Instability of Pressure-Treated Reconstituted Skim Milk to Acidification

When high-pressure (HP)-treated reconstituted skim milks (200–600 MPa/5–30 min) were acidified with glucono-δ-lactone, the elastic modulus (G′) displayed atypical behaviour with pH, increasing as the pH decreased between 6.0 and 5.3, indicating that a weak gel had formed as soon as the pH of the milk decreased. The formation of a weak gel at pH 6.0 to 5.3 indicates that HP milks are more unstable to acidification than untreated or heated milks; this effect has not been previously reported. Untreated and heated (90 °C/30 min) milks did not show an increase in G′ until the pH was below 4.9 and 5.3, respectively. Frequency sweeps confirmed that the HP-treated milks formed weak gels at pH much higher than where typical acid gelation of milk occurs. Microstructural and particle size analyses indicated that the HP-treated milks started aggregating as soon as the pH declined whereas the heated milks did not aggregate until the pH was below 5.5. Heat treatment of milk either before or after HP treatment completely eliminated the weak gelation as these samples did not form gels until the pH decreased below pH 5.3. It is apparent that the restructured colloidal particles formed when milk is HP treated are unstable to acidification, and it is proposed that the redistributed κ-casein cannot stabilize these particles when the milk is acidified. The role of denatured whey proteins in the weak gelation phenomenon is unclear.     

Whey Protein/Polysaccharide-Stabilized Oil Powders for Topical Application—Release and Transdermal Delivery of Salicylic Acid from Oil Powders Compared to Redispersed Powders

Oil-in-water (o/w) emulsions are commonly converted into solid-like powders in order to improve their physical and chemical stabilities. The aim of this study was to investigate whether whey protein/polysaccharide-stabilized o/w emulsions could be converted into stable oil powders by means of freeze-drying. Moreover, during this study, the effects of pH and polymer type on release and trans(dermal) delivery of salicylic acid, a model drug, from these oil powders were investigated and compared to those of the respective template emulsions and redispersed oil powders. Physical characterization of the various formulations was performed, such as droplet size analysis and oil leakage, and relationships drawn with regards to release and trans(dermal) delivery. The experimental outcomes revealed that the oil powders could be redispersed in water without changing the release characteristics of salicylic acid. pH and polymer type affected the release of salicylic acid from the oil powders, template emulsions, and redispersed powders similarly. Contrary, the transdermal delivery from the oil powders and from their respective redispersed oil powders was differently affected by pH and polymer type. It was hypothesized that the release had been influenced by the electrostatic interactions between salicylic acid and emulsifiers, whereas the transdermal performance could have been determined by the particle or aggregate sizes of the formulations.KEY WORDS: carrageenan, chitosan, oil powders, release, salicylic acid, topical delivery, whey proteins     

Development and Optimisation of Spironolactone Nanoparticles for Enhanced Dissolution Rates and Stability

Stable solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) formulations to enhance the dissolution rates of poorly soluble drug spironolactone (SP) were being developed. Probe ultra-sonication method was used to prepare SLNs and NLCs. All NLCs contained stearic acid (solid lipid carrier) and oleic acid (liquid lipid content), whereas, SLNs were prepared and optimised by using the solid lipid only. The particles were characterised in terms of particle size analysis, thermal behaviour, morphology, stability and in vitro release. The zeta sizer data revealed that the increase in the concentration of oleic acid in the formulations reduced the mean particle size and the zeta potential. The increase in concentration of oleic acid from 0 to 30% (w/w) resulted in a higher entrapment efficiency. All nanoparticles were almost spherically shaped with an average particle size of about ～170 nm. The DSC traces revealed that the presence of oleic acid in the NLC formulations resulted in a shift in the melting endotherms to a higher temperature. This could be attributed to a good long-term stability of the nanoparticles. The stability results showed that the particle size remained smaller in NLC compared to that of SLN formulations after 6 months at various temperatures. The dissolution study showed about a 5.1- to 7.2-fold increase in the release of the drug in 2 h compared to the raw drug. Comparing all nanoparticle formulations indicated that the NLC composition with a ratio of 70:30 (solid:liquid lipid) is the most suitable formulation with desired drug dissolution rates, entrapment efficiency and physical stability.     

The development of transgenic mice for the expression of large amounts of human lysozyme in milk

Human lysozyme (hLYZ) has important potential applications as antimicrobial medicine and food additive. To develop a robust expression vector that ensures expression of large amounts of hLYZ in milk, here a 26,267 bp chimeric mouse whey acidic protein (mWAP)::hLYZ cassette was constructed and used as a mammary gland-specific expression vector, in which a 3,010 bp genomic sequence in the 24,466 bp mWAP gene locus was substituted by a 4,811 bp genomic sequence of hLYZ, exactly from the start codon to the stop codon. Corresponding transgenic mice were generated, and enzymatically-active hLYZ was expressed at 18.4–35 g l^?1 in the milk of most transgenic mouse lines. Our transgenic mice carrying chimeric mWAP::hLYZ represent a model system for cost-effective production of hLYZ.     

Encapsulation of β-carotene in Nanoemulsion-Based Delivery Systems Formed by Spontaneous Emulsification: Influence of Lipid Composition on Stability and Bioaccessibility

Nanoemulsion-based delivery systems are finding increasing use in food, pharmaceutical, agrochemical, and personal care applications due to their ability to increase the stability and/or activity of lipophilic functional components. In this study, a low-energy homogenization method (spontaneous emulsification) was used to encapsulate β-carotene in nanoemulsions. The main objective was to optimize lipid phase composition to form stable nanoemulsions that would effectively enhance β-carotene bioavailability. Lipid phase composition was varied by mixing long chain triglycerides (LCT) with medium chain triglycerides (MCT) or flavor oil (orange oil). LCT was added to promote bioaccessibility, whereas MCT or orange oil was added to facilitate nanoemulsion formation. Our hypothesis was that an optimum level of LCT is required to form stable nanoemulsions with good bioaccessibility characteristics. Stable nanoemulsions could be formed at LCT-to-orange oil ratios of 1:1 (d ₃₂ = 109 nm) and at LCT-to-MCT ratios of 1:2 (d ₃₂ = 145 nm). Thus, higher LCT loading capacities and smaller droplet sizes could be obtained using orange oil. The influence of oil composition on the potential gastrointestinal fate of the nanoemulsions was studied using a simulated gastrointestinal tract (GIT) consisting of mouth, stomach, and small intestine phases. The transformation and bioaccessibility of β-carotene in the GIT was highly dependent on lipid phase composition. In particular, β-carotene bioaccessibility increased with increasing LCT level due to greater solubilization in mixed micelles. These results are useful for optimizing the design of nanoemulsion-based delivery systems for encapsulation and release of lipophilic nutraceuticals and pharmaceuticals.     

Encapsulation of Bixin with High Amylose Starch as Affected by Temperature and Whey Protein

Microencapsulation of bixin using high-amylose corn starch was carried out by the acidification method. Bixin powders were characterized by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), FT-IR spectrometry, color parameters, encapsulation efficiency, bixin release profile. In addition, the effect of whey protein (WP) on the microencapsulation process was investigated. The results obtained from DSC, X-ray diffraction and FT-IR spectrometry indicated that only in the samples prepared at 90 °C (B0WP90°C, B10WP90°C, and B20WP90°C) there was formation of crystalline structures, with melting temperatures at 117.2°, 105° and 104 °C, respectively. The possible interactions between bixin, WP and amylose starch are also discussed.     

Simultaneous single-cell protein production and COD removal with characterization of residual protein and intermediate metabolites during whey fermentation by K. marxianus

Cheese whey fermentation with Kluyveromyces marxianus was carried out at 40 °C and pH 3.5 to examine simultaneous single-cell protein production and chemical oxygen demand (COD) removal, determine the fate of soluble whey protein and characterize intermediate metabolites. After 36 h of batch fermentation, the biomass concentration increased from 2.0 to 6.0 g/L with 55 % COD reduction (including protein), whereas soluble whey protein concentration decreased from 5.6 to 4.1 g/L. It was confirmed through electrophoresis (SDS-PAGE) that the fermented whey protein was different from native whey protein. HPLC and GC–MS analysis revealed a change in composition of organic compounds post-fermentation. High inoculum concentration in batch fermentation resulted in an increase in biomass concentration from 10.3 to 15.9 g/L with 80 % COD reduction (including protein) within 36 h with residual protein concentration of 4.5 g/L. In third batch fermentation, the biomass concentration increased from 7.3 to 12.4 g/L with 71 % of COD removal and residual protein concentration of 4.3 g/L after 22 h. After 22 h, the batch process was shifted to a continuous process with cell recycle, and the steady state was achieved after another 60 h with biomass yield of 0.19 g biomass/g lactose and productivity of 0.26 g/L h. COD removal efficiency was 78–79 % with residual protein concentration of 3.8–4.2 g/L. The aerobic continuous fermentation process with cell recycle could be applied to single-cell protein production with substantial COD removal at low pH and high temperature from cheese whey.     

A PROCEDURE FOR THE PURIFICATION OF BETA-LACTOGLOBULIN FROM BOVINE MILK USING GEL FILTRATION CHROMATOGRAPHY AT LOW pH

A simple and rapid procedure for the purification of beta-lactoglobulin (β-LG) from bovine milk is described. The procedure exploits the major difference in molecular mass of β-LG and other whey components and the existence of the former in monomeric form at acidic pH. Gel filtration of whey was carried out using a Bio-Gel P10 column at pH 3.0. Residual caseins and other milk proteins were excluded from the gel and β-LG and alpha-lactalbumin (α-LA) emerged as two fully resolved peaks. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) suggested that β-LG was purified to apparent homogeneity, while absorption, fluorescence, and circular dichroism spectroscopy indicated the native-like conformation of the protein. Western blot analysis revealed that the antibodies raised against the purified β-LG in rabbits also readily react with the commercial bovine protein. This procedure requires only 4–5 hr for the purification of about 10 mg of β-LG from a single run while using a small column (2.3 cm × 83 cm) of Bio-Gel P10 and has the potential for scaling up.     

Formation,Stability and In Vitro Digestion of β-carotene in Oil-in-Water Milk Fat Globule Membrane Protein Emulsions

The formation, stability and in vitro digestion of milk fat globule membrane (MFGM) proteins stabilized emulsions with 0.2 wt% β-carotene were investigated. The average particle size of β-carotene emulsions stabilized with various MFGM proteins levels (1%, 2%, 3%, 4%, 5% wt%) decreased with the increase of MFGM proteins levels. When MFGM proteins concentration in emulsions is above 2%, the average particle size of β-carotene emulsions is below 1.0 μm. A quite stable emulsion was formed at pH 6.0 and 7.0, but particle size increased with decrease in acidity of the β-carotene emulsion. β-carotene emulsions stabilized with MFGM proteins were stable with a certain salt concentrations (0–500 mMNaCl). β-carotene emulsions were quite stable to aggregation of the particles at elevated temperature and time (85 °C for 90 min). At the same time, β-carotene emulsions were stable against degradation under heat treatment conditions. In vitro digestion of β-carotene emulsion showed the mean particle size of β-carotene emulsions stabilized with MFGM proteins in the simulated stomach conditions and intestinal conditions is larger than that of initial emulsions and simulated mouth conditions. Confocal laser scanning microscopy of β-carotene MFGM proteins emulsions also showed the corresponding results to different vitro digestion model. There was a rapid release of free fatty acid (FFA) during the first 10 min and after this period, an almost constant 70% digestion extent was reached. Approximately 80% of β-carotene was released within 2 h of incubation under the simulated intestinal fluid. These results showed that MFGM protein can be used as a good emulsifier in emulsion stabilization, β-carotene rapid release as well as lipophilic bioactive compounds delivery.     

Effect of Sodium Alginate Addition on Physical Properties of Rennet Milk Gels

Effect of addition of sodium alginate (alginate) to milk on the storage modulus (G′), water holding capacity (WHC) and hardness of rennet gels was evaluated as a function of alginate (0–0.25 g/100 g) and fat (0.5–3.0 g/100 g) concentrations. There was a significant effect of alginate addition on ionic calcium in milk and whey (Ca²⁺), and particle size distribution in alginate added milk. Results showed a positive correlation of alginate with WHC; negative correlation of alginate and positive correlation of fat with G′; and negative correlation of interaction of fat and alginate with gel hardness of rennet gels. Hence, the rennet gels with lower fat content and higher added alginate tended to be softer due to the high water holding capacity of the alginate particles.     

Effect of Pectin Type on Association and pH Stability of Whey Protein—Pectin Complexes

The purpose of this study was to investigate the influence of pectin type on complex formation between whey protein isolate (WPI) and high methoxy pectins with varying degrees of esterification (DE), and their pH stability. The biopolymer particles with protein-to-polysaccharide mass ratio set to 2:1 were formed at pH 3–7 by heating at 85 °C for 20 min. The particle size, electrical charge, turbidity and microstructure of the biopolymer complexes were evaluated. The optimal conditions for forming WPI-pectin complexes were at the initial pH of 4.5–4.75, just below the isoelectric point of the WPI, where complex formation occurs. At this pH range, the smallest biopolymer complexes (d?=?225–300 nm) could be created. Pectins with 50, 55, 62 and 70 % DE formed relatively small and monomodal complexes with WPI, except for pectin with 71 % DE, which showed major aggregation. The pH stability against aggregation was best with the biopolymer complexes assembled from pectins with 50 % DE (stable at pH 3.5–6.0) and with 62 % DE (stable at pH 3.0–6.0). The results suggest that pectins with varying DE can be used to form small particles and therefore can offer new possibilities in designing novel hierarchical structures and delivery systems.     

Using Goat’s Milk,Barley Flour,Honey, and Probiotic to Manufacture of Functional Dairy Product

Stirred yogurt manufactured using probiotic culture which usually called Rayeb milk in the Middle East region is one of the most important functional fermented milk products. To increase the health and functionality properties to this product, some ingredients like fruits, cereal, and whey protein are used in production. This study was carried out to prepare functional Rayeb milk from goat’s milk, barley flour (15%) and honey (4%) mixtures using ABT culture. Also, vanilla and cocoa powder were used as flavorings. Adding barley flour and honey to goat’s milk increased curd tension and water-holding capacity and decreased coagulation time and susceptibility to syneresis. The values of carbohydrate, total solids, dietary fiber, ash, total protein, water soluble nitrogen, total volatile fatty acids, unsaturated fatty acids, oleic, linoleic, α-linolenic acids, and antioxidant activity were higher in Rayeb milk supplemented with barley flour and honey than control. The viabilities of Lactobacillus acidophilus and Bifidobacterium lactis Bb12 (Chr. Hansen’s Lab A/S) increased in fortified Rayeb milk. The recommended level of 10⁷ cfu g^?1 of bifidobacteria as a probiotic was exceeded for these samples. Addition of vanilla (0.1%) or cocoa powder (0.5%) improved the sensory properties of fortified Rayeb milk.     

EXTRACELLULAR LIPOLYTIC ENZYME ACTIVITY OF A NEWLY ISOLATED DEBARYOMYCES HANSENII

A strain isolated from waste of a milk products plant and exhibited extracellular lipolytic activity was identified as Debaryomyces hansenii by 5.8S rRNA and 28S rRNA gene sequence analyses. Lipolytic activity was assayed spectrophotometrically by using p-nitrophenylpalmitate. Higher specific lipolytic activities were obtained in the presence of tristearin (0.68 U/mg prot), oleic acid (0.56 U/mg prot), and soybean oil (0.36 U/mg prot) than other triglycerides, fatty acids, and vegetable oils considered as carbon sources. Cheese whey appeared to be a good alternative to lipidic substances for lipolytic activity. Among various organic and inorganic nitrogen sources, soy flour was found to attain the lipolytic activity similar to that provided by universal yeast medium components. This work is the first report on the discussion of lipolytic activity enhancement by D. hansenii through modulating the cultivation medium. It also proposes low cost medium nutrients that could be of industrial value and could serve as basal nutrients for further optimization studies on the lipase production by D. hansenii.     

Bioconversion of cheese whey permeate into fungal oil by <Emphasis Type="Italic">Mucor circinelloides</Emphasis>

Background

Oleaginous fungi are efficient tools to convert agricultural waste streams into valuable components. The filamentous fungus Mucor circinelloides was cultivated in whey permeate, a byproduct from cheese production, to produce an oil-rich fungal biomass. Response surface methodology was used to optimize the fermentation conditions such as pH and temperature for increased biomass yield and lipid accumulation. Quantification and characterization of the fungal biomass oil was conducted.

Results

Upstream lactose hydrolysis of the whey permeate increased the biomass yield from 2.4 to 7.8 (g dry biomass/L) compared to that of non-hydrolyzed whey permeate. The combination of low pH (4.5) and pasteurization minimized microbial competition, thus favoring fungal growth. A central composite rotatable design was used to evaluate the effects of temperature (22.4–33.6 °C) and a lower pH range (3.6–4.7) on biomass yield and composition. The highest biomass yield and oil content was observed at high temperature (33.6 °C), while the pH range evaluated had a less pronounced effect. The predictive model was validated at the optimal conditions of 33.6 °C and pH 4.5. The fungal biomass yield plateaued at 9 g dry cell weight per liter, while the oil content and lipid yield reached a maximum of 24% dry biomass and 2.20 g/L, respectively, at 168 h. Triacylglycerides were the major lipid class (92%), which contained predominantly oleic (41%), palmitic (23%), linoleic (11%), and γ-linolenic acid (9%).

Conclusions

This study provided an alternative way of valorization of cheese whey permeate by using it as a substrate for the production of value-added compounds by fungal fermentation. The fatty acid profile indicates the suitability of M. circinelloides oil as a potential feedstock for biofuel production and nutraceutical applications.

     

Phase Behaviour and Formation of Fatty Acid Esters Nanoemulsions Containing Piroxicam

Fatty acid esters are long-chain esters, produced from the reaction of fatty acids and alcohols. They possess potential applications in cosmetic and pharmaceutical formulations due to their excellent wetting behaviour at interfaces and a non-greasy feeling when applied on the skin surfaces. This preliminary work was carried out to construct pseudo-ternary phase diagrams for oleyl laurate, oleyl stearate and oleyl oleate with surfactants and piroxicam. Then, the preparation and optimization study via ‘One-At-A-Time Approach’ were carried out to determine the optimum amount of oil, surfactants and stabilizer using low-energy emulsification method. The results revealed that multi-phase region dominated the three pseudo-ternary phase diagrams. A composition was chosen from each multi-phase region for preparing the nanoemulsions systems containing piroxicam by incorporating a hydrocolloid stabilizer. The results showed that the optimum amount (w/w) of oil for oleyl laurate nanoemulsions was 30 and 20 g (w/w) for oleyl stearate nanoemulsions and oleyl oleate nanoemulsions. For each nanoemulsions system, the amount of mixed surfactants and stabilizer needed for the emulsification to take place was found to be 10 and 0.5 g (w/w), respectively. The emulsification process via high-energy emulsification method successfully produced nano-sized range particles. The nanoemulsions systems passed the centrifugation test and freeze–thaw cycle with no phase failures, and stable for 3 months at various storage temperatures (3°C, 25°C and 45°C). The results proved that the prepared nanoemulsions system cannot be formed spontaneously, and thus, energy input was required to produce nano-sized range particles.     

Immunodetection of added glycomacropeptide in milk formulas and milk powders

The present study aimed the detection of fraudulent manipulation of milk powder with a low cost component--whey powder, by applying the immunochromatographic assay to identify glycomacropeptide. Five commercial milk powder samples of various brands from the national market were analyzed: lactose enriched milk powder type 26, two whole milk powders, vitamin enriched milk powder and full cream milk powder. Our results showed additional whey (1-2%) in 60% of the selected samples after casein removal by precipitation with 20% trichloracetic acid. Another investigated sample--the enriched UHT milk for children aged 4-12 years--proved addition of whey. Other two commercial toddler formula milk powder samples of different brands were used for comparison for the presence of glycomacropeptide. The first sample which was regularly labeled as containing whey protein concentrate was found positive for glycomacropeptide in accordance with the label information, while the second one not containing whey proteins as specified by the product label, was found negative for glycomacropeptide, these two samples being in accordance with the actual legislation.     

Experimental studies and two-dimensional modelling of a packed bed bioreactor used for production of galacto-oligosaccharides (GOS) from milk whey

In the present study, extensive experimental investigations and detailed theoretical analysis of a two-dimensional packed bed bioreactor, employed for the production of galacto-oligosaccharides (GOS) from milk whey were performed. Model equations, in one- and two-dimensions, capable of predicting the substrate concentration distribution in the bioreactor were developed by coupling mass balance equation with appropriate velocity distribution equation and solved numerically. Validation of the proposed model equations was done by a set of experimental data obtained from the bioreactor. The effects of reactor to catalyst particle diameter ratio (d _t/d _p), feed flowrate (10^?6–10^?9 m³ s^?1), and initial lactose concentration (50–200 kg m^?3) on substrate concentration distribution were investigated in detail. While, the distribution of substrate concentration in axial direction was independent of d _t/d _p, it was observed that for d _t/d _p <40, significant radial concentration distribution existed. It was further observed that the substrate conversion and product yield obtained experimentally showed an excellent agreement (97 ± 2 %) with the results predicted by the two-dimensional model equation, whereas, the results predicted by the one-dimensional model equation did not lie within the desired confidence level (<90 %). The results were confirmed by both curve fitting and statistical analysis. The prediction of substrate concentration distribution in axial and radial directions using the developed two-dimensional model equation is necessary for computing the bioreactor volume to achieve the desired GOS yield.     

Effects of Enterococcus faecium and dried whey on broiler performance,gut histomorphology and intestinal microbiota

Abstract

The experiment was conducted to study the effects of supplementing a broiler starter diet with the probiotic Enterococcus faecium NCIMB 10415 and dried whey (80% lactose) on chick performance, gut histomorphology and intestinal microbiota. One-day-old male Ross 308 strain broiler chickens were fed diets containing: (i) control feed, (ii) control + 3.5% dried whey, (iii) control + 0.2%E. faecium, and (iv) control + 3.5% dried whey + 0.2%E. faecium. Birds were maintained in battery brooders confined in an environmentally controlled experimental room. The experiment lasted for 21 days. Birds fed E. faecium or E. faecium + dried whey exhibited significantly improved weight gain and feed conversion rate (FCR). Weight gain and FCR of treatment groups 1 – 4 were 628.7, 657.8, 690.9, 689.3 and 1.218, 1.193, 1.107, 1.116, respectively. Lactic acid bacteria counts in both the ileal content and excreta were significantly affected by dietary treatment. Supplementation of the E. faecium and dried whey separately and in combination increased lactic acid bacteria colonization in the ileal content from 4.2 to 5.0, 7.8 and to 5.1 log cfu/g, respectively (treatments 1 – 4). Similarly, supplementation of dried whey and E. faecium separately and in combination increased lactic acid bacteria in the excreta from 5.3 to 5.5, 8.0 and to 7.2 log cfu/g, respectively. Addition of the probiotic E. faecium increased villus height in the ileum (p < 0.05). Thus, supplementation of E. faecium enhanced broiler chick performance with respect to weight gain and FCR. No additive effect of E. faecium and dried whey was detected. Further studies are needed to investigate the relationship between E. faecium and dried whey with respect to gut histomorphology.     

Formulation and <Emphasis Type="Italic">In vitro</Emphasis> Characterization of Eudragit® L100 and Eudragit® L100-PLGA Nanoparticles Containing Diclofenac Sodium

The aim of this study was to formulate and characterize Eudragit® L100 and Eudragit® L100-poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing diclofenac sodium. Diclofenac generates severe adverse effects with risks of toxicity. Thus, nanoparticles were prepared to reduce these drawbacks in the present study. These nanoparticles were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, and in vitro drug release in pH 6.8. The prepared nanoparticles were almost spherical in shape, as determined by atomic force microscopy. The nanoparticles with varied size (241–274 nm) and 25.8–62% of entrapment efficiency were obtained. The nanoparticles formulations produced the release profiles with an initial burst effect in which diclofenac sodium release ranged between 38% and 47% within 4 h. The extent of drug release from Eudragit® L100 nanoparticles was up to 92% at 12 h. However, Eudragit®/PLGA nanoparticles showed an initial burst release followed by a slower sustained release. The cumulative release at 72 h was 56%, 69%, and 81% for Eudragit®/PLGA (20:80), Eudragit®/PLGA (30:70) and Eudragit®/PLGA (50:50) nanoparticles, respectively. The release profiles and encapsulation efficiencies depended on the amount of Eudragit in the blend. These data demonstrated the efficacy of these nanoparticles in sustaining the diclofenac sodium release profile.     

Characteristics of Biocalcium Powders from Pre-Cooked Tongol (<Emphasis Type="Italic">Thunnus tonggol</Emphasis>) and Yellowfin (<Emphasis Type="Italic">Thunnus albacores</Emphasis>) Tuna Bones

Characteristics of biocalcium powder from pre-cooked tongol tuna bone (BTG) and yellowfin tuna bone (BYF) were investigated, in comparison with their calcined bone powder named CTG and CYF, respectively. Average calcium (40.3%) and phosphorus (19.19%) contents of CTG and CYF were higher than those of BTG and BYF (Ca: 26.74%, P: 12.72%). Nevertheless, similar mole Ca/P ratio (1.62–1.63) was observed among all samples. Mean particle size of all samples was approximately 14 μm. Both CTG and CYF powders exhibited the interconnected granular structure. BTG had higher b*- value than BYF (p < 0.05). Generally, CTG and CYF had lower b*-values with slightly higher L*-values than both BTG and BYF (p < 0.05). X-ray diffraction results indicated the presence of hydroxyapatite in all samples, in which their crystallinities were increased from 54% to 90% after calcination. Hydroxyproline and protein were detected in both biocalcium powders, but were not detectable in calcined bone powders. The abundance of volatile compounds was noticeably lower in BYF, compared to BTG. Negligible volatiles were detected in both calcined bone powders. Based on a simulated gastrointestinal tract study, both BTG and BYF had higher soluble calcium content than calcium carbonate and their corresponding calcined bone powders, indicating the higher availability for absorption.