enzyme substrate ratio 1.90% (w/w). The properties obtained were: nitrogen solubility at pH 7 of ≥75%, nitrogen solubility at pH 4.5 of ≥33% and oil-absorption capacity of ≥4.1 g/g. Finally, it was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis that protein breakdown was selective. Practical Applications Bambara bean grain legume is a source of cheap, accessible and good nutritional quality protein which could be used in various food formulations as ingredient. However, utilization of the protein concentrate is limited by low functionality. Therefore, it is necessary to improve the functional properties and to adapt these properties to the specific needs in the food industry. Functional properties of Bambara bean protein hydrolysates, as a function of hydrolysis parameters (time, solid-to-liquid ratio, enzyme-to-substrate ratio), were adequately modeled in this study. In addition, optimum conditions where hydrolysates presented higher functional properties were determined. This hydrolysate could find application in the fortification of acid beverages for increasing the nutritional quality, as well as in meat products such as sausages where high oil-absorption capacity is required.

Mechanism of fiber/matrix bond and properties of wood polymer composites produced from alkaline-treatedDaniella oliveriwood flour

The effects of sodium hydroxide (NaOH) concentration and time of treatment on the mechanism of fiber/matrix bond and functional properties of Daniella oliveri reinforced wood polymer composites (WPCs) were investigated. The WPCs were evaluated using Fourier transform infrared spectroscopy, mechanical testing, scanning electron microscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry. The fiber/matrix adhesion mechanism could be attributed to the disruption of hydrogen bonding in the D. oliveri wood fiber network structure and the removal of lignin, wax and oils covering the external surface of the fiber cell wall. This leads to an increase in desirable functional properties as alkaline concentrations reached 4 wt%, but subsequently reduced at higher concentrations, while they increased with treatment time. Analysis of the fractographs of the WPCs suggests optimization of interfacial fiber–matrix adhesion and functional properties when D. oliveri wood fiber was treated with a 4 wt% solution of NaOH for 150 min. POLYM. COMPOS., 37:2657–2672, 2016. © 2015 Society of Plastics Engineers

Determination of ground-state and low-energy structures of perovskite superlattices from first principles

In the development of first-principles high-throughput searches for materials with desirable functional properties, there is a clear need for an efficient method to determine the ground state and low-energy alternative structures of superlattices. A method based on a simple strategy -- to generate starting structures based on low-energy structures of the constituent compounds, which are then optimized via structural relaxation calculations -- is proposed. This "stacking method" is demonstrated on the 2:2 PbTiO$_3$/SrTiO$_3$ superlattice, which has been the subject of recent experimental and theoretical interest. Considerations relevant to wider use of the method are discussed.

Dynamic method to characterize rehydration of powdered cocoa beverage: Influence of sugar nature, quantity and size

Powdered cocoa beverages are a class of instant foods that contain cocoa powder often mixed with high quantities of sugar. One of the desirable functional properties of these beverages is their aptitude to rehydration. Unfortunately, cocoa is a poorly dispersible powder and this is one of the reasons why sugar is added to the initial mix. The influence of sugar nature (sucrose or lactose), sugar size (30 or 480μm) and sugar percentage (from 70 to 90%) on the rehydration properties at 20°C are investigated. Two techniques were tested and compared: classical static (Standards) and dynamic (Quicpic Analyser). It was concluded that the static method usually used for milk powder can correctly discriminate the influence of sugar nature and sugar percentage. The dynamic method was found to be an interesting complementary tool and allow a better sensibility than the static one. In addition, this dynamic method may be of interest to industrialists. Both, the possibility to obtain kinetics and “in situ” images of particles during rehydration are strongly interesting to interpret size changes.

Nonlinear Machine Learning of Patchy Colloid Self-Assembly Pathways and Mechanisms

Bottom-up self-assembly offers a means to synthesize materials with desirable structural and functional properties that cannot easily be fabricated by other techniques. An improved understanding of the structural pathways and mechanisms by which self-assembling materials spontaneously form from their constituent building blocks is of value in understanding the fundamental principles of assembly and in guiding inverse building block design. We present an approach to infer systematically assembly pathways and mechanisms by nonlinear data mining of molecular simulation trajectories using diffusion maps. We have validated our methodology in applications to Brownian dynamics simulations of the assembly of anisotropic "patchy colloids" into polyhedral aggregates. For particles designed to form tetrahedral aggregates, we identify two divergent assembly pathways leading to chains of interlocking dimers and tetramers and chains of interlocking trigonal planar trimers. For particles designed to assemble icosahedral aggregates, our approach recovers two distinct assembly pathways corresponding to monomeric addition and budding from a disordered liquid phase. These assembly routes were previously reported by inspection of simulation trajectories by Wilber et al. ( J. Chem. Phys. 2007, 127, 085106 ; J. Chem. Phys. 2009, 131, 175102 ), validating the capacity of our approach to systematically recover assembly mechanisms previously discernible only by trajectory visualization.

Application of enzymes for efficient extraction, modification, and development of functional properties of lime pectin

The objective of the present study was to transform “Waste to Food” using enzymes to recover value-added food ingredients from biomass. Six commercial cellulases were screened to generate proof of concept that enzymes are selective and efficient catalysts for opening of lime peel biomass to recover pectin. The most efficient enzyme preparation was Laminex C2K derived from Penicillium funiculosum which, during 4 h treatment at pH 3.5, 50 °C, released pectin with similar yield (23% w/w), molecular weight (69 kDa), and functional properties e.g. gelling, stabilization of acidified milk drinks and viscosity as the classically acid-extracted pectins (8 h treatment at 70 °C, pH < 2). Carbohydrate microarray analysis showed that enzymatically extracted pectin mainly contained highly methylated pectin (chemical compositional analysis indicated degree of esterification up to 82%), whereas acidically extracted pectins were more heterogeneous with regard to degree of esterification and had lower degrees of esterification (67–74%). A high degree of esterification in enzymatically extracted pectin may be directly exploited commercially as the so-called Ultra-Rapid-Set pectin, which gels particularly fast at higher temperatures. The Laminex CK2 extracted pectin polymers were not sensitive to the presence of Ca2+ ions, they formed a gel at low pH in the presence of sugar and were able to stabilize acidified milk drinks. Further modification by enzymatic de-esterification of the pectin extracted with Laminex C2K improved its calcium sensitivity and ability to stabilize acidified milk drinks. The present study demonstrates that it is possible to substitute classical acid-based extraction by enzymatic catalysis and obtain pectin products with desirable functional properties.

Comparative study of the functional properties of three legume seed isolates: adzuki, pea and soy bean.

The aim of this work was to compare functional properties including solubility, emulsifying and foaming properties of native and thermally treated adzuki, soy and pea protein isolates prepared under the same conditions. These functional properties were tested at four pH values: pH3.0, pH5.0, pH7.0 and pH8.0. The lowest solubility at all pH values were obtained for isolate of adzuki whereas isolates of soybean had the highest values at almost all pHs. Thermal treatment reduced solubility of soy and pea isolates at all pH values, whereas solubility of adzuki isolate was unchanged, except at pH8. Native isolate of adzuki had the best emulsifying properties at pH7.0 whereas at the other pH values some of native pea and soybean protein isolates were superior. After thermal treatment, depending on tested pH and selected variety all of three species could be a good emulsifier. Native soy protein isolates formed the most stable foams at all pHs. Thermal treatment significantly improved foaming properties of adzuki isolate, whereas reduced foaming capacity of soy and pea isolates, but could improve foam stability of these isolates at specific pH. Appropriate selection of legume seed as well as variety could have great importance in achievement of desirable functional properties of final products. All three tested species could find specific application in wide range of food products.

Modeling the Impact of Extraction Conditions on Functional Properties of Gelatin from Scales of Blackspotted Croaker (Protonibea diacanthus)

Utilization of waste from fish processing industry for value added products is gaining considerable attention as it addresses environmental pollution issues and adds economic returns to the industry. Scales of Blackspotted croaker were utilized for the extraction of gelatin and response surface methodology (RSM) with central composite design was employed to determine the optimal conditions of three independent variables namely concentration of sodium hydroxide (X1), extraction temperature (X2) and extraction time (X3) on yield (%), gel strength (g), viscosity (cP) and melting point (°C). The models obtained by RSM produced a satisfactory fit to the data with respect to gelatin yield (R2 = 0.931, p < 0.01), gel strength (R2 = 0.957, p < 0.001), viscosity (R2 = 0.847, p < 0.05) and melting point (R2 = 0.876, p < 0.05). The maximum values of the responses were obtained at a combined condition of sodium hydroxide concentration, extraction temperature and extraction time of 0.4 %, 80 °C and 3 h respectively. The predicted maximum response values obtained from the models (7.82 % yield, 248.4 g gel strength, 10.11cP viscosity and 21.4 °C melting point) were experimentally verified. Results from the present study clearly revealed that the mathematical models derived from RSM help in extracting gelatin from fish scales with the desirable functional properties.

Structural and Functional Properties of Ovalbumin Glycated by Dry-Heating in the Presence of Maltodextrin

Ovalbumin is the main constituent of egg white protein. Improvements in the functional properties of ovalbumin are of great importance in the food industry. Therefore, in this article, the structural and functional properties of ovalbumin, which were glycated by dry-heating, were investigated. The micrographs showed that glycated ovalbumin was smaller and more homogeneous than native and dry-heated ovalbumin. Although changes in the random coil structure of ovalbumin measured by circular dichroism were mild, increased surface hydrophobicity and decreased tryptophan fluorescence intensity were observed following glycation. Glycation improved the stability against heat induced insolubility, emulsifying properties, water and oil binding capacity of ovalbumin. These results suggested that dry-heating glycation is a useful method for improving the functional properties of ovalbumin. The attention on the structural and functional changes in this work will be contributed to the understanding of the structure-function relationship. These insights would have important implications for the creation of desirable structure and functional properties of food products.