Higher Emulsion Stability Research Articles

INFLUENCE OF EMULSIFICATION METHODS AND SPRAY DRYING PARAMETERS ON THE MICROENCAPSULATION OF TURMERIC OLEORESIN

Turmeric (Curcuma longa L.) oleoresin possess valuable phenolic compounds that are susceptible to degradation, and microencapsulation is a powerful technique to increase its stability. Emulsification is a preponderant step in microencapsulation of hydrophobic compounds and physical-chemical properties of the parent emulsion affects effectiveness of spray-drying process and functional properties of the produced microcapsules. The present work aimed to evaluate the influence of emulsion formulation, emulsification methods, and spray-drying operational conditions on the encapsulation efficiency of turmeric oleoresin using maltodextrin/gelatin blends as wall material. The effects of different concentrations of maltodextrin (12 - 31.7 wt %) and gelatin (0.6 - 6 wt %), combined with three methods of emulsification - high shear homogenization with and without emulsifier addition, and sonication – were evaluated regarding emulsion droplet mean diameter and stability. Based on the results, an emulsion formulated with 26 g of maltodextrin and 0.6 g of gelatin per 100 g of emulsion was selected to study the influence of spray drying conditions - drying-air temperature (124 – 190 oC), atomization airflow (275 – 536 L h-1), and emulsion feeding flow (1.4 – 8.6 mL min-1) - on encapsulation efficiency, water content, and solubility of turmeric oleoresin microcapsules. Sonication resulted in higher emulsion stability and, although drying-air temperature did not affect significantly the microcapsule properties, the best set of spray drying conditions was drying-air at 160 ºC, atomization airflow of 420 L h-1, and emulsion feeding flow of 6 mL min-1. Combinations of higher atomization airflow and lower emulsion feeding flow resulted in lower values of curcumin encapsulation efficiency.

Performance and displacement mechanism of a surfactant/compound alkaline flooding system for enhanced oil recovery

Monoethanolamine and sodium carbonate were simultaneously applied with sulfonate surfactant to form a surfactant/compound alkaline flooding system, whose optimized composition is 0.20% SLPS, 0.15% Na2CO3, and 0.10% MEA. This system has better anti-salt performance. It can significantly decrease the oil/water interfacial tension (IFT) to ultra-low (＜10−3 mN/m) when NaCl concentration is lower than 40,000 mg/L, CaCl2 concentration is less than 400 mg/L, and the temperature is below 90℃. Because of the synergistic effect among SLPS, MEA and Na2CO3, the flooding system shows obviously higher emulsion stability. Micro displacement experiments were performed to investigate the displacement mechanisms of the system. Results indicate that the oil/water IFT reduction and interfacial film softening are two fundamental micro mechanisms which can make crude oil easy to be emulsified by the flooding system. According to the flow velocity and the contact time between crude oil and the system, turbulent-emulsification and self-emulsification are main emulsification mechanisms. During the migration process of emulsion in porous media, the coalescence-entrainment and the coalescence-dispersion phenomena appear, which both can improve the displacement efficiency of remaining and irreducible oil and ultimately enhance the crude oil recovery.

A Comprehensive Approach from Interfacial to Bulk Properties of Legume Protein-Stabilized Emulsions

The correlation between interfacial properties and emulsion microstructure is a topic of special interest that has many industrial applications. This study deals with the comparison between the rheological properties of oil-water interfaces with adsorbed proteins from legumes (chickpea or faba bean) and the properties of the emulsions using them as the only emulsifier, both at microscopic (droplet size distribution) and macroscopic level (linear viscoelasticity). Two different pH values (2.5 and 7.5) were studied as a function of storage time. Interfaces were characterized by means of dilatational and interfacial shear rheology measurements. Subsequently, the microstructure of the final emulsions obtained was evaluated thorough droplet size distribution (DSD), light scattering and rheological measurements. Results obtained evidenced that pH value has a strong influence on interfacial properties and emulsion microstructure. The best interfacial results were obtained for the lower pH value using chickpea protein, which also corresponded to smaller droplet sizes, higher viscoelastic moduli, and higher emulsion stability. Thus, results put forward the relevance of the interfacial tension values, the adsorption kinetics, the viscoelastic properties of the interfacial film, and the electrostatic interactions among droplets, which depend on pH and the type of protein, on the microstructure, rheological properties, and stability of legume protein-stabilized emulsions.

Linum usitatissimum L. seeds: Flax gum extraction, physicochemical and functional characterization

Flax gum (FG) was extracted and purified from flaxseed (Linum usitatissimum L.) locally called as Alsi. Physicochemical and functional aspects of separated gum were interrogated in detail. Fourier Transform Infrared Spectroscopy analysis depicted variety of peaks in region of 3308.8, 2923.60, 1739.97 & 1149.68 cm−1 which are feature of typical polysaccharide. Functional properties of FG depicted higher water holding ability and lower oil holding aptitude compared to reference materials. Foaming capacity, swelling index and foaming stability of FG were 27.5%, 55.0% and 10.5% respectively which were higher than reference gums. Highest emulsion stability was evident at 0.5% concentration >95.Monosaccharide composition depicted the acidic and neural behavior of heteopolysaccharide FG. Thermal analysis revealed that FG was highly stable. XRD analysis depicted amorphous behavior. SEM imaging indicated a splendor and shiny surface of FG. In conclusion, FG is suitable for variety of food formulations as a thickener, stabilizer, and moisture-retaining agent.

Environmentally-compatible alkyd paints stabilized by wood hemicelluloses

Wood biorefining currently involves large-scale industrial processes where a notable portion of raw materials, namely hemicelluloses and lignin, are either lost with the process water, degraded, or burnt for energy. Value-added utilization of polymeric hemicelluloses is challenging due to their intermediate molar mass and the presence of other wood components, such as phenolic residues or wood extractives. Oil-in-water (O/W) emulsions represent a diverse and abundant class of applications in which the natural properties of wood hemicelluloses are beneficial. In the current work, we present highly promising new technical alkyd paint emulsion systems stabilized with hardwood glucuronoxylans (GX) and softwood galactoglucomannans (GGM). Samples from three isolation methods and their further fractionation by ethanol precipitation were systematically compared with regard to hemicellulose composition, interfacial activity, and functionality in emulsions. Emulsification of alkyd resins was successful with both GX and GGM obtained by various biorefining strategies. The highest emulsion stability over storage was achieved using crude non-purified GX and GGM fractions, and was correlated with the presence of phenolic compounds and extractives, interfacial activity, and small droplet size. Hardwood GX and softwood GGM are envisioned as natural emulsifiers of alkyd O/W emulsions, which are examples of diverse and abundantly-used technical dispersions. This study can be utilized as a guideline for targeted extraction of hemicelluloses with desired functionality, and as a protocol for developing environmentally-compatible industrial dispersions.

Effects of different drying conditions on the starch content, thermal properties and some of the physicochemical parameters of whole green banana flour.

The physicochemical and thermal properties of whole green banana flour obtained from oven air-drying (ODF) at three temperatures (50, 80 and 110 °C) and freeze-drying (FDF) were compared to wheat flour (WF). Lightness and yellowness were negatively affected by the temperature increment. The FDF samples exhibited higher a* and L* values and had the closest browning index to WF (P-value < 0.01). Also, the ODF50 samples had the highest emulsion activity, whereas FDF had the highest emulsion stability (P-value < 0.05). The oil holding and water holding capacities of the FDF samples were significantly higher than all other samples (P-value < 0.05). A higher resistant starch content was found in the FDF (46.72%) and ODF50 (44.58%) samples. The ODF50 samples had the highest amylose content and degree of crystallinity (P-value < 0.05) as well as the lowest gelatinization temperature amongst the green banana flour samples (4.69 °C). Oven air-drying increased the gelatinization temperature drastically for all GBF samples (P-value < 0.05). In conclusion, drying the whole green banana at 50 °C resulted in the least negative effects on RS content compared to the other drying temperatures investigated in this study and was the closest to the characteristics of the FDF samples.

Protein concentrates obtained from pig by-products using pH-shifting technique: a preliminary study

ABSTRACT: This study aimed to investigate the extraction and characterization of protein concentrates from pig by-products (heart, liver and kidneys) using the pH-shifting technique. From the solubility profiles (pH 2 to 12), the protein extraction was performed at alkaline pH (10.0 to 11.5), obtaining two fractions: soluble (SC) and insoluble (IC). Higher protein content (71 to 77%) and extractability (214 to 459 mg/g) were observed in heart and liver concentrates; whereas, for water holding capacity (WHC) the highest values (4.20 to 4.54 g water/g protein) were for the heart (SC) and kidney (SC and IC) concentrates. All concentrates had high emulsion stability and higher WHC than commercial protein extenders (whey and soybean). The concentrates obtained from the soluble fraction were redder (higher a* values and lower h values) and darker (lower L* values) than insoluble fraction, especially heart and liver concentrates. Use of concentrates in sausage production slightly altered the color chroma (C*) of samples. It was concluded that the pig by-products protein concentrates had great potential of use as extenders in sausage production.

Quality of Chicken Patties with Different Levels of Tapioca Flour Prepared by Using Food Processer

A study was conducted to prepare spent hen meat patties by incorporation of tapioca flour and to compare the quality and economics of such patties processed by using food processor and bowl chopper. Chicken meat patties with 3% maida (control) and different levels of tapioca flour (3, 5 and 7%) prepared by using food processor were subjected to physico-chemical, chemical composition and sensory analysis. Results revealed that patties containing 5 and 7% tapioca flour had significantly (P 0.05) differences were observed in sensory quality of patties containing different levels of tapioca flour, but 5% tapioca flour incorporated patties had non-significantly higher overall acceptability. The patties prepared with incorporation of 3 and 5% tapioca flour had significantly (P<0.05) higher protein and fat contents than patties containing 7% tapioca flour. Hence, formulation with 5% tapioca flour was selected over 3% tapioca flour to replace more meat portion. The patties processed by using bowl chopper had significantly (P<0.05) higher emulsion stability (95.26%) and texture score (7.63) compared to patties processed by using food processor, but all other parameters remained unaffected. Quality of patties prepared by using food processor and bowl chopper were comparable. The cost of production of patties prepared by incorporating different levels of tapioca flour by replacing the meat decreased proportionately. Since the food processor is very cheap (Rs 5000), it is economical to prepare patties by incorporating 5% tapioca flour using food processor without affecting sensory and physico-chemical qualities for small scale production.

Pilot Performance of Chemical Demulsifier on the Demulsification of Produced Water from Polymer/Surfactant Flooding in the Xinjiang Oilfield

Purification of produced water (PW) from polymer/surfactant flooding is a challenge for the petroleum industry due to the high emulsion stability. Demulsification using chemical demulsifiers has been expected to be an effective way to treat PW. In this paper, five cationic (branched quaternary ammonium chloride) and four nonionic (copolymer of propylene oxide and ethylene oxide) demulsifiers with different molecular weights were employed to test their respective demulsification performance in the treatment of PW from polymer/surfactant flooding. The cationic demulsifiers, in general, exhibited better performance than the nonionic ones and one cationic demulsifier (CP-1) exhibiting the best demulsification efficiency was further employed for a pilot experiment in the Xinjiang Oilfield. The oil content of PW could be successfully reduced from 128~7364 to less than 10 mg/L with a dosage of CP-1 for 350 mg/L and polyaluminum chloride (PAC, 30% w/w Al2O3) for 500 mg/L under ambient temperature (14~22 °C). At the same time, partially hydrolyzed polyacrylamide (HPAM) was removed from 176.9~177.1 to 2.8~3.9 mg/L while petroleum sulfonate was not removed too much (from 35.5~43.8 to 25.5~26.5 mg/L). The interfacial rheology analysis on simulated PW from HPAM/petroleum sulfonate flooding revealed that the addition of CP-1 led to a significant increase of the oil-water interfacial tension (from 7 to 15~20 mN/m) and zeta potential (from −32.5 to −19.7 mV). It was, thus, assumed that the decreased net charge on the dispersed oil droplets surface and weakened oil/water film due to the formation of complex between the cationic demulsifier and HPAM may have facilitated the destabilization of the emulsion. The result of this study is useful in better understanding the demulsification processes as well as selecting suitable demulsifiers in the treatment of PW from polymer/surfactant flooding.

Valorization of Opuntia monacantha (Willd.) Haw. cladodes to obtain a mucilage with hydrocolloid features: Physicochemical and functional performance

Opuntia monacantha mucilage was investigated for its physicochemical characteristics and functional properties. The mucilage extraction yield was 12% (DW) and it consisted of 80.12% carbohydrates, 15.14% ashes, 3.55% proteins, and 1.19% lipids. Monosaccharide profiling demonstrated a predominantly presence of galactose, glucuronic acid, and arabinose. Viscosimetric measurements gave an intrinsic viscosity of 9.02 dL/g and a molar mass of 1.12 × 106 g/mol. Reconstituted mucilage solution (1% w/v) had a mean particle diameter (D4,3) of 648 nm and solubility above 85%. Its emulsifying capacity improved with the increment of mucilage solution in the emulsion; likewise, it provided high emulsion stability through different ratios of oil to polysaccharide solution. It displayed good foaming capacity, although its foam stability progressively reduced over time. In addition, its blending with ovalbumin resulted in a foaming capacity enhancement and in a markedly greater foam stability compared to ovalbumin alone. The rheological studies indicated the mucilage solutions exhibited shear-thinning behavior at concentrations between 1 and 10% and fairly stable viscous properties in the temperature range of 5–80 °C. These outcomes support that O. monacantha mucilage may find potentially useful applications in food systems, particularly as an emulsifying, foaming and thickening agent, or as a stabilizer.

Extraction, characterization and functional properties of soluble proteins from edible grasshopper (Schistocerca gregaria) and honey bee (Apis mellifera)

In our research soluble proteins from edible grasshopper (S. gregaria) and honey bee brood (A. mellifera) were exposed to defatting, alkaline, and sonication-assisted extractions. New nitrogen-to-protein conversion factors based on amino acid analysis were estimated for both insects: 4.5 for adult grasshopper, and 4.9 and 5.6 for pupae and larvae of honey bee respectively, in contrary to 6.25 commonly used for insects. All fractions were characterized by their composition, yield, color, protein solubility, and functional properties in comparison to whey protein concentrate. Besides an increase in protein content up to 57.5 and 55.2% for grasshopper and honey bee respectively, protein-enriched fractions showed improved foaming and emulsifying abilities. The highest emulsion stability after 120 min was determined for grasshopper powder extracted with sonication (85.5%) and whey proteins (89.8%). The protein-enriched fractions of both insects had significantly higher foaming stability (74.1% for grasshopper fraction after alkaline extraction and 55.5% for sonication-assisted honey bee fraction) than raw and defatted powder. All fractions obtained from honey bee brood showed significantly higher protein heat coagulation than grasshopper and whey proteins. Changes in protein functionality were found related to alteration in protein charge, surface hydrophobicity, and distribution of proteins according to their molecular weight. Therefore, our results showed that S. gregaria and A. mellifera have a potential for future applications for food, feed, or insect-based dietary supplements.

Functional attributes of ethnically edible ectomycorrhizal wild mushroom Amanita in India

d products. This study evaluates functional properties of an ectomycorrhizal wildmushroom Amanita sp. occurring in the lateritic scrub jungles of southwestern India. Based onthe ethnic knowledge, immature cooked fruit bodies of this mushroom are edible. Standardprotocols were followed to evaluate functional properties of uncooked and cooked immaturefruit bodies (pH-dependent protein solubility; least gelation concentration; water- and oilabsorptioncapacities; emulsion and foam properties). The protein solubility was significantlyhigher in uncooked against cooked samples (pH 2-8, p 0.05) despite water-absorption and oil-absorption capacities were higher in cookedsamples. The emulsion activity (p 0.05) were higher in cooked than uncooked samples. The PrincipalComponent Analysis (PCA) between proximal and functional properties reveals that the crudeprotein, total lipids and crude fibre influenced the protein-solubility, emulsion stability and foamcapacity in uncooked samples. In cooked samples, the crude fibre and carbohydrates influencedall the functional properties studied except for protein solubility. It is assumed that thecomposition and proportion of proximal components influence the functional attributes ofAmanita sp. The properties like high emulsion activity, emulsion stability and foam capacity incooked mushroom will be useful in formulation of value-added foods or nutraceutical products.

English

A portion of okra seed protein-rich extract (PRE) prepared with NaCl solution (5 g/L) was hydrolyzed at 110°C for 5 h (1 atm. pressure). The PRE (sample A), hydrolyzed PRE-B, whole okra seed flour-C and gelatin-D were tested for emulsification capacity (EMC) and emulsion stability (ES). The emulsions were prepared and tested in (i) normal environmental condition (o/w and w/o), (ii) current carrying beaker-CB, (iii) Ohmic heating beaker-OB. The tests were carried out at zero to 240 V. The results showed that at 200 V, the EMC were 85.71, 80.50, 88.23, 85.31, 94.71, 94.70, 90.68, and 83.3% for ACB, AOB, BCB, BOB, CCB, COB, DCB, and DOB, respectively. The respective ES are 23, 31, 25, 43, 98, 61, 98, and 65%. At 200 V, okra product CCB had the highest EMS and ES (94 and 98%, respectively). At 95% oil (w/o) emulsion, EMC for PRE and gelatin were 6.0 and 1.9%, respectively. At 5% oil (o/w) emulsion, the corresponding EMS and ES is 84 and 94%. Hydrolyzed okra seed PRE-CCB is possibly a hydrophilic emulsifier, combining high (94%) EMC with high (98%) ES. Key words: Okra seed, protein-rich extract, hydrolysis, emulsification, electric field.

Fabrication and Characterization of Quinoa Protein Nanoparticle-Stabilized Food-Grade Pickering Emulsions with Ultrasound Treatment: Interfacial Adsorption/Arrangement Properties.

The natural quinoa protein isolate (QPI) was largely reflected in the nanoparticle form at pH 7.0 (∼401 nm), and the ultrasound at 20 min progressively improved the contact angle (wettability) and surface hydrophobicity of the nanoparticles. Ultrasound process also modified the type of intraparticle interaction, and the internal forces of sonicated particles were largely maintained by both disulfide bonds and hydrophobic interaction forces. In emulsion system, the ultrasound progressively increased the emulsification efficiency of the QPI nanoparticles, particularly at high protein concentration ( c > 1%, w/ v) and higher emulsion stability against coalescence. As compared with the natural QPI-stabilized emulsions, the 20 min sonicated emulsions exhibited higher packing and adsorption at the protein interface. The microstructure of emulsions that occurs is bridging flocculation of droplets at low c (≤1%, w/ v), while the amount of protein particles could be high enough to cover the droplet surface at high c ( >1%, w/ v) with hexagonal array model arrangement. Thus these results illustrated that both natural and sonicated QPI nanoparticles could be performed as effective food-grade stabilizer for Pickering emulsion; however, the sonicated QPI nanoparticles exhibited much better emulsifying and interfacial properties.

Surface charge effect of nanogel on emulsification of oil in water for fossil energy recovery

Crosslinked polymeric hydrogels in nano-size, termed as nanogels, have significant technological applications by stabilizing Pickering emulsion. Herein, we present our experimental observations and the results of the emulsion stability analysis on the effects of nanogel concentration, oil-to-water ratio, nanogel charge, and ambient temperature. The nanogel with neutral-charge showed extraordinarily high emulsifying ability, interfacial tension between decane and water was reduced from 51.98 mN·m−1 to less than 6.04 mN·m−1, compared to 47.5 mN·m−1 by nanosilica. When treated with neutral-charged nanogel, the oil-in-water emulsion exhibited long-term stabilization, 90% emulsion remained after one month at room temperature, showing the highest stability among the reported literature of Pickering emulsions. However, inorganic silica nanoparticles displayed emulsion stability in minutes. Of particular interest was that the emulsion volume remained 82% after thermal treatment at 65 °C for 48 h. The resulting high emulsion stability was attributed to a combination of high hydrophilicity, sufficient steric repulsion, and high surface coverage of nanogel. These observations indicated that the resulting nanogel can be a promising candidate toward enhanced oil recovery.

Evaluation of Variation in Protein Composition on Solubility, Emulsifying and Gelling Properties of Soybean Genotypes Synthesizing β' Subunit

AbstractThe effects of subunit composition of two major proteins of soybean: glycinin (11S) and β‐conglycinin (7S) in nine different genotypes, on solubility and emulsifying and gelling properties at different pH (3, 5, 6, and 8) were examined. High‐protein genotypes (more than 40%) contained low amounts of the β′ subunit. The main factors influencing solubility at pH 6 were the content of α′, α (r = 0.89 and r = 0.91 at P &lt; 0.05, respectively) and β′ subunit contents (r = −0.71 at P &lt; 0.05) of β‐conglycinin, while at pH 3 acidic subunits in glycinin had a positive correlation with solubility (r = 0.69 at P &lt; 0.05). Emulsion activity at pH 6 was higher for genotypes synthesizing β′ subunit (r = 0.57 at P &lt; 0.05). Genotypes synthesizing higher amounts of α′ and α subunit had higher emulsion stability at pH 6 (r = 0.85 and r = 0.92 at P &lt; 0.05, respectively) and pH 8 (r = 0.91 and r = 0.97 at P &lt; 0.05, respectively). The rheological measurements showed that genotypes with 11S/7S ratio higher than 2.2 formed gels with enhanced storage moduli. This influence was largely due to the high content of SH groups in glycinin acidic polypeptides resulting in stabilization of gels via disulfide bonding. Gels prepared from genotypes containing higher amounts of β′ subunit of β‐conglycinin exhibited reduced elastic properties. Genotypes showing better solubility also had higher emulsion stability, but formed weaker gels and had lower emulsion activity near neutral pH.

Effects of Jerusalem Artichoke Powder and Sodium Carbonate as Phosphate Replacers on the Quality Characteristics of Emulsified Chicken Meatballs.

Today incorporation of natural ingredients as inorganic phosphate replacers has come into prominence as a novel research topic due to health concerns about phosphates. In this study, we aimed to investigate the quality of emulsified chicken meatballs produced with Jerusalem artichoke powder (JAP), either alone or in combination with sodium carbonate (SC) as sodium tripolyphosphate (STPP) replacers. The results showed that naturally dried JAP showed favorable technological properties in terms of water-oil binding and gelling. Emulsion batters formulated with JAP-SC mixture showed lower jelly and fat separation, higher water-holding capacity and higher emulsion stability than control samples with STPP. In final product, incorporation of JAP-SC mixture increased moisture and reduced lipid and energy values, and kept the pH value similar to control. Added JAP lead to increments in b* values whereas decreases L* values. Cook yield was similar to control in phosphate-free samples formulated with JAP-SC mix. Either low or medium ratios of JAP in combination with SC managed to protect most of the sensory parameters, while sensory scores tend to decrease in samples containing high levels of JAP. Addition of JAP to formulations presented samples that have equivalent behavior to phosphates in terms of lipid oxidation. In conclusion, our study confirms that utilization of JAP in combination with SC had promising effects as phosphate replacers by presenting natural solutions and providing equivalent quality to standard phosphate containing products.

Gold Nanoparticles Conjugated Levofloxacin: For Improved Antibacterial Activity Over Levofloxacin Alone.

Levofloxacin is a potent antibiotic with severe side effects due to its high doses. Bacterial resistance may be due to frequent use of antibiotics. Biogenic gold nanoparticles conjugated levofloxacin (Au-HSA-LvN-NPs) were developed by Human Serum Albumin (HSA) and nitrate reductasemediated pathways. Au-HSA-LvN-NPs (size = 27.2 ± 1 nm) were readily generated with high emulsion stability zeta potential (-13.3 mV). The developed nanoparticles were also characterized by UVvisible spectroscopy, Transmission Electron Microscopy and Dynamic Light Scattering techniques. The optimized nanoparticles were found efficient against both Gram-positive bacteria and Gramnegative bacteria specifically S. aureus (MIC-0.373 µg/ml), E. coli (MIC-0.149 µg/ml) and P. aeruginosa (MIC-0.346 µg/ml) respectively. The efficiency of bioconjugated levofloxacin got improved by 1.94 times, 2.89 times and 1.46 times against S. aureus, E. coli and P. aeruginosa respectively, in comparison to pure levofloxacin.

Production of squid emulsion sausages using pork skin and coconut powder mixture as fat replacers

SummaryHow to improve the inferior properties of squid products is a big challenge for producers. Pork skin and coconut powder (PSCP) mixture were assessed as fat replacers in squid emulsion sausages. The modified treatment containing 100% PSCP had 62.58% less fat, 4.82% more protein and 8.79% more moisture than those of the control (P &lt; 0.05). High PSCP concentration resulted in lower cooking loss, higher emulsion stability and better textural properties. Texture profile analysis (TPA) showed that the addition of PSCP significantly (P &lt; 0.05) increased the hardness, cohesiveness and chewiness of the sausages. The three‐dimensional network structures of the sausages containing PSCP were more compact and homogeneous. Sensory evaluation results produced by a sensory panel comprised of 100 panellists indicated that the sausages had an excellent flavour and overall acceptability when the substitution was 60%. Therefore, pork skin and coconut powder can be used to replace the pork back fat in the squid emulsion sausage without sacrificing the quality.

Response surface methodology for investigating structure–function relationship of grain legume proteins

Effect of physicochemical properties and secondary structure conformation, on the functional properties of protein concentrates prepared from grain legumes was investigated using response surface methodology. Appropriate models were built on the basis of the best subset technique. Oil-holding capacity was mainly influenced by the secondary structure of proteins, particularly unordered structure, β-sheet, and β-turn. Protein solubility depended on secondary structure and surface hydrophobicity of proteins, and solubility decreased with increasing hydrophobicity. Interaction between solubility and hydrophobicity was significant for emulsifying activity, and EA increased with increasing solubility and hydrophobicity. High emulsion stability of legume proteins necessitated high β-turn secondary structure proportion, solubility, and hydrophobicity. Protein unfolding, particularly high unordered, and β-turn structures and high solubility were required for high foaming ability of legume proteins. In summary, the importance of this study was to increase the utilization of grain legume proteins in the food and non-food industry. Practical applications It is important during food processing or when using an underutilized grain legume protein source as ingredient or supplement in the formulation of food products, to predict the functional properties of the protein. Functional properties are important for the consumer acceptance of food product. The physicochemical properties of protein such as surface hydrophobicity and secondary structure could be used as a basis to predict functionality. In this connection, this study provided effects of the variation of physicochemical properties and secondary structure of grain legume proteins on oil-holding capacity, solubility, emulsifying and foaming properties. The aim of this study was to enhance the utilization of grain legume proteins as nutritional and functional ingredient.