Spray drying and ultrasonication processing of camel whey protein concentrate: Characterization and impact on bioactive properties.

The production of whey protein concentrates (WPCs) from camel milk whey represents an effective approach to valorize this processing by-product. These concentrates harbor active ingredients with significant bioactive properties. Camel WPCs were spray-dried (SD) at inlet temperature of 170, 185 and 200°C, or Ultrasonicated (US) for 5, 10 and 15 min, then freeze-dried to obtain fine powder. The impact of both treatments on protein degradation was studied by sodium dodecyl sulfate-PAGE and reverse-phase ultraperformance liquid chromatography (RP-UPLC) techniques. Significantly enhanced protein degradation was observed after US treatment when compared with SD. Both SD and US treatments slightly enhanced the WPCs samples' antioxidant activities. The US exposure for 15 min exhibited highest 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity (12.12 mmol TE/g). Moreover, US treatment for 10 min exhibited the highest in vitro anti-diabetic properties (α-amylase and α-glucosidase inhibition), and dipeptidyl-peptidase-IV inhibitory activity among all samples. In addition, the ultrasonication for 10 min and SD at 170°C showed the lowest IC50 values for in vitro anti-hypercholesterolemic activities in terms of pancreatic lipase and cholesteryl esterase inhibition. Conclusively, these green techniques can be adapted in the preservation and processing of camel milk whey into active ingredients with high bioactive properties.

Dragon's Blood Sap Microencapsulation within Whey Protein Concentrate and Zein Using Electrospraying Assisted by Pressurized Gas Technology.

Dragon's blood sap (DBS) obtained from the bark of Croton lechleri (Müll, Arg.) is a complex herbal remedy of pharmacological interest due to its high content in polyphenols, specifically proanthocyanidins. In this paper, electrospraying assisted by pressurized gas (EAPG) was first compared with freeze-drying to dry natural DBS. Secondly, EAPG was used for the first time to entrap natural DBS at room temperature into two different encapsulation matrices, i.e., whey protein concentrate (WPC) and zein (ZN), using different ratios of encapsulant material: bioactive compound, for instance 2:1 w/w and 1:1 w/w. The obtained particles were characterized in terms of morphology, total soluble polyphenolic content (TSP), antioxidant activity, and photo-oxidation stability during the 40 days of the experiment. Regarding the drying process, EAPG produced spherical particles with sizes of 11.38 ± 4.34 µm, whereas freeze-drying produced irregular particles with a broad particle size distribution. However, no significant differences were detected between DBS dried by EAPG or freeze-drying in TSP, antioxidant activity, and photo-oxidation stability, confirming that EAPG is a mild drying process suitable to dry sensitive bioactive compounds. Regarding the encapsulation process, the DBS encapsulated within the WPC produced smooth spherical microparticles, with average sizes of 11.28 ± 4.28 µm and 12.77 ± 4.54 µm for ratios 1:1 w/w and 2:1 w/w, respectively. The DBS was also encapsulated into ZN producing rough spherical microparticles, with average sizes of 6.37 ± 1.67 µm and 7.58 ± 2.54 µm for ratios 1:1 w/w and 2:1 w/w, respectively. The TSP was not affected during the encapsulation process. However, a slight reduction in antioxidant activity measured by DPPH was observed during encapsulation. An accelerated photo-oxidation test under ultraviolet light confirmed that the encapsulated DBS showed an increased oxidative stability in comparison with the non-encapsulated DBS, with the stability being enhanced for the ratio of 2:1 w/w. Among the encapsulating materials and according to the ATR-FTIR results, ZN showed increased protection against UV light. The obtained results demonstrate the potential of EAPG technology in the drying or encapsulation of sensitive natural bioactive compounds in a continuous process available at an industrial scale, which could be an alternative to freeze-drying.

Complex coacervation and freeze drying using whey protein concentrate, soy protein isolate and arabic gum to improve the oxidative stability of chia oil.

BACKGROUND: Chia oil (CO) is popular for being the richest vegetable source of α-linolenic acid (60-66%). However, this content of polyunsaturated fatty acids (PUFA) limits the incorporation of bulk CO in food products due to its high probability of oxidation. This justifies the study of alternative wall materials for microencapsulation. No reports regarding the use of dairy protein/vegetable protein/polysaccharide blends as wall material for the microencapsulation of CO have been published. Therefore, this work analyzed the behavior of a whey protein concentrate (WPC)/soy protein isolate (SPI)/arabic gum (AG) blend as wall material. The complex coacervation (CC) process was studied: pH, 4.0; total solid content, 30% w/v; WPC/SPI/AG ratio, 8:1:1 w/w/w; stirring speed, 600 rpm; time, 30 min; room temperature. RESULTS: The oxidative stability index (OSI) of CO (3.25 ± 0.16 h) was significantly increased after microencapsulation (around four times higher). Furthermore, the well-known matrix-forming ability of AG and WPC helped increase the OSI of microencapsulated oils. Meanwhile, SPI contributed to the increase of the encapsulation efficiency due to its high viscosity. Enhanced properties were observed with CC: encapsulation efficiency (up to 79.88%), OSIs (from 11.25 to 12.52 h) and thermal stability of microcapsules given by the denaturation peak temperatures of WPC (from 77.12 to 86.00 °C). No significant differences were observed in the fatty acid composition of bulk and microencapsulated oils. CONCLUSION: Microcapsules developed from complex coacervates based on the ternary blend represent promising omega-3-rich carriers for being incorporated into functional foods.

Physicochemical and structural characterization of whey protein concentrate-tomato pectin conjugates.

BACKGROUND: Protein-pectin conjugates, obtained through a controlled Maillard reaction in blends of precursors, are studied for their contribution to improving the emulsifying and thermal properties of proteins. The objective was to obtain a conjugate between whey protein concentrate (WPC) and non-conventional pectins extracted in acid (acid tomato pectin, ATP) and aqueous medium (water tomato pectin, WTP) from industrialized tomato residues (tomato waste, TW), characterize the conjugates and study their emulsion properties. The Maillard reaction was carried out at 60 °C and 75% relative humidity in blends with 2:1 proportions; 1:1 and 1:2 (mprotein :mpectin ) for 3, 6 and 12 days. Conjugates were compared concerning treated and untreated WPC. RESULTS: The WPC-ATP conjugate showed significant increases in color difference (ΔE). The electrophoresis profile of the conjugates showed diffuse bands of molecular weight between 37 and 250 kDa and a reduction in the intensity of bands characteristic of WPC (α-lactalbumin and ß-lactoglobulin). Thermal analysis showed an increase in the peak temperature and a reduction in the enthalpy change in protein denaturation, associated with the formation of conjugates. The infrared spectroscopy of the conjugates, in the amide III zone (1300-1100 cm-1 ), indicated an increase in the relative peak area associated with the unfolding and exhibition of the hydrophobic zones of the WPC fraction. The emulsions formulated with the conjugates showed a significant increase in the emulsifying stability index (ESI) (P < 0.05) concerning the treated and untreated WPC emulsions. CONCLUSION: The formation of conjugates increased the emulsifying properties and improved the thermal stability of WPC, showing an innovative and alternative food ingredient too. © 2023 Society of Chemical Industry.

Incorporating oregano (Origanum vulgare L.) Essential oil onto whey protein concentrate based edible film towards sustainable active packaging.

The study's objectives were to develop a packaging film incorporating oregano essential oil, and evaluate the antioxidant, antibacterial, mechanical, and physicochemical activities of the film toward grapes packaging. The films were developed by casting method, after adding nano-emulsion of essential oil into WPC-glycerol film forming solution. The effects of the Oregano Essential Oil (OEO) at different concentrations of 1, 2, 3, and 4% (w/w) in the WPC edible films were studied. The light transmittance, colour aspects, water aspects, mechanical, antioxidant, antimicrobial activities, FTIR, SEM microstructure, and biodegradability of the film were studied. Acidity, weight, TSS, pH and 9-point hedonic sensory analysis of grapes packed in WPC-OEO film were evaluated. Results showed that 3% OEO incorporated WPC film displayed positive inhibition towards pathogenic bacteria; Staphylococcus aureus and Escherichia coli (25.36 ± 0.52-28.0 ± 0.5 mm), the antioxidant activity of 86.89 ± 0.087% and 51.24 ± 0.031% for DPPH, FRAP respectively and degradation after 10 days. The film displayed reduced light transmittance, lower water solubility (44.04 ± 2.361%) and prominent surface characteristics in SEM microstructure and FTIR spectra. The grapes packed in WPC-3% OEO film were firmer, had less surface colour change and showed negligible change in weight, pH, acidity, and Brix value throughout the storage period. Thus, the developed film displayed excellent antibacterial and antioxidant properties that potentially extended the quality of fresh grapes during refrigerated storage. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05763-7.

Effect of protein addition in properties of gels produced with jackfruit (Artocarpus integrifolia) seed starch: rheological and texture properties.

Starches and proteins are two major types of biopolymer components in many foods. The interactions of protein with starches greatly influence the matrix structure and properties of starch-based food systems. In this study, the physical-chemical properties and the effect of the commercial whey protein concentrate in the texture and rheological properties of jackfruit starch gels were evaluated. The experimental design was completely randomized, using a 4 × 4 complete factorial scheme, with four levels of starch (3, 6, 9 and 12%) and four levels of protein (0, 2, 4 and 6%). In higher concentrations of starch the addition of proteins delayed the beginning of gelatinization, led to an increase in G' and G″ and decrease in the tan (δ) values, characterizing the gel as strong, e.g., the gel network became more structured. However, in the treatment with 6% starch the addition of protein led to a decrease in gel strength. For gels with 9% starch the increase in protein concentration, led a slight increase in the hardness and cohesiveness, characterizing a more rigid and cohesive gel. Overall, gels with 3 and 6% of starch showed characteristic behavior of a weak gel and with 9 and 12% of strong gel. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05793-1.

Effect of CaCl2 on 2 heat-induced whey protein concentrate fibrillation pathways: Spontaneous and nuclear induction.

Amyloid fibrils have many excellent functional properties that facilitate their applications in the food industry. There are 2 pathways for whey protein concentrate (WPC) to form amyloid fibril aggregates: spontaneous pathway and nuclear induction pathway. Low ionic strength is a necessary condition for the spontaneous pathway to proceed successfully. In this paper, the effect of salt ions on 2 WPC fibrillation pathways was investigated by adding CaCl2. The results demonstrated WPC fibrils were unable to form normally through spontaneous pathway as adding CaCl2; but still could form through nuclear induction pathway with 20 to 30 mM CaCl2, the nuclei accelerated the fibrillation process led to the resistance to the disordered aggregation brought by CaCl2. Moreover, divalent cations (Ca2+, Mg2+) had much stronger effects than monovalent cations (Na+) on fibril formation, and the results of X-ray photoelectron spectrum together with Fourier-transform infrared spectroscopy suggested that Ca2+ had a greater effect on the fibril formation than Cl-.

Formation and characterization of noncovalent ternary complexes based on whey protein concentrate, high methoxyl pectin, and phenolic acid.

Protein-polysaccharide-polyphenol noncovalent ternary complexes possess unique physicochemical, structural, and functional properties. In the present study, ternary complexes based on whey protein concentrate (WPC; 2%, wt/vol) and high methoxyl pectin (HMP; 0.5%, wt/vol) complexes and 0.2 to 0.6% (wt/vol) chlorogenic acid (CA) or rosmarinic acid (RA) were formed and characterized at 3 pH values (4, 4.5, and 5). The pH conditions were decided according to phase diagram of WPC and HMP during acidification. Fluorescence quenching experiments indicated that WPC-HMP complexes bound RA stronger than CA and the binding constant increased with increasing pH for both phenolic acids. Particle size of ternary complexes decreased and absolute ζ-potential increased with pH values changing from 4 to 5, and RA influenced the particle size of WPC-HMP complexes greater than CA. The CA and RA in ternary complexes showed good stability against UV light with pH order of pH 5 > pH 4.5 > pH 4. Fourier-transform infrared spectroscopy spectra indicated the involvement of hydrogen bonding between WPC-HMP and CA or RA. Antibacterial tests showed that ternary complexes had good antibacterial activity against Staphylococcus aureus and Escherichia coli at concentrations of 6.2 mg/mL and the ability increased with decreasing pH values. All ternary complexes possessed strong scavenging radical capacities with median inhibitory concentration (IC50) values ranging from 2.71 ± 0.05 to 6.20 ± 0.41 µg/mL. Antioxidative ability of ternary complexes increased as pH went up and WPC-HMP-RA showed significantly higher antioxidative property compared with WPC-HMP-CA. Data may provide useful information for rational design of ternary complexes and applications of the formed complexes in food matrices such as beverages and emulsions.

Characterization of encapsulated γ-oryzanol powder by spray drying using whey protein and maltodextrin as wall materials.

Characterizations of encapsulated γ-oryzanol powder (EOP) using whey protein concentrate (WPC) and maltodextrin as wall materials were studied. Rice bran oil (RBO) with 2% γ-oryzanol was encapsulated using different concentrations of WPC (0.2-1.0%) combined with 10% of maltodextrin before spray drying. The physicochemical characteristics and reconstitution of EOP were investigated. The results found that different concentrations of WPC affected EOP characteristics. The EOP coated 1% WPC exhibited low moisture content and water activity (aw) containing high γ-oryzanol content and encapsulation efficiency. Morphology of EOP using SEM displayed spheroid shape with smooth and crack-free surface. However, EOP emulsion had relatively larger particle size and lower solubility index than the fresh emulsion after reconstitution, but a good creaming stability of reconstituted EOP was observed. Therefore, it can be concluded that using 1% WPC combined with 10% maltodextrin provided good performance of encapsulated RBO with 2% γ-oryzanol using spray drying. According to physicochemical characteristics, the EOP has good potential as a food ingredient for food industry and as an excipient for pharmaceutical and cosmetic industries.

Effect of incorporation of iron-whey protein concentrate (Fe-WPC) conjugate on physicochemical characteristics of dahi (curd).

Dahi samples were prepared from milk incorporated with spray-dried iron-whey protein concentrate (Fe-WPC) conjugate and ferrous sulfate (FeSO4) with three different concentrations of iron i.e. 15, 20 and 25 mg/L and their quality characteristics were determined. Fe-WPC conjugate incorporated dahi showed better sensory, textural and physical attributes as compared with those of FeSO4 fortified and control dahi. Non-significant (p > 0.05) changes were observed in attributes like acidity and flavor, color and appearance, body and texture scores of dahi fortified with Fe-WPC conjugate with upto 20 mg/L iron as compared to those of control. In contrast, definite metallic flavor was perceptible in case of FeSO4 incorporated dahi even at 15 mg/L level. Water holding capacity, viscosity and firmness were significantly (p < 0.05) higher in 20 mg/L Fe-WPC conjugate incorporated dahi samples as compared with those of 20 mg/L FeSO4 incorporated dahi samples. In vitro bio accessibility of iron from Fe-WPC conjugate incorporated dahi was found to be significantly (p < 0.05) higher than that from FeSO4 incorporated dahi. Therefore, the results indicated that Fe-WPC conjugate can be fortified in dahi with upto 20 mg/L without significantly altering its physicochemical properties and with a higher bioaccessibillity of iron.

Significance of whey protein hydrolysate on anti-oxidative, ACE-inhibitory and anti-inflammatory activities and release of peptides with biofunctionality: an in vitro and in silico approach.

The study aimed to investigate potent antioxidant activities (ABTS assay, Hydroxyl free radical scavenging assay, and Superoxide free radical assay), ACE inhibitory activity, and anti-inflammatory activity in the WPC (whey protein concentrate) hydrolysate using Alcalase. The hydrolysis conditions (addition rate and incubation times) for peptide synthesis were also optimized using proteolytic activity. The generation of proinflammatory cytokines by lipopolysaccharide-treated murine macrophages was reduced when the protein hydrolysate concentration was low. In comparison to unhydrolyzed WPC, SDS-PAGE examination revealed no protein bands in WPC hydrolysates. Two-Dimensional (2D) gel electrophoresis did not show any protein spots. Using the 'In-solution trypsin digestion' approach, the trypsin digested protein samples were put into RPLC/MS for amino acid sequencing. Peptides were also identified using RPLC/MS on fractions of 3 and 10 kDa permeates and retentates. The MASCOT database was used to look up the raw masses of LC/MS. By comparing hydrolyzed whey protein to the BLASTp (NCBI), PIR, BIOPEP, and AHTPDB databases, novel antioxidative and ACE inhibitory peptides were reported. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05282-3.

Effect of liquid whey protein concentrate-based edible coating enriched with cinnamon carbon dioxide extract on the quality and shelf life of Eastern European curd cheese.

Fresh unripened curd cheese has long been a well-known Eastern European artisanal dairy product; however, due to possible cross-contamination from manual production steps, high moisture content (50-60%), and metabolic activity of present lactic acid bacteria, the shelf life of curd cheese is short (10-20 d). Therefore, the aim of this study was to improve the shelf life of Eastern European acid-curd cheese by applying an antimicrobial protein-based (5%, wt/wt) edible coating. The bioactive edible coating was produced from liquid whey protein concentrate (a cheese production byproduct) and fortified with 0.3% (wt/wt, solution basis) Chinese cinnamon bark (Cinnamomum cassia) CO2 extract. The effect of coating on the cheese was evaluated within package-free (group 1) and additionally vacuum packaged (group 2) conditions to represent types of cheeses sold by small and big scale manufacturers. The cheese samples were examined over 31 d of storage for changes of microbiological (total bacterial count, lactic acid bacteria, yeasts and molds, coliforms, enterobacteria, Staphylococcus spp.), physicochemical (pH, lactic acid, protein, fat, moisture, color change, rheological, and sensory properties). The controlled experiment revealed that in group 1, applied coating affected appearance and color by preserving moisture and decreasing growth of yeasts and molds during prolonged package-free cheese storage. In group 2, coating did not affect moisture, color, or texture, but had a strong antimicrobial effect, decreasing the counts of yeasts and molds by 0.79 to 1.55 log cfu/g during 31 d of storage. In both groups, coating had no effect on pH, lactic acid, protein, and fat contents. Evaluated sensory properties (appearance, odor, taste, texture, and overall acceptability) of all samples were similar, indicating no effect of the coating on the flavor of curd cheese. The edible coating based on liquid whey protein concentrate with the incorporation of cinnamon extract was demonstrated to efficiently extend the shelf life of perishable fresh curd cheese, enhance its functional value, and contribute to a more sustainable production process.

Effect of pullulan concentration and pH on the interactions between whey protein concentrate and pullulan during gelation.

BACKGROUND: Whey protein concentrate (WPC)/pullulan (PUL) hydrogel is applied as a microencapsulation wall material to protect probiotics. However, the interactions between WPC and PUL during gelation have not been clarified. In the present study, the effects of PUL concentration and pH on the interactions between WPC and PUL during gelation were evaluated with respect to appearance, zeta-potential, sulfhydryl group amount, surface hydrophobicity and infrared spectroscopy measurements. The rheological properties of WPC/PUL gels were also determined. RESULTS: The results obtained showed that a proper concentration (0.40 g mL-1 ) of PUL could improve the gel by enhancing the strength of hydrogen bonding, electrostatic interactions and exposure of hydrophobic groups, whereas too much PUL inhibited the formation of disulfide bonds. Furthermore, hydrophobic interactions, disulfide bonds and hydrogen bonds were destroyed in varying degrees under an alkaline environment. The rheological results also demonstrated a similar effect of PUL concentration and pH on the storage modulus (G') of WPC/PUL gels. CONCLUSION: When the WPC/PUL gel was formed at PUL concentration of 0.40 g mL-1 and pH 7.0, the interaction between WPC and PUL could be enhanced, which is beneficial for the future application of WPC/PUL gels in the food industry. © 2020 Society of Chemical Industry.

Toxicity study and blood pressure-lowering efficacy of whey protein concentrate hydrolysate in rat models, plus peptide characterization.

We evaluated the acute (single-dose) and subacute (repeated-dose) oral toxicity of alcalase-hydrolyzed whey protein concentrate. Our acute study revealed no death or treatment-related complications, and the median lethal dose of whey protein concentrate hydrolysate was >2,500 mg/kg. In the subacute study, when the hydrolysate was fed at 3 different concentrations (200, 400, and 800 mg/kg), no groups showed toxicity changes compared with controls. Then, whey protein concentrate hydrolysate was orally administered to spontaneously hypertensive rats. Results revealed significant reductions in blood pressure in a dose-dependent manner, and dosing at 400 mg/kg led to significant blood pressure reduction (-47.8 mm Hg) compared with controls (blood pressure maintained) and the findings of previous work (-21 mm Hg). Eight peptides-RHPEYAVSVLLR, GGAPPAGRL, GPPLPRL, ELKPTPEGDL, VLSELPEP, DAQSAPLRVY, RDMPIQAF, and LEQVLPRD-were sequentially identified and characterized. Of the peptides, VLSELPEP and LEQVLPRD showed the most prominent in vitro angiotensin-I converting enzyme inhibition with half-maximal inhibitory concentrations of 0.049 and 0.043 mM, respectively. These findings establish strong evidence for the in vitro and in vivo potential of whey protein concentrate hydrolysate to act as a safe, natural functional food ingredient that exerts antihypertensive activity.

Phospholipid analysis in whey protein products using hydrophilic interaction high-performance liquid chromatography-evaporative light-scattering detection in an industry setting.

The main objective of this work was to develop an analytical method that can be used in a dairy manufacturing facility for the quantitation of phospholipids in dairy products. Total lipids from a dairy matrix were obtained first by Folch extraction. The total lipid extract was then applied to a silica gel-based solid-phase extraction column, and triglycerides and other nonpolar lipids were separated from the phospholipids and sphingolipids. Quantitation was performed by hydrophilic interaction HPLC coupled to evaporative light-scattering detection using a quaternary separation method. The method was validated using a commercial whey protein phospholipid concentrate and was used to analyze phospholipid and sphingolipid composition in buttermilk, whey protein concentrate, whey protein phospholipid concentrate, and several other dairy ingredients. This method was sensitive and reproducible and can be used in the dairy industry as a research tool to develop new value-added dairy phospholipid products, then later as a standard protocol for quality assurance analysis of current and future products.

Comparative experiments of electrical conductivity from whey protein concentrates conventional film and nanofibril film.

We compared the electrical conductivity from two different aggregates of whey protein concentrates (WPC) film: conventional amorphous aggregation at natural pH (pH 6.5) and amyloid fibrils at a low pH (pH 2.0) far away from the isoelectric point. The two types of film fabricated by these solutions with different aggregate structures showed large variations in electrical conductivity and other properties. The WPC fibril film (pH 2.0) exhibited higher electrical conductivity than that of the conventional WPC film (pH 6.5), improved mechanical properties and oil resistance, due to varying morphology, higher surface hydrophobicity and more (absolute value) surface charge of film-forming solutions. The evidence from this study suggests that fibrilized WPC with high-ordered and ß-sheets-rich structures fabricated high electrical conductivity film, which broadens the potential application of fibrils as functional bio-nanomaterials.

In Vitro Induction of Trained Innate Immunity by bIgG and Whey Protein Extracts.

Bovine immunoglobulin G (bIgG) was previously shown to enhance innate immune responses to toll-like receptor (TLR) stimulation, via induction of trained immunity. In this study, we investigated whether minimally processed dairy streams with high levels of whey proteins as potential infant nutrition ingredients could also induce trained immunity, and to what extent this can be explained by the presence of bIgG. The minimally processed whey ingredients serum protein concentrate (SPC) and whey protein concentrate (WPC) were tested for their ability to induce trained immunity in human peripheral blood monocytes. Both ingredients induced trained immunity as evidenced by an increased production of TNF-α and, to a lesser extent, of IL-6 upon stimulation with TLR ligands. This was comparable to isolated bovine immunoglobulin G (bIgG) that served as positive control. Depletion of bIgG from both whey protein-containing ingredients did not significantly inhibit the induction of trained immunity, suggesting that the streams contain other components in addition to bIgG that are able to induce trained immunity. These results indicate that minimally processed whey ingredients may contribute to protection against infections through enhancing innate immune responsiveness to pathogens.

Structure and stability of W1/O/W2 emulsions as influenced by WPC and NaCl in inner aqueous phase.

Effect of WPC and NaCl in internal aqueous phase (W1) of W1/O/W2 type double emulsions was studied. Pre-emulsion and final emulsion were prepared using microfluidizer and Ultra-Turrax high shear mixer, respectively. The emulsions prepared using salt exhibited uniform droplet size distribution and structural integrity. WPC at 6% and NaCl at 2 or 4% levels demonstrated better sedimentation stability (> 99%) and encapsulation stability (> 95%) during preparation and storage of double emulsions. Samples without added NaCl showed poor emulsion stability and structural integrity. Higher level of WPC i.e. 8% resulted in poor stability and encapsulation efficiency of double emulsions at all salt levels. Combined use of optimum levels of WPC and NaCl along with processing interventions resulted in stable double emulsions even after storage at room temperature for 10 days. This study highlights the fact that structural integrity of internal aqueous phase (W1) depends upon presence of osmotic agent i.e. salt and stabilising proteins i.e. WPC.

Pearl millet protein bar: nutritional, organoleptic, textural characterization, and in-vitro protein and starch digestibility.

Pearl millet, a nutritionally remarkable cereal with a sustainable yield in the grey regions of India, is not consumed much. Consumption of Nutrition bars has gained momentum in recent years and considering this, in the present study pearl millet-based protein bars are formulated to increase its consumption rate and establish it as a reliable source of protein and other nutrients. The proximate and mineral composition of the three variants of pearl millet incorporated (25, 27.5, 30%) protein bars were analyzed using standard protocols. The acceptability of the bars was assessed using the 9-point hedonic scale among twenty panelists. The textural parameters were measured by Perten TVT 6700 Texture Analyzer. The in-vitro digestibility of protein (IVPD) and starch (IVSD) of the best variant was also estimated. The bars provide 15.74-18.32 g of protein, 332-379 kcal energy, 74.53-83.87 mg calcium, and 555.93-603.80 mg phosphorous per 100 g. The results showed that the organoleptic parameters of the bars were not affected by the proportion of ingredients. Whereas the increase in pearl millet incorporation marginally increased textural properties such as hardness, cohesiveness, and chewiness. The IVPD of the selected variant is 75.65 ± 0.02% and IVSD revealed 252.00 ± 10.00 mg of maltose is released per 100 g of the sample. The protein bars are nutritionally beneficial and appealing. This study gives scope for the production of pearl millet-based convenience foods that will raise the consumption pattern of pearl millet at the household level.

Spray-Dried Whey Protein Concentrate-Iron Complex: Preparation and Physicochemical Characterization.

Poor absorption of iron from food and oral iron formulations results in extensive use of high-dose oral iron, which is not tolerated. Disposal of whey, a byproduct of the cheese industry, causes environmental pollution. Whey proteins have the ability to bind significant amount of iron, thereby reducing its chemical reactivity and incompatibility with other components in foods. To make iron compatible with food, it was complexed with whey protein concentrate (WPC). After complexation, centrifugation and ultrafiltration techniques were utilised to eliminate the insoluble and free iron from the solution. To enable the availability of whey protein concentrate-iron (WPC-Fe) complex in the powder form, spray drying technique was used. Optimized spray drying conditions used for the preparation were: inlet temperature 180 °C, flow rate 2.66 mL/min and solution of total solids 15%. The complex was observed to be stable under different processing conditions. The in vitro bioaccessibility (iron uptake) of the bound iron from the WPC-Fe complex was significantly higher (p<0.05) than that from iron(II) sulphate under simulated gastrointestinal conditions. WPC-Fe complex with improved iron bioaccessibility could safely substitute iron fortificants in different functional food preparations.