scholarly journals Encapsulation of peach waste extract in Saccharomyces cerevisiae cells

2021 ◽  
pp. 1-1
Author(s):  
Dragoljub Cvetkovic ◽  
Aleksandra Ranitovic ◽  
Vanja Seregelj ◽  
Olja Sovljanski ◽  
Jelena Vulic ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Encapsulation Efficiency ◽  
Freeze Drying ◽  
Cell Structure ◽  
Natural Antioxidants ◽  
Yeast Cells ◽  
Ecological Problem ◽  
Freeze Dried ◽  
Excellent Method ◽  
Valuable Compounds

As a secondary industry product, peach waste (PW) presents an ecological problem, but a potentially rich source of natural antioxidants. A potential and novel way to improve the phytochemical stability of waste rich in phytochemicals is encapsulation in yeast cells which possess good structure characteristics. In the present study, PW extract was encapsulated in non-plasmolyzed, plasmolyzed, and living Saccharomyces cerevisiae cells by freeze-drying method. HPLC analysis revealed that ?-carotene is the most abundant carotenoid, while epicatechin and catechin are the most abundant phenolics in PW. The highest encapsulation efficiency of carotenoids (86.59%), as well as phenolics (66.98 %), was obtained with freeze-dried non-plasmolyzed yeast cells used as carriers. Although plasmolysis can cause some changes in yeast cell structure and properties, it did not enhance the encapsulation efficiency of present phytochemicals. Successful encapsulation of PW extract in yeast cells was confirmed by FTIR spectroscopy and SEM imaging. The obtained results present the encapsulation of sensitive compounds in yeast cells by freeze-drying as an excellent method for preserving valuable compounds and their potential use in the food and pharmaceutical industry.

scholarly journals Microencapsulation of beetroot pomace extractin cells of Saccharomyces cerevisiae

2019 ◽  
Vol 25 (4) ◽  
pp. 321-327
Author(s):  
Jelena Vulic ◽  
Aleksandra Ranitovic ◽  
Vesna Tumbas-Saponjac ◽  
Gordana Cetkovic ◽  
Jasna Canadanovic-Brunet ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Freeze Drying ◽  
Natural Antioxidants ◽  
Good Method ◽  
Cell Number ◽  
Yeast Cells ◽  
Ecological Problem ◽  
Phenolic Contents ◽  
Ft Ir ◽  
Pharmaceutical Industries

Beetroot pomace is an industrial by-product and ecological problem, as well as a potential rich source of natural antioxidants and pigments. In the present study, beetroot pomace extract (BPE) was encapsulated in non-plasmolysed, plasmolysed, and living Saccharomyces cerevisiae yeast cells by a freezedrying method. Living and dead yeast cells were microscopically assessed by using Neubauer chamber in order todetermine how the freeze-drying procedure affects changes in the yeast cell number. Total and surface phenolic contents were determined using the Folin-Ciocalteu method and encapsulation efficiency (EE) was calculated. The best EE was achieved in the case when BPE was encapsulated in living yeast cells. The successful encapsulation of BPE in yeast cells was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). These results report the encapsulation of sensitive compounds in yeast cells by freeze-drying, showing that it is a good method for valuable compound preservation and has a potential use in food and pharmaceutical industries.

scholarly journals Pressurized Extraction as an Opportunity to Recover Antioxidants from Orange Peels: Heat treatment and Nanoemulsion Design for Modulating Oxidative Stress

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5928
Author(s):  
Lucía Castro-Vázquez ◽  
María Victoria Lozano ◽  
Virginia Rodríguez-Robledo ◽  
Joaquín González-Fuentes ◽  
Pilar Marcos ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Value Added ◽  
Orange Peel ◽  
Natural Antioxidants ◽  
Volatile Components ◽  
Orange Peels ◽  
Freeze Dried ◽  
Food Applications ◽  
By Products ◽  
Terpene Derivatives

Orange peel by-products generated in the food industry are an important source of value-added compounds that can be potentially reused. In the current research, the effect of oven-drying (50–70 °C) and freeze-drying on the bioactive compounds and antioxidant potential from Navelina, Salustriana, and Sanguina peel waste was investigated using pressurized extraction (ASE). Sixty volatile components were identified by ASE-GC-MS. The levels of terpene derivatives (sesquitenenes, alcohols, aldehydes, hydrocarbons, and esters) remained practically unaffected among fresh and freeze-dried orange peels, whereas drying at 70 °C caused significative decreases in Navelina, Salustriana, and Sanguina peels. Hesperidin and narirutin were the main flavonoids quantified by HPLC-MS. Freeze-dried Sanguina peels showed the highest levels of total-polyphenols (113.3 mg GAE·g−1), total flavonoids (39.0 mg QE·g−1), outstanding values of hesperedin (187.6 µg·g−1), phenol acids (16.54 mg·g−1 DW), and the greatest antioxidant values (DPPH•, FRAP, and ABTS•+ assays) in comparison with oven-dried samples and the other varieties. Nanotechnology approaches allowed the formulation of antioxidant-loaded nanoemulsions, stabilized with lecithin, starting from orange peel extracts. Those provided 70–80% of protection against oxidative UV-radiation, also decreasing the ROS levels into the Caco-2 cells. Overall, pressurized extracts from freeze-drying orange peel can be considered a good source of natural antioxidants that could be exploited in food applications for the development of new products of commercial interest.

Effect of culture age, protectants, and initial cell concentration on viability of freeze-dried cells ofMetschnikowia pulcherrima

2010 ◽  
Vol 56 (10) ◽  
pp. 809-815 ◽  
Author(s):  
Davide Spadaro ◽  
Annalisa Alessandra Ciavorella ◽  
Jorge Giovanny Lopez-Reyes ◽  
Angelo Garibaldi ◽  
Maria Lodovica Gullino
Keyword(s):  
Freeze Drying ◽  
Cell Concentration ◽  
Yeast Cells ◽  
Initial Cell Concentration ◽  
Commercial Development ◽  
Culture Age ◽  
Biocontrol Efficacy ◽  
High Viability ◽  
Freeze Dried ◽  
Drying Conditions

The effect of freeze-drying using different lyoprotectants at different concentrations on the viability and biocontrol efficacy of Metschnikowia pulcherrima was evaluated. The effects of initial yeast cell concentration and culture age on viability were also considered. Yeast cells grown for 36 h were more resistant to freeze-drying than were 48 h cells. An initial concentration of 108cells·mL–1favoured the highest survival after freeze-drying. When maltose (25%, m/v) was used as protectant, a high cell viability was obtained (64.2%). Cells maintained a high viability after 6 months of storage at 4 °C. The biocontrol efficacy of freeze-dried cells was similar to the activity of fresh cells on ‘Gala’ apples and was slightly lower on ‘Golden Delicious’ apples. After optimizing freeze-drying conditions, the viability of M. pulcherrima cells was similar to that obtained in other studies. The results constitute a first step towards the commercial development of M. pulcherrima as a biocontrol agent.

scholarly journals Combinatorial Effects of Protective Agents on Survival Rate of the Yeast Starter, Saccharomyces cerevisiae 88-4, after Freeze-Drying

2021 ◽  
Vol 9 (3) ◽  
pp. 613
Author(s):  
Young-Wook Chin ◽  
Saerom Lee ◽  
Hwan Hee Yu ◽  
Seung Jae Yang ◽  
Tae-Wan Kim
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Response Surface Methodology ◽  
Survival Rate ◽  
Response Surface ◽  
Freeze Drying ◽  
Skim Milk ◽  
Fermented Foods ◽  
Brewing Yeast ◽  
Protective Agents ◽  
Freeze Dried

A yeast starter is formulated for commercial practices, including storage and distribution. The cell viability of the yeast starter is one of the most important factors for manufacturing alcoholic beverages to ensure their properties during the fermentation and formulation processes. In this study, 64 potential protective agents were evaluated to enhance the survival rate of the brewing yeast Saccharomyces cerevisiae 88-4 after freeze-drying. In addition, the optimized combination of protective agents was assessed for long-term storage. Finally, response surface methodology was applied to investigate the optimal concentration of each protectant. Twenty of the 64 additives led to an increase in the survival rate of freeze-dried S. cerevisiae 88-4. Among the various combinations of protectants, four had a survival rate >95%. The combination of skim milk, maltose, and maltitol exhibited the best survival rate of 61% after 42 weeks in refrigerated storage, and the composition of protectants optimized by response surface methodology was 6.5–10% skim milk, 1.8–4.5% maltose, and 16.5–18.2% maltitol. These results demonstrated that the combination of multiple protectants could alleviate damage to yeasts during freeze-drying and could be applied to the manufacturing starters for fermented foods.

scholarly journals Changes in Physicochemical Properties and Volatile Compounds of Roselle (Hibiscus sabdariffa L.) Calyx during Different Drying Methods

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6260
Author(s):  
Nurul Hanisah Juhari ◽  
Helle Jakobe Martens ◽  
Mikael Agerlin Petersen
Keyword(s):  
Moisture Content ◽  
Physicochemical Properties ◽  
Volatile Compounds ◽  
Freeze Drying ◽  
Cell Structure ◽  
Vacuum Drying ◽  
Drying Methods ◽  
Oven Drying ◽  
Sun Drying ◽  
Freeze Dried

Fresh roselle are high in moisture and deteriorate easily, which makes drying important for extending shelf-life and increasing availability. This study investigated the influence of different drying methods (oven-drying, freeze-drying, vacuum-drying, and sun-drying) on the quality of roselle calyx expressed as physicochemical properties (moisture content, water activity, soluble solids, color), volatile compounds, and microstructure. Oven-drying and freeze-drying reduced moisture content most while vacuum-drying and sun-drying were not as efficient. All drying methods except sun-drying resulted in water activities low enough to ensure safety and quality. Vacuum-drying had no impact on color of the dry calyx and only small impact on color of water extract of calyx. Drying reduced terpenes, aldehydes, and esters but increased furans. This is expected to reduce fruity, floral, spicy, and green odors and increase caramel-like aroma. Sun-drying produced more ketones, alcohols, and esters. Scanning electron microscopy revealed that freeze-drying preserved the cell structure better, and freeze-dried samples resembled fresh samples most compared to other drying techniques. The study concludes that freeze-drying should be considered as a suitable drying method, especially with respect to preservation of structure.

scholarly journals Evaluation of Freeze Drying and Electrospinning Techniques for Saffron Encapsulation and Storage Stability of Encapsulated Bioactives

2021 ◽  
Vol 5 (12) ◽  
pp. 326
Author(s):  
Fatemeh Golpira ◽  
Neda Maftoonazad ◽  
Hosahalli S. Ramaswamy
Keyword(s):  
Bioactive Compounds ◽  
Encapsulation Efficiency ◽  
Freeze Drying ◽  
Storage Stability ◽  
Control Sample ◽  
Storage Period ◽  
Diameter Distribution ◽  
Freeze Dried ◽  
Drying Techniques ◽  
Saffron Extract

Saffron extract was encapsulated into a gelatin matrix by means of electrospinning and freeze drying techniques and the degradation kinetics of bioactive compounds were evaluated during their storage at 4, 24, and 35 °C as compared to non-encapsulated control. The encapsulation efficiency, thermal properties, storage stability, morphology, and diameter distribution of the encapsulated saffron extract were evaluated as output parameters. In general, both encapsulation techniques demonstrated superior retention of bioactive compounds compared to samples without encapsulation during the entire storage period. Electrospinning and freeze drying techniques were able to retain at least 96.2 and 93.7% of crocin, respectively, after 42 days of storage at 35 °C with the 15% saffron extract. The half-life (t1/2) time parameter for the control sample (with 15% saffron extract without encapsulation) was 22 days at 4 °C temperature, while that encapsulated by electrospinning was 138 days and that obtained for freeze drying was 77 days, The half-lives were longer at lower temperatures. The encapsulation efficiency of crocin, picrocrocin, and safranal associated with the electro-spun gelatin fibers were 76.3, 86.0, and 74.2%, respectively, and in comparison, the freeze drying encapsulation efficiencies were relatively lower, at 69.0, 74.7, and 65.8%, respectively. Electro-spun gelatin fibers also had higher melting and denaturation temperatures of 78.3 °C and 108.1 °C, respectively, as compared to 65.4 °C and 93.2 °C, respectively, for freeze-dried samples. Thus, from all respects, it was concluded that electrospinning was a better and more effective technique than freeze drying in terms of preserving saffron bioactive compounds.

Subcellular localization of diffusible ions in the yeast Saccharomyces cerevisiae: quantitative microprobe analysis of thin freeze-dried sections

1976 ◽  
Vol 21 (1) ◽  
pp. 119-127
Author(s):  
G.M. Roomans ◽  
L.A. Seveus
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Microprobe Analysis ◽  
Total Concentration ◽  
Yeast Cells ◽  
Fresh Weight ◽  
Ion Distribution ◽  
Yeast Saccharomyces Cerevisiae ◽  
Thin Sections ◽  
X Ray ◽  
Freeze Dried

In yeast cells, of which the intracellular potassium had been partly replaced by rubidium or caesium, the intracellular ion distribution was studied by means of energy-dispersive X-ray microanalysis. The cells were rapidly frozen and thin sections were cut at low temperature on a cryo-ultramicrotome without the use of a trough liquid. By this dry cryosectioning procedure, complete retention of the diffusbile ions in the cells was obtained. Unless the sections had been exposed to moisture, no signs of redistribution were apparent. For quantitative determinations a gelatin standard, containing known amounts of the elements of interest, was prepared in the same way as the cells. The concentrations of potassium, rubidium, caesium and chloride in the nucleus, the cytoplasm and the vacuole could be measured. The intracellular distributions of potassium, rubidium and caesium were very similar. The concentrations of these ions in the cytoplasm were about equal to those in the nucleus and twice those in the vacuole. The total concentration in the cytoplasm was 180–190 mmol/kg fresh weight, in the nucleus 190–200 mmol/kg fresh weight and in the vacuole 75–90 mmol/kg fresh weight. The permeability of the yeast cell for chloride is markedly lower than for the cations.

scholarly journals Effect of oven and freeze drying on antioxidant activity, total phenolic and total flavonoid contents of fig (Ficus carica L.) leaves

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 2114-2121
Author(s):  
I.M. Elshaafi ◽  
K.H. Musa ◽  
N. Abdullah Sani
Keyword(s):  
Freeze Drying ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Total Flavonoid ◽  
Ficus Carica ◽  
Total Phenolic ◽  
Antioxidant Power ◽  
Oven Drying ◽  
Freeze Dried

Effect of drying processes on the antioxidant activities, total phenolic (TPC) and total flavonoid (TFC) contents of three fig (Ficus carica L.) leaves’ cultivars namely Brown Turkey Masuri 6 (BTM 6), Masui Dauphine Jumbo (MD-J) and Taiwan Golden Fish Jumbo (TGF-J) were studied. Oven drying which was conducted at 40oC, 50oC, 60oC and freeze drying at -80oC were run for 48 hrs. Antioxidant activities were evaluated using radical-scavenging capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3- ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric-reducing antioxidant power (FRAP) and cupric reducing antioxidant capacity (CUPRAC) assays. TPC and TFC were evaluated using Folin-Ciocaltue and aluminum chloride assays respectively. It was found that using oven drying at 40oC revealed significantly (p<0.05) the highest antioxidant activities of the three fig cultivars followed by oven drying at 50oC, freeze dried and oven drying at 60oC respectively. Fresh leaves revealed the significantly lowest antioxidant activities for all antioxidant assays and for all fig cultivars. Regardless of the drying process, fig cultivar BTM 6 revealed significantly (p<0.05) the highest antioxidant activities followed by TGF-J and MD-J. Positive correlations between antioxidant, TPC and TFC activities of fig leaves extracts were observed at oven drying at 40oC, oven drying at 60oC and freeze drying but not with oven drying at 50oC and fresh samples. High levels of antioxidant activities were obtained in F. carica L. leave samples (all cultivars), indicating that the leaves have potential as a source of natural antioxidants compounds.

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.

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