E/Z isomerization of astaxanthin and its monoesters in vitro under the exposure to light or heat and in overilluminated Haematococcus pluvialis cells

AbstractThermo- and photoisomerization of astaxanthin was investigated in a model system (solutions in methanol and chloroform), and the dynamics of astaxanthin isomers and esters content was analyzed in Haematococcus pluvialis green algal cells exposed to factors inducing astaxanthin accumulation. In both systems, the astaxanthin isomerization process seems to be defined by a) the action of light (or heat), and b) the dielectric constant of the surrounding medium. Upon heating, the accumulation of Z-isomers occurred in a model system during the entire incubation period. For the first 5 h of illumination, both Z-isomers accumulated in the solutions up to 5%, and then their content decreased. The accumulated amount of the Z-isomers in the cells of H. pluvialis was found to reach 42% of the total content of astaxanthin initially, and then it decreased during the experiment. The results lead to a conclusion that both cultivation of H. pluvialis culture in specific conditions and heat treatment of the resulting extracts from it might be efficient for obtaining large amounts of economically useful astaxanthin Z-isomer.

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Effect of Temperature on ADP-Induced Platelet Aggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647758 ◽

1973 ◽

Vol 29 (01) ◽

pp. 183-189

Author(s):

C. A Praga ◽

E. M Pogliani

Keyword(s):

Platelet Aggregation ◽

Incubation Period ◽

Room Temperature ◽

Important Variable ◽

Practical Significance ◽

Effect Of Temperature ◽

Induce Platelet Aggregation ◽

Cuvette Holder ◽

Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

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“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649839 ◽

1995 ◽

Vol 74 (03) ◽

pp. 868-873 ◽

Cited By ~ 9

Author(s):

Silvana Arrighi ◽

Roberta Rossi ◽

Maria Giuseppina Borri ◽

Vladimir Lesnikov ◽

Marina Lesnikov ◽

...

Keyword(s):

Heat Treatment ◽

Animal Model ◽

Factor Viii ◽

Hepatitis A ◽

Hepatitis A Virus ◽

Virus Inactivation ◽

Enveloped Viruses ◽

Model Studies ◽

Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

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The Human Breast Cancer Cell DNA Synthesome Can Serve as a Novel in Vitro Model System for Studying the Mechanism of Action of Anticancer Drugs

10.21236/ada384124 ◽

1999 ◽

Author(s):

Haiyan Jiang

Keyword(s):

Breast Cancer ◽

Human Breast Cancer ◽

In Vitro Model ◽

Model System ◽

Human Breast Cancer Cell ◽

Human Breast ◽

Dna Synthesome ◽

In Vitro Model System ◽

Vitro Model

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Growth of Haematococcus pluvialis on a Small-Scale Angled Porous Substrate Photobioreactor for Green Stage Biomass

Applied Sciences ◽

10.3390/app11041788 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1788

Author(s):

Thanh-Tri Do ◽

Binh-Nguyen Ong ◽

Tuan-Loc Le ◽

Thanh-Cong Nguyen ◽

Bich-Huy Tran-Thi ◽

...

Keyword(s):

Light Intensity ◽

Algal Biomass ◽

Haematococcus Pluvialis ◽

Biomass Productivity ◽

Pilot Scale ◽

Small Scale ◽

Porous Substrate ◽

Low Light ◽

Green Algal ◽

Green Stage

In the production of astaxanthin from Haematococcus pluvialis, the process of growing algal biomass in the vegetative green stage is an indispensable step in both suspended and immobilized cultivations. The green algal biomass is usually cultured in a suspension under a low light intensity. However, for astaxanthin accumulation, the microalgae need to be centrifuged and transferred to a new medium or culture system, a significant difficulty when upscaling astaxanthin production. In this research, a small-scale angled twin-layer porous substrate photobioreactor (TL-PSBR) was used to cultivate green stage biomass of H. pluvialis. Under low light intensities of 20–80 µmol photons m−2·s−1, algae in the biofilm consisted exclusively of non-motile vegetative cells (green palmella cells) after ten days of culturing. The optimal initial biomass density was 6.5 g·m−2, and the dry biomass productivity at a light intensity of 80 µmol photons m−2·s−1 was 6.5 g·m−2·d−1. The green stage biomass of H. pluvialis created in this small-scale angled TL-PSBR can be easily harvested and directly used as the source of material for the inoculation of a pilot-scale TL-PSBR for the production of astaxanthin.

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Impact of the Simulated Gastric Digestion Methodology on the In Vitro Intestinal Proteolysis and Lipolysis of Emulsion Gels

Foods ◽

10.3390/foods10020321 ◽

2021 ◽

Vol 10 (2) ◽

pp. 321

Author(s):

Camila Mella ◽

Michelle Quilaqueo ◽

Rommy N. Zúñiga ◽

Elizabeth Troncoso

Keyword(s):

Heat Treatment ◽

Protein Isolate ◽

Gastric Digestion ◽

Human Gastrointestinal Tract ◽

Gel Structure ◽

Intestinal Digestion ◽

Food Digestion ◽

The Impact ◽

Digestion Methods

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.

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Effect of moist and dry-heat treatment processes on the structure, physicochemical properties, and in vitro digestibility of wheat starch-lauric acid complexes

Food Chemistry ◽

10.1016/j.foodchem.2021.129303 ◽

2021 ◽

Vol 351 ◽

pp. 129303

Author(s):

Xuemin Kang ◽

Wei Gao ◽

Bin Wang ◽

Bin Yu ◽

Li Guo ◽

...

Keyword(s):

Heat Treatment ◽

Physicochemical Properties ◽

Lauric Acid ◽

Wheat Starch ◽

In Vitro Digestibility ◽

Dry Heat ◽

Treatment Processes ◽

Dry Heat Treatment

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Effect of Heat Treatment on the Antioxidant Activity as Well as In vitro Digestion Stability of Herring (Clupea harengus) Protein Hydrolysates

Journal of Aquatic Food Product Technology ◽

10.1080/10498850.2021.1946630 ◽

2021 ◽

pp. 1-20

Author(s):

Klaudia Róża Korczek ◽

Joanna Tkaczewska ◽

Iwona Duda ◽

Władysław Migdał

Keyword(s):

Heat Treatment ◽

Antioxidant Activity ◽

In Vitro Digestion ◽

Protein Hydrolysates ◽

Clupea Harengus

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PSVII-35 Late-Breaking Abstract: Microwave heat treatment feed effect on ruminal degradability and intestinal protein digestibility - a brief review

Journal of Animal Science ◽

10.1093/jas/skaa278.607 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 342-343

Author(s):

Md Safiqur Rahaman Shishir ◽

Muhammad Jamal Khan ◽

Hassan Khanaki ◽

Graham Brodie ◽

Brendan Cullen ◽

...

Keyword(s):

Heat Treatment ◽

Protein Digestibility ◽

Soya Bean ◽

Canola Meal ◽

Canola Seed ◽

Intestinal Protein ◽

Bean Meal ◽

Ruminal Degradability ◽

Soya Bean Meal

Abstract Rumen degradability of crude protein (CP) of feed is a major factor that determines the utilization of CP in ruminant production. This study briefly reviewed the findings from six international studies of microwave (MW) heat treatment effect on feed CP rumen degradability and intestinal CP digestibility. Six in vitro studies of concentrate feed (canola seed, canola meal, soya bean meal, cottonseed meal, corn, and barley) showed a decrease in effective rumen degradability of dry matter and protein by 4–40% and 17–40%, respectively compared to control group (untreated concentrate feed). Among the six studies, four studies identified the MW heat treatment effect on intestinal protein digestibility. Due to MW heat treatment, canola seed, canola meal, soya bean meal, and cottonseed meal showed an increase in intestinal CP digestibility by 17%, 20%, 21%, and 19%, respectively. Overall the briefly reviewed studies showed that, MW heat treatment substantially reduced feed CP ruminal degradability and increased in vitro CP digestibility of ruminally undegraded CP.

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