scholarly journals Application of Freeze-Dryers of Chamber Type in the Collections of Pathogenic Microorganisms

2014 ◽  
pp. 65-68 ◽  
Author(s):  
N. S. Chervyakova ◽  
T. V. Valova ◽  
A. V. Osin
Keyword(s):  
Shelf Life ◽  
Freeze Drying ◽  
Pathogenic Bacteria ◽  
Pathogenic Microorganisms ◽  
Biological Safety ◽  
Freeze Dried ◽  
Mass Reproduction ◽  
Long Storage

By the example of Martin Christ Epsilon 2-6D device carried out was assessment of the possibility to use freeze-dryers of the chamber type for conservation of pathogenic microorganisms collection strains. Elaborated was algorithm of lyophilisation of the III-IV pathogenicity groups bacteria, which incorporated conditions of freeze-drying and biological safety provision of this process. Indices of viability and survivability were defined for freeze-dried cells of pathogenic bacteria strains. Using thermostability test calculated were predicted timelines of storage of collection strains preparations freeze-dried in the flasks in Martin Christ Epsilon 2-6D. It was determined that in the collections of pathogenic microorganisms freeze-dryers of the chamber type could be used most prospectively for the III-IV pathogenicity groups bacteria conservation requiring mass reproduction and not intended for long storage. At the same time their application for freeze-drying of the strains of the I-II pathogenicity groups bacteria intended for a long storage, requires further adaptation of these devices as regards biological safety provision and prolongation of the shelf life.

scholarly journals Determination of shelf-life using accelerated shelf-life testing (ASLT) method and characterization of the flavour components of freeze-dried durian (Durio zibethinus) products

Food Research ◽  
2021 ◽  
Vol 5 (S2) ◽  
pp. 98-106
Author(s):  
S. Darniadi ◽  
D.D. Handoko ◽  
S. Sunarmani ◽  
S. Widowati
Keyword(s):  
Moisture Content ◽  
Shelf Life ◽  
Volatile Compounds ◽  
Freeze Drying ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Life Testing ◽  
Tropical Fruit ◽  
Durio Zibethinus ◽  
Freeze Dried

Durian is a unique tropical fruit that has a strong smell and distinctive taste. It is a seasonal fruit and has a few days shelf-life. Freeze drying is known for preserving foods while maintaining its original shape and provide excellent rehydrated products. This study aimed to determine the shelf-life of freeze-dried (FD) durian products using the accelerated shelf-life testing (ASLT) method and to assess the flavour changes in fresh and freeze-dried durian products. The parameters used to determine shelf-life were moisture content and L* a* b* colour values of FD durian products for 28 days of storage at 30, 40, and 50oC. Flavour analysis using Solid Phase Microextraction (SPME) and Gas Chromatography-Mass Spectrometry (GCMS) was carried out on fresh durian pulp, FD durian for 30 hrs, and FD durian for 36 hrs. The estimation of shelf-life of FD durian products at storage temperatures of 25 and 30oC, respectively, were based on the following parameters: (1) moisture content: 41 and 37 days, (2) L*(brightness): 467 and 311 days, (3) a* (redness): 144 and 171 days, and (4) b*(yellowness): 43 and 46 days. A total of twenty-four volatile compounds contributed to the flavour of fresh durian fruit and five of them had concentrations of more than 10 ppm. The losses percentage of these five volatile compounds were in a range of 78-95% (FD durian for 30 hrs) and a range of 0- 100% (FD durian for 36 hrs). Freeze-drying technique on durian was able to extend shelflife and preserve flavour compounds.

scholarly journals Shelf-Life Evaluation and Lyophilization of PBCA-Based Polymeric Microbubbles

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 433 ◽  
Author(s):  
Tarun Ojha ◽  
Vertika Pathak ◽  
Natascha Drude ◽  
Marek Weiler ◽  
Dirk Rommel ◽  
...  
Keyword(s):  
Shelf Life ◽  
Rhodamine B ◽  
Freeze Drying ◽  
Pharmaceutical Products ◽  
Acoustic Properties ◽  
Signal Generation ◽  
Freeze Dried ◽  
Different Temperatures ◽  
The Stability ◽  
Commercial Platform

Poly(n-butyl cyanoacrylate) microbubbles (PBCA-MB) are extensively employed for functional and molecular ultrasound (US) imaging, as well as for US-mediated drug delivery. To facilitate the use of PBCA-MB as a commercial platform for biomedical applications, it is important to systematically study and improve their stability and shelf-life. In this context, lyophilization (freeze drying) is widely used to increase shelf-life and promote product development. Here, we set out to analyze the stability of standard and rhodamine-B loaded PBCA-MB at three different temperatures (4 °C, 25 °C, and 37 °C), for a period of time of up to 20 weeks. In addition, using sucrose, glucose, polyvinylpyrrolidone (PVP), and polyethylene glycol (PEG) as cryoprotectants, we investigated if PBCA-MB can be lyophilized without affecting their size, concentration, US signal generation properties, and dye retention. Stability assessment showed that PBCA-MB remain largely intact for three and four weeks at 4 °C and 25 °C, respectively, while they disintegrate within one to two weeks at 37 °C, thereby compromising their acoustic properties. Lyophilization analyses demonstrated that PBCA-MB can be efficiently freeze-dried with 5% sucrose and 5% PVP, without changing their size, concentration, and US signal generation properties. Experiments involving rhodamine-B loaded MB indicated that significant dye leakage from the polymeric shell takes place within two to four weeks in case of non-lyophilized PBCA-MB. Lyophilization of rhodamine-loaded PBCA-MB with sucrose and PVP showed that the presence of the dye does not affect the efficiency of freeze-drying, and that the dye is efficiently retained upon MB lyophilization. These findings contribute to the development of PBCA-MB as pharmaceutical products for preclinical and clinical applications.

scholarly journals Microencapsulation of indigenous probiotic Lactobacillus plantarum Dad-13 by spray and freeze-drying: strain-dependent effect and its antibacterial property

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 2181-2189
Author(s):  
R.Z. Kamil ◽  
R. Yanti ◽  
A. Murdiati ◽  
M. Juffrie ◽  
E.S. Rahayu
Keyword(s):  
Antibacterial Activity ◽  
Lactobacillus Plantarum ◽  
Freeze Drying ◽  
Pathogenic Bacteria ◽  
Suitable Method ◽  
Wall Material ◽  
Drying Method ◽  
Dependent Effect ◽  
Freeze Dried ◽  
Strain Dependent

Lactobacillus plantarum Dad-13 is a potential probiotic candidate, and microencapsulation is the method for extending its shelf-life. Furthermore, spray or freeze -drying is a common method for microencapsulation, and its effect on the stability of probiotic is strain-dependent. This research was aimed to evaluate the strain-dependent effect of probiotic microencapsulation and to choose a suitable method for further research. In this research, for strain-dependent analysis, L. plantarum strain Mut-7 was used as a comparison. Probiotics were encapsulated with 10% (w/v) skim milk and 1 % (w/v) sucrose as wall material by spray and freeze-drying method. The obtained probiotics powder was then analyzed for physicochemical, sublethal injury and stability during storage. Freeze-dried L. plantarum Dad-13 was than analyze the antibacterial activity against pathogenic bacteria. The results showed that aw, color and particle diameter were significantly different between the spray and freeze-dried probiotics. Hence, the microstructure of spray-dried microcapsule was spherical and wrinkle, while the freezedried microcapsule was porous. However, the viable cell of freeze-dried probiotic was significantly higher and more stable during eight weeks of storages. From both strains, we found that there was no strain-dependent effect on viable cells after the drying method. Thus, we deduced that freeze-drying was the suitable method for microencapsulation L. plantarum strain Dad-13, considering the freeze-dried L. plantarum Dad-13 still had antibacterial activity.

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.

Impact of different cryoprotectants on the survival of freeze-dried Lactobacillus rhamnosus and Lactobacillus casei/paracasei during long-term storage

2015 ◽  
Vol 6 (3) ◽  
pp. 381-386 ◽  
Author(s):  
A. Jofré ◽  
T. Aymerich ◽  
M. Garriga
Keyword(s):  
Shelf Life ◽  
Lactobacillus Casei ◽  
Freeze Drying ◽  
Lactobacillus Rhamnosus ◽  
Skim Milk ◽  
Storage Period ◽  
Starter Cultures ◽  
Long Term Storage ◽  
Freeze Dried ◽  
The Stability

The production of long shelf-life highly concentrated dried probiotic/starter cultures is of paramount importance for the food industry. The aim of the present study was to evaluate the protective effect of glucose, lactose, trehalose, and skim milk applied alone or combined upon the survival of potentially probiotic Lactobacillus rhamnosus CTC1679, Lactobacillus casei/paracasei CTC1677 and L. casei/paracasei CTC1678 during freeze-drying and after 39 weeks of storage at 4 and 22 °C. Immediately after freeze-drying, the percentage of survivors was very high (≥94%) and only slight differences were observed among strains and cryoprotectants. In contrast, during storage, survival in the dried state depended on the cryoprotectant, temperature and strain. For all the protectants assayed, the stability of the cultures was remarkably higher when stored under refrigeration (4 °C). Under these conditions, skim milk alone or supplemented with trehalose or lactose showed the best performance (reductions ≤0.9 log units after 39 weeks of storage). The lowest survival was observed during non-refrigerated storage and with glucose and glucose plus milk; no viable cells left at the end of the storage period. Thus, freeze-drying in the presence of appropriate cryoprotectants allows the production of long shelf-life highly concentrated dried cultures ready for incorporation in high numbers into food products as starter/potential probiotic cultures.

scholarly journals Anti-Migraine Activity of Freeze Dried-Latex Obtained From Calotropis Gigantea Linn.

2021 ◽  
Author(s):  
Saurabh Bhatia ◽  
Ahmed Al-Harrasi ◽  
Arun Kumar ◽  
Tapan Behl ◽  
Aayush Sehghal ◽  
...  
Keyword(s):  
Shelf Life ◽  
Freeze Drying ◽  
Dependent Manner ◽  
Order Kinetic ◽  
Herbal Products ◽  
Mk 801 ◽  
Calotropis Gigantea ◽  
Climbing Behavior ◽  
Biological Potential ◽  
Freeze Dried

Abstract Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post harvesting stability issues of latex affects its biological potential. Freeze drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun rays dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze drying microencapsulation technique and evaluation of its antimigraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C* and E*), moisture, water activity, solubility and hygroscopicity. Additionally, apomorphine -induced climbing behavior, l-5-HTP induced syndrome and MK 801 induced hyperactivity were used to evaluate the antimigraine potential of powdered latex. FDCG showed good physico-chemical properties due to its higher concentration of phenolic and flavonoid content. Moreover, FDCG significantly reduced the apomorphine -induced climbing behavior, l-5-HTP -induced syndrome and MK 801 -induced hyperactivity in a dose dependent manner through dopaminergic and serotonergic receptors interaction. In conclusion, method developed for shelf-life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential, thus it can be effectively utilized in the treatment or management of migraine.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

scholarly journals Effect of Freeze Drying and Simulated Gastrointestinal Digestion on Phenolic Metabolites and Antioxidant Property of the Natal Plum (Carissa macrocarpa)

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1420
Author(s):  
Faith Seke ◽  
Vimbainashe E. Manhivi ◽  
Tinotenda Shoko ◽  
Retha M. Slabbert ◽  
Yasmina Sultanbawa ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Array Detector ◽  
Gastrointestinal Digestion ◽  
Liquid Chromatograph ◽  
Antioxidant Power ◽  
Intestinal Phase ◽  
Glucosidase Activity ◽  
Freeze Dried ◽  
Small Intestinal ◽  
The Impact

Natal plums (Carissa macrocarpa) are a natural source of bioactive compounds, particularly anthocyanins, and can be consumed as a snack. This study characterized the impact of freeze drying and in vitro gastrointestinal digestion on the phenolic profile, antioxidant capacity, and α-glucosidase activity of the Natal plum (Carissa macrocarpa). The phenolic compounds were quantified using high performance liquid chromatography coupled to a diode-array detector HPLC-DAD and an ultra-performance liquid chromatograph (UPLC) with a Waters Acquity photodiode array detector (PDA) coupled to a Synapt G2 quadrupole time-of-flight (QTOF) mass spectrometer. Cyanidin-3-O-β-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside (Cy-3-G) were the dominant anthocyanins in the fresh and freeze-dried Natal plum powder. Freeze drying did not affect the concentrations of both cyanidin compounds compared to the fresh fruit. Both cyanidin compounds, ellagic acid, catechin, epicatechin syringic acid, caffeic acid, luteolin, and quercetin O-glycoside from the ingested freeze-dried Natal plum powder was quite stable in the gastric phase compared to the small intestinal phase. Cyanidin-3-O-β-sambubioside from the ingested Natal plum powder showed bioaccessibility of 32.2% compared to cyanidin-3-O-glucoside (16.3%). The degradation of anthocyanins increased the bioaccessibility of gallic acid, protocatechuic acid, coumaric acid, and ferulic acid significantly, in the small intestinal digesta. The ferric reducing antioxidant power (FRAP), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) activities, and inhibitory effect of α-glucosidase activity decreased in the small intestinal phase. Indigenous fruits or freeze-dried powders with Cy-3-Sa can be a better source of anthocyanin than Cy-3-G due to higher bioaccessibility in the small intestinal phase.

Process for production of microencapsulated anthocyanin pigments from Rosa pimpinellifolia L. fruits: optimization of aqueous two-phase extraction, microencapsulation by spray and freeze-drying, and storage stability evaluation

2020 ◽  
Vol 16 (9) ◽  
Author(s):  
Halil İbrahim Odabaş ◽  
Ilkay Koca
Keyword(s):  
Freeze Drying ◽  
Fold Increase ◽  
Drying Methods ◽  
Phase Extraction ◽  
Extraction Temperature ◽  
Two Phase ◽  
Freeze Dried ◽  
Anthocyanin Pigments ◽  
Promising Source ◽  
Aqueous Two Phase Extraction

AbstractRosa pimpinellifolia L. fruits (RPF) are promising source of anthocyanin pigments. The objectives of this study were to optimization of the aqueous two-phase extraction (ATPE) process of anthocyanin from RPF and microencapsulation of anthocyanin-rich RPF extract. The optimal ATPE conditions were as follows: 0% HCl, 30% ethanol, 19% ammonium sulfate, and liquid to solid ratio 51.71, 97.71 min, and 30°C extraction temperature. Predicted anthocyanin yield at the optimum conditions was 1578.90 mg cyanidin 3-glucoside equivalent/100 g dry fruit. ATPE resulting in 1.80-fold increase in the purity of anthocyanins when compared to conventional solvent extraction (CSE). The composition of the anthocyanins were determined with HPLC-QTOF-MS. Freeze-drying and spray-drying methods were employed for the production of microencapsulated anthocyanin pigments. The half times of microencapsulated anthocyanins at 4, 25 and 37°C were determined as 12.16, 6.60 and 3.12 months for freeze-dried microcapsules, and 16.50, 9.24 and 4.29 months for spray-dried microcapsules, respectively.

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