scholarly journals Polysaccharide Matrices for the Encapsulation of Tetrahydrocurcumin—Potential Application as Biopesticide against Fusarium graminearum

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3873
Author(s):  
Anne Loron ◽  
Vesta Navikaitė-Šnipaitienė ◽  
Deimantė Rosliuk ◽  
Ramunė Rutkaitė ◽  
Christian Gardrat ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Freeze Drying ◽  
Environmental Issues ◽  
Pathogenic Fungi ◽  
Political Awareness ◽  
Freeze Dried ◽  
Osa Starch ◽  
Spray Dried ◽  
Curcumin Derivative ◽  
Scanning Electron

Cereals are subject to contamination by pathogenic fungi, which damage grains and threaten public health with their mycotoxins. Fusarium graminearum and its mycotoxins, trichothecenes B (TCTBs), are especially targeted in this study. Recently, the increased public and political awareness concerning environmental issues tends to limit the use of traditional fungicides against these pathogens in favor of eco-friendlier alternatives. This study focuses on the development of biofungicides based on the encapsulation of a curcumin derivative, tetrahydrocurcumin (THC), in polysaccharide matrices. Starch octenylsuccinate (OSA-starch) and chitosan have been chosen since they are generally recognized as safe. THC has been successfully trapped into particles obtained through a spray-drying or freeze-drying processes. The particles present different properties, as revealed by visual observations and scanning electron microscopy. They are also different in terms of the amount and the release of encapsulated THC. Although freeze-dried OSA-starch has better trapped THC, it seems less able to protect the phenolic compound than spray-dried particles. Chitosan particles, both spray-dried and lyophilized, have shown promising antifungal properties. The IC50 of THC-loaded spray-dried chitosan particles is as low as 0.6 ± 0.3 g/L. These particles have also significantly decreased the accumulation of TCTBs by 39%.

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.

Preparation and characterization of dried cellulose nanofibrils

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jianping Ni ◽  
Chen Gong ◽  
Zhenghua Su ◽  
Chao Tian
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Cellulose Nanofibrils ◽  
Time Dependent ◽  
X Ray ◽  
Original State ◽  
Final Mass ◽  
Freeze Dried ◽  
Spray Dried

Abstract One of the main manufacturing challenges is to obtain dried cellulose nanofibrils (CNFs) so that they can be cost effectively transported to customers. This work presents a study on using two methods of drying: freeze drying and spray drying; these dried CNFs were then characterized. The dried CNFs from either freeze drying or spray drying could not recover their original state after simple re-dispersion in water. Compared to spray dried CNFs, the microstructure of the freeze dried CNFs remained in a better shape. This was because the packing of nanofibrils as a result of freeze drying was not as tight as that from spray drying. It was demonstrated by the lower final mass residue and crystallinity of the freeze-dried CNFs, which led to better re-dispersion in water. X-ray diffractometry proved the occurrence of aggregation/hornification of the dried CNFs with increased crystallinity. Time-dependent sedimentation confirmed that the dried CNFs were incapable of forming stable water-re-dispersible suspensions.

scholarly journals Effects of Vacuum Freeze-Drying and Vacuum Spray-Drying on Biochemical Properties and Functionalities of Myofibrillar Proteins from Silver Carp

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Jianzhen Niu ◽  
Binfan Zhao ◽  
Xiujin Guo ◽  
Tao Yin
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Silver Carp ◽  
Biochemical Properties ◽  
Molecular Structures ◽  
Drying Methods ◽  
Myofibrillar Proteins ◽  
Fish Protein ◽  
Freeze Dried ◽  
Spray Dried

Fish protein powders were produced from silver carp myofibrillar proteins using vacuum freeze-drying and vacuum spray-drying. Biochemical properties and functionalities of freeze-dried and spray-dried powders were determined. The myofibrillar proteins were partially denatured under both the drying methods which were evidenced by the increase of free sulfhydryl content, surface hydrophobicity, and intrinsic fluorescence while the decrease of the Ca2+-ATPase activity and percentage of the α-helical structure. With respect to vacuum freeze-drying, the proteins were denatured to a higher degree by vacuum spray-drying. The spray-dried fish protein powder showed a higher water retention capacity and emulsifying stability index, but the same solubility and emulsifying activity index. The micrographs indicate that vacuum freeze-dried powder formed a spongy structure, while the powder under vacuum spray-drying mostly appeared spherical in shape with hollow inside. Thus, the two drying methods can be used to manufacture fish protein powders with varied molecular structures and functionalities.

scholarly journals Optimization of Spray-Drying Process of Jerusalem artichoke Extract for Inulin Production

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1674
Author(s):  
Zhenzhou Zhu ◽  
Mailing Wu ◽  
Jie Cai ◽  
Shuyi Li ◽  
Krystian Marszałek ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Content ◽  
Spray Drying ◽  
Freeze Drying ◽  
Heating Temperature ◽  
Great Influence ◽  
Jerusalem Artichoke ◽  
Drying Methods ◽  
Freeze Dried ◽  
Spray Dried

Jerusalem artichoke is an important natural matrix for inulin production. In this experiment, response surface methodology (RSM) was employed to optimize the spray-drying parameters in order to determine the maximal inulin yield. For this study, three independent variables (heating temperature (Tª, 110–120 °C), creep speed (V, 18–22 rpm) and pressure (P, 0.02–0.04 MPa)) were used in the experimental design. Using the Box–Behnken design, the optimal parameters obtained were: drying temperature 114.6 °C, creep speed 20.02 rpm, and pressure: 0.03 MPa. The inulin yield, water content and particle size of inulin obtained by spray-drying and freeze-drying were compared. In this regard, the spray-dried inulin consisted of a white powder having a fine particle size, and the freeze-dried inulin had a pale-yellow fluffy floc. On the other hand, the drying methods had a great influence on the appearance and internal structure of inulin powder, since the spray-dried inulin had a complete and uniform shape and size, whereas the freeze-dried inulin had a flocculated sheet structure. The analysis showed that the spray-drying led to a higher inulin yield, lower water content and better surface structure than freeze-drying.

scholarly journals α-amylase activity in freeze-dried and spray-dried honey

2020 ◽  
Author(s):  
Anete Keke ◽  
◽  
Ingmars Cinkmanis ◽  
Keyword(s):  
High Performance ◽  
Freeze Drying ◽  
Negative Impact ◽  
Amylase Activity ◽  
Drying Methods ◽  
Sugar Solution ◽  
Powder Concentration ◽  
Freeze Dried ◽  
Spray Dried

Honey is a naturally supersaturated sugar solution, which tends to crystallize. The crystallization of honey can lead to unwanted fermentation that can have a negative impact to honey quality. The production of honey powder could be an alternative method to prevent honey from fermentation. Honey powder could be used as alternative substitute to liquid honey that would allow to use this product more widely in the food industry. α-amylase activity is one of the most important parameters to evaluate the quality of honey. The aim of this study was to investigate the effect of freeze-drying and spray-drying on honey α-amylase activity. Detection of α-amylase activity was carried out by spectrophotometric method. High-performance liquid chromatography was used to determine the content of hydroxymethylfurfural in the powders. The obtained results showed that both drying methods had a negative impact to the enzyme activity in the samples. The lowest activity of α-amylase (8.3 DN) was measured in the spray-dried honey powder. Concentration of hydroxymethylfurfural (HMF) in the powders did not exceed required concentration 40 mg kg-1.

A Comparison of Spray-Drying and Freeze-Drying for the Production of Stable Silybin Nanosuspensions

2020 ◽  
Vol 20 (6) ◽  
pp. 3598-3603 ◽  
Author(s):  
Yingying Ma ◽  
Jin Gao ◽  
Wankui Jia ◽  
Yangyang Liu ◽  
Lanying Zhang ◽  
...  
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Drying Methods ◽  
Dry Powders ◽  
Term Stability ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Spray Dried

Spray-drying and freeze-drying are effective approaches to improve the long-term stability of nanosuspensions. This research explored the effect of spray-drying and freeze-drying techniques on PVP K30-stabilized silybin nanosuspensions. The morphology was observed by scanning electron microscopy (SEM): The spray-dried sample was spherical, and the freeze-dried samples were rodlike with smooth surfaces. The redispersibility was studied via dynamic light scattering (DLS): The size, PDI, and zeta of the spray-dried sample were 133.27 nm, 0.214, and 24.37 mV, respectively; the size, PDI, and zeta of the freeze-dried sample were 298.70 nm, 0.114, and 20.98 mV, respectively. The in vitro dissolution was studied, and the two dry powders showed a significant increase compared to silybin. The two dried powders had better long-term stability than the liquid starting material. Overall, spray-drying and freeze-drying are appropriate drying methods for the preparation of silybin nanosuspensions with better stability and dissolution velocity.

Freeze-Drying Methods for the Scanning Electron-Microscopical Study of the Protozoon Spirostomum Ambiguum and the Statocyst of the Cephalopod Mollusc Loligo Vulgaris

1969 ◽  
Vol 4 (1) ◽  
pp. 223-239
Author(s):  
A. BOYDE ◽  
V. C. BARBER
Keyword(s):  
Hair Cells ◽  
Freeze Drying ◽  
Sensory Epithelium ◽  
Microscopical Study ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Spirostomum Ambiguum ◽  
Electron Microscopical ◽  
Scanning Electron

The present study concerns methods of preparing ciliated surfaces for direct examination in the scanning electron microscope. Air-drying methods provide good results with some ciliated structures but do not always preserve the cilia of ciliated protozoons, although the pellicle is well preserved. Air-drying is not suitable for certain epitheia because considerable shrinkage and tearing occur. Freeze-drying methods, with or without pre-fixing, are described. These preserve the cilia in the protozoon Spirostomum in a fairly life-like position. There are some differences in the appearance of unfixed and fixed freeze-dried material--for example, the peristomial membranelles are not seen in the unfixed material. Freeze-drying again proved to be a better method of preparing the sensory epithelium lining the statocyst of the cephalopod mollusc Loligo, because it was successful in preventing the distortion due to shrinkage. The number of hair cells, their orientation, and the area covered by the cells was determined for the macula. The crista was found to be asymmetrical.

Microstructural Characteristics of Dried Carrot Pieces and Real Time Observations during Their Exposure to Moisture

2007 ◽  
Vol 3 (4) ◽  
Author(s):  
Bronwen G Smith ◽  
Bryony J James ◽  
Christine A.L. Ho
Keyword(s):  
Cellular Structure ◽  
Freeze Drying ◽  
Environmental Scanning Electron Microscopy ◽  
Vacuum Drying ◽  
Environmental Scanning ◽  
Original Structure ◽  
Drying Methods ◽  
Microstructural Characteristics ◽  
Freeze Dried ◽  
Scanning Electron

The effects of different drying methods on the cellular structure of carrots were examined. Carrots were dried by vacuum drying, freeze drying and oven drying in combination with microwave pre-drying. Dried and fresh untreated samples were analysed by light microscopy and environmental scanning electron microscopy (ESEM). The cellular structure of vacuum dried as well as microwave pre-dried samples was found to be very different from that of fresh samples. Most, if not all, of the original microstructure was lost during drying with these techniques, though traces of original structure were preserved on external surfaces. Most of the original microstructure was preserved in the freeze dried carrot. ESEM was also used to observe the behaviour of the dried samples in an atmosphere of increasing humidity and showed that dried tissues did not regain their original cellular structure though some turgidity was regained by the freeze dried samples.

Microencapsulation of Bioactive Compounds from Hibiscus Calyces Using Different Encapsulating Materials

2018 ◽  
Vol 14 (1) ◽  
Author(s):  
Alessandra Piovesana ◽  
Caciano Pelayo Zapata Noreña
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Guar Gum ◽  
Gum Arabic ◽  
Spherical Shape ◽  
Freeze Dried ◽  
Microscopy Analysis ◽  
Powder Properties ◽  
Partially Hydrolyzed Guar Gum ◽  
Spray Dried

Abstract:Hibiscus calyces extract was microencapsulated by freeze drying and spray drying using partially hydrolyzed guar gum (PHGG), polydextrose (PD) or gum Arabic (GA) at 10 % as encapsulating agents. The retention of anthocyanins ranged from 59.8 to 64.6 % and from 66.4 to 74.3 %, and for antioxidant activity from 66.54 to 71.71 and 69.90 to 73.26 %, for spray-dried and for freeze-dried powders, respectively. The best result obtained, for the anthocyanins content, reducing capacity and ABTS, was for the powder produced by freeze drying using GA. Regarding physical powder properties, samples produced by spray drying using GA, followed by PHGG had the best results, with values of 95.80 and 95.20 %, 31.33 and 28.87 %, 17.43 and 10.96°C for solubility, hygroscopicity and Tg, respectively. Microscopy analysis also indicated that powders produced by spray drying using GA and PHGG had the best structures, showing particles of spherical shape and without agglomeration.

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