Sesame Protein Isolate Research Articles

Designing of ω-3 PUFA enriched biocompatible nanoemulsion with sesame protein isolate as a natural surfactant: Focus on enhanced shelf-life stability and biocompatibility

Natural polymeric proteins, isolated from sesame meal, had already shown promise as potent nutraceutical. This polymeric protein was employed as a natural alternative surfactant for designing a nanoemulsion based delivery system for ω-3 PUFA rich fish oil (FO) in the present study. The process parameters of the high pressure nanoemulsification were optimized with the CCD guided RSM analysis. Results with highest desirability [cumulative droplet size 125.87±2.54nm, PdI 0.199±0.01 and D90 Particle size 268.98±13.89nm] was obtained with 40 Kpsi homogenization pressure and 10 homogenization cycles and upto 1.5% (w/v) FO. The nanoemulsion formulation with SPI at 0.5% (w/v) concentration in combination with Tween 20 and Span 80 (1:1) had minimized the hydrodynamic droplet size to 89.68±2.375nm and also enhanced the shelf-life stability of the nanoformulations substantially, along an 8 week long storage period. Inclusion of SPI as surfactant also contributed to ≥90% of fatty acid release from the fish oil rich nanoemulsion droplets, at a steady gradient during 120min of simulated two-step in vitro digestion. The MTT assay had confirmed the formulation to be non-toxic towards rat PBMCs. The informations obtained in this study will facilitate the application of SPI to formulate nutraceuticals-loaded nanoemulsion delivery system with better functional benefits.

Edible films developed from carboxylic acid cross-linked sesame protein isolate: barrier, mechanical, thermal, crystalline and morphological properties.

Films were developed from sesame protein crosslinked with three different carboxylic acids (malic acid, citric acid and succinic acid) at 1, 3 and 5% (w/w, on protein isolate basis). The effect of crosslinking on physical, mechanical, thermal and morphological properties was studied. Succinic acid crosslinked films exhibited least water vapor permeability the highest tensile strength and overall showed superlative properties among other films. X-ray diffraction showed single main crystalline reflection at 20° indicating amorphous structure of films. DSC curves of films indicated single melting peak in the range of 103-161°C. All films exhibited weight loss in three stages. FTIR exhibited peak at 1700cm-1 confirming crosslinking reaction between carboxylic acids and protein. Crosslinked films were compact, nonporous and smooth as compared to film from native sesame protein isolate.

Thermal, structural and rheological characterization of protein isolate from sesame meal

Sesame protein can be considered as a good source of protein due to high content of methionine present in it. In this study, sesame protein isolate (SPI) from sesame meal was isolated and its thermal, structural, and rheological properties were evaluated. X-ray diffraction exhibited two diffraction peaks, one at 10° (small intensity) and other at 19.5° (high intensity). Thermo-gravimetric analysis showed complete degradation of protein on increase of temperature to more than 450 °C. In differential scanning calorimetry, onset temperature for SPI started at 176.0 °C and peak denaturation temperature for SPI was observed at 210 °C. FTIR of SPI indicated the presence of Amide A, Amide B and Amide I to V bands. SPI exhibited shear thinning behaviour characterized with viscosity decrease with increase in shear rate. Minimum viscosity was observed when shear rate varied from 700 to 800 s−1. Visco-elastic behaviour of SPI gel was observed during temperature sweep test, with G′ dominating G″ throughout the test. Overall, observed parameters showed that sesame protein exhibit good thermal stability and appropriate rheological properties necessary for industrial application and hence can be considered as an efficient source of protein supplemented foods.

Composite film developed from the blends of sesame protein isolate and gum rosin and their properties thereof

Composite films from sesame protein isolate and gum rosin were prepared at different ratios by casting method. The effect of gum rosin (GR) addition on the physical, mechanical, thermal, optical, and morphological properties were investigated. Maximum tensile strength and minimum water vapor permeability was observed for composite film at 80:20 ratio. Transparency of sesame protein film was observed to be lower as compared with composite films. ΔE values increased with increase in concentration of GR. X‐ray diffraction of sesame protein film and composite films indicated amorphous structure of films. Differential scanning calorimetric curves of all films showed single Tg in the range of 108°C–158.66°C. All films exhibited weight loss in three stages (temperature ranged between 130°C and 590°C). Sesame protein film exhibited high degree of porosity. With the addition of GR porosity decreased and compactness increased. POLYM. COMPOS., 39:1480–1487, 2018. © 2016 Society of Plastics Engineers

Sesame protein based edible films: Development and characterization

Sesame protein isolate prepared from defatted sesame meal can be used as a valuable source for edible film formation. Edible films from sesame protein isolate were prepared and effect of protein concentration (3–9%), pH (9–12), temperature (70–90 °C) and plasticizer (10–50% on a protein basis) were evaluated. Response surface methodology (RSM) was employed for optimization of parameters for preparation of edible film and optimized film was further characterized. Water vapor permeability (WVP), tensile strength and solubility were considered as response variables. All independent variables (protein concentration, pH, temperature and plasticizer) significantly (p ≤ 0.05) affected the water vapor permeability, tensile strength and solubility of edible films. WVP of edible films ranged from 0.90 to 1.62 × 10−11 g m/Pa.s.m2, tensile strength from 0.47 MPa to 3.03 MPa, and solubility from 51.06 to 87%. Optimized values indicated that the edible films prepared at protein concentration of 9%, pH 12, temperature 90 °C and plasticizer 10% (on protein basis) resulted in lower water vapor permeability, maximum tensile strength and lower solubility. DSC curve of film exhibited single Tg of 50 °C. TGA scans for optimized film evinced good thermal stability. Film exhibited weight loss in three stages (temperature ranged between 150 °C and 590 °C). The XRD of film displayed only one main crystalline reflection at 2θo which indicates the major structure of films was amorphous.

Assessment of functionality of sesame meal and sesame protein isolate from Indian cultivar

Plant proteins are cheaper source of proteins as compared to animal proteins. So they have great potential as functional food ingredient and could be supplemented in human diets. The use of isolated proteins depends on their ability to impart properties in processed foods. So for effective utilization of particular protein, it is necessary to study its all types of properties and characteristics which is necessary for development of methodology for their use. Sesame protein isolate (SPI) was extracted from sesame meal. The physicochemical and functional properties of both sesame meal and SPI were evaluated. The solubility was maximum (94.13 %) at pH 12. Foaming capacity and foam stability of SPI was pH dependent. SPI showed increase in emulsion stability (ES) with increase in pH. Gelling ability of SPI increased with alkaline pH.

Thermal processing, salt and high pressure treatment effects on molecular structure and antigenicity of sesame protein isolate

Sesame protein is a recognized food allergen in many countries. Conditions used during processing can affect its detection in foods. In this study, the effect of different extraction conditions, pH, high pressure (HP) (100–500MPa) and thermal processing (boiling, microwave heating and dry roasting) on the antigenic properties of sesame protein isolates were studied. Isolates prepared using water, sodium chloride at different concentrations, and ammonium sulfate at different percent saturation showed different immunoreactivity responses. Higher immunoreactivity was observed with the water, low salt (0.2M NaCl), and ammonium sulfate isolated extracts compared to those extracted with higher salt (0.6–1M NaCl) likely due to differences in the types of proteins extracted. High pressure treatment markedly decreased antigenicity at all pH values. Boiling and dry roasting increased the ELISA response, whereas microwaving decreased it. FTIR results showed significant changes in sesame protein conformation due to unfolding and/or denaturation which could have modified the antigenic properties of the sesame proteins.

Sesame protein isolate: Fractionation, secondary structure and functional properties

This study investigated the selective fractionation of sesame proteins using sodium chloride and ammonium sulfate. Maximum protein extraction occurred at pH 7–10 and in the presence of 0.6–1M NaCl. Sesame protein isolate (Ses-PI) yield increased from 12.5% in the absence of NaCl to 54.6% at 1M NaCl. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated differences in the electrophoretic pattern of water-extracted Ses-PI compared to the NaCl extracts. However, changing the NaCl concentration did not affect the principal components in the profile of the sesame protein extracts. With ammonium sulfate (AS) precipitation, the 11S fraction was preferentially extracted at 30% saturation (AS30%). More 2S and 7S polypeptide bands were found in the AS50% fraction, whereas the AS70% sample had a higher concentration of the 7S fraction. FTIR analysis revealed that heat treatment as well as use of NaCl and AS at lower concentrations induced changes in protein conformation, whereas at higher concentrations the protein conformation was more stable. CD analysis revealed a predominance of α-helices in the water extract which decreased with increasing NaCl content toward more β-strand structures. Changes in secondary structure were also observed as the ammonium sulfate concentration was increased from 30 to 70%. The functional properties of (Ses-PI-1M NaCl) were compared to that of soy protein isolate (Soy-PI). Ses-PI-1M NaCl had significantly (P<0.05) lower protein solubility, water holding and fat binding capacities, but much greater emulsifying and foaming properties compared to Soy-PI.

EFFECT OF VARYING LEVELS OF ADDED CALCIUM ON THE BIOCHEMISTRY, TEXTURE AND MICRO-STRUCTURE OF FRESH CHEESE CONTAINING SESAME PROTEIN ISOLATE

This article investigates the impact of sesame protein isolate (SPI) and increased calcium in milk on the biochemistry, rheology and micro-structure of cheese. The characteristics of two sets of cheeses made from raw milk and milk of 8% protein substituted by SPI (SPI milk) with 0, 5, 10 and 20 mM calcium addition were investigated. Adding SPI to milk resulted in rennet gel formation with longer coagulation time and lower storage modulus (G′) at 60 min in cheesemaking. The synergistic influence of SPI and calcium resulted in increased hardness, cohesiveness, adhesiveness and meltability during 21 days of cheese aging. Adding calcium to SPI milk resulted in a more compact and regular micro-structure in cheese. Scanning electron microscopy indicated the associative effect of sesame protein and calcium generated greater aggregation in complex cheese micelles, which was key in SPI cheese property formation. Sodium dodecyl sulfate polyacrylamide gel electrophoresis gel electrophoretograms of the wheys and caseins indicated the interaction of sesame protein and casein with calcium. This study is of benefit in the manufacture of novel cheese with traditional orient food to meet with the taste of Chinese people. PRACTICAL APPLICATION This research is focused on the influence of sesame protein and calcium ions on the properties of fresh cheese. In recent years, cheese has become increasingly popular in China and its market has increased more than 50% year upon year. To further promote cheese consumption, its nutritional benefits have been emphasized and various efforts have been made to promote cheese and to make it more acceptable to Chinese tastes. The addition of typical Chinese food ingredients into cheese could provide sensory familiarity to local consumers, and at the same time could also help to improve nutritional balance. The result of this research is of great value to the application of plant proteins as they may serve as novel ingredients added to cheese to meet the requirements of this new and fast-growing market.

Novel Approach to Recover Natural Antioxidants from Oil Seed Meal in Ultrafiltration-Nanofiltration-Based Technique

This study describes an innovative approach for recovery and concentration of sesame glucosides from defatted sesame cake using membrane separation route. Simple aqueous extraction of the seed meal at suitable pH value followed by two steps membrane fractionation (ultrafiltration-nanofiltration) was done to obtain sesame glucoside concentrate. In this process, about 0.7% ± 0.29 recovery of total meal glucoside was achieved along with coproduct sesame protein isolate at yield value of 36.50%. Several in vitro analyses were carried out to assay the antioxidative potential of recovered glucosides in different reaction models. Recovered glucosides have shown comparable α,α′-diphenyl-1-picryl-hydrazyl radical scavenging activity and Cu2+ ion chelation capacity with solvent extracted glucosides. Sesame glucosides have shown unique antioxidant activity for 29 h in an induced oxidation system of linoleic acid emulsion. This study includes a detail analysis on membrane performance parameters and fouling characteristics of ultrafiltration membrane, which are crucial factors to consider for industrial relevance. All findings point toward the potentiality of ultrafiltration-nanofiltration-based technique for recovery of polar antioxidants from various raw materials.

Antihyperlipidemic Effect of Sesame (Sesamum indicum L.) Protein Isolate in Rats Fed a Normal and High Cholesterol Diet

The dietary influence of sesame protein isolate (protein content 91.5%), produced from dehulled, defatted sesame meal, on blood and tissue lipid profile and lipid peroxidation has been assessed in normal and hypercholesterolemic rats. To evaluate their hypocholesterolemic and antioxidative activity in vivo, we fed 18% sesame protein isolate with or without 2% cholesterol in comparison with casein to rats for 28 d. We determined plasma total protein, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triacylglycerol as well as susceptibility of plasma and erythrocyte membrane lipid to oxidation ex vivo. Liver tissue lipid, cholesterol, phospholipids, and lipid peroxidations were also determined. The total cholesterol, LDL-cholesterol and triacylglycerol levels were significantly reduced in the sesame protein isolate and isolate containing cholesterol group than the corresponding control casein groups. HDL-cholesterol level was also increased in sesame protein isolate (41%) and protein isolate containing cholesterol group (38%) than the corresponding control casein and casein containing cholesterol groups. There was 49% and 64% lowering of plasma lipid peroxidation as well as 36% and 56% lowering of lipoprotein oxidation susceptibility (LOS) in the 2 experimental groups (sesame protein isolate and isolate containing cholesterol group) than the corresponding control (casein and casein containing cholesterol) groups. There was significant lowering of erythrocyte membrane lipid peroxidation (68% and 63% lowering in sesame protein isolate and isolate containing cholesterol groups) and liver lipid peroxidation (61% and 76% lowering in the 2 experimental groups than the corresponding control casein groups). Therefore, our results indicate that sesame protein isolate decreases cholesterol concentration in plasma, increases HDL-cholesterol, and also decreases plasma and erythrocyte membrane lipid peroxidation with or without cholesterol fed diet in rats.

Effect of sesame protein isolate in partial replacement of milk protein on the rheological, textural and microstructural characteristics of fresh cheese

Soft cheeses were manufactured from bovine milk with the addition of 0–12% sesame protein isolate (SPI) were utilised to investigate rheology, texture and microstructure at different stages of cheese making. SPI addition reduced the speed of milk fermentation, kappa-casein proteolysis of rennet and elongated the time of cheese curd formation. Renneted milk storage modulus G′60min was decreased and coagulation time increased with increasing SPI content. Low SPI supplements (4% and 8%) enhanced the hardness, cohesiveness, adhesiveness and gumminess of the soft cheese, while high SPI addition (12%) deteriorated the texture. In the cheese curd gel matrix, SPI distributed as specific SPI-gel clusters on the surface of curd fractures, stacked or fused with ball-shaped casein micelles and wrapped up to casein gel strands. In summary, SPI actively interacted with casein colloid throughout the cheese making process.

Studies on Membrane Processing of Sesame Protein Isolate and Sesame Protein Hydrolysate using Rotating Disk Module

Proteolytic enzyme modifications of sesame (Sesamum indicum L.) protein isolate produce a protein hydrolysate containing small peptides. These small peptides are mainly used for therapeutic applications. This work was carried out to fractionate protein hydrolysate into small peptides and large peptides fractions using ultrafiltration and to study the effect of different operating parameters to optimize the process. Membrane rotation reduces concentration polarization and enhances the permeate flux value and found to be more effective than stirrer rotation. Maximum rejection and minimum flux were observed at the isoelectric point of the protein. So, ultrafiltration is a potential route to produce sesame peptides of desired properties.

Preparation and characterization of papain-modified sesame (Sesamum indicum L.) protein isolates.

Defatted sesame meal ( approximately 40-50% protein content) is very important as a protein source for human consumption due to the presence of sulfur-containing amino acids, mainly methionine. Sesame protein isolate (SPI) is produced from dehulled, defatted sesame meal and used as a starting material to produce protein hydrolysate by papain. Protein solubility at different pH values, emulsifying properties in terms of emulsion activity index (EAI) and emulsion stability index (ESI), foaming properties in terms of foam capacity (FC) and foam stability (FS), and molecular weight distribution of the SPI hydrolysates were investigated. Within 10 min of hydrolysis, the maximum cleavage of peptide bonds occurred as observed from the degree of hydrolysis. Protein hydrolysates have better functional properties than the original SPI. Significant increase in protein solubility, EAI, and ESI were observed. The greatest increase in solubility was observed between pH 5.0 and 7.0. The molecular weight of the hydrolysates was also reduced significantly during hydrolysis. These improved functional properties of different protein hydrolysates would make them useful products, especially in the food, pharmaceutical, and related industries.

Effect of sesame seed protein supplementation on the nutritional, physical, chemical and sensory properties of wheat flour bread

Sesame products (sesame meal, roasted and autoclaved sesame meals, sesame protein isolate and concentrate) were added to red wheat flour to produce blends at protein levels of 14, 16, 18 and 20%. Dough properties were studied using a Brabender Farinograph. Loaves were prepared from the various blends using the straight dough procedure and then evaluated for volume, crust and crumb colour, crumb texture, flavour and overall quality. The water absorption, development time and dough weakening were increased ( P < 0.05) as the protein level increased in all blends; however, dough stability decreased. Sesame products could be added to wheat flour up to 18% protein level (sesame protein isolate) and up to 16% protein level (for other sesame products) without any observed detrimental effects on bread sensory properties. No significant differences ( P > 0.05) were recorded in loaf volume between control and breads containing sesame protein isolate (up to 18% protein level) and either autoclaved sesame meal or sesame protein concentrate (up to 14% protein level). Also, addition of these products increased the contents of protein, minerals, total essential amino acids, especially lysine, and also improved the in vitro protein digestibility and computed biological value.

Effect of sesame seed proteins supplementation on the nutritional, physical, chemical and sensory properties of wheat flour bread.

Sesame products (sesame meal, roasted and autoclaved sesame meal, sesame protein isolate and concentrate) were added to Red wheat flour to produce blends at protein levels of 14, 16, 18 and 20 percent. Dough properties were studied using a Brabender Farinograph. Loaves were prepared from the various blends using the straight dough procedure and then evaluated for volume, crust and crumb colour, crumb texture, flavour and overall quality. The water absorption, development time and dough weakening were increased (p < 0.05) as the protein level increased in all blends; however, dough stability decreased. Sesame products could be added to wheat flour up to 18 percent protein level (sesame protein isolate) and up to 16 percent protein level (other sesame products) without any observed detrimental effect on bread sensory properties. No significant differences (p > 0.05) were recorded in loaf volume between control and breads containing sesame protein isolate (up to 18 percent protein level) and either autoclaved sesame meal or sesame protein concentrate (up to 14 percent protein level). Addition of sesame products increased the content not only of protein but also minerals and total essential amino acids, especially lysine. The addition also improved in-vitro protein digestibility.