scholarly journals Some factors affecting preservability of freeze-dried bacteria

1961 ◽  
Vol 59 (1) ◽  
pp. 77-91 ◽  
Author(s):  
Yoji Obayashi ◽  
Sunao Ota ◽  
Shiro Arai
Keyword(s):  
Freeze Drying ◽  
Survival Rates ◽  
Heat Stability ◽  
Soluble Starch ◽  
Optimal Concentration ◽  
Sodium Glutamate ◽  
Sublimation Rate ◽  
Factors Affecting ◽  
Freeze Dried ◽  
Significant Difference

1. The use of sodium glutamate as a medium for freeze-drying Lact. bifidus significantly enhanced the stability of the dried product, especially the heat stability.2. The optimal concentration of sodium glutamate, as a drying medium, was found to depend on the bacilliary concentration; the higher the concentration of the bacilliary suspension used the higher was found to be the optimal concentration of the sodium glutamate.3. It was possible to classify various drying media according to the degree of sublimation of the product during the process of freeze-drying. Two types were observed; in the first, which included sodium glutamate and glucose, the sublimation rate diminished with the increasing concentration of the medium, whereas in the second group, which included polyvinyl pyrrolidon K 90 (PVP), soluble starch and dextran, no such diminution was observed when the concentration of the medium was increased.4. By the combination of sodium glutamate or glucose with a medium belonging to the second group sublimation was found to be promoted.5. The stabifity-conferring effect of sodium glutamate on dried Lact. bifidus was markedly enhanced when the glutamate was combined with a drying medium belonging to the second group. This effect is attributed to a desiccation-promoting property of the latter medium.6. Lact. bifidus as a freeze-dried preparation showed a somewhat better survival rate when sealed in air than when sealed in vacuo. In the case of other anaerobic organisms tested there was no significant difference in the survival rates under the two methods of storage.

scholarly journals Effect of suspending media on freeze-drying and preservation of vaccinia virus

1970 ◽  
Vol 68 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Masatoshi Suzuki
Keyword(s):  
Protective Effect ◽  
Vaccinia Virus ◽  
Carboxymethyl Cellulose ◽  
Freeze Drying ◽  
Chorioallantoic Membrane ◽  
Soluble Starch ◽  
Sodium Glutamate ◽  
Freeze Dried ◽  
Different Temperatures ◽  
Subsequent Storage

SummaryUnpurified and purified smallpox vaccines were prepared from calf dermal pulp, or chorioallantoic membrane (CAM) of hen eggs infected with vaccinia virus, and freeze-dried. The protective effect of various suspending media was investigated both in the course of the freeze-drying and in the period of subsequent storage of the dried product at different temperatures, including 100° C.Single media consisting of either sodium glutamate or peptone were effective in the preservation of both unpurified and purified vaccines prepared from calf dermal pulp or CAM. It was shown that there was an optimal concentration of sodium glutamate for the preservation of the vaccine preparations, especially of the purified vaccine.Combined media, consisting of soluble starch, polyvinylpyrrolidone or sodium carboxymethyl cellulose with sodium glutamate, were effective with the purified vaccine when the concentration of sodium glutamate exceeded the optimum necessary for preservation.

scholarly journals Effect of Drying Process, Encapsulation, and Storage on the Survival Rates and Gastrointestinal Resistance of L. salivarius spp. salivarius Included into a Fruit Matrix

2020 ◽  
Vol 8 (5) ◽  
pp. 654
Author(s):  
Ester Betoret ◽  
Noelia Betoret ◽  
Laura Calabuig-Jiménez ◽  
Cristina Barrera ◽  
Marco Dalla Rosa
Keyword(s):  
Survival Rate ◽  
Physicochemical Properties ◽  
Freeze Drying ◽  
Molecular Mechanisms ◽  
Survival Rates ◽  
In Vitro Digestion ◽  
Hot Air ◽  
Freeze Dried ◽  
And Storage

In a new probiotic food, besides adequate physicochemical properties, it is necessary to ensure a minimum probiotic content after processing, storage, and throughout gastrointestinal (GI) digestion. The aim of this work was to study the effect of hot air drying/freeze drying processes, encapsulation, and storage on the probiotic survival and in vitro digestion resistance of Lactobacillus salivarius spp. salivarius included into an apple matrix. The physicochemical properties of the food products developed were also evaluated. Although freeze drying processing provided samples with better texture and color, the probiotic content and its resistance to gastrointestinal digestion and storage were higher in hot air dried samples. Non-encapsulated microorganisms in hot air dried apples showed a 79.7% of survival rate versus 40% of the other samples after 28 days of storage. The resistance of encapsulated microorganisms to in vitro digestion was significantly higher (p ≤ 0.05) in hot air dried samples, showing survival rates of 50–89% at the last stage of digestion depending on storage time. In freeze dried samples, encapsulated microorganisms showed a survival rate of 16–47% at the end of digestion. The different characteristics of the food matrix after both processes had a significant effect on the probiotic survival after the GI digestion. Documented physiological and molecular mechanisms involved in the stress response of probiotic cells would explain these results.

scholarly journals THE DIFFERENCE OF TENSILE STRENGTH AND YIELD FIBRINOGEN ON FIBRIN GLUE PREPARATIVE BY CRYOPRESIPITATE WITH AND WITHOUT FREEZE DRYING METHODS

2019 ◽  
Vol 25 (3) ◽  
pp. 349
Author(s):  
Brilliant Margalin ◽  
S. P. Edijanto ◽  
Paulus B. Notopuro
Keyword(s):  
Tensile Strength ◽  
Fibrin Glue ◽  
Freeze Drying ◽  
Drying Methods ◽  
Drying Process ◽  
Freeze Dried ◽  
Significant Difference ◽  
Fibrinogen Content

Fibrin glue is a useful biological product to stop bleeding, adhesive tissue and accelerate wound healing. Preparation of Fibrin Glue requires fibrinogen and thrombin components. The routine cryoprecipitation method performed at the Blood Bank can be used to improve the quality of the fibrinogen component. The Freeze Drying process can increase the retention time of plasma products at room temperature. Yield Fibrinogen and Tensile Strength is a quantitative and qualitative parameter of preparation quality of fibrin glue. This study focused on finding differences between Tensile Strength and Yield Fibrinogen on fibrin glue preparative by cryoprecipitate with and without freeze drying methods.This study is in vitro laboratory experiments design by comparing the Yield Fibrinogen and Tensile Strength of fibrin glue preparation from cryoprecipitic plasma with and without freeze dried process. The results were analyzed comparatively using paired T test.The plasma fibrinogen content of the sample was 237.66 ± 67.10 mg / dL. The fibrinogen content of the cryoprecipitate component without freeze drying process was 327.74 ± 103.42 mg / dL with a yield fibrinogen of 1.38 ± 0.25. The fibrinogen content of the cryoprecipitate component with freeze drying process was 251.20 ± 103.91 mg / dL with yield fibrinogen 1.04 ± 0.25. Tensile strength of fibrin glue from cryoprecipitate without freeze drying process was found to average 0.52 ± 0.18. Tensile strength of fibrin glue from cryoprecipitate with freeze drying process was found to average 0.33 ± 0.12. There was a significant difference between yield fibrinogen and tensile strength of fibrin glue preparation of cryoprecipitation method with and without freeze dried process.There is a significant difference on yields fibrinogen and tensile strength in the preparation of fibrin glue by the freeze drying process which is probably due to changes in the structure and function of fibrinogen proteins.

scholarly journals Effects of Carbohydrates, Prebiotics and Salts on Survival of Saccharomyces boulardii During Freeze-Drying

2018 ◽  
Vol 22 (2) ◽  
pp. 59-66
Author(s):  
Guowei Shu ◽  
Xin Yang ◽  
Zhangteng Lei ◽  
Dan Huang ◽  
Yaling ZHAI
Keyword(s):  
Survival Rate ◽  
Phosphate Buffer ◽  
Freeze Drying ◽  
Saccharomyces Boulardii ◽  
Sodium Ascorbate ◽  
Sodium Glutamate ◽  
Viable Cells ◽  
Freeze Dried ◽  
Probiotic Yeast ◽  
Addition Amount

Abstract Saccharomyces boulardii, as a probiotic yeast, had been commonly used in food, medicine and feed to treat diarrhea in humans or livestock. However, there are few researches focusing on the preparation of its freeze-drying S.boulardii powder. In this study, the effect of carbohydrates (glucose, sucrose, maltose, fructose, lactose, mannose and trehalose), prebiotics (isomalto-oligosaccharide, xylo-oligosaccharide, raffinose, stachyose, inulin, galacto-oligosaccharide and fructo-oligosaccharide) and salts (NaHCO3, MgSO4, sodium glutamate, sodium ascorbate, and phosphate buffer) on the freeze-dried survival of S. boulardii were investigated to screen the cryoprotectant by using single factor experiments. As the result, trehalose and XOS had better protective effect, the survival rate was 23.72% and 20.70% respectively, the number of viable cells reached 0.91×1010 CFU/g and 0.85×1010 CFU/g respectively; the addition amount of NaHCO3 was 0.3%, the freeze-dried survival rate reached the maximum value of 12.92%. The phosphate buffer additive amount and the bacterial sludge weight were 0.8:1, the freeze-dried survival rate reached a maximum of 14.14%, the freeze-dried survival rate of sodium glutamate, sodium ascorbate and MgSO4 groups was increasing, reaching a maximum of 20.26%, 16.47% and 6.29% when the addition amount was 2%, 10%, 0.5%.

scholarly journals Optimization of the bioactive compounds content in raspberry during freeze-drying using response surface method

2015 ◽  
Vol 21 (1-1) ◽  
pp. 53-61 ◽  
Author(s):  
Vesna Tumbas-Saponjac ◽  
Gordana Cetkovic ◽  
Sladjana Stajcic ◽  
Jelena Vulic ◽  
Jasna Canadanovic-Brunet ◽  
...  
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Bioactive Compounds ◽  
Freeze Drying ◽  
Optimal Conditions ◽  
Total Anthocyanin ◽  
Factors Affecting ◽  
Surface Method ◽  
Freeze Dried ◽  
Experimental Values

The production of high-quality freeze-dried raspberry was studied by response surface method. Two independent variables, temperature (X1) and time (X2) were determined as the most important factors affecting the final product quality estimated by the responses: total phenol (Y1), total anthocyanin (Y2), vitamin C (Y3) and total bioactive compounds (Y4) content. A two-factor central composite design was used for freeze-drying experiments. The second order polynomial models obtained were found to be significant (p<0.05) for all responses. The statistical analysis of experimental data indicated that only quadratic time variable (X22) had significant (p<0.05) effect on all responses. The optimal conditions for all responses combined were found to be: -31 ?C and 35 h. The experimental values of all responses obtained under optimal conditions were in good agreement with predicted values which enables the use of the proposed mathematical models for optimization of investigated process.

scholarly journals Assessment of the Durability and Bio-effectiveness of Three Long-Lasting Insecticidal Nets in Three Different Communities After the 2017 Mass Net Distribution Campaign in Benin

2020 ◽  
Vol 11 (2) ◽  
pp. 263
Author(s):  
Idelphonse Bonaventure Ahogni ◽  
Albert Sourou Salako ◽  
Jean Fortuné Dagnon ◽  
Wilfrid Sèwade ◽  
Prudenciène Agboho ◽  
...  
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Good Condition ◽  
Survival Rates ◽  
Factors Affecting ◽  
Significant Difference ◽  
Hole Index ◽  
Key Variables ◽  
Fabric Weight ◽  
Long Lasting Insecticidal Nets

Long-lasting insecticidal nets (LLINs) are an essential tool in the fight against malaria. Physical integrity, durability and bio-effectiveness are key variables in the effectiveness of LLINs. The objective of this study was to identify the main factors affecting the survival of three brands of LLINs with different physical characteristics and to assess their bio-effectiveness. A cohort consisting of 1500 LLINs (500 of each) of the brands: DawaPlus®2.0 (polyester, 150 denier, 40 g/m2 fabric weight), PermaNet®2.0 and Yorkool® (polyester, 75 denier, alternating knit pattern with 85 g/m2 fabric weight) was monitored every 6 months in the communes of Ketou, Dogbo and Djougou (from October 2017 to September 2019) based on attrition and integrity measures and median survival in years. We also determined bio-efficacy using the WHO cone test. The physical presence rate was 26.4%, 21.4% and 48.6% respectively for DawaPlus®2.0, PermaNet®2.0 and Yorkool®. The main cause of loss of the three LLINs was displacement, 43.6% (in rural areas) versus 43.2% (in urban areas) with no significant difference (p ˃ 0.05). The median proportional hole index (pHI) ranged from 578 (IQR: 219-843) at 6 months to 196 (IQR: 46-524.5). After 24 months of use, 86.1% were in good condition (0≤pHI<65), 9% were damaged (65≤pHI<643) and 4.2% were too torn (643≤pHI). A significant decrease in physical survival of LLINs (all brands) was observed at 24 months (37.9%, range 34.7-41.3%) compared to 6 months (90.3%, range 88.7-91.8%) (p<0.001). The 24-hour mortality of the three LLINs met WHO requirements for efficacy. The decline in LLIN survival rates during this study highlights the need to develop and implement new strategies to manage this important vector control tool.

Effect of freeze-drying on viability andin vitroprobiotic properties of a mixture of lactic acid bacteria and yeasts isolated from kefir

2010 ◽  
Vol 78 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Patricia A Bolla ◽  
María de los Angeles Serradell ◽  
Patricio J de Urraza ◽  
Graciela L De Antoni
Keyword(s):  
Freeze Drying ◽  
Survival Rates ◽  
Probiotic Properties ◽  
Milk Product ◽  
Yeast Strains ◽  
Freeze Dried ◽  
Lactobacillus Kefir ◽  
Ad Libitum ◽  
Different Strains

The effect of freeze-drying on viability and probiotic properties of a microbial mixture containing selected bacterial and yeast strains isolated from kefir grains (Lactobacillus kefir,Lactobacillus plantarum,Lactococcus lactis,Saccharomyces cerevisiaeandKluyveromyces marxianus) was studied. The microorganisms were selected according to their potentially probiotic propertiesin vitroalready reported. Two types of formulations were performed, a microbial mixture (MM) suspended in milk and a milk product fermented with MM (FMM). To test the effect of storage on viability of microorganisms, MM and FMM were freeze-dried and maintained at 4°C for six months. After 180 days of storage at 4°C, freeze-dried MM showed better survival rates for each strain than freeze-dried FMM. The addition of sugars (trehalose or sucrose) did not improve the survival rates of any of the microorganisms after freeze-drying. Freeze-drying did not affect the capacity of MM to inhibit growth ofShigella sonnei in vitro, since the co-incubation of this pathogen with freeze-dried MM produced a decrease of 2 log inShigellaviability. The safety of freeze-dried MM was tested in mice and non-translocation of microorganisms to liver or spleen was observed in BALB/c mice feedad libitumduring 7 or 20 days. To our knowledge, this is the first report about the effect of freeze-drying on viability,in vitroprobiotic properties and microbial translocation of a mixture containing different strains of both bacteria and yeasts isolated from kefir.

Mechanical Properties of Tendons: Changes With Sterilization and Preservation

1996 ◽  
Vol 118 (1) ◽  
pp. 56-61 ◽  
Author(s):  
C. W. Smith ◽  
I. S. Young ◽  
J. N. Kearney
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Freeze Drying ◽  
Dynamic Testing ◽  
Young's Modulus ◽  
Testing Machine ◽  
Ultimate Tensile Stress ◽  
Tissue Banks ◽  
Freeze Dried ◽  
Significant Difference

Tendon allografts are commonly used to replace damaged anterior cruciate ligaments (ACL). Some of the sterilization and preservation techniques used by tissue banks with tendon allografts are thought to impair the mechanical properties of graft tissues. The tensile mechanical properties of porcine toe extensor tendons were measured using a dynamic testing machine following either freezing, freeze-drying, freezing then irradiation at 25 kGy (2.5 MRad), freeze-drying then irradiation, or freeze-drying then ethylene oxide gas sterilization. There was a small but significant difference in Young’s modulus between the frozen group (0.88 GPa ± 0.09 SD) and both the fresh group (0.98 GPa ± 0.12 SD) and the frozen irradiated group (0.97 GPa ± 0.08 SD). No values of Young’s modulus were obtained for the freeze-dried irradiated tendons. The ultimate tensile stress (UTS) of the freeze-dried irradiated group (4.7 MPa ± 4.8 SD) was significantly different from both the fresh and the frozen irradiated groups, being reduced by approximately 90 percent. There were no significant changes in UTS or Young’s modulus between any of the other groups. If irradiation is to be used to sterilize a tendon replacement for an ACL it must take place after freeze-drying to maintain mechanical properties.

Comparative Survival Rates of Lactic Acid Bacteria Isolated from Blood, Following Spray-drying and Freeze-drying

2006 ◽  
Vol 12 (1) ◽  
pp. 77-84 ◽  
Author(s):  
L. M. Zamora ◽  
C. Carretero ◽  
D. Parés
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Spray Drying ◽  
Freeze Drying ◽  
Survival Rates ◽  
Storage Period ◽  
Cellular Damage ◽  
Viable Cells ◽  
Porcine Blood ◽  
Freeze Dried

The effect of two dehydration technologies, spray-drying and freeze-drying, on the viability of 12 lactic acid bacteria (LAB) were compared. All LAB cultures had been previously isolated from porcine blood and were candidates to be used as biopreservatives in order to maintain the quality of porcine blood until further processing to obtain added-value blood derivatives is carried out. The residual viability and the reductions in microbial counts in dried LAB samples at 20 °C and 5 °C during 60-day storage were determined. Cellular damage due to freeze-drying was observed immediately after drying whereas cellular damage due to spray-drying did not become evident until the subsequent phase of storage. For most of the strains, the faster decrease in viability of spray-dried as compared to freeze-dried cultures was compensated by the higher percentage of viable cells obtained after dehydration, leading to comparable survival rates at the end of the storage period. Dehydration resulted in a good alternative to freezing at 80 °C for preservation purposes. Spray-drying has been shown to be as suitable as freeze-drying for preserving LAB strains during a 2-month storage period. Results suggest the possibility of achieving a good formulation system for the LAB strains with a high number of viable cells to be used for the industrial development of bioprotective cultures.

scholarly journals In vitro Alpha Lipoic Acid supplementation in freeze-dried human sperm: the impact on DNA fragmentation index

2021 ◽  
Vol 5 (1) ◽  
pp. 125
Author(s):  
Rezia Octarina ◽  
M. P. B. Dyah Pramesti ◽  
Agustinus Agustinus
Keyword(s):  
Dna Fragmentation ◽  
Lipoic Acid ◽  
Freeze Drying ◽  
Human Spermatozoa ◽  
Alpha Lipoic Acid ◽  
Fragmentation Index ◽  
Freeze Dried ◽  
Significant Difference ◽  
The Impact ◽  
Dna Fragmentation Index

Freeze-drying technique is an alternative method on sperm preservation. However, this process can results in DNA damage. Adding antioxidants before freezing can reduce the detrimental effects of ROS on spermatozoa. Alpha lipoic acid (ALA) is one of the potent antioxidant that can be used to protect the sperm DNA. This study was aimed to determine the effect of ALA supplementation before freeze-drying on the DNA fragmentation index (DFI) of human spermatozoa. Nine semen samples were collected and evaluated for DFI (O1) then divided into 3 groups; freeze-drying without ALA (O2), freeze-drying with ALA 1,25 mg (O3) and freeze-drying with ALA 2,5 mg (O4).All three groups were stored at 4oC for 1 week. Sperm DFI were evaluated before and after freeze-drying. The result of this study showed a significant increase in sperm DFI in all three groups after freeze-drying (p<0,05) when compared to DFI before freeze-drying (14,67 ±3,295). However there was no significant difference between O2 (26,90 ±9,180) and O4 (29,29 ±5,524) group where the supplementation of 2,5 mg ALA did not have significant effect on protecting the DNA of freeze-dried human spermatozoa. The highest DFI was in the O3 group (44,64 ±11,717). Therefore, ALA supplementation before freeze-drying does not have a significant effect on protecting the DNA of freeze-dried human spermatozoa.

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