Effect of Dielectric Material on Microwave Freeze Drying of Skim Milk

2005 ◽  
Vol 23 (1-2) ◽  
pp. 317-340 ◽  
Author(s):  
Wei Wang ◽  
Guohua Chen ◽  
Furong Gao
Keyword(s):  
Freeze Drying ◽  
Dielectric Material ◽  
Skim Milk

scholarly journals Optimization of Protective Agents for The Freeze-Drying of Paenibacillus polymyxa Kp10 as a Potential Biofungicide

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2618
Author(s):  
Hayatun Syamila Nasran ◽  
Hidayat Mohd Yusof ◽  
Murni Halim ◽  
Nor’Aini Abdul Rahman
Keyword(s):  
Fungal Pathogens ◽  
Crop Production ◽  
Freeze Drying ◽  
Fungal Infections ◽  
Skim Milk ◽  
Paenibacillus Polymyxa ◽  
Protective Agent ◽  
Protective Agents ◽  
Chemical Fungicides

Anthracnose is a fungal disease causing major losses in crop production. Chemical fungicides widely used in crop plantations to combat fungal infections can be a threat to the environment and humans in the long term. Recently, biofungicides have gained much interest as an alternative to chemical fungicides due to their environmentally friendly nature. Biofungicide products in powder form can be formulated using the freeze-drying technique to provide convenient storage. Protective agent formulation is needed in maintaining the optimal viable cells of biofungicide products. In this study, 8.10 log colony-forming unit (CFU)/mL was the highest cell viability of Paenibacillus polymyxa Kp10 at 22 h during incubation. The effects of several selected protective agents on the viability of P. polymyxa Kp10 after freeze-drying were studied. Response surface methodology (RSM) was used for optimizing formulation for the protective agents. The combination of lactose (10% w/v), skim milk (20% w/v), and sucrose (27.5% w/v) was found to be suitable for preserving P. polymyxa Kp10 during freeze-drying. Further, P. polymyxa Kp10 demonstrated the ability to inhibit fungal pathogens, Colletotrichum truncatum and C. gloeosporioides, at 60.18% and 66.52% of inhibition of radial growth, respectively.

Effect of different encapsulating agent combinations on viability of Lactobacillus casei Shirota during storage, in simulated gastrointestinal conditions and dairy dessert

2019 ◽  
Vol 25 (7) ◽  
pp. 608-617 ◽  
Author(s):  
Osman Gul ◽  
Ilyas Atalar ◽  
Latife Betul Gul
Keyword(s):  
Lactobacillus Casei ◽  
Freeze Drying ◽  
Survival Rates ◽  
Skim Milk ◽  
Gum Arabic ◽  
Storage Conditions ◽  
Ternary Mixtures ◽  
Gastrointestinal Conditions ◽  
Lactobacillus Casei Shirota ◽  
Free Cells

In this study, the effects of various matrices consisting of maltodextrin and reconstitute skim milk and their binary and ternary mixtures with gum Arabic in the microencapsulation of Lactobacillus casei Shirota by freeze-drying technique were assessed. Microcapsules produced with reconstitute skim milk showed high viability (>99%) after freeze drying. While the free cells were completely inactivated after exposure to simulated gastrointestinal conditions, the survival rates of microencapsulated L. casei Shirota were found high for all microcapsules except for maltodextrin and maltodextrin:gum Arabic formulas. The viability of microencapsulated L. casei Shirota during storage at refrigerate and room temperatures decreased between 0.39 and 2.43 log cycles and microcapsules produced with reconstitute skim milk:gum Arabic was found more durable at the both storage conditions. Reduction in the number of free cells was higher than encapsulated L. casei Shirota numbers during production of dessert, however the viability of encapsulated L. casei Shirota was found stable for 14 days of storage and consequently desserts containing encapsulated L. casei Shirota (except maltodextrin) showed stable pH values. This study revealed that combination of reconstitute skim milk:gum Arabic was an effective wall matrix for microencapsulation of L. casei Shirota by freeze drying and also very resistant against gastrointestinal fluids and storage conditions in view of protection of L. casei Shirota.

scholarly journals Physicochemical and antioxidant properties of freeze-dried dromedary skim colostrum and milk powder

Mljekarstvo ◽  
2020 ◽  
Vol 71 (1) ◽  
pp. 69-78
Author(s):  
Olfa Oussaief ◽  
Keyword(s):  
Bulk Density ◽  
Freeze Drying ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Milk Powder ◽  
Skim Milk ◽  
Reducing Power ◽  
Skim Milk Powder ◽  
Chelating Activity

This study aimed to determine the physicochemical properties and antioxidant activities of dromedary skim colostrum and milk powder produced by freeze-drying. Results of the study showed that skim colostrum powder possessed higher protein content compared to milk powder whereas this latter had greater lactose and ash content. The analysis of mineral content revealed that calcium and magnesium levels were higher in skim colostrum powder while the iron level did not differ significantly between skim colostrum and milk powder. The measurements of colour characteristics indicated that dromedary skim colostrum powder was redder, but less yellow and white than dromedary skim milk powder. Further, dromedary skim milk powder had higher bulk density and tapped bulk density. Protein solubility of skim colostrum powder exceeded that of skim milk powder over a wide range of pH (3-8). The antioxidant activities were evaluated using various in vitro tests, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, ferric reducing power assay and ferrous chelating activity. Both dromedary skim colostrum and milk powder exhibited antioxidant activities in a dose dependent manner. DPPH and ABTS radical scavenging activities were almost similar for skim colostrum and milk powder whereas ferric reducing power and ferrous chelating activity were more pronounced in dromedary skim colostrum powder whatever the concentration tested. Hence, freeze-drying process could be used as an effective tool for producing powder from dromedary skim colostrum and milk with nutritional and antioxidant properties.

scholarly journals Preservation of Indigenous Fungal Cultures by Freeze Drying Technique using Skim Milk and Honey as the Protectants

2021 ◽  
pp. 36-42
Author(s):  
G. B. Olukotun ◽  
B. B. Adamu ◽  
O. J. Asake ◽  
S. S. Leh-Togi Zobeashia
Keyword(s):  
Freeze Drying ◽  
Academic Research ◽  
Skim Milk ◽  
Cassava Starch ◽  
Living Condition ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Residual Water ◽  
Microbial Cultures ◽  
Freeze Dried

COVID-19 pandemic movement restrictions as part of the control measures put in place by countries in Sub-Saharan Africa (SSA) has implications on many sectors which include very high costs of importing materials owing to high exchange rates as well as non- availability of microbial cultures for food/ industrial productions, medical/academic research and applications because of fear of new microbial infections and bio-terrorism. Overcoming these challenges in SSA requires developing better policies and packages to confront the challenges by way of rebooting their strategies and policies for sustainable economic growth through reawakening the potentials they have. The maintenance and production of reliable pure microbial cultures with desirable quality is a key operation and is the first significant stage in the success of fungal applications in any scientific venture where they are used. For many years the process of freeze-drying (lyophilisation) has been employed primarily with the purpose of preserving living materials, including microorganisms, for extended periods of time; this is possible because, upon dehydration, substances no longer change as a consequence of the usual turnover of metabolic reactions characteristic of the living condition. This study assessed lyophilization (freeze drying) of some indigenous filamentous fungal cultures (Spores) using skim milk and honey (supports being maize and cassava flours) as the protectants and then critically compared the two protective media for the preservation of active filamentous fungi spores for the first time, and from the data obtained, their applications were optimised. Some fungal isolates(Aspergillus sp., Mucor sp., Penicillum sp., Fusarium sp., Rhizopus sp., Cladosporium sp. Alternaria sp. and Geotricum sp.) previously purified and identified were obtained from the Products Development Unit, National Biotechnology Development Agency, Abuja, Nigeria and were re-validated where their viability and purity were confirmed. The samples were Freeze Dried in the respective medium and monitored immediately after. After the freeze‐drying, the residual water contents were between 0.20-0.32%, 0.39-0.49% and 0.33-0.41%, respectively, with skim milk, Honey with Cassava Starch and honey with Maize Starch. The driedspore viabilities were between 96% (Aspergillus spores in Reconstituted Skim Milk) and 21% (Geotricum spores in Honey with Cassava Starch. Among the protective agents used, skim milk was found to be the best protectant.Each fungal isolate was considered viable if the rate of growth present was the same as that of the original culture and if the morphology of the colony matched the fungal identification documented for each species. All lyophilized fungal species were found viable from both type of lyophilized materials, skim milk and honey and showed the initial colony characteristics and growth rates.

scholarly journals Viability of Bifidobacterium Pseudocatenulatum G4 after Spray-Drying and Freeze-Drying

2010 ◽  
Vol 3 ◽  
pp. MBI.S2728 ◽  
Author(s):  
Stephenie Wong ◽  
Barka Mohammed Kabeir ◽  
Shuhaimi Mustafa ◽  
Rosfarizan Mohamad ◽  
Anis Shobirin Meor Hussin ◽  
...  
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Skim Milk ◽  
The Other ◽  
Outlet Temperature ◽  
Residual Moisture Content ◽  
Drying Process ◽  
Residual Moisture ◽  
Heat Adaptation ◽  
C 30

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%.

Blueberries as an additive to increase the survival of Lactobacillus johnsonii N6.2 to lyophilisation

2019 ◽  
Vol 10 (4) ◽  
pp. 473-482
Author(s):  
D. Cai ◽  
N.A. Harrison ◽  
D.N. Kling ◽  
C.F. Gonzalez ◽  
G.L. Lorca
Keyword(s):  
Freeze Drying ◽  
Culture Media ◽  
Whey Proteins ◽  
Skim Milk ◽  
Bacterial Strains ◽  
Lactobacillus Johnsonii ◽  
Growth And Survival ◽  
Attractive Option ◽  
Potential Benefits ◽  
Stationary Phase Survival

Effective cultivation methods, total cost, and biomass preservation are key factors that have a significant impact on the commercialisation and effectiveness of probiotics, such as Lactobacillus. Sugar polymers, milk and whey proteins have been suggested as good additives for industrial preparations. Alternative compounds, such as phytophenols, are a more attractive option, given their potential benefits to human health. The overall goal of this study was to determine if the addition of blueberry phytophenols improves the survival of Lactobacillus johnsonii N6.2 during the freeze-drying process. The addition of blueberry aqueous extract (BAE) stimulated the growth of L. johnsonii under aerobic conditions and improved the stationary phase survival of the bacteria. Furthermore, the addition of BAE to the culture media improved the endurance of L. johnsonii N6.2 to freeze-drying stress, as well as to storage at 4 °C for up to 21 weeks. Moreover, blueberry extract performed more effectively as a lyophilising additive compared to skim milk and microencapsulation with whey protein/sodium alginate. In sum, this study demonstrates that BAE is an effective additive to increase the growth and survival of L. johnsonii N6.2 when added to the culture medium and/or used as a lyophilising preservative. Moreover, BAE or other polyphenols sources might likely enhance growth and increase survival of more probiotic lactic acid bacterial strains.

scholarly journals Microencapsulation of Lactobacillus plantarum NRRL B-1927 with Skim Milk Processed via Ultra-High-Pressure Homogenization

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3863 ◽  
Author(s):  
Kevin E. Mis Solval ◽  
George Cavender ◽  
Nan Jiang ◽  
Jinru Chen ◽  
Rakesh Singh
Keyword(s):  
High Pressure ◽  
Lactobacillus Plantarum ◽  
Freeze Drying ◽  
Skim Milk ◽  
Cost Effective ◽  
High Pressure Homogenization ◽  
Particle Agglomeration ◽  
Mixed Flow ◽  
Protective Properties ◽  
Ultra High Pressure

Several health benefits are associated with the consumption of probiotic foods. Lyophilized probiotic cultures are commonly used to manufacture probiotic-containing products. Spray drying (SDR) is a cost-effective process to microencapsulate probiotics. However, the high temperatures of the drying air in SDR can inactivate significant numbers of probiotic cells. Ultra-high-pressure homogenization (UHPH) processing can modify the configuration of proteins found in skim milk which may increase its protective properties as microencapsulating agent towards probiotic cells during SDR. The aim of this study was to evaluate the effect of microencapsulating probiotic Lactobacillus plantarum NRRL B-1927 (LP) with UHPH-treated skim milk after SDR or freeze drying (FD). Dispersions containing LP were made with either UHPH-treated (at 150 MPa or 300 MPa) or untreated skim milk and dried via concurrent SDR (CCSD), mixed-flow SDR (MXSD) or FD. Higher cell survival (%) of LP was found in powders microencapsulated with 150 MPa-treated skim milk than in those microencapsulated with non-UHPH-treated and 300 MPa-treated skim milk via FD followed by MXSD and CCSD, respectively. Increasing UHPH pressures increased the particle size of powders produced via CCSD; and reduced particle agglomeration of powders produced via MXSD and FD. This study demonstrated that UHPH processes improves the effectiveness of skim milk as a microencapsulating agent for LP, creating powders that could be used in probiotic foods.

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).

Sign in / Sign up

Export Citation Format

Share Document