Spray Freeze Research Articles

Functional characterization and microencapsulation of probiotic bacteria from koozh.

Koozh is a traditional fermented millet beverage unique to south India. Analysis of six market samples of koozh for their microbial profile resulted in 69 isolates of presumptive lactic acid bacteria (LAB). They were grouped as Leuconostoc sp., Enterococcus sp., Streptococcus sp. and Lactobacillus sp. based on morphological characteristics and biochemical tests. Eight among them showed probiotic features: resistance to acid (2.5 pH for 6h), resistance to 0.3% ox bile, moderate hydrophobicity (40%), antibacterial activity against 10 pathogens, susceptibility to 50% of antibiotics tested. Sequencing of 16srDNA showed them to be five strains of Enterococcus hirae and one each of Enterococcus facecalis, Bacillus amyloliquefaciens and Lactobacillus plantarum. The probiotic isolates were encapsulated in skim milk powder by two different drying techniques: freeze drying and spray drying. The encapsulated probiotic isolates survived both in simulated gastric fluid and simulated intestinal fluid with high cell viability (98-99%). Storage for 16weeks at room temperature (27°C), resulted in 2 log reduction, but better survival with only 1 log reduction was observed at 4°C and was best at -20°C. Survival of isolates was similar in both spray and freeze dried products.

Dry powder inhaler formulation of high-payload antibiotic nanoparticle complex intended for bronchiectasis therapy: Spray drying versus spray freeze drying preparation

Inhaled nano-antibiotics have recently emerged as the promising bronchiectasis treatment attributed to the higher and more localized antibiotic exposure generated compared to native antibiotics. Antibiotic nanoparticle complex (or nanoplex in short) prepared by self-assembly complexation with polysaccharides addresses the major drawbacks of existing nano-antibiotics by virtue of its high payload and cost-effective preparation. Herein we developed carrier-free dry powder inhaler (DPI) formulations of ciprofloxacin nanoplex by spray drying (SD) and spray freeze drying (SFD). d-Mannitol and l-leucine were used as the drying adjuvant and aerosol dispersion enhancer, respectively. The DPI formulations were evaluated in vitro in terms of the (1) aerosolization efficiency, (2) aqueous reconstitution, (3) antibiotic release, and (4) antimicrobial activity against respiratory pathogen Pseudomonas aeruginosa. The SFD powders exhibited superior aerosolization efficiency to their SD counterparts in terms of emitted dose (92% versus 66%), fine particle fraction (29% versus 23%), and mass median aerodynamic diameter (3μm versus 6μm). The superior aerosolization efficiency of the SFD powders was attributed to their large and porous morphology and higher l-leucine content. While the SFD powders exhibited poorer aqueous reconstitution that might jeopardize their mucus penetrating ability, their antibiotic release profile and antimicrobial activity were not adversely affected.

Effects of freeze drying and spray drying on the microstructure and composition of milk fat globules

Freeze drying and spray drying are conventional methods for converting milk into powder in the dairy industry.

Seleksi Bakteri Asam Laktat dan Pemanfaatannya Sebagai Starter Kering Menggunakan Matriks Tapioka Asam

The development of industrial fermentation food could not separate with the availability of culture starter that suffice to support its production. Dried starter can be an option to use in fermentation industry because it can be stored for longer time without rejuvenation. However, in the process of production of dried starter needs the matrix to maintain cell viability, economically and availability of raw material. This research was conducted to use selected dried starter of indigenous lactic acid bacteria by using sour cassava starch matrix. Eleven local isolates lactic acid bacteria isolates from spontaneous fermentation of carbohydrates commodity were selected based on their acid production capabilities and antibiotics susceptibilities. Isolate of E 1222 showed the best result and was identified as Pediococcus pentosaceus. The isolate was encapsulated with sour cassava starch matrix for making dried starter by using freeze dryer and spray dryer. Freeze dried starter culture could maintained the cell viability higher than spray dried starter culture i.e 10.34 log CFU/g and 8.91 log CFU/g, respectively. Finally, freeze dried starter culture could maintain the percentage of cell viability until 89.38% during four-weeks storage at 4 oC.

Optimization of pectin extraction and antioxidant activities from Jerusalem artichoke

Jerusalem artichoke is an economic crop widely planted in saline-alkaline soil. The use of Jerusalem artichoke is of great significance. In this study, the response surface method was employed to optimize the effects of processing variables (extraction temperature, pH, extraction time, and liquid-to-solid ratio) on the yield of Jerusalem artichoke pectin. Under the optimal extraction conditions: pH 1.52, 63.62 min, 100A degrees C and a liquid-to-solid ratio of 44.4 mL/g, the maximum pectin yield was predicted to be 18.76%. Experiments were conducted under these optimal conditions and a pectin yield of 18.52 +/- 0.90% was obtained, which validated the model prediction. The effects of diff erent drying methods (freeze drying, spray drying and vacuum drying) on the properties of Jerusalem artichoke pectin were evaluated and they were compared with apple pectin. FTIR spectral analysis showed no major structural diff erences in Jerusalem artichoke pectin samples produced by various drying treatments. The antioxidant activities of pectin dried by diff erent methods were investigated using in vitro hydroxyl and DPPH radical scavenging systems. The results revealed that the activities of spray dried pectin (SDP) and apple pectin (AP) were stronger than those of vacuum oven dried pectin (ODP) and vacuum freeze dried pectin (FDP). Therefore compared with the other two drying methods, the spray drying method was the best.

Refractance Window drying of pomegranate juice: Quality retention and energy efficiency

Refractance Window (RW) drying system utilizes circulating hot water as a means to carry thermal energy to materials to be dehydrated. Products are spread on a transparent plastic conveyer belt that moves over circulating water in a shallow trough. In this study the quality retention characteristics of pomegranate juice (PJ) concentrate dried in a continuous pilot scale RW drying system were evaluated against freeze drying and spray drying methods. Samples of PJ concentrate (Brix 64) mixed with Gum Arabic as a carrier (35%, dry basis) were dried by the RW drying, freeze drying and spray drying methods. Physicochemical properties including moisture content, solubility, bulk density and color parameters of samples dried using different methods were compared. Chemical analysis and color measurements of reconstituted samples showed that RW dryer can produce high-quality products with anthocyanins content, anthocyanins color and antioxidant activity equal or greater than those of the freeze dried and spray dried samples. Energy consumption of the RW dryer was about one third and 1/40 of those of spray drying and freeze drying systems, respectively.

A Review of Methods for Evaluating Particle Stability in Suspension Based Pressurized Metered Dose Inhalers.

Advances in particle engineering techniques, such as spray drying, freeze drying and supercritical fluid precipitation, have greatly enhanced the ability to control the structure, morphology, and solid state phase of inhalable sized particles (1 - 5 µm) for formulation in pressurized metered dose inhalers (pMDI). To optimize the properties of these engineered particles for formulation in hydrofluoroalkane propellants (HFA 134a / 227) it is necessary to measure both bulk and individual particle properties before, after, and during formulation. This review examines established and recently developed methods for evaluating a variety of particle properties including but not limited to size, surface and internal morphology, chemical composition, and solid state phase. Novel methods for evaluating particle physical and chemical stability directly in propellant or similar environments are also discussed.

Dry Powder Formulation of Plasmid DNA and siRNA for Inhalation.

Nucleic acid therapeutics has huge potential for the treatment of a wide range of diseases including respiratory diseases. Plasmid DNA (pDNA) and small interfering RNA (siRNA) are the two most widely investigated nucleic acids for therapeutic development. However, efficient and safe delivery of nucleic acids is still a major hurdle in translating nucleic acid therapy into clinical practice. For the treatment of respiratory diseases, administration via inhalation is the most direct and effective way to deliver therapeutic nucleic acids to the lungs. Although liquid aerosol formulation is investigated in most of the studies, it is not desirable in terms of maintaining the stability of nucleic acid especially during long-term storage. This problem could be circumvented by formulating the therapeutic nucleic acids into dry powder for inhalation, and should be considered as the future direction of developing inhalable nucleic acids. In this review, the three major particle engineering methods investigated for the preparation of inhalable pDNA and siRNA formulations, including spray drying (SD), spray freeze drying (SFD) and supercritical fluid (SFC) drying, are discussed and compared. Moreover, common assessment methods and the challenges of evaluating the biological activities of inhalable nucleic acid powders are also reviewed.

Development of Biodegradable Polycation-Based Inhalable Dry Gene Powders by Spray Freeze Drying.

In this study, two types of biodegradable polycation (PAsp(DET) homopolymer and PEG-PAsp(DET) copolymer) were applied as vectors for inhalable dry gene powders prepared by spray freeze drying (SFD). The prepared dry gene powders had spherical and porous structures with a 5~10-μm diameter, and the integrity of plasmid DNA could be maintained during powder production. Furthermore, it was clarified that PEG-PAsp(DET)-based dry gene powder could more sufficiently maintain both the physicochemical properties and in vitro gene transfection efficiencies of polyplexes reconstituted after powder production than PAsp(DET)-based dry gene powder. From an in vitro inhalation study using an Andersen cascade impactor, it was demonstrated that the addition of l-leucine could markedly improve the inhalation performance of dry powders prepared by SFD. Following pulmonary delivery to mice, both PAsp(DET)- and PEG-PAsp(DET)-based dry gene powders could achieve higher gene transfection efficiencies in the lungs compared with a chitosan-based dry gene powder previously reported by us.

Effects of freeze-drying and spray drying processes on functional properties of phosphorylation of egg white protein

Egg white protein (EWP) was phosphorylated with Sodium Tripolyphosphate (STP) at pH 4.5. Freeze drying and spray drying were used for drying purpose and the effects of these drying methods on the functional properties were investigated. The functional properties of native and modified proteins were also determined. The results demonstrated that phosphorylation of EWP markedly improved its functional properties, and that it was more effective for the food industry. The freeze-dried STP-EWP powders were superior in terms of solubility, emulsion stability, water holding capacity, oil and water absorption capacity and heat gel strength than spray-dried STP-EWP powders. The results in viscosity showed no significant differences between freeze-dried and spray dried. The spray-dried powders were better in terms of foaming ability and foam stability than freeze-dried powders. However, the spray drying required the longest time to produce. Freeze drying was found to be the best method in terms of production of modified EWP powders with superior functional properties. Keywords: freeze drying, spray drying, egg white protein, phosphorylation, functional properties DOI: 10.3965/j.ijabe.20150804.1942 Citation: Liu L L, Wang H, Ren G Y, Duan X, Li D, Yin G J. Effects of freeze-drying and spray drying processes on functional properties of phosphorylation of egg white protein. Int J Agric & Biol Eng, 2015; 8(4): 116－123.

Conjugation of Hot-Melt Extrusion with High-Pressure Homogenization: a Novel Method of Continuously Preparing Nanocrystal Solid Dispersions.

Over the past few decades, nanocrystal formulations have evolved as promising drug delivery systems owing to their ability to enhance the bioavailability and maintain the stability of poorly water-soluble drugs. However, conventional methods of preparing nanocrystal formulations, such as spray drying and freeze drying, have some drawbacks including high cost, time and energy inefficiency, traces of residual solvent, and difficulties in continuous operation. Therefore, new techniques for the production of nanocrystal formulations are necessary. The main objective of this study was to introduce a new technique for the production of nanocrystal solid dispersions (NCSDs) by combining high-pressure homogenization (HPH) and hot-melt extrusion (HME). Efavirenz (EFZ), a Biopharmaceutics Classification System class II drug, which is used for the treatment of human immunodeficiency virus (HIV) type I, was selected as the model drug for this study. A nanosuspension (NS) was first prepared by HPH using sodium lauryl sulfate (SLS) and Kollidon® 30 as a stabilizer system. The NS was then mixed with Soluplus® in the extruder barrel, and the water was removed by evaporation. The decreased particle size and crystalline state of EFZ were confirmed by scanning electron microscopy, zeta particle size analysis, and differential scanning calorimetry. The increased dissolution rate was also determined. EFZ NCSD was found to be highly stable after storage for 6months. In summary, the conjugation of HPH with HME technology was demonstrated to be a promising novel method for the production of NCSDs.

Effect of different drying methods on the structure and digestibility of short chain amylose crystals

Short chain amylose (SCA) was obtained by debranched waxy rice starch. The SCA crystals was formed by crystallization and dried by freeze drying, air drying and spray drying. The physicochemical properties and digestibility of the dried crystals were investigated. Light microscope and scanning electron microscopy revealed that the air dried crystals exhibited compact structure, but freeze dried crystals showed loose and porous morphology. Spray dried crystals showed sphere morphology. Air dried crystals had a higher relative crystallinity and a higher melting temperature as compared with the crystals dried by freeze and spray drying. The digestibility analysis showed that air drying was the preferred method for the formation of resistant starch in SCA crystals, while spray drying favor to obtain products with high level of slowly digestible starch. The tight pack of double helix could be responsible for the enzyme resistance of air dried crystals.

The drying rates of spray freeze drying systems increase through the use of stratified packed bed structures

It is shown that when in the spray freeze drying process stratified packed beds are employed where the smallest in size particles are located near the surface of the lower heating plate while the largest particles are occupying the upper part of the stratified packed bed whose outermost surface is in contact with the atmosphere of the drying chamber of the freeze dryer, the duration times of the primary and secondary drying stages can be substantially reduced when compared with those required by a spray freeze drying process which uses a single packed bed formed by particles all having the same particle size and the total amount of solids in the packed bed is the same as that in the stratified packed bed.

Evaluation of nano spray drying as a method for drying and formulation of therapeutic peptides and proteins.

OPINION article Front. Pharmacol., 07 July 2015Sec. Drugs Outcomes Research and Policies Volume 6 - 2015 | https://doi.org/10.3389/fphar.2015.00140

Comparison of spray drying, freeze drying and convective hot air drying for the production of a probiotic orange powder

Survival of two LAB in orange powders obtained by spray-(SD), freeze-(FD) and convective hot air drying (CD) was investigated during drying and subsequent storage. Colour and vitamin C content of the powders were also evaluated. There was no decrease in the cell number during SD and FD, but a reduction of ~2 log cycles was obtained in CD. During storage at 4 °C no significant differences (p > 0.05) in the survival of Lactobacillus plantarum 299v were observed for the orange powder obtained by the different techniques. However, during storage at room temperature, its survival was better in orange powders prepared by CD. For Pediococcus acidilactici HA-6111-2, reductions during storage were minimal for most of the conditions investigated. Considering the initial cell number obtained after each drying process, SD and FD allowed survival of an increased number of cells after storage period. The best colour retention was obtained by FD, with no maltodextrin, and the higher total vitamin C retention was achieved in SD and FD powders. By the high production costs and long drying times of FD, it can be concluded that SD could be a good method to produce a new functional non-dairy product, such as a probiotic orange juice powder.

Short-Term Cryotherapy--Putting Dynamic Foot and Ankle Stability at Risk?

The application of ice or other forms of cooling represent a common method to treat acute musculoskeletal injuries during sporting events in order to reduce pain. Often athletes return to competition immediately after cooling. It is not known if short-term cryotherapy in the form of ice spray has an influence on the joint's dynamic stability. The aim of this study was to investigate if application of ice spray to the ankle has an effect on the dynamic stability of the joint in healthy participants. A randomized controlled single-blind pilot study with crossover-design was conducted. 22 healthy athletic participants (15 women, 7 men, mean age 31.8 years ± 5.7) were included. Time-to-stability (TTS) was used to investigate the effect of the interventions, ice spray and water spray, applied on the lateral ankle. TTS was assessed in medio-lateral (ML) and antero-posterior (AP) direction on a force plate with two different tests (side step down and 1-leg jump). Collected co-variables were age, gender, height, weight, previous ankle injuries, Tegner activity scale and leg dominance. There were no significant differences between the two tests (side step down and 1-leg jump) in TTS after the application of ice spray or a water spray compared to the baseline (p > 0.05). There was no significant difference between the two interventions. The testing of the co-variable "previous ankle injury" showed a significant influence on the TTS in medio-lateral direction in the 1-leg jump test of the non-dominant leg after application of ice spray (p = 0.027). On the dominant leg same tendency could be found (p = 0.062). The application of ice spray to the lateral ankle does not have an effect on dynamic stability in healthy participants. In participants with a previous ankle injury a significant decrease in dynamic stability after application of ice spray could be shown. Whether further factors affecting stability such as fatigue and the influence of an opponent player or the application of ice spray on adjacent muscles may augment this effect should be subject to future investigations.

Microencapsulation of green tea polyphenols and its effect on incorporated bread quality

Green tea polyphenols are potential antioxidants, anti-carcinogenic and effective against various degenerative disorders. Polyphenols are more sensitive to high temperature and alkaline pH. To improve the stability of polyphenols, green tea extract was microencapsulated by freeze drying and spray drying technique using three different wall materials such as maltodextrin (MD), β-cyclodextrin (CD) and combination of both (MD + CD). Freeze dried encapsulates exhibited higher encapsulation efficiency (60–76%) and antioxidant activity (IC50 value 54.77–60.26 μg/ml) than spray dried encapsulates. Comparatively, MD encapsulates had higher encapsulation efficiency and antioxidant activity than other encapsulates. Hence spray dried and freeze dried MD encapsulates were incorporated into bread and evaluated for their quality characteristics. Green tea extract and encapsulates incorporated bread retained their quality in terms of volume and crumb firmness and almost similar to control. Moreover, there was not much significant difference on total polyphenol content of green tea extract and microencapsulates incorporated breads.

Dendrite Growth during Freezing of Millimeter-Scale Eicosane Droplets

The freezing characteristics of small diameter eicosane (Tmelt = 37°C) droplets are studied here for their use in novel dry-cooling strategies based on spray freezing of recirculating phase change materials (PCM). PCM can be used to store thermal energy with relatively small changes in temperature (due to latent heat), as well as volume (due to small density changes). 4.2 mm diameter eicosane droplets are superheated to 40°C, placed on a cold stage at 10°C, and imaged during freezing (a). Similarly, liquid eicosane is enclosed within a custom-built experimental package creating a 5 mm diameter, 100 μm thick disc geometry with a temperature controlled boundary that is rapidly dropped from 40°C to 10°C (b). In both cases the liquid-solid interface is tracked, as well as the formation and growth of long dendrite structures which have been observed to play a critical role in the freezing process. (c) and (d) show the vertical position normalized by the droplet height , y/H, and the radial position (measured inward) normalized by the disc radius, r/R, of both the interface location and the average dendrite tip location. The total freezing time is observed visually, resulting in characteristic Fourier numbers of Fo = 0.55 ± 0.15 (droplet) and Fo = 3.5 ±0.15 (disc) at identical Stefan numbers of St = 0.3 ± 0.03, where the characteristic lengths are taken as the ratio of the eicosane volume to the cooled surface area.

Effects of processing conditions on powder properties of black glutinous rice (Oryza sativa L.) bran anthocyanins produced by spray drying and freeze drying

Black glutinous rice (BGR) was milled and the bran was collected for anthocyanins extraction. The broken rice fraction was enzymatically produced as black glutinous rice maltodextrins (BRM) with 3 dextrose equivalents (DE), including DE10 (BRM10), 20 (BRM20) and 30 (BRM30). The BRMs were used as wall materials in microencapsulation processes. Feed mixtures were spray dried at 3 inlet air temperatures (140, 160 and 180 °C) and freeze dried at −45 °C. Process yield, anthocyanin retention, and powder properties were investigated. The results demonstrated that increasing the inlet air temperature caused a decrease in the bulk density and anthocyanin retention. Moreover, increasing the inlet air temperature enhanced dehydration, process yield, solubility, dispersibility, flowability and smooth particle surface. The suggested conditions for the spray drying process were 180 °C of inlet air temperature combined with BRM20, and the suggested wall material for the freeze drying process was also BRM20. A comparison between the BRMs and a commercial maltodextrin (DE10) showed that microencapsulation of anthocyanin using BRM20 had a higher process yield while the other powder properties were similar. The results suggest that BRM can be applied to replace commercial maltodextrin for anthocyanin microencapsulation.

Survival of Microencapsulated Probiotic Bacteria after Processing and during Storage: A Review

The use of live probiotic bacteria as food supplement has become popular. Capability of probiotic bacteria to be kept at room temperature becomes necessary for customer's convenience and manufacturer's cost reduction. Hence, production of dried form of probiotic bacteria is important. Two common drying methods commonly used for microencapsulation are freeze drying and spray drying. In spite of their benefits, both methods have adverse effects on cell membrane integrity and protein structures resulting in decrease in bacterial viability. Microencapsulation of probiotic bacteria has been a promising technology to ensure bacterial stability during the drying process and to preserve their viability during storage without significantly losing their functional properties such acid tolerance, bile tolerance, surface hydrophobicity, and enzyme activities. Storage at room temperatures instead of freezing or low temperature storage is preferable for minimizing costs of handling, transportation, and storage. Concepts of water activity and glass transition become important in terms of determination of bacterial survival during the storage. The effectiveness of microencapsulation is also affected by microcapsule materials. Carbohydrate- and protein-based microencapsulants and their combination are discussed in terms of their protecting effect on probiotic bacteria during dehydration, during exposure to harsh gastrointestinal transit and small intestine transit and during storage.