The effects of particle size on the physicochemical properties of optimized astaxanthin-rich Xanthophyllomyces dendrorhous-loaded microparticles

To improve the entrapment efficiency (EE) of astaxanthin-rich Xanthophyllomyces dendrorhous (ASX)-loaded calcium alginate gel (ASX-CAG) microparticles, we used a response surface methodology to optimize preparation conditions including the ratio of ASX to total material (X₁), alginate concentration (X₂), and CaCl₂ concentration (X₃). The EE and the mean size of the ASX-CAG microparticles were 76.7 g/100 g and 210.26 μm, respectively, after preparation under optimal conditions: 24 g ASX/100 g total material, 1.0 g/100 g alginate, and 200 mmol/L CaCl₂. The effects of particle size on different characteristics were evaluated with increasing microparticle size; an increase in microparticle size significantly increased EE and the antioxidant activity of ASX, but resulted in a decrease in the release of entrapped ASX. Most importantly, the lipid peroxidation inhibitory activity of encapsulated ASX (55.1%) was significantly higher and longer-lasting than that of non-encapsulated ASX (40.5%) after 36 h of storage as determined using the thiobarbituric acid method.     

Encapsulation by spray drying of bioactive components, physicochemical and morphological properties from purple sweet potato

Purple-fleshed sweet potato flour could be used to enhance the colour, flavour and nutrients in food products. Thus, the investigation was to produce encapsulated flours from purple-fleshed sweet potato by spray drying using combinations of various levels of ascorbic acid (5 g kg⁻¹ and 10 g kg⁻¹) and maltodextrin (30 g kg⁻¹ and 100 g kg⁻¹) and to evaluate their effects on bioactive components, physicochemical and morphological properties. Encapsulated flours had higher total phenolic content, antioxidant capacity and water solubility index than non-encapsulated flour. There were no significant differences in anthocyanin content between encapsulated and non-encapsulated flours. However, water absorption index and flavonoids content of encapsulated flours depended on concentrations of ascorbic acid and maltodextrin. In addition, the high concentrations of ascorbic acid and maltodextrin encapsulated flours had higher glass transition temperature as compared to that of lower concentrations. In respect to morphology, the particles of encapsulated flours with high concentration of ascorbic acid and maltodextrin were more aggregated than those encapsulated with lower concentrations. Therefore, flours encapsulated with 10 g kg⁻¹ ascorbic acid and 30 g kg⁻¹ maltodextrin could be used to enhance the antioxidant activities of functional food ingredients.     

Microencapsulation of probiotic cells by means of rennet-gelation of milk proteins

Probiotic cells were microencapsulated in milk protein matrices by means of an enzymatic induced gelation with rennet. Water insoluble, spherical capsules with a volume-based median of 68 ± 5 μm were obtained from a novel developed emulsifying and subsequent internal gelation process. A high encapsulation yield was found due to the encapsulation procedure for Lactobacillus paracasei ssp. paracasei F19 and Bifidobacterium lactis Bb12. After incubation at low pH-values, microencapsulation yielded higher survival rates compared to non-encapsulated probiotic cells. The viable cell numbers of encapsulated Lactobacillus paracasei and Bifidobacterium lactis were 0.8 and 2.8 log units CFU g⁻¹ higher compared to free cells after 90 min incubation at pH 2.5. The improved survival of encapsulated cells can probably be explained by a higher local pH-value within the protein matrix of the capsules caused by the protein buffering capacity, protecting the cells during incubation under simulated gastric conditions at low pH. The study indicates that rennet-induced gelation of skim-milk concentrates for the microencapsulation of probiotic cells can be a suitable alternative to current available technologies, mainly based on ionotrophic gelation of plant-polymer solutions.     

Encapsulation of the phenolic compounds of the blackberry (Rubus fruticosus)

Microencapsulated phenolic extracts of blackberry (PE) were obtained by lyophilization in matrixes of β-cyclodextrin (β-CDS), chitosan (C), xanthan (X) and hydrogel (H). The encapsulation was confirmed by Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA); their antioxidant activity, controlled release of phenolics and efficiency of encapsulation were determined. However, coated chitosan and xanthan only showed the characteristic shape. In fact, encapsulation efficiency depended on the phenolic compound and the encapsulated coating used; gallic acid and epicatechin were predominantly in microcapsules coated with β-cyclodextrin and xanthan. The highest antioxidant activity in microcapsules coated with β-cyclodextrin (84.43 ± 3.5%) and xanthan (90.75 ± 0.09%) was related to the equitable presence of encapsulated phenolic compounds. The controlled release of phenolic extract capsules was influenced by coating, solvent and pH.     

Enhanced alginate microspheres as means of oral delivery of bacteriophage for reducing Staphylococcus aureus intestinal carriage

Bacteriophage therapy could provide additional treatment for control of intestinal colonization of microbial pathogens. But, efficacy of its oral application may be reduced by sensitivity of certain phages to the low pH in the stomach. The aim of this study was to develop an improved encapsulation formulation with enhanced acid protection for oral delivery of Staphylococcus aureus phage K. Calcium carbonate microparticles were co-encapsulated with phage K into alginate microspheres and tested their efficacy for improved phage viability under in vitro acidic conditions. Free phage was completely destroyed when exposed to simulated gastric fluid (SGF) of pH 2.5. In contrast, alginate encapsulated phage K had a decrease of only 2.4 log units in viability when incubated for 1 h in SGF at pH 2.5. By adding calcium carbonate as an antacid excipient to the alginate microspheres, the survival of encapsulated phage K in SGF was significantly improved, with only a 0.17 log units reduction after 2 h exposure to SGF at pH 2.5. A number of protective agents including trehalose, sucrose, skim milk, and maltodextrin were also tested and were found to increase the viability of encapsulated phage K when subjected to drying. The protective effects varied with the type and concentration of each incorporated additives. The improved encapsulation formulation increased efficacy of phage K survival when exposed to the simulated gastric condition. Here we tested S. aureus phage K as a model but further improvement of the encapsulation formulation could provide a potential technology for reducing intestinal colonization of other pathogens.     

Effect of pH and Temperature on the Activity of Enzymatic Extracts from Pineapple Peel

This study was carried out to characterize a crude extract from pineapple peel after precipitation by three methods with the aim of obtaining an enzymatic extract from agro-industrial waste. The characterization of these extracts involved the determination of both protein content and specific protease activities. The effects of pH and temperature on specific protease activity and on the stability of the extracts were also evaluated. The optimal values of specific activity for the crude extract (CE) were pH 6.0 (5.76 U mg⁻¹ protein) and 7.0 (5.71 U mg⁻¹ protein) and a temperature of 70 °C (16 U mg⁻¹ protein). The average values for the relative specific activity were 17.4% (pH 3.0 to 9.0) and 42.7% (at 30, 50, and 70 °C). The ethanolic extract had the highest specific activity (10.7 U mg⁻¹ protein) in comparison to the best results obtained for the isoelectric precipitation (7.7 U mg⁻¹ protein) and the ammonium sulfate precipitation (4.7 U mg⁻¹ protein). Moreover, the ethanolic extract was more stable than the CE, retaining 60.9% and 53.7% of the initial specific activity during the evaluation of the stability at different pH and temperature values, respectively. The optimal values of pH and temperature were almost the same for the crude and the ethanolic extracts. In addition, the ethanolic extract was more stable than the CE in the experimental conditions tested in this work.     

Biopolymer nanoparticles as potential delivery systems for anthocyanins: Fabrication and properties

Biopolymer nanoparticles and microparticles may be used as delivery systems for bioactive compounds in food and pharmaceutical applications. In this study, biopolymer nanoparticles were assembled from whey protein isolate (WPI) and beet pectin (BP) using thermal processing and electrostatic complexation. This approach involved mixing the two biopolymers at pH 5.8, heating (90 °C, 5 min) to induce protein nanoparticle formation and then adjusting the solution to pH 4.0 to promote coating of the protein nanoparticles with pectin. This process led to the formation of relatively small anionic biopolymer nanoparticles (d < 200 nm) at pH 4. The biopolymer particles had a high negative charged from pH 8 to 4.0 but became less anionic at lower pH values. The mean particle diameter was relatively small (d < 200 nm) around pH 4.0 but increased appreciably at lower and higher pH due to particle flocculation. The biopolymer nanoparticles were loaded with an anthocyanin-rich extract. A higher loading efficiency was observed when anthocyanin was added before heating the WPI-BP solution (LE = 55%) rather than after (LE = 35%), which was attributed to increased protein–polyphenol interactions. The encapsulation of anthocyanins within biopolymer particles improved their heat stability. However, encapsulated anthocyanin had a lower antioxidant activity than non-encapsulated anthocyanin, which was attributed to the thermal processing step required during particle fabrication and the binding of anthocyanins to biopolymers within the nanoparticles. Color measurements indicated that the encapsulation of anthocyanin within biopolymer particles did not inhibit its degradation after ascorbic acid addition. Overall, our results show that the encapsulation of anthocyanins within the biopolymer particles fabricated in this study was not particularly effective at improving their antioxidant activity or color stability. Alternative strategies are therefore needed to encapsulate this important color and nutraceutical agent.     

解淀粉芽孢杆菌(Bacillus amyloliquefaciens)DC-4产豆豉溶栓酶发酵条件的优化

解淀粉芽孢杆菌DC 4是从豆豉中筛选得到 ,产生的豆豉溶栓酶具有较好的体外溶栓效果。利用单因素实验和正交分析获得该菌株产生豆豉溶栓酶的最佳发酵条件为 :接种量为 7% ;发酵培养基组分为纤维蛋白 2 0 % ,蛋白胨 0 5 % ,糊精 2 0 % ,酵母膏 0 1 5 % ,K2 HPO40 4% ,NaH2 PO40 0 4 % ,CaCO30 3% ,pH7 0 ;培养温度为 32℃ ;2 5 0mL三角瓶装量为 5 0mL ;2 1 0r/min振荡培养 72h ,其发酵上清液纤溶活性可达到 82 0U/mL。     

Characterization of phenoloxidase activity of carapace and viscera from cephalothorax of Norway lobster (Nephrops norvegicus)

The characterization of phenoloxidase activity was performed in both carapace and viscera extracts of Norway lobster. Phenoloxidase activity rose with increasing temperature up to 60 °C. The carapace enzymatic extract showed the highest themostability, retaining about 80% of maximum activity at 45 °C and 40% at 65 °C. On the other hand, both enzymatic extracts showed a single peak activity at neutral-slightly alkaline pH and were quite resistant to inactivation at alkaline pH (pH > 8), but phenoloxidase activity became unstable at pH lower than 5.5. The enzymatic extract obtained from viscera showed a higher affinity for catechol (K_M 5.97 mM) than carapace extract (K_M 19.40 mM). Both mono- and diphenoloxidase activities were found in carapace and viscera. Polyphenoloxidase and converted-hemocyanin into PPO-like enzyme could be the main responsible for these activities.     

Microencapsulation of Propolis in Protein Matrix Using Spray Drying for Application in Food Systems

Propolis presents several health benefits due to the presence of bioactive compounds, mainly phenolic compounds; however, its application in food is limited due to undesirable odor and low water solubility. The bioactive compounds are usually susceptible to degradation by exposure to light, heat, or oxygen or by interaction with other compounds, which may limit its biological activity. The study aimed the propolis extract microencapsulation using rice, pea, soybean, and ovoalbumin proteins as wall material by spray drying and to analyze their in vitro digestion. The propolis extract presented a high concentration of apigenin. Encapsulation efficiency was greater than 70%, and it was maintained the antioxidant activity of propolis (88% inhibition of DPPH for propolis extract and >?73% for the microparticles). The DSC, ATR-FTIR, and X-ray diffraction techniques confirmed the encapsulation. The microparticles showed different shapes, sizes, and physical characteristics. The microparticles encapsulated with pea protein could be used in formulations of Minas Frescal cheese due to the controlled released, whereas the other microparticles could be used in pudding formulations.     

Development and characterization of solid lipid microparticles loaded with ascorbic acid and produced by spray congealing

The aim of this work was to produce solid lipid microparticles loaded with ascorbic acid (AA). The microparticles were produced using spray congealing technique with a theoretical AA loading of 15, 25 or 40% (w/w). Fully hydrogenated palm oil and vegetable glycerol monostearate were used as carriers. The microparticles were characterized in terms of yield, morphology (SEM), mean size, size distribution, thermal behavior (DSC), encapsulation efficiency and stability of AA. The microparticles were spherical, the process yield was over 81% and the encapsulation efficiency ranged from 74 to 84%. The stability of the encapsulated AA was over 75% after 56 days of storage. The type of carrier, the AA concentration and the storage temperature did not significantly influence the stability. In conclusion microencapsulation by spray congealing is an important alternative to ensure AA stability, even at temperatures higher than those commonly used in food storage.     

Stabilization of anthocyanin extract from jabuticaba skins by encapsulation using supercritical CO2 as solvent

Anthocyanins are one of most important group of water-soluble and vacuolar pigments in nature. This phytochemical has attracted great interest to the food industry due to the wide range of biological activities including antioxidant and anti-inflammatory activities. However, the introduction of anthocyanins into food and/or medical fields has proved to be a major technological challenge since these compounds have low stability to environmental conditions during processing and storage. In this context, the present study evaluates the encapsulation of anthocyanin extract obtained from jabuticaba (Myrciaria cauliflora) skins in Polyethyleneglycol using supercritical CO₂ as solvent and ethanol as co-solvent. For comparison, a conventional method, ionic gelification, was employed to produce encapsulated particles by entrapment in Ca-alginate beads. The encapsulation efficiency of the extract in Ca-alginate beads was higher (98.67%) than those obtained by Rapid Expansion of Supercritical Solution (RESS) process (79.78%). Encapsulated particles made by RESS at different pressures, and temperatures, retained the extracts' biological activity. The best operating RESS process condition for anthocyanin extract encapsulation was determined as 313.15 K and 20 MPa. The degradation studies indicated that both encapsulated systems were more stable to light and temperature than the free extract. Ca-alginate encapsulated Anthocyanin extract release in acid buffer solution was incomplete and slower than when the extract was encapsulated by PEG. Both systems increased the stability of anthocyanin, although presenting different characteristics.     

Production and Evaluation of Yogurt with Concentrated Grape Juice

Fruit yogurt was prepared by adding concentrated grape juice (pekmez) CGJ, to milk. Optimum CGJ concentration and its influence on quality and fermentation process of yogurt were evaluated. The pH, titratable acidity, protein content, viscosity, whey syneresis, starter bacteria, mold and yeast counts were determined weekly at 4°C for 1 month. Addition of 10% CGJ provided desired sweetness. After 4h incubation of 5–10–15% CGJ-added yogurts the pH was 4.44, 4.98 and 5.90, respectively, and the control was pH 4.26. CGJ addition increased fermentation time and decreased viscosity. During storage, acidity of 10% CGJ-added yogurt remained lower (P<0.05) than controls. CGJ did not affect (P>0.05) protein content and molds or yeasts were not detected.     

Optimisation of process parameters to develop nutritionally rich spray‐dried honey powder with vitamin C content and antioxidant properties

The aim of present research was to optimise the conditions to develop nutritionally rich honey powder using honey, whey protein concentrate (WPC), aonla (Emblica officinalis. Gaertn) and basil (Ocimum sanctum) extract with the help of co‐current spray drier. Response surface methodology was applied to study the effects of inlet temperature (160–180 °C), whey protein concentrate (25–35%), feed flow rate (0.08–0.13 mL s^?1), aonla extract (6–8%) and basil extract (6–8%) on product responses, viz. bulk density, hygroscopicity, antioxidant activity (AOA), total phenolic content (TPC) and vitamin C. Statistical analysis revealed that independent variables significantly affected all the responses. The results demonstrated that increasing inlet temperature lowered the bulk density, hygroscopicity, AOA, TPC and vitamin C, whereas addition of aonla extract and basil extract increased the AOA (82.73%), TPC (63.27%) and total vitamin C content (94.89%) as these functional compounds were encapsulated by WPC. Similarly, with increase in feed flow rate and WPC, there was increase and decrease in the bulk density and hygroscopicity, respectively. The recommended optimum spray‐drying conditions were inlet air temperature (170 °C), feed rate (0.11 mL s^?1), whey protein concentrate (35%), aonla (8%) and basil extract (6%).     

Study of the Extraction,Concentration, and Partial Characterization of Lipases Obtained from <Emphasis Type="Italic">Penicillium verrucosum</Emphasis> using Solid-State Fermentation of Soybean Bran

Microbial lipases constitute an important group of enzymes with high biotechnological potential, but their application is limited due to production costs. The present study aimed to evaluate the extraction conditions, concentration with ammonium sulfate, and the partial characterization of the enzyme extracts (in terms of the optimum temperature and pH and their stability at low temperatures). It was shown that the optimal extraction conditions were established at 37 °C and pH of 7.0 and that the best conditions for precipitation with ammonium sulfate were with 60% saturation for 5 h. In the partial characterization of the concentrated extract, the optima conditions were obtained at 42 °C and pH of 8.5. In a study carried out with the concentrated enzymatic extract, the hydrolytic activity was shown to be practically the same as the initial value after 91 days of storage at both 4 and −10 °C.     

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.     

Kiwifruit protease extract injection reduces toughness of pork loin muscle induced by freeze–thaw abuse

Kiwifruit juice injection was used to tenderize freeze–thaw abused porcine meat, and the enzyme activity in relation to meat tenderness was determined. Whole pork loins (Longissimus lumborum) were subjected to 5 freeze–thaw cycles (–29 °C ↔ 4 °C). Non-frozen control and freeze–thaw treated loins were either non-injected or injected with 10% water or diluted kiwifruit juice (meat weight basis). After 48 h of incubation, samples were analyzed for pH, proteolysis, cooking loss, and Warner-Bratzler shear force. Shear force of meat increased 2-fold (P < 0.05) after 1 freeze–thaw cycle but decreased when loins were subjected to additional freeze–thaw treatments. The kiwifruit juice injection lowered the pH of meat from 5.6 to 5.2 and increased the cooking loss from 21% to 30% (P < 0.05). However, as indicated by the shear force reduction, tenderness of meat improved more than 2-fold (P < 0.05) after kiwifruit juice injection, in agreement with the SDS–PAGE patterns that showed substantial degradation of myosin in samples treated with kiwifruit juice. The actinidin assay confirmed the existence of significant proteolytic activity in kiwifruit juice extract and in injected loin samples, i.e., 4.65 units/mL and 1.27 units/g, respectively.     

Effect of microencapsulation on viability and other characteristics in Lactobacillus acidophilus ATCC 43121

Lactobacillus acidophilus ATCC 43121 were microencapsulated with sodium alginate by dropping method. The effects of microencapsulation on the changes in survival rate of the L. acidophilus ATCC 43121 during exposure to artificial gastrointestinal and on the change in heat susceptibility of L. acidophilus ATCC 43121 during the heat treatment were studied. In addition, cholesterol assimilation and intestinal adhesion of non-encapsulated and encapsulated L. acidophilus ATCC 43121 were also investigated to explore the effect of microencapsulation on health beneficial effect of lactic acid bacteria. Non-encapsulated cells were completely destroyed when exposed to artificial gastric juice (AGJ) of pH 1.2 and 1.5, while the treatment declined the viable count of encapsulated samples only by 3 log. Encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice (AIJ) and heat treatment than non-encapsulated samples. The assimilative reductions of cholesterol by non-encapsulated and encapsulated L. acidophilus ATCC 43121 were 35.98% and 32.84%, respectively. However, encapsulation did not significantly (P>0.05) affect the adherence of L. acidophilus ATCC 43121 onto the human intestinal epithelial cell lines HT-29. The microencapsulation effectively protected the microorganisms from heat and acid treatment in delivering the viable cells to intestine without any significant adverse effect on their functionalities.     

Light stability of spray-dried bixin encapsulated with different edible polysaccharide preparations

Bixin was encapsulated by spray-drying with gum arabic or maltodextrin, and the stability was evaluated in aqueous solution both under illumination or in the dark at 21 °C. The microcapsules containing emulsifier, such as gum arabic or maltodextrin + Tween 80, showed the highest encapsulation efficiency, respectively 86% and 75%, less superficial imperfections and higher stability than bixin encapsulated with maltodextrin alone or blended with sucrose. The kinetic behavior of bixin photodegradation in all encapsulated systems was composed by two first-order decays, due to the presence of bixin outside and inside the microcapsules. Bixin encapsulated with gum arabic was 3 to 4 times more stable than that encapsulated with maltodextrin. In all systems, greater bixin stability (<two orders of magnitude) was observed in the dark than under illuminated conditions. In addition, 10 times greater bixin stability was observed for encapsulated solutions as compared to the non-encapsulated systems in the absence of light.     

Development of an oral immunoadjuvant from cheonggukjang that is efficacious for both mucosal and systemic immunity

Immunological properties of a 50% ethanol/aqueous extract of cheonggukjang (CGJ), a fermented soybean product, were investigated as a potent, orallyavailable, and cost-effective immunoadjuvant. Different from cholera toxin, a widely used experimental oral adjuvant with effects limited to mucosal immunity in the gut, oraladministration of the CGJ extract had positive effects on both mucosal and systemic immunity. Administration of keyhole limpet hemocyanin (KLH) with the CGJ extract resulted in hyper-production of KLH-specific IgA in the gut and KLH-specific IgG in the serum. Oral-administration of the CGJ extract resulted in promotion of both Th1 and Th2 immune responses, thus eliminating concerns over an imbalanced Th1 and Th2 immune bias that is often observed upon administration of other commonly used immunoadjuvants. Ethanol/aqueous extraction of CGJ resulted in enrichment of polyphenolic compounds, including flavonoids, providing a potential extra health benefit.