Cover Caption

April Online Cover : Schematic representations of the obtention of GA‐loaded zein nanoparticles by electrospraying process and of equipment parameters on particle size and morphology; and infrared spectra of powders and nanoparticles, from “Gallic Acid‐Loaded Zein Nanoparticles by Electrospraying Process” by José Agustín Tapia‐Hernández, Carmen Lizette Del‐Toro‐Sánchez, Francisco Javier Cinco‐Moroyoqui, Saúl Ruiz‐Cruz, Josué Juárez, Daniela Denisse Castro‐Enríquez, Carlos Gregorio Barreras‐Urbina, Guadalupe Amanda López‐Ahumada, and Francisco Rodríguez‐Félix. p. 818.     

Nanoencapsulation of black seed oil by coaxial electrospraying: characterisation,oxidative stability and in vitro gastrointestinal digestion

In this study, black seed oil-loaded zein nanoparticles were produced via coaxial electrospraying. Nanoparticles obtained under optimised conditions had a uniform morphology with a mean diameter of 136 nm and a core–shell structure verified by confocal laser scanning microscope. The encapsulation efficiency of the oil in nanoparticles ranged from 65.3 to 97.2%. The peroxide value of oil in nanoparticles with high encapsulation efficiency was approximately three times lower than unencapsulated oil when stored at 60 °C for 55 days. The totox value of the encapsulated oil in nanoparticles stored at 25 °C was lower than the critical totox value of 30. The amount of thymoquinone released from encapsulated oil was low at the end of the gastric digestion, but the bioaccessibility of thymoquinone from encapsulated oil increased during intestinal digestion compared with free oil. These results demonstrated the successful nanoencapsulation of black seed oil with the improved oxidative stability due to the coaxial structures formed. Black seed oil-loaded zein particles may have the potential to expand the use of black seed oil as a functional ingredient for food systems.     

Preservation of strawberry fruit quality via the use of active packaging with encapsulated thyme essential oil in zein nanofiber film

Strawberry is highly perishable with a short shelf life mainly due to physiological deterioration and microbiological decay. Thyme essential oil (TEO), which is a natural antimicrobial and antioxidant agent, encapsulated in zein (Z) nanofiber could be used by electrospinning to examine the ability of the nanofiber for strawberry quality preservation. Test groups were designated as zein nanofiber film, and zein loaded with TEO nanofiber film (Z/TEO). The fruit packed in PET container without film on its lid was used as the control group. Packages of fruits were then stored in a cool room at 4 ± 0.5 °C and 85 ± 5% RH for 15 days. Results indicated that the scanning electron microscopy images of nanofibers had a linear morphology, smooth surface and bead-free structure. Fourier transform infrared also showed that the encapsulation of TEO in the zein was a physical process and no chemical interactions occurred between ingredients during electrospinning. Moreover, differential scanning calorimetry data confirmed the thermal stability of TEO encapsulated in zein nanofibers. Active packaging including nanofiber films significantly preserved the biochemical and microbial properties of fruit. Indeed, stored fruit in packages containing nanofiber Z/TEO (Zein loaded with TEO nanofiber film) significantly (p˂0.05) lowered total bacterial counts, fungi and yeast, and maintained the total phenols content, antioxidant activity and titratable acidity of the strawberries during 15 days of storage at 4 °C. In conclusion, this study revealed the benefits of incorporating TEO into zein films, which may have a great potential in active packaging and preservation of strawberry fruits.     

Coaxial electrospraying of biopolymers as a strategy to improve protection of bioactive food ingredients

Coaxial electrospraying is a promising technique for the production of multilayer encapsulation structures whose potential has already been demonstrated for pharmaceutical and biomedical applications. The aim of this work was to extend its application to the food sector by developing novel coaxially electrosprayed microcapsules using all food-grade materials. For this purpose, zein and gelatin were used as shell biopolymers to microencapsulate two model bioactive ingredients, i.e. epigallocatechin gallate (EGCG) as a model hydrophilic compound and α-linolenic acid (ALA) as a model hydrophobic molecule. The performance of the coaxially-obtained particles in terms of protection was evaluated in comparison with that of uniaxially electrosprayed materials. Particle sizes varied with composition and encapsulation efficiency (EE) was dependent on the chemical affinity between the shell matrix and the bioactive compound, but in general, greater EE was obtained in the coaxial systems. Moreover, enhanced bioactive protection ability was demonstrated by the coaxial structures, as observed in thermal degradation assays (for ALA) and antioxidant activity after in-vitro digestion (for EGCG).Industrial relevanceThis work emphasizes the usefulness of the electrospraying technique for the production of encapsulation structures for bioactive protection using all food-grade materials, without the need of applying high temperatures and generating small capsule sizes (in the submicron range). It also demonstrates that the coaxial configuration may be used to design encapsulation systems with enhanced protection ability for both hydrophilic and hydrophobic bioactive compounds.     

Characterisation of gelatin nanoparticles encapsulated with Moringa oleifera bioactive extract

This study describes the preparation and characterisation of nanoparticles with gelatin as the wall matrix to encapsulate Moringa oleifera (MO) extract using an electrospraying technique. The electrospraying conditions for voltage, flow rate and emitter/collector distance were 20 kV, 0.5 mL h^?1 and 10 cm, respectively. Nanoparticles with encapsulated MO extract (1–5%, w/w) were successfully produced and characterised in relation to spectroscopic, morphological and thermal properties. Increasing amounts of MO extract resulted in a significant decrease in the nanocapsule size (ranging from 140 and 179 nm) produced. Spectroscopic analysis indicated no chemical interactions between core and wall materials. The encapsulation efficiency (EE) of MO extract‐loaded nanocapsules obtained was 83.0 ± 4.0%. Surface analysis showed that roughness decreased from 91 nm (empty beads) to 57.5 nm with addition of 3% MO extract. The thermal stability of encapsulated nanoparticles slightly increased and the glass transition temperature (T_g) disappeared due to increase in crystallinity.     

Fabrication of nanoparticles using partially purified pomegranate ellagitannins and gelatin and their apoptotic effects

Scope: Nanoparticles possess unique chemical and biological properties compared to bulk materials. Bioactive food components encapsulated in nanoparticles may have increased bioavailability and bioactivities. Methods and results: Self‐assembled nanoparticles made of partially purified pomegranate ellagitannins (PPE) and gelatin were fabricated using three PPE‐to‐gelatin mass ratios (1:5, 5:5, and 7:5). The PPE contained 16.6% (w/w) of punicalagin A, 32.5% (w/w) of punicalagin B, and a small amount of ellagic acid‐hexoside and ellagic acid (1%, w/w). Nanoparticles fabricated using the ratio 5:5 had a particle size of 149.3±1.8 nm, positive zeta‐potential of 17.8±0.9 mV, production efficiency 53.0±4.2%, and spherical morphology under scanning electron microscopy. Loading efficiency of punicalagin A and punicalagin B in these particles were 94.2±0.4% and 83.8±0.5 %, respectively. Loading capacity was 14.8±1.5% and 25.7±2.2%, respectively. Only punicalagin anomers were able to bind with gelatin to form nanoparticles, whereas ellagic acid‐hexoside or ellagic acid could not. Fourier transform infrared spectroscopy suggested that the interactions between ellagitannins and gelatin were hydrogen bonding and hydrophobic interactions. PPE‐gelatin nanoparticle suspension was less effective than PPE in inducing the early stage of apoptosis on human promyelocytic leukemia cells HL‐60. But they had similar effects in inducing late stage of apoptosis and necrosis. Conclusion: Pomegranate ellagitannins bind with gelatin to form self‐assembled nanoparticles. Ellagitannins encapsulated in nanoparticles had decreased apoptotic effects on leukemia cells HL‐60.     

玉米醇溶蛋白/多糖基复合抗菌膜的制备及性能表征

为了提升玉米醇溶蛋白（Zein）的应用价值,改善传统石油基对环境造成的污染。研究以Zein、琼脂（Agar,AG）和卡拉胶（Carrageenan,CA）为成膜基材,明胶为增强剂、甘油增塑剂,纳他霉素和乳酸链球菌素为抗菌剂通过流延的方式来制备复合抗菌膜,并对其理化性能及保鲜效果进行了研究。结果表明,三种复合抗菌膜中Zein-AG膜的机械性能和光学性能较高,机械强度为7.12±0.91 MPa、透光率为25.40±1.00%;Zein-AG膜的透气性和水溶性较高;Ze-CA/AG膜的抑菌性能强,与其他复合膜相比具有显著性差异（P<0.05）,其中对黑曲霉及根霉的抑菌圈直径为35.155±0.85 mm和23.17±0.94 mm,并且还能有效地抑制金黄色葡萄球菌和大肠杆菌的繁殖。在保鲜方面,Ze-CA/AG膜对于葡萄的失重率、硬度及营养指标的控制上呈现了较好的效果,有利于延长葡萄的保鲜期。研究为拓宽Zein的开发与利用及在制备绿色环保包装材料的研究上提供了参考依据。     

Encapsulation of food grade antioxidant in natural biopolymer by electrospinning technique: A physicochemical study based on zein–gallic acid system

Gallic acid was successfully incorporated into zein ultra-fine fibres at different loading amount (5%, 10% and 20%) in order to develop an encapsulating technology for functional ingredient delivery using electrospinning. The produced fibres exhibit diameters ranging from 327 to 387 nm. The physical and thermal properties of encapsulated gallic acid were determined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC); and the interaction between gallic acid and zein was attested by attenuated total reflection-Fourier transform infrared (ATR-FTIR). Thermogravimetric analysis (TGA) demonstrated a different thermal stability of the fabricated complex before and after the gallic acid incorporation. Lastly, the 1,1′-diphenyl-2-picrylhydrazyl (DPPH) assay showed that the gallic acid had retained its antioxidant activity after incorporation in zein electrospun fibres. Overall, electrospinning technique had shown promising results as an efficient and effective method for the preparation of sub-micron structured encapsulated functional ingredient that may find uses in food industry.     

玉米醇溶蛋白-多酚相互作用及复合物制备与表征

采用荧光分光光度计、紫外分光光度计等探究玉米醇溶蛋白与3 种多酚在醇溶体系以非共价方式结合机理及其对蛋白质结构及抗氧化性的影响,并且通过浊度、粒径及微观形貌等指标对其形成的复合胶体颗粒进行表征,初步探讨多酚对玉米醇溶蛋白胶体颗粒自组装的影响。结果表明：将多酚引入玉米醇溶蛋白体系后,蛋白质发生荧光猝灭现象,猝灭类型主要为静态猝灭。玉米醇溶蛋白与单宁酸（tannic acid,TA）及表没食子儿茶素没食子酸酯（epigallocatechin gallate,EGCG）以氢键作用结合,升温使其结合常数降低,不利于结合,玉米醇溶蛋白与没食子酸（gallic acid,GA）以疏水相互作用结合形成复合物,逐渐升高温度有利于GA与玉米醇溶蛋白的相互作用;3 种多酚与玉米醇溶蛋白结合的物质的量比约为1∶1。此外,多酚与玉米醇溶蛋白结合后复合物紫外吸收强度明显增加,蛋白质折叠方式发生改变,非共价结合复合物抗氧化性及热稳定性均有所增加。玉米醇溶蛋白与TA发生非共价相互作用使玉米醇溶蛋白与TA复合颗粒的粒径增大,表面电荷降低,其微观结构呈现规则的球形,且TA可作为一种交联剂,使颗粒间发生交联作用。玉米醇溶蛋白与EGCG及GA形成的复合纳米颗粒的表面特性及微观结构同样发生了改变,然而胶体颗粒间并未发生明显的交联现象,仍然呈现均匀分散的状态。     

Electrospraying and Electrospinning of Chocolate Suspensions

Novel applications of efficient and economical techniques such as electrospraying and electrospinning in chocolate processing could be a strategy to help manufacturers improve declining sales growth rate in a saturated confectionery market. In this study, electrosprayed near-monodisperse particles have been produced using chocolate suspensions. Electrospun fibres have also been created from a commercial chocolate sauce. The effects of process parameters such as sugar concentration, addition of electrolytes (NaCl), flow rate, applied voltage and collection distance on the production and morphology of as-sprayed chocolate particles were studied. A positive linear trend in the electrosprayed chocolate particle diameter and diameter distribution range with increasing sugar concentration in the chocolate suspension was demonstrated. Sugar concentrations of 30–35%w/w resulted in very fine, near-monodisperse chocolate particles. Trace amounts of electrolyte at 1%w/w were found to decrease the average particle diameter and improve the monodispersity of the particles produced. The addition of NaCl at low concentrations increased the electrical conductivity and, to a lesser extent, the surface tension of the chocolate samples. Further increases in NaCl concentration to 3%w/w did not bring any additional decrease in the average diameter of the chocolate particles. In addition, the observed modes of electrospraying and the characteristics of chocolate particles obtained under these were investigated. Bead-on-string morphology was commonly observed among electrospun chocolate fibres. Moreover, satellite particles and very fine fibres were obtained during the transition between electrospraying and electrospinning. The continuous alternating shape of elongated spheres and thin fibres may have the potential for varying the microtexture of the chocolate products.     

基于玉米醇溶蛋白/没食子酸复合纳米颗粒提升玉米油Pickering乳液的氧化稳定性

以玉米醇溶蛋白（Zein）和没食子酸（gallic acid，GA）为原料，通过反溶剂沉淀法制备玉米醇溶蛋白/没食子酸复合纳米颗粒（zein/gallic acid composite nanoparticles，ZGP），并利用ZGP作为稳定剂制备具有抗氧化能力的Pickering乳液。结果表明，ZGP呈现纳米级别且分散性良好，Zeta电位呈正值。Zein和GA主要通过氢键结合，通过X射线衍射结果证明了二者结合后呈现非定形结构。热力学分析证明Zein和GA之间的反应为自发放热反应，随着GA添加量增加，ZGP的表面疏水性逐渐下降，ZGP的热稳定性增强。此外，由ZGP稳定的Pickering乳液呈现剪切稀化现象，属于非牛顿流体，且储能模量（G’）高于损耗模量（G”）。在贮藏期间（50 ℃、20 d）初级氧化产物和次级氧化产物均随着GA添加量的增多而逐渐减少，说明由ZGP稳定的Pickering乳液具有一定的抗氧化能力，能在一定程度上抑制油脂氧化。     

Electrospraying method for fabrication of essential oil loaded-chitosan nanoparticle delivery systems characterized by molecular,thermal, morphological and antifungal properties

Fabrication of essential oil loaded-chitosan nanoparticles using electrospraying technique appears to be a novel strategy to develop thermally stable nanoparticles possessing higher encapsulation efficiency and particle stability. This study aims to fabricate chitosan nanoparticles (CNPs) loaded with Origanum vulgare essential oil (OEO, Origanum vulgare L.) at different proportions (OEO/CH proportions of 0:1, 0.0625:1, 0.125:1, 0.25:1 and 0.5:1 mL/g) using electrospraying technique. The CNPs were characterized in term of their particle size and stability (dynamic light scattering), encapsulation efficiency (spectrophotometry), and molecular (Fourier transform infrared spectroscopy), thermal (differential scanning calorimetry/thermogravimetric analysis), morphological (scanning electron microscopy) and antifungal (agar dilution method) and fungistatic activity properties. The average particle sizes of the CNPs ranged between 290 and 483 nm with a spherical morphology. Positively charged surface characteristics were observed to increase with the increment of OEO concentration in CNPs. The encapsulation efficiency values were determined in the range of 70.1 and 79.6%. The molecular and thermal analyses exposed very decent encapsulation of OEO into thermally stable chitosan nanoparticles. Morphological analysis verified the spherical shapes of these nanoparticles. Above all, the antifungal effectiveness of OEO against the Alternaria alternata AY1 could be significantly (p < 0.05) increased by its encapsulation into chitosan nanoparticles fabricated by the electrospraying technique. Consequently, it can be stated that the electrospraying technique developed is able to fabricate thermally stable nanoparticles owning higher encapsulation efficiency and particle stability. The results and findings suggest that the electrospraying technique would be a promising method to fabricate chitosan-based nanoparticles as an antimicrobial agent to control their release in a prolonged preservative effect in cosmetic, pharmaceutical and food applications for adjustable dosage forms.Industrial relevanceThe fungal agents such as Alternaria alternata cause great damages on post-harvest fresh fruits and vegetables, thus leading to a great economical lose. Therefore, a great variety of methods in struggling with disease have been previously proposed. Nowadays, the most effective leading methods to struggle against plant diseases are those applied with synthetic fungicides to minimize such lose in post-harvest fruit and vegetables. However, intensive and unconscious use of the fungicides leads the pathogens to develop resistance against these agents as well as to accumulation of chemical residues in soil, water and air and finally to formation of carcinogenic effects on human health. Nowadays, a great effort is being exerted to develop novel biodegradable and natural antimicrobial agents for struggling fungal spoilage in postharvest products. Essential oils are among the most widely used natural struggling methods. Essential oils obtained from plants have been extensively used since they are natural antimicrobial agents. However, they cannot be effectively used in spite of their extensive applications. Recently, some researches in the field of nanotechnology have demonstrated that the effectiveness of active substances could be increased by using some techniques. In this respect, we aimed at developing essential-oil-loaded-chitosan-nanoparticle delivery systems using an electrospraying deposition system to prevent fungal colonization on food and plant materials. By increasing antifungal effectiveness of essential oils by their encapsulation into nanoparticles, it will be possible to decrease the levels of regularly applied dose and reflect the obtained outcomes to the food and agriculture industry. This study is the first example of production of essential oil loaded nanoparticles using the electrospraying-hydrodynamic process and showed that encapsulation of oregano essential oil into chitosan based nanoparticles (CNPs) by using the electrospraying deposition technique considerably increased the antifungal effectiveness of the Origanum vulgare essential oil. Our results highlight the potential use of the chitosan nanoparticles (CNPs) loaded with different amounts of Origanum vulgare in food and agriculture industry as an effective fungicidal material against Alternaria alternata, suggesting that the CNPs can be promising tools to compete with synthetic fungicide counterparts and limit use of synthetic ones for struggling of food and plant pathogens. Therefore, the results of this study should be of great importance to industrial applications in terms of development of natural, but effective preservatives as alternative to synthetic ones. In this respect, the CNPs would find a great industrial application area in the food and agriculture industry which seek natural preservatives due to the recent health concerns.     

Preparation of pickering emulsion stabilised by Zein/Grape seed proanthocyanidins binary composite

This paper introduced a kind of binary composite particle constructed by zein particles and grape seed proanthocyanidins (PAs). The physicochemical performance of the zein/PAs complex colloidal particles (ZPAPs) was systematically evaluated. Fourier transform infrared spectroscopy (FTIR) showed that the interactions between zein and PAs were mainly hydrogen bonds and hydrophobic interactions. The three-phase contact angle (θo/w) of zein particles was around 120.7 ± 0.7°, and it was decreased to 100.8 ± 0.6° after the addition of PAs, indicating that ZPAPs were more suitable for stabilising Pickering emulsion. ZPAPs stabilised peanut oil Pickering emulsion (ZPAPEs) at 0.5–0.7 (v/v) oil fractions had no obvious phase separation during a 30-day storage, indicating its good storage stability. Rheological results showed that ZPAPEs had excellent plasticity and viscoelasticity. Confocal laser scanning microscopy (CLSM) showed that particles had stably anchored on the surface of oil droplets which could effectively prevent from Ostwald ripening. The incorporation of PAs to zein endowed zein with stronger affinity, thus enhancing the stability of Pickering emulsion. This research constructed a new novel food-grade emulsifier to prepare Pickering emulsion with potential applications, and further broaden the bioavailability of PAs.     

Gel‐like emulsions prepared with zein nanoparticles produced through phase separation from acetic acid solutions

In this article, we report the microstructure and rheological property of Pickering emulsions stabilised with zein nanoparticles prepared through phase separation from acetic acid solution. The fresh emulsions showed liquid‐like behaviour and reasonable small droplet size. Interestingly, after 3 days of storage at 25° C, the emulsions changed into solid‐like state. The viscosity remarkably increased, and the storage modulus was much larger than the loss modulus. These results indicate the formation of the gel‐like network in emulsions. The droplet size also showed an obvious increase, while the big droplets could be disrupted into small ones in the presence of sodium dodecyl sulphate. The particle network in the continuous phase was seen in the confocal laser scanning microscopy. Therefore, it is suggested that the gel‐like network is formed by the flocculation of oil droplets and particle network in continuous, mainly through the hydrophobic interactions between the particles.     

Stabilization of a Nutraceutical Omega-3 Fatty Acid by Encapsulation in Ultrathin Electrosprayed Zein Prolamine

Abstract: Docosahexaenoic acid (DHA) is a long chain polyunsaturated fatty acid of the omega-3 series (ω-3), which exerts strong positive influences on human health. The target of this study was the stabilization by encapsulation of this bioactive ingredient in zein ultrathin capsules produced by electrospraying. The zein ultrathin DHA encapsulation was observed by ATR-FTIR spectroscopy to be more efficient against degradation under both ambient conditions and in a confined space (so-called headspace experiment). In the latter case, that more closely simulates a sealed food packaging situation, the bioactive DHA was considerably more stable. By fitting the degradation data to a specific auto-decomposition food lipids kinetic model, it was seen that the encapsulated ω-3 fatty acid showed a 2.5-fold reduction in the degradation rate constant and also had much higher degradation induction time. Moreover, the ultrathin zein-DHA capsules resulted to be more stable across relative humidity and temperature. Finally, headspace analysis by gas chromatography coupled with mass spectrometry showed that the presence of 3 main flavor-influencing aldehydes in the headspace was much lower in the zein encapsulated DHA, suggesting that the encapsulated bioactive also releases much less off-flavors. Electrosprayed ultrathin capsules of zein are shown to exhibit potential in the design of novel functional foods or bioactive packaging strategies to enhance the stability of functional ingredients. Practical Application : This article presents a novel methodology for the stabilization by encapsulation of omega 3 nutraceuticals via electrospraying and has potential application in the development of functional foods.     

Effect of acid and base treatments on structural,rheological, and antioxidant properties of α-zein

Five pH levels were experimented to study their effect on zein structural, rheological, and antioxidant properties. Structural changes, including secondary structures, surface charge, molecular weight, particle size distribution, and morphology were evaluated using a spectrum of instruments. Zein rheology, including the viscosity and viscoelastic property, was examined by a rheometer. The antioxidant efficacy was determined by measuring the scavenging activity of 1,1-diphenyl-2-picrylhydrazyl free radical and the reducing power of 1,10-phenanthroline-iron with a spectrophotometer. Results indicated that under proper acidic or basic conditions, zein structures, rheological behaviour, and antioxidant properties changed significantly. Decreased contents for α-helix, β-sheet, and β-turn were detected by the Fourier transform infrared spectroscopy for zein samples at acidic and basic conditions comparing to those in a near neutral condition, which were attributed to the deamidation of glutamine to glutamic acid/glutamate in zein. However, no obvious zein fragmentation or oligomerization was detected by the sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The mild deamidation without fragmentation led to a decreased viscosity and an improved antioxidant property of zein. Modified rheological behaviour and enhanced antioxidant properties resulting from a pH treatment may facilitate novel application development of zein in food and pharmaceutical industries.     

Growth performance,digestibility, blood metabolites,ruminal fermentation,and bacterial communities in response to the inclusion of gallic acid in the starter feed of preweaning dairy calves

The objective of this study was to evaluate the effects of feeding gallic acid on the growth, nutrient digestibility, plasma metabolites, rumen fermentation, and bacterial community in the rumen fluid and feces of preweaning calves. Thirty-six female Holstein calves with similar ages (means ± SD; 3.1 ± 1.39 d) and body weights (40.8 ± 2.87 kg) were randomly assigned to receive 3 treatments. Calves were fed 1 of 3 treatments as follows: basal diet with no gallic acid (control), 0.5 g/kg gallic acid in starter diet (low), and 1 g/kg gallic acid in starter diet (high). The results showed that feeding gallic acid increased growth by improving the starter intake and average daily gain of the calves. The fecal score tended to decrease in a linear manner with the addition of gallic acid. Total-tract apparent protein digestibility tended to increase linearly with feeding gallic acid. Feeding gallic acid led to a linear increase in the plasma total protein and β-hydroxybutyrate levels. In addition, feeding gallic acid linearly increased catalase and total antioxidant capacity levels and decreased malondialdehyde and tumor necrosis factor-α concentrations. The concentrations of total volatile fatty acids, propionate, butyrate, and valerate in the rumen fluid increased linearly with the addition of gallic acid, resulting in a linear pH reduction. Feeding gallic acid linearly increased the relative abundances of Prevotella_1, Saccharofermentans, and Prevotellaceae_UCG-001 and linearly decreased the relative abundance of Prevotella_7 in the rumen fluid. The Shannon index of ruminal bacterial communities linearly increased by feeding gallic acid. Feeding gallic acid linearly increased the relative abundances of Ruminococcaceae_UCG-005, Bacteroides, and Christensenellaceae_R-7_group in the feces. In summary, feeding gallic acid improved growth, antioxidant function, and rumen fermentation and altered the bacterial community in the rumen fluid and feces of preweaning dairy calves.     

Exploring solid lipid nanoparticles to enhance the oral bioavailability of curcumin

Scope : Curcumin, a molecule with pluripharmacological properties, was loaded into solid lipid nanoparticles (SLNs) with a view to improve its oral bioavailability (BA). Methods and results : Curcumin‐loaded solid lipid nanoparticles (C‐SLNs) with an average particle size of 134.6 nm and a total drug content of 92.33±1.63% was produced using a microemulsification technique. The particles were spherical in shape, with high drug entrapment of 81.92±2.91% at 10% drug loading. The in vitro release was predominantly by diffusion phenomenon and was prolonged up to 7 days. No significant variation in particle size and curcumin content of C‐SLNs was observed, upon storage, over a period of 12 months at 5±3°C. In vivo pharmacokinetics performed after oral administration of C‐SLNs (50, 25, 12.5 and 1 mg/kg dose) and (free) solubilized curcumin (C‐S; 50 mg/kg), using a validated LC‐MS/MS method in rat plasma revealed significant improvement (at p<0.05) in BA (39 times at 50 mg/kg; 155 times at 1 mg/kg; and, 59 and 32 times at 12.5 and 25 mg/kg, respectively) after administration of C‐SLNs at all the doses with respect to C‐S. Conclusions : Enhanced and reliable BA will help in establishing its therapeutic usefulness especially for neurodegenerative and cancerous disorders in humans.     

Phenolic acid composition and antioxidant properties of Malaysian honeys

Abstract: The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) radical‐scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51– 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27– 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97– 363.38 ± 10.57 μM Fe[II]/kg), and high IC₅₀ of DPPH radical‐scavenging activities (5.24 ± 0.40– 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans‐cinnamic, p‐coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical‐scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical‐scavenging activities.     

Formation of zein nanoparticles by electrohydrodynamic atomization: Effect of the main processing variables and suitability for encapsulating the food coloring and active ingredient curcumin

Nanoparticles with a compact spherical structure and a narrow size distribution were prepared from a zein protein polymer by electrohydrodynamic atomization. The effects of key parameters of the process (polymer concentration, flow rate and applied voltage) on the size and morphology of the particles was studied. Zein nanoparticles could be obtained from zein concentrations ranging from 2.5% to 15% (w/w). The sizes of these particles, ranging from 175 to 900 nm, increased with increasing polymer concentration. Compact nanostructures were obtained for 2.5% and 5% zein solutions whereas 10% and 15% solutions yielded collapsed and shrunken particles. Flow rate also exerted an effect, the lower the flow rate the smaller the nanoparticles. The morphology of the nanoparticles did not change after incorporating curcumin in proportions ranging from 1:500 to 1:10 (curcumin:zein), and the encapsulation efficiency was around 85–90%. Fluorescence microscopy images showed that the nanostuctures obtained took the form of matrix systems with the curcumin homogeneously distributed in the zein matrix. The curcumin remained in the amorphous state in the nanoparticle, as revealed by X-Ray diffractometry, evidencing intimate contact with the polymer. After three months of storage at 23 °C and 43% relative humidity in the dark, neither the size or the morphology of the nanoparticles had undergone significant changes, nor had the curcumin content altered. Thanks to encapsulation, the curcumin presented good dispersion in an aqueous food matrix: semi-skimmed milk.