Impact of the freeze-drying process on product appearance, residual moisture content, viability, and batch uniformity of freeze-dried bacterial cultures safeguarded at culture collections

2016 ◽  
Vol 100 (14) ◽  
pp. 6239-6249 ◽  
Author(s):  
Jindrich Peiren ◽  
Ann Hellemans ◽  
Paul De Vos
Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 127 ◽  
Author(s):  
Alicia Conde-Islas ◽  
Maribel Jiménez-Fernández ◽  
Denis Cantú-Lozano ◽  
Galo Urrea-García ◽  
Guadalupe Luna-Solano

The purpose of this study was to investigate how the properties of Mexican kefir grains (MKG) are affected by the operating parameters used in the freeze-drying process. The factors investigated were the freezing time (3–9 h), freezing temperature (−20 to −80 °C), pressure (0.2–0.8 mbar), and lyophilization time (5–20 h). The maximum range of change and one-way analysis of variance showed that lyophilization time and freezing time significant affects (p < 0.05) the response variables, residual moisture content and water activity, and pressure had a significant effect on the color difference and survival rate of probiotic microorganisms. The best drying conditions were a freezing time of 3 h, a freezing temperature of −20 °C, a pressure of 0.6 mbar, and a lyophilization time of 15 h. Under these conditions, we obtained a product with residual moisture content below 6%, water activity below 0.2, and survival rates above 8.5 log cfu per gram of lactic acid bacteria and above 8.6 log for yeast.


2010 ◽  
Vol 3 ◽  
pp. MBI.S2728 ◽  
Author(s):  
Stephenie Wong ◽  
Barka Mohammed Kabeir ◽  
Shuhaimi Mustafa ◽  
Rosfarizan Mohamad ◽  
Anis Shobirin Meor Hussin ◽  
...  

Viability of Bifidobacterium pseudocatenulatum G4 following spray-drying and freeze-drying in skim milk was evaluated. After spray-drying, the strain experienced over 99% loss in viability regardless of the air outlet temperature (75 and 85 °C) and the heat-adaptation temperature (45 and 65 °C, 30 min). The use of heat-adaptation treatment to improve the thermotolerance of this strain was ineffective. On the other hand, the strain showed a superior survival at 71.65%–82.07% after freeze-drying. Viable populations of 9.319–9.487 log10 cfu/g were obtained when different combinations of skim milk and sugar were used as cryoprotectant. However, the addition of sugars did not result in increased survival during the freeze-drying process. Hence, 10% (w/v) skim milk alone is recommended as a suitable protectant and drying medium for this strain. The residual moisture content obtained was 4.41% ± 0.44%.


1985 ◽  
Vol 57 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Yrjö Roos ◽  
Jorma J. Laine

This study deals with the freeze-drying of berries, vegetables, roots and pork produced in Finland. The products were freeze dried whole, in slices or cubes. The pressure in the drying chamber was 10—20 Pa and the maximum surface temperature +23—+ 40°C. The products were packed after freeze-drying into glass jars under air and in polyester-aluminium-polyethene foil under vacuum or nitrogen atmosphere. The drying temperatures and drying times were measured. During storage for 4 months, the differences in quality were evaluated. The drying times ranged from 8 to 25 hours. The moisture content of the dry products was 1—3 %. The sublimation rate at the beginning of the drying process was very rapid, being there after constant. Bilberries, carrots and radishes collapsed during drying. Most of the products dried moistened and underwent aroma changes during storage in glass jars under air. The products packed under vacuum or nitrogen atmosphere proved stable.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 400-407
Author(s):  
Elissa J Flaumenhaft ◽  
Terry Khat ◽  
Susanne Marschner

ABSTRACT Introduction Terumo BCT is developing a system to produce a freeze-dried plasma product, Terumo’s freeze-dried plasma (TFDP), that is stored in a rugged, light-weight plastic package suitable for field use, which retains a stable level of specific coagulation factors and proteins within clinical range, when stored for up to 2 years at room temperature and 4°C. Materials and Methods Plasma frozen within 24 hours of phlebotomy (PF24) were thawed, sampled, and individually lyophilized to produce a corresponding TFDP unit. Fresh frozen plasma (FFP) units were thawed, sampled, pooled in groups of 10 units (also sampled) and lyophilized to produce 2 lots of TFDP. Each TFDP unit was reconstituted with water for injection (WFI) and tested for pH, prothrombin time, activated partial thromboplastin time, factors V and VIII, fibrinogen, protein C, and protein S. Results were compared with PF24/FFP. Additional FFP units were thawed, sampled, pooled, divided to generate 2 TFDP units for each time point (1, 2, 3, 6, 12, 18, and 24 months, one each stored at 4°C and 25°C) and lyophilized. Postlyophilization, TFDP units were stored at 4°C or 25°C, reconstituted with WFI, and tested for the factors listed above. Residual moisture content of the lyophilized plasma was also tested. Results Coagulation factor activity of TFDP was ±20% of PF24/FFP. Pooling standardized variation in TFDP coagulation factor activities, which were within clinical ranges postlyophilization. The pH of TFDP and PF24/FFP were within required range. Residual moisture content of TFDP was &lt;2%. Conclusions The TFDP process had no negative impact on coagulation factor activity. Input plasma and anticoagulant type did not affect TFDP quality. Pooling FFP normalized factor variability in TFDP and did not negatively impact product quality. The TFDP is stable for up to 24 months at room and refrigerated temperatures. Terumo’s freeze-dried plasma is comparable to PF24/FFP. It does not require complex logistics or time-consuming thawing. Terumo’s freeze-dried plasma may be suitable for rapid treatment of coagulopathies with logistical advantages over PF24/FFP.


2021 ◽  
Vol 71 (1) ◽  
pp. 81-98
Author(s):  
Maja Preskar ◽  
Danijel Videc ◽  
Franc Vrečer ◽  
Mirjana Gašperlin

AbstractThis study explores the use of a statistical model to build a design space for freeze-drying two formulations with ibuprofen. A 2 × 3 factorial experimental design was used to evaluate independent variables (filling volume and annealing time) and responses as residual moisture content, specific surface area and reconstitution time. A statistical model and response surface plots were generated to define the interactions among the selected variables. The models constructed for both formulations suggest that 1 mL of filled volume and no annealing should be used to achieve optimal residual moisture content, specific surface area and reconstitution time. The proposed models were validated with additional experiments, in which the responses observed were mainly in close agreement with the predicted ones. Additionally, the established models demonstrate the reliability of the evaluation procedure in predicting the selected responses.


1997 ◽  
Vol 62 (4) ◽  
pp. 693-695 ◽  
Author(s):  
PABLO BONELLI ◽  
CAROLINA SCHEBOR ◽  
ANA L. CUKIERMAN ◽  
MARIA P. BUERA ◽  
JORGE CHIRIFE

Sign in / Sign up

Export Citation Format

Share Document