Rebuttal on Comparison of the Total Phenolic and Ascorbic Acid Content of Freeze-Dried and Air-Dried Marionberry, Strawberry, and Corn Grown Using Conventional, Organic, and Sustainable Agricultural Practices

2004 ◽  
Vol 52 (1) ◽  
pp. 150-152 ◽  
Author(s):  
Alyson E. Mitchell ◽  
Diane M. Barrett
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.


Author(s):  
Nida Akram ◽  
Mahmood Ul Hasan ◽  
Rana Naveed Ur Rehman ◽  
Rana Muhammad Ateeq Ahmad ◽  
Zeeshan Ahmed ◽  
...  

Chilling injury is the critical issue in sweet pepper fruit under low temperature storage. Present work was aimed to evaluate the effect of different concentration of methyl salicylate (MS) and L-arginine (Arg) on chilling injury and overall quality of sweet pepper fruits cv. ‘Winner’. The treatments were T1 = Control, T2 = 0.01mM MS, T3 = 0.05 mM MS, T4 = 1mM Arg, T5 = 1.5mM Arg and T6 = 0.01mM MS+1.5mM Arg. After respective treatment (for 10 min) fruits were kept at 5 ± 1 ◦C with 85-90 % RH for 28+2 days of storage. Physical, biochemical, and phytochemical parameters were studied at 7 days interval followed by two days of reconditioning at ambient conditions (25 ± 2 °C). On last removal (28+2days), sweet pepper fruits treated with combined MS and Arg treatment (T6) showed highly significant results in lower fruit weight loss (8.3%), maintained fruit colour (0.3 score) and firmness (13.4N), and reduced wrinkling (2 score), disease incidence (0.4 score), ion leakage (45.4%), alleviated chilling injury (1.7 score), retained total antioxidants (49.1%) and total phenolic content (74.4 mg 100 g-1 GAE FW) as compared to control. In addition, the ascorbic acid content was observed higher in all treatments in comparison with untreated control fruits. In conclusion, MS and Arg combine treatment improved storage potential with reduced chilling injury by maintaining higher total phenolic concentrations, ascorbic acid content and total antioxidants in terms of DPPH radical scavenging activities, and markedly maintained overall quality of sweet pepper under cold storage condition at 5 °C for 28 days.


1964 ◽  
Vol 19 (12) ◽  
pp. 1146-1149 ◽  
Author(s):  
Wolfgang Franke ◽  
Ulrich Heber

Leaves, which had been killed in liquid air, were freeze dried and then fractionated by a nonaqueous method. Two fractions were obtained, one consisting of chloroplasts and the other of cytoplasm, vacuolar constituents, cell walls and residual chloroplasts. Calculation of the intracellular distribution of ascorbic acid based on the analysis of the two fractions revealed that 40 to 50% of the total ascorbic acid content of the cells is located within the chloroplasts. Since chloroplasts occupy less than 10% of the total volume of the cells, this high figure is direct evidence of an unequal distribution of ascorbic acid within the leaf cell.


2017 ◽  
Vol 35 (No. 6) ◽  
pp. 469-475 ◽  
Author(s):  
Filiz Bilge Ertekin ◽  
Korkmaz Nazli ◽  
Budak Nilgun H ◽  
Seydim Atif C ◽  
Seydim Zeynep B Guzel

The antioxidant activity and content of phenolic substances in vegetable broths were determined. Green beans, beetroots, courgettes, onions, parsley, carrots, cabbages, celery, broccoli, spinach, cauliflowers, and tomatoes were subjected to boiling. Fresh vegetables and vegetable broths were analysed for ascorbic acid content, total phenolic content, ORAC and TEAC values. Phenolic acids were quantified using HPLC. The ascorbic acid content of vegetables ranged from 5–109 mg/100 ml, while no ascorbic acids could be detected in vegetable broths. Total phenolic content was between 17–1729 mg GAE/l for all samples. ORAC and TEAC values of vegetable broths were between 0–3 µmol TE/ml and 0–2 µmol TE/ml, respectively. Gallic, chlorogenic, caffeic, p-coumaric, and ferulic acid were detected in both fresh vegetables and vegetable broths. The highest phenolic acid content was observed in water in which beetroots were boiled. It was found that the vegetable broths of beetroots, celery stalks, cabbages, parsley and broccoli harboured remarkable antioxidant activity.


2017 ◽  
Vol 45 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Violeta NOUR ◽  
Ion TRANDAFIR ◽  
Sina COSMULESCU

In the present work, four of the most widely used culinary herbs (parsley, dill, lovage and celery leaves) in the Romanian traditional cuisine were assessed for some nutritional quality parameters (moisture content, titratable acidity, ascorbic acid content and mineral content), total phenolics content, total flavonoids content and antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. In addition, high-performance liquid chromatography (HPLC) coupled with diode-array detection was applied for the identification and quantification of some individual phenolic compounds in the selected aromatic herbs. Although parsley showed the highest ascorbic acid content (206.32 mg/100 g fw), it registered the lowest antioxidant activity. Fresh lovage recorded the highest total phenolic content (577.04 mg GAE/100 g), total flavonoids content (298.38 mg QE/100 g) and antioxidant activity, followed by dill and celery leaves. Among the identified phenolic acids, ellagic acid was predominant in lovage and celery leaves whereas sinapic and vanillic acids were prevalent in dill. Among flavonoids, myricetin was predominant in parsley and celery leaves whereas rutin was predominant in dill and lovage.


Foods ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 251 ◽  
Author(s):  
Zoran Stamenković ◽  
Ivan Pavkov ◽  
Milivoj Radojčin ◽  
Aleksandra Tepić Horecki ◽  
Krstan Kešelj ◽  
...  

Raspberries are one of Serbia’s best-known and most widely exported fruits. Due to market fluctuation, producers are looking for ways to preserve this fresh product. Drying is a widely accepted method for preserving berries, as is the case with freeze-drying. Hence, the aim was to evaluate convective drying as an alternative to freeze-drying due to better accessibility, simplicity, and cost-effectiveness of Polana raspberries and compare it to a freeze-drying. Three factors were in experimental design: air temperature (60, 70, and 80 °C), air velocity (0,5 and 1,5 m · s−1), and state of a product (fresh and frozen). Success of drying was evaluated with several quality criteria: shrinkage (change of volume), color change, shape, content of L-ascorbic acid, total phenolic content, flavonoid content, anthocyanin content, and antioxidant activity. A considerable influence of convective drying on color changes was not observed, as ΔE was low for all samples. It was obvious that fresh raspberries had less physical changes than frozen ones. On average, convective drying reduced L–ascorbic acid content by 80.00–99.99%, but less than 60% for other biologically active compounds as compared to fresh raspberries. Convective dried Polana raspberry may be considered as a viable replacement for freeze-dried raspberries.


2020 ◽  
Vol 1 (2) ◽  
pp. 9-18
Author(s):  
Haq Nawaz ◽  
Hina Andaleeb ◽  
Sobia Aziz ◽  
Saba Rehman

In the present study leaves and seeds of two different varieties of Fenugreek plant viz. Trigonella foenum gracium and Trigonella corniculata, collected from Bahawalpur, Pakistan were subjected to the biochemical, phytochemical and antioxidant analysis. The content of total sugars, non reducing sugars and reducing sugars in selected parts of these varities were found to be 5.007±0.101 to 8.133±0.223, 4.255±0.150 to 7.099±0.316 and 0.751±0.064 to 1.410±0.071 g/100g of dry weight respectively. Water soluble, salt soluble and total salt soluble protein content range from 1.172±0.001 to 6.015±0.132, 1.517±0.038 to 1.174±0.006 and 0.013±0.001 to 0.018±0.001 g/100 g of dry weight respectively and the total free amino acids ranged from 1.198±0.014 to 4.554±0.006 g/100 g of dry weight. The range of tannins and saponin contents in analyzed parts of these varities was found to be 0.057±0.009 to 0.117±0.025 and 0.083±0.012 to 0.0151±0.045 g /100g of dry weight respectively. Similarly, flavonoids and hydrogen cyanide content ranged from 0.021±0.000 to 0.055±0.004 and 0.0234±0.008 to 0.307±0.009 g/100g of dry weight respectively; while ascorbic acid content was found to be in the range of 0.068±0.08 to 0.267±0.031 g/100g of dry weight. Total phenolic acid content of the selected parts of these varities were estimated on the basis of difference in dipole moment and its range was observed from 0.0539±0.024 to 0.856±0.064 g/100g of dry weight. The total antioxidants analysis showed that ascorbic acid and trolox contents (mg Eqv./100g of extract) were found to be lower in Trigonella corniculata seeds (0.066±0.001 and 0.047±0.001 mg Eqv./100g respectively) and higher in Trigonella corniculata leaves (0.069±0.001 and 0.050±0.001 mg Eqv./100g respectively).The DPPH radical scavenging activity and reducing power were found to be in the range of 31.736±2.430 to 39.590±2.432 and 0.974±0.231 to 2.301±0.068 respectively. The different parts of studied varities of fenugreek plant, having higher values of %DPPH inhibition and reducing power showed least count of IC50 and vice versa.


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