scholarly journals Quality of Coloured Varieties of Potatoes

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S310-S313 ◽  
Author(s):  
K. Hejtmánková ◽  
V. Pivec ◽  
E. Trnková ◽  
K. Hamouz ◽  
J. Lachman

Coloured potatoes <I>Solanum tuberosum</I> L.) were evaluated as important source of natural antioxidants. Eight varieties of these potatoes (Salad Blue, Shetland Black, Blue Congo, Blaue St. Galler, Highland Burgundy Red, Violette, Valfi, Vitelotte) grown in four different locations in the Czech Republic (Přerov nad Labem, Suchdol, Valečov and Stachy) were analysed. Content of majority antioxidants (anthocyanins, chlorogenic acid and ascorbic acid) was determined and the obtained results were correlated with antioxidant activity. Total anthocyanin content and antioxidant activity were determined spectrophotometrically and phenolic acids by HPLC-DAD. The best positive correlation was observed between total anthocyanin content and antioxidant activity (<I>R</I><sup>2</sup> = 0.64). Good correlation was found between chlorogenic acid content and antioxidant activity (<I>R</I><sup>2</sup> = 0.55); however, no correlation between ascorbic acid content and antioxidant activity (<I>R</I><sup>2</sup> = 0.08) was found.

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.


2011 ◽  
Vol 57 (No. 10) ◽  
pp. 478-485 ◽  
Author(s):  
K. Hamouz ◽  
J. Lachman ◽  
K. Pazderů ◽  
J. Tomášek ◽  
K. Hejtmánková ◽  
...  

The aim of this study was to determine that the total anthocyanin content (TAC) and antioxidant activity (AOA) in potato flesh with different colours grown in the Czech Republic. Four yellow- or white-, six purple- and four red-fleshed varieties were grown in 2009 at two different sites (Valečov &ndash; highland, seed potato area at 460 m a.s.l., Přerov nad Labem &ndash; lowland, new potatoes area at 178 m a.s.l.) in precise field trials. For purple- and red-fleshed varieties, average TAC values ranged from 61.5 to 573.5 cyanidin mg/kg of FM and significant effect of the variety of the TAC was found. High content reached the Violette and Vitelotte varieties with dark purple flesh, and the lowest content the Blue Congo variety with light purple marbled flesh. Significantly higher TAC was found in a lowland area Přerov nad Labem, which is probably related to drought stress. The lowest AOA was achieved by a group of varieties with yellow or white flesh &ndash; averaging 82.8 mg ascorbic acid equivalent/kg FM, in a group of red-fleshed varieties it was higher 4.34 times and in a group of purple-fleshed varieties even 5.03 times higher. Also between purple-and red-fleshed varieties significant differences in AOA were found, both high and low values of AOA showed the same varieties as in the case of the TAC. Among experimental sites higher AOA was also demonstrated at Přerov nad Labem. Correlation analysis showed a strong correlation between AOA and TAC (r = 0.8099).


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.


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.


Author(s):  
Pranabendu Mitra ◽  
Venkatesh Meda ◽  
Rick Green

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.


2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Pranabendu Mitra ◽  
Venkatesh Meda ◽  
Rick Green

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.


2018 ◽  
Vol 3 (3) ◽  
pp. 99-103 ◽  
Author(s):  
Mohammad Ehsan Taghavizadeh Yazdi ◽  
Jalil Khara ◽  
Mohammad Reza Housaindokht ◽  
Hamid Reza Sadeghnia ◽  
Sedigheh Esmaeilzadeh Bahabadid ◽  
...  

Currently, there have been lots of interests in phytochemicals as bioactive components. The roles of fruit, vegetables, and red pigments in preventing diseases have been partly accredited to the antioxidant properties of their constituent polyphenols, flavonoid, anthocyanins, and etc. Biochemistry parameters including the relative levels of antioxidant activity, total phenolic content, total flavonoid, total anthocyanin, soluble and insoluble sugar content of Ribes khorasanicum, have been calculated in this project. The total anthocyanin content of the investigated Ribes khorasanicum measured to be 62.9 mg/g in dry weight, while displaying high levels when compared to other components, which indicates that the anthocyanin content was the predominant antioxidant components in the investigated plant. This particular plant has the potential to serve as the important source of antioxidant that can be utilized in different biological and medical applications.


2018 ◽  
Vol 46 (2) ◽  
pp. 639-652 ◽  
Author(s):  
Onur Tolga OKAN ◽  
İlhan DENİZ ◽  
Nurettin YAYLI ◽  
İhsan Güngör ŞAT ◽  
Mehmet ÖZ ◽  
...  

Commercial blueberry production has been a viable industry throughout the world for 95 years; because of blueberry is a good source of antioxidant. Blueberries are especially rich in anthocyanin, a flavonoid with potent antioxidant capacity. The aim of this study was to compare the phenolic quantities, antioxidant activities, anthocyanin, sugar and phenolic compounds of blueberries produced in Turkey with those of similar blueberry varieties produced around the world. As a result of the conducted analysis, the total phenolic content (TPC) amount found in the berries was 77.26-215.12 mg GAE/100 g, the total flavonoid content (TFC) was 30.44-91.69 mg QE/100 g and the total anthocyanin content (TAC) was 43.03-295.06 mg c3-GE/100 g. Examining the antioxidant activities of the berries, DPPH between 1.10-5.65 mg/ml, FRAP between 454.93-36832.96 µmol troloks/100 g, β-Carotene between 40.66-86.48%. It was determined that the natural berries contained much more phenolic compounds and higher antioxidant activity than that of the cultivars The result of HPLC analysis, chlorogenic acid is determined to be the dominant compound in all berries. Furthermore, fructose and glucose are found in all fruits in different quantities while sucrose is found in certain varieties of berries as well. At the end of the performed study the data indicate that wild and cultivars of blueberries are rich sources of antioxidants for local as well international industries importing this fruit for food processing and enormous products.


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