scholarly journals The Effect of the Drying Method on the Quality of Dried Kiwi Slices

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.

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.


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.


2009 ◽  
Vol 8 (3) ◽  
pp. 273-279 ◽  
Author(s):  
Masashi Yamamoto ◽  
Takanori Koga ◽  
Mayuko Fukuda ◽  
Tatsuya Kubo ◽  
Shigeto Tominaga

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.


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 38 (4Supl1) ◽  
pp. 2505
Author(s):  
Flávia Aparecida De Carvalho Mariano-Nasser ◽  
Maurício Dominguez Nasser ◽  
Karina Aparecida Furlaneto ◽  
Juliana Arruda Ramos ◽  
Rogério Lopes Vieites ◽  
...  

The increased consumption of acerola in Brazil was triggered because it is considered as a functional food mainly for its high ascorbic acid content, but the fruit also has high nutritional value, high levels of phenolic compounds, total antioxidant activity, anthocyanins and carotenoids in its composition. The objective was to evaluate the chemical, physical-chemical and antioxidant activity of eight varieties of acerola tree. The acerolas used in the research were the harvest 2015, 8 varieties: BRS 235 - Apodi, Mirandópolis, Waldy - CATI 30, BRS 238 - Frutacor, Okinawa, BRS 236 - Cereja, Olivier and BRS 237 - Roxinha, from the Active Bank Germplasm APTA Regional Alta Paulista in Adamantina - SP. Avaluated the following attributes: pH, titratable acidity, soluble solids, reducing sugar, instrumental color, ascorbic acid, total phenolics, flavonoids and antioxidant activity. The design was completely randomized, 8 varieties and 3 replications of 20 fruits each. Acerola fruit of the analyzed varieties prove to be good sources of phenolic compounds and antioxidant activity, ensuring its excellent nutritional quality relative to combat free radicals. The variety BRS 236 - Cereja presents higher ascorbic acid content, antioxidant activity and phenolic compounds, and the lowest value for flavonoid, which was higher than the other cultivars, especially Olivier and Waldy CATI-30.


2016 ◽  
Vol 1 (01) ◽  
pp. 116-118
Author(s):  
Anant Kumar ◽  
Virendra Pal ◽  
S. P. Singh ◽  
Santosh Verma

A field experiment was carried out during summer season of 2013 and 2014 to find out the effect of inorganic and bio-fertilizers on the growth, yield and quality of tomato (Lycopersicon esculentum Mill.) cv. Pusa Hybrid -2. The results revealed that plants growth and yield of tomato can be increased with the application of Azospirillum along with recommended dose of NPK (120kg N + 60kg P + 60kg K/ha). The ascorbic acid content of fruits were found maximum with the 80kg N + 40kg P + 60kg K/ha with Azospirillum. The TSS was improved by the application of 80kg N + 40kg P + 60kg K/ha with Phosphobacteria.


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.


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