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.

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.

Investigations on the Nature of Hemophilia A

1963 ◽  
Vol 09 (01) ◽  
pp. 030-052 ◽  
Author(s):  
Eberhard Mammen
Keyword(s):  
Factor Viii ◽  
Human Plasma ◽  
Barium Sulfate ◽  
Freeze Drying ◽  
Room Temperature ◽  
Hemophilia A ◽  
Normal Human Plasma ◽  
Normal Human ◽  
And Storage ◽  
Prothrombin Activation

SummaryIn this paper an inhibitor is described that is found in hemophilic plasma and serum different from any till now described inhibitor. The inhibitor only inhibits prothrombin activation in the “intrinsic clotting systems”. This inhibitor is probably not present in normal human plasma or serum. It is destroyed by ether and freeze drying, is labile to acid and storage at room temperature. It is stable upon dialysis and has not been adsorbed on barium sulfate, aluminum hydroxide or kaolin. It precipitates at 50% v/v saturation with alcohol. The nature of this inhibitor seems to be a protein or lipoprotein.Factor VIII was isolated from hemophilic plasma. The amount isolated was the same as from normal plasma and the activity properties were not different. Hemophiliacs have normal amounts of factor VIII.

scholarly journals The influence of selected preservation methods and storage time on the content of antioxidants in blackthorn (Prunus spinosa L.) fruits

2019 ◽  
Vol 74 (1) ◽  
pp. 53-62
Author(s):  
KATARZYNA OLESIŃSKA ◽  
DANUTA SUGIER ◽  
ŁUKASZ SĘCZYK
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Antioxidant Properties ◽  
Iron Ions ◽  
Polyphenol Content ◽  
Total Polyphenols ◽  
Dried Fruits ◽  
Prunus Spinosa ◽  
Freeze Dried ◽  
And Storage

The aim of the study was to determine the influence of selected methods of preservation and storage time on the content of antioxidants in blackthorn fruit (Prunus spinosa L.). Preserved fruits were stored for 13 and 26 weeks without light at room temperature (freeze-dried and convection dried) and at –20°C (frozen samples). It was shown that both the method of preservation and the storage time had significant influence on the content of polyphenols (anthocyanins, flavonoids, total polyphenols) and antioxidant properties (Fe3+ reduction strength) of blackthorn fruit. As the storage time progressed, the anthocyanins content decreased in all preservation variants. In the case of frozen fruit after 26 weeks of storage, the content of flavonoids (by 12.5%), total polyphenols (by 48%) and the ability to reduce the iron ions were increased (by 55%). In turn, in the dried fruits after this period, the anthocyanins content, the polyphenol content and reduction strength were reduced. The highest values of the parameters evaluated after the assumed storage time has been demonstrated in lyophilizates.

Effect of Drying on the Bioactive Compounds and Antioxidant Activity of Rubus lambertianus

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Jun Yu ◽  
Zijian Shangguan ◽  
Xingju Yang ◽  
Dan Sun ◽  
Baoqing Zhu ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Freeze Drying ◽  
Antioxidant Activities ◽  
Drying Methods ◽  
Protective Effects ◽  
Red Raspberry ◽  
Hot Air Drying ◽  
Hot Air ◽  
Freeze Dried ◽  
Total Anthocyanins

AbstractDifferent drying methods, including hot air drying (HAD), freeze drying (FD), spray drying and vacuum drying (VD), were investigated to determine their influence on the chromatic coordinates, phenolics, anthocyanins and antioxidant activities of dried red raspberry (Rubus lambertianus). Pelargonidin-3-O-glucoside and catechin were found to be the main anthocyanin and non-anthocyanin phenolics, respectively, in fresh red raspberry. The most effective method for controlling browning was FD. The highest protective effects against bioactive compounds were observed in freeze-dried powders, when measuring the total anthocyanins, the scavenging of DPPH (1,1-diphenyl-2-picrylhydrazyl) and hydroxyl radicals and the inhibition effects on lard oxidation. HAD was effective for the preservation of total phenolics, while VD was useful for protecting catechin and procyanidin B1.

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.

Stability of freeze-dried plasma rich in growth factors eye drops stored for 3 months at different temperature conditions

2020 ◽  
pp. 112067212091303 ◽  
Author(s):  
Eduardo Anitua ◽  
María de la Fuente ◽  
Francisco Muruzábal ◽  
Jesús Merayo-Lloves
Keyword(s):  
Growth Factors ◽  
Room Temperature ◽  
Storage Condition ◽  
Eye Drops ◽  
Temperature Conditions ◽  
Healthy Donors ◽  
Freeze Dried ◽  
And Storage ◽  
Blood Centrifugation ◽  
Human Keratocytes

Purpose: The purpose of this study was to analyze the biological content and activity of freeze-dried plasma rich in growth factors eye drops after their storage at 4°C and at room temperature for 3 months with respect to fresh samples (time 0). Methods: Plasma rich in growth factors was obtained after blood centrifugation from three healthy donors. After platelet activation, the obtained plasma rich in growth factors eye drops were lyophilized alone or in combination with lyoprotectant (trehalose), then they were stored for 3 months at room temperature or at 4°C. Several growth factors were analyzed at each storage time and condition. Furthermore, the proliferative and migratory potential of freeze-dried plasma rich in growth factors eye drops kept for 3 months at different temperature conditions was evaluated on primary human keratocytes. Results: The different growth factors analyzed maintained their levels at each time and storage condition. Freeze-dried plasma rich in growth factors eye drops stored at room temperature or 4°C for 3 months showed no significant differences on the proliferative activity of keratocytes in comparison with fresh samples. However, the number of migratory human keratocytes increased significantly after treatment with lyophilized plasma rich in growth factors eye drops kept for 3 months compared to those obtained at time 0. No significant differences were observed between the freeze-dried plasma rich in growth factors eye drops whether mixed or not with lyoprotectant. Conclusion: Freeze-dried plasma rich in growth factors eye drops preserve the main growth factors and their biological activity after storage at room temperature or 4°C for up to 3 months. Lyophilized plasma rich in growth factors eye drops conserve their biological features even without the use of lyoprotectants for at least 3 months.

The effect of heat on the vitamin B6 of milk: II. A comparison of biological and microbiological tests of evaporated milk

1959 ◽  
Vol 26 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Mary K. Davies ◽  
Margaret E. Gregory ◽  
Kathleen M. Henry
Keyword(s):  
Vitamin B6 ◽  
Experimental Error ◽  
Freeze Drying ◽  
Room Temperature ◽  
Raw Milk ◽  
Vitamin B ◽  
Experimental Conditions ◽  
Freeze Dried ◽  
Microbiological Research ◽  
Chick Diet

1. For chicks and rats pyridoxine, pyridoxal and pyridoxamine were equally active in terms of the free bases when given separately from the diet.2. Under our experimental conditions pyridoxine mixed with the chick diet was stable, but 20% of pyridoxamine, and a variable amount of pyridoxal was lost.3. The vitamin B6 activities measured with Saccharomyces carlsbergensis, chicks and rats respectively and expressed as μg. pyridoxine/g. freeze-dried milk were: raw milk 3·4, 3·2 and 4·9; evaporated milk 1·0, 2·1 and 2·7; stored evaporated milk 0·6, 1·4 and 2·0. For the chicks the milks were mixed with the diets; they were given separately to the rats.4. The microbiological and biological results for raw milk agreed within the limits of experimental error. For the processed milks the differences between biological and microbiological tests were statistically significant.5. All three methods of assay showed a 45–70% loss of vitamin B6 activity on processing and a further loss of 30% of the remainder after storage for 6 months at room temperature.We are indebted to Mr J. Rothwell, Department of Dairying, University of Reading, for preparing the evaporated milk and to Dr B. Record, Ministry of Supply, Microbiological Research Establishment, Porton, for freeze-drying the milk. We should like to thank Dr S. K. Kon for his interest in this work.

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 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.

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.

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