scholarly journals The effect of freeze-drying media and storage temperature on ultrastructure and DNA of freeze-dried buffalo bull spermatozoa

2016 ◽  
Vol 5 (6) ◽  
pp. 524-535 ◽  
Author(s):  
Mohamed I. Shahba ◽  
Reda I. El-Sheshtawy ◽  
Abdel-Salam I. El-Azab ◽  
Alaa E. Abdel-Ghaffar ◽  
Maha S. Ziada ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Storage Temperature ◽  
Freeze Dried ◽  
And Storage

scholarly journals Viability of L. casei during fermentation in soymilk and freeze-dried soymilk; effect of cryoprotectant, rehydration and storage temperature

2006 ◽  
Vol 52 ◽  
pp. 17-24
Author(s):  
Lela Acevska ◽  
Kristina Mladenovska ◽  
Tanja Petreska Ivanovska ◽  
Maja Jurhar Pavlova ◽  
Milena Petrovska ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Storage Temperature ◽  
Acid Stress ◽  
Titratable Acidity ◽  
Therapeutic Level ◽  
Freeze Dried ◽  
Different Temperatures ◽  
And Storage

Viability of L. casei during fermentation in soymilk and freeze-dried soymilk; effect of cryoprotectant, rehydration and storage temperature The aim of the work was to investigate the behaviour of L. casei and the effect of sorbitol on its viability during fermentation in soymilk drink. Values for pH, ranging from 6.82 to 3.42 in the soymilk drink without sorbitol and from 6.74 to 3.41 in the drink with sorbitol were noted during 72 h of fermentation at 25oC. The corresponding values for titratable acidity ranged from 0.071% to 0.758% and from 0.073% to 0.761%, respectively. Soymilk was found to support the growth of L. casei with improvement in viability for 0.24 log at the end of fermentation when sorbitol was added. Survival of L. casei and the effectiveness of sorbitol in improving viability during freeze-drying, subsequent rehydration and during a 5-week period of storage under different temperatures were also investigated. After freeze-drying, L. casei exhibited a survival percent of approximately 46%. Sorbitol improved the viability of L. casei by 0.51 log immediately after freeze-drying and by 1.30 log and 0.47 log during five weeks of storage at 25oC and 4oC, respectively. Further study revealed that the freeze-dried fermented soymilk rehydrated at 45oC was optimum for the recovery of L. casei with improvement in recovery for 0.68 log when sorbitol was added. A higher percent of survival was noted when the dried soymilk was stored at 4oC than at 25oC with improved viability at the end of 5 weeks storage for approximately 6 log for drinks with and without sorbitol. Fermented dried soymilk with sorbitol afforded significant tolerance of L. casei to acid stress. Generally, a stable probiotic diary product was prepared in which the concentration of L. casei remained above therapeutic level of 107 cfu/ml.

Viability, Efficacy, and Storage Stability of Freeze-Dried Biocontrol Agent Candida sake Using Different Protective and Rehydration Media

2001 ◽  
Vol 64 (6) ◽  
pp. 856-861 ◽  
Author(s):  
M. ABADIAS ◽  
N. TEIXIDÓ ◽  
J. USALL ◽  
A. BENABARRE ◽  
I. VIÑAS
Keyword(s):  
Freeze Drying ◽  
Storage Stability ◽  
Storage Temperature ◽  
Penicillium Expansum ◽  
Freeze Dried ◽  
Skimmed Milk ◽  
The Stability ◽  
Candida Sake ◽  
Initial Starting ◽  
And Storage

Viability, efficacy against Penicillium expansum on Golden Delicious apples, and storage stability of freeze-dried Candida sake strain CPA-1 were studied. The effect of several protective agents and rehydration media was investigated in the freeze drying of C. sake. Skimmed milk at 10% concentration was a good rehydration medium for all protectants tested. In general, good viability results were obtained when the same solution was used as a protectant and as a rehydration medium. The best survival was obtained when C. sake cells were protected with 10% lactose + 10% skimmed milk and rehydrated with skimmed milk (85% viability). The potential for biocontrol of the best freeze-dried treatments against P. expansum on apples was compared with that of fresh cells. Freeze-dried treatments at 1 × 107 CFU/ml reduced the incidence of decay by 45 to 66%. The best biocontrol effect was obtained with cells that had been freeze dried using 10% lactose + 10% skimmed milk as a protectant and 1% peptone as a rehydration medium, with a 66% reduction in rot incidence. However, in all treatments, the efficacy of freeze-dried cells was significantly lower than fresh cells. The stability of freeze-dried samples decreased during storage and was influenced by storage temperature. In the best treatment, storage of C. sake cells for 60 days at 4°C resulted in final concentrations of 2.5 × 108 CFU/ml, which was a 10-fold reduction in relation to the initial starting concentration of cells prior to freeze drying.

scholarly journals Protective Effects of Tropical Fruit Processing Coproducts on Probiotic Lactobacillus Strains during Freeze-Drying and Storage

2020 ◽  
Vol 8 (1) ◽  
pp. 96 ◽  
Author(s):  
Caroliny Mesquita Araújo ◽  
Karoliny Brito Sampaio ◽  
Francisca Nayara Dantas Duarte Menezes ◽  
Erika Tayse da Cruz Almeida ◽  
Marcos dos Santos Lima ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Freeze Drying ◽  
Room Temperature ◽  
Membrane Integrity ◽  
Added Value ◽  
Protective Effects ◽  
Tropical Fruit ◽  
Freeze Dried ◽  
Fruit Processing ◽  
And Storage

This study evaluated the protective effects of coproducts from agroindustrial processing of the tropical fruits acerola (Malpighia glabra L., ACE), cashew (Anacardium occidentale L., CAS), and guava (Psidium guayaba L., GUA) on the probiotics Lactobacillus paracasei L-10, Lactobacillus casei L-26, and Lactobacillus acidophilus LA-05 during freeze-drying and storage. The occurrence of damage to membrane integrity, membrane potential, and efflux activity of Lactobacillus cells after freeze-drying was evaluated by flow cytometry, and viable counts were measured immediately after freeze-drying and during 90 days of storage under refrigerated or room temperature conditions. Probiotic strains freeze-dried without substrate had the overall highest count reductions (0.5 ± 0.1 to 2.9 ± 0.3 log cycles) after freeze-drying. Probiotics freeze-dried with fruit processing coproducts had small cell subpopulations with damaged efflux activity and membrane potential. Average counts of probiotics freeze-dried with ACE, CAS, or GUA after 90 days of storage under refrigerated or room temperature were in the range of 4.2 ± 0.1 to 5.3 ± 0.2 and 2.6 ± 0.3 to 4.9 ± 0.2 log CFU/g, respectively, which were higher than those observed for strains freeze-dried without substrate. The greatest protective effects on freeze-dried probiotics were overall presented by ACE. These results revealed that ACE, CAS, and GUA can exert protective effects and increase the stability of probiotic lactobacilli during freeze-drying and storage, in addition to supporting a possible added-value destination for these agroindustrial coproducts as vehicles for probiotics and for the development of novel functional foods.

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.

EFFECTS OF FREEZING, FREEZE-DRYING, AND STORAGE IN THE FREEZE-DRIED AND FROZEN STATE ON VIABILITY OF ESCHERICHIA COLI CELLS

1961 ◽  
Vol 7 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Mary T. Clement
Keyword(s):  
Escherichia Coli ◽  
Freeze Drying ◽  
Storage Temperature ◽  
Stable State ◽  
Skim Milk ◽  
Escherichia Coli Cells ◽  
Freeze Dried ◽  
C 23 ◽  
Frozen State ◽  
Final Survival

Escherichia coli cells in concentrations of 2 × 109cells per ml were resistant to freezing at −78 °C and to low temperatures encountered during freeze-drying when suspended in distilled water, 7.5% glucose, 4.5% glycerol, skim milk, or serum but not when in saline. Survival immediately after freeze-drying varied with the drying interval and composition of the suspending medium and was highest (70–100%) in media containing 7.5% added glucose. Survival during storage in freeze-dried suspensions in serum containing 7.5% added glucose was inversely related to storage time and temperature; after 1 year at 32 °C, 21 °C, and 4 °C, survival was 0, 25%, and 80% respectively. When suspensions in water, glucose, glycerol, and serum were frozen directly and stored in the frozen state at −18 °C, −23 °C, and −40 °C, the cells showed a diminishing death rate and eventually attained a stable state. The final survival level varied with the composition of the suspending medium and the storage temperature. Glycerol provided most consistent protection (minimum survival 65%). Survival in water and glucose was inversely proportional to the storage temperature. Viability in water was higher than in glucose and was equal to glycerol in storage at −40 °C (80% after 2 years).

scholarly journals Freeze-drying techniques for preserving aphids (Homoptera, Aphidodea)

1994 ◽  
Vol 5 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Anders Albrecht
Keyword(s):  
Freeze Drying ◽  
Body Shape ◽  
Vacuum Drying ◽  
Drying Methods ◽  
Drying Time ◽  
Freeze Dried ◽  
Drying Techniques ◽  
Wax Coating ◽  
And Storage

Techniques for collection, preparation and storage of freeze-dried aphid samples, including galls, are described. Freeze-drying can be done with the aid of a home freezer, a drying agent, and suitable containers alone, but drying time can be reduced considerably with cheap and simple vacuum drying equipment. Freeze-drying methods have several advantages compared with traditional mounting techniques. Body shape, colours, wax coating and microsculpture are excellently preserved. The labour required per sample, for preparation as well as for identification, is reduced to a minimum, and complete colony samples can be stored as entities. Aspects of practical handling and study of freeze-dried aphid samples are discussed.

scholarly journals Freeze-Drying of Sweet Peppers

1969 ◽  
Vol 54 (1) ◽  
pp. 133-148
Author(s):  
M. A. González ◽  
E. Díaz Negrón ◽  
H. Cancel ◽  
A. C. Rivera
Keyword(s):  
Shelf Life ◽  
Freeze Drying ◽  
Drying Rate ◽  
Microbial Count ◽  
Drying Time ◽  
Hot Air ◽  
Freeze Dried ◽  
And Storage ◽  
Index Of Quality ◽  
Platen Temperature

Studies were conducted to dehydrate garden sweet peppers by means of hot-air and freeze-drying. Sweet peppers have tough, leathery skins which makes escape of moisture difficult and prolongs drying time. Our data indicates that dehydration of half-cut or slitted fruit is accomplished either by conventional hot-air or by freeze-drying in reasonably shorter periods of time than whole fruit. Change in color or shape was not observed in sweet peppers during freezedrying. Great deterioration in the green color was observed in the samples dehydrated with hot-air at 165° F. The shelf-life of the freeze-dried product is superior to that of the conventionally hot-air dried product. For freeze-drying the sweet peppers within a reasonable period of time, and to obtain a product with shape and color similar to the fresh fruit, a platen temperature of 180° F. should be used during 2 hours and then reduced to 150° F. during the rest of the drying period. Heat treatment to inactivate microbial activity of sweet peppers prior to freeze-drying greatly reduces the microbial count and does not affect the drying rate, quality and shelf-life of the end product. Deterioration of sweet peppers during drying and storage is characterized by development of off-flavor and color. Because the measurement of off-flavor is difficult in a mild pungent fruit such as sweet peppers, these studies indicate that measurement of changes in color can be used as an index of quality.

scholarly journals Effects of Lyophilization and Storage Temperature on Wuchereria bancrofti Antigen Sensitivity and Stability

2018 ◽  
Author(s):  
Edem Y. Agbozo ◽  
Edward Dumashie ◽  
Daniel A. Boakye ◽  
Dziedzom K. de Souza
Keyword(s):  
Storage Temperature ◽  
Wuchereria Bancrofti ◽  
Rapid Diagnostic Tests ◽  
Plasma Samples ◽  
Freeze Dried ◽  
Duration Of Storage ◽  
Control Programmes ◽  
Increasing Temperature ◽  
And Storage ◽  
Blood Spot

Antigen-based rapid diagnostic tests for Lymphatic filariasis do not come with quality control (QC) materials, and research and disease control programmes rely on stored positive plasma samples. This study was undertaken to evaluate the use of freeze-dried Wuchereria bancrofti antigen positive plasma samples to serve as QC materials for LF RDTs. 10 well characterized W. bancrofti positive samples were lyophilized and stored at 4°C, 28°C and 40°C. The samples were evaluated using the Filaria Test Strips before lyophilization and after one and three (3) months of storage. The sensitivity and stability of the lyophilized samples were evaluated. The results revealed a loss of sensitivity and stability with increasing temperature and duration of storage. The results are further discussed in terms of the use of Dried Blood Spot (DBS) in diagnostics studies on LF requiring quantitative assessments, and the need for thoughtful DBS preparation and storage.

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