scholarly journals Effect of Platelets on Apparent Leucocyte Ascorbic Acid Content

Author(s):  
Richard M Evans ◽  
Lilias Currie ◽  
Allan Campbell

The leucocyte ascorbic acid content is widely used as a measure of tissue ascorbic acid status. Standard methods of analysis, however, isolate both leucocytes and platelets (buffy layer), with consequent overestimation, since platelet ascorbic acid is attributed to the leucocytes. Fourteen healthy individuals on ascorbic acid supplements and 11 patients on mega dose ascorbic acid therapy were studied. A significant correlation was demonstrated between the ‘leucocyte’ ascorbic acid content and the platelet: leucocyte ratio (r = 0·70, p<0·001). It is suggested that changes in the relative distribution of platelets and leucocytes in the blood will result in an apparent change in the ‘leucocyte’ ascorbic acid content regardless of any actual change in the ascorbic acid content of the cells.

2017 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
Kamyar Movagharnejad ◽  
Sepideh Pouya

Abstract— Drying is known as a food preservation method which increases the food’s storage time by water reduction. Traditional drying consisted of open sun-drying, but different industrial dryers have been widely used in recent times. The new dryers consist of convective, infrared, ultrasound, freeze fluidized bed and freeze dryers. All of these dryers reduce the water content but under different mechanisms which leads to the end products with different qualities. In this study we aim to compare the difference in quality of kiwi fruit slices dried by three different dryers: 1. Convective tray dryer, 2. Microwave dryer and 3. Freeze dryer. The tray dryer experiments were conducted in two air temperatures of 60 and 80oC in the constant air velocity of 0.8 m/s. The microwave dryer operated in 3 output powers of 180, 270 and 360 W. The condenser temperature and pressure in the freeze dryer reduced to -50oC and 0.1 mbar, respectively. The operating conditions and time were regulated so that the moisture content of all dried samples reduced to nearly 10% in the wet basis. The three parameters of color change, ascorbic acid and antioxidant reduction were selected as the measuring criteria for the comparison of the product qualities. The experiments show that the freeze drying caused the minimum color change while the microwave drying in the maximum power of 360W caused the maximum amount of color change. The concentration of ascorbic acid was measured in the fresh fruits and dried samples by standard methods. The measurements proved that the ascorbic acid content of the freeze dried samples was 80% of the fresh fruits. The ascorbic acid content of other samples was much lower. The antioxidant activity of the dried samples and the fresh fruits was also measured by standard methods and the experimental data also showed that the freeze drying causes the minimum reduction in the antioxidant activity.


Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
A Haskovic ◽  
A Copra Janicijevic ◽  
A Topcagic ◽  
L Klepo ◽  
A Kapur ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dalila Lopes da Silva ◽  
Renato de Mello Prado ◽  
Luis Felipe Lata Tenesaca ◽  
José Lucas Farias da Silva ◽  
Ben-Hur Mattiuz

AbstractCalcium (Ca) deficiency in cabbage plants induces oxidative damage, hampering growth and decreasing quality, however, it is hypothesized that silicon (Si) added to the nutrient solution may alleviate crop losses. Therefore, this study aims at evaluating whether silicon supplied in the nutrient solution reduces, in fact, the calcium deficiency effects on cabbage plants. In a greenhouse, cabbage plants were grown using nutrient solutions with Ca sufficiency and Ca deficiency (5 mM) without and with added silicon (2.5 mM), arranged as a 2 × 2 factorial in randomized blocks, with five replications. At 91 days after transplanting, the plants were harvested for biological evaluations. In the treatment without added Si, Ca deficiency promoted oxidative stress, low antioxidant content, decreased dry matter, and lower quality leaf. On the other hand, added Si attenuated Ca deficiency in cabbage by decreasing cell extravasation while increasing both ascorbic acid content and fresh and dry matter, providing firmer leaves due to diminished leaf water loss after harvesting. We highlighted the agronomic importance of Si added to the nutrient solution, especially in crops at risk of Ca deficiency.


1987 ◽  
Vol 67 (1) ◽  
pp. 331-335
Author(s):  
HAK-YOON JU ◽  
W. JOHN MULLIN

The ascorbic acid (vitamin C) content of fresh imported field tomatoes and Nova Scotia greenhouse and field tomatoes was determined on a bi-weekly basis during the period of availability of each type of tomato to the Nova Scotia consumer in 1984. The average ascorbic acid contents of imported and Nova Scotia field and greenhouse tomatoes were 13.3, 16.7 and 17.7 mg 100 g−1 fresh weight, respectively. A study of nine recommended or promising field tomatoes for the Atlantic region showed significant differences in ascorbic acid content among the cultivars. The cultivar Quick Pick had the highest ascorbic acid content of 22.5 ± 1.5 mg 100 g−1, the cultivar Campbell 18 had the lowest content, 12.0 ± 2.9 mg 100 g−1. In Dombito greenhouse tomatoes the stage of maturity and the effect of cluster location were tested against ascorbic acid content. The lowest ascorbic acid content of 9.1 ± 1.0 mg 100 g−1 was found with the small green tomatoes while others from mature green to overripe contained 14.0–16.7 mg 100 g−1. Tomatoes from different cluster locations showed no significant difference in ascorbic acid content.Key words: Vitamin C, L-ascorbic acid, tomatoes


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Vijendren Krishnan ◽  
Syahida Ahmad ◽  
Maziah Mahmood

Plants from Gynura family was used in this study, namely,Gynura procumbensandGynura bicolor.Gynura procumbensis well known for its various medicinal properties such as antihyperglycaemic, antihyperlipidaemic, and antiulcerogenic; meanwhile,G. bicolorremains unexploited. Several nonenzymatic antioxidants methods were utilized to study the antioxidant capacity, which include ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, total flavonoid content, total phenolic content, and ascorbic acid content determination. DPPH assay revealsG. procumbensshoot as the lowest (66.885%) andG. procumbensroot as the highest (93.499%) DPPH radical inhibitor. In FRAP assay, reducing power was not detected inG. procumbensleaf callus (0.000 TEAC mg/g FW) wherebyG. procumbensroot exhibits the highest (1.103 TEAC mg/g FW) ferric reducing power. Total phenolic content and total flavonoid content exhibited similar trend for both the intact plants analysed. In all antioxidant assays,G. procumbenscallus culture exhibits very low antioxidant activity. However,G. procumbensroot exhibited highest phenolic content, flavonoid content, and ascorbic acid content with 4.957 TEAC mg/g FW, 543.529 QEµg/g FW, and 54.723 µg/g FW, respectively. This study reveals thatG. procumbensroot extract is a good source of natural antioxidant.


1957 ◽  
Vol 35 (5) ◽  
pp. 609-613
Author(s):  
D. Pelluet

The amount of ascorbic acid in the slug Arion subfuscus has been estimated quantitatively at laboratory temperatures and at 0°–2 °C. The results show that the effect of the exposure to the low temperature reduces the amount-present in the ovotestis significantly. In general, the amount of ascorbic acid in the cold treated animals does not exceed that of the controls. This result does not agree with the cytological appearance of the ovotestis exposed to the same conditions, in which the cold treated animals show an increased number of granules of ascorbic acid after an initial decrease.


2021 ◽  
Vol 180 ◽  
pp. 111622
Author(s):  
Yating Zhang ◽  
Nikolaos Ntagkas ◽  
Dimitrios Fanourakis ◽  
Georgios Tsaniklidis ◽  
Jiantao Zhao ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document