Ethanol pretreatment in taioba leaves during vacuum drying

2021 ◽  
Vol 45 ◽  
Author(s):  
João Renato de Jesus Junqueira ◽  
Jefferson Luiz Gomes Corrêa ◽  
Nathane Silva Resende ◽  
Thaisa Carvalho Volpi Balbinoti ◽  
Isabella Pereira Gatti ◽  
...  

ABSTRACT Non-conventional vegetables are those with limited distribution, restricted to certain regions. As a globalization and food industrialization result, its cultivation and consumption has decreased. The taioba [Xanthosoma sagittifolium (L.) Schott] is an example of this vegetable category. The drying process increases the food stability, but it can negatively alter the nutritional value and the final quality of the product. Ethanol pretreatment reduces the drying time and can assist in the preservation of the nutritional characteristics. The aim of this work was to evaluate the effect of vacuum drying and ethanol pretreatment on the drying behavior, mathematical modeling, and final quality of taioba leaves. Higher temperatures and ethanol pretreatment lead to a shorter drying time. Thin-layer equations were evaluated for their ability to predict the drying kinetics, of which the Logarithmic and Midilli & Kuçuk equations performed best. A significant difference (p ≤ 0.05) was observed in the ascorbic acid content, antioxidant activity and total phenolic compounds in the different treatments. There was preservation in ascorbic acid content in treatments in which ethanol was applied; moreover, lower total phenolic compounds and antioxidant activity were observed when ethanol was used. There was no significant difference (p > 0.05) in pH values and titratable acidity.

2019 ◽  
Vol 49 (4) ◽  
pp. 255-260 ◽  
Author(s):  
Gulcin Yildiz ◽  
H. Feng

This study was conducted to investigate the effects of ultrasound treatment on the physiological quality of cherry juice. Cherry fruits purchased from a local market were sonicated at 20 kHz and 100% amplitude for 2,3,5, and 10 minutes and then stored at 4 oC for 14 days. Quality attributes such as color, total antioxidants, total phenolic and ascorbic acid contents of the cherry juices were compared. The results showed that the ultrasonic treatment had significant effects on the physiological quality of the cherry juices When the treatment time was increased from 2 to 10 min higher levels of total phenolic content, antioxidant activity, and ascorbic acid were observed. A 10 min treated cherry juices showed higher lightness (L) values compared to the fresh cherry juice during a two-week period. Ultrasonic treatment showed potential as a method to maintain and improve the overall quality of cherry juice during cold storage.  


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.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1224
Author(s):  
Constanza Córdova ◽  
Juan P. Vivanco ◽  
Julián Quintero ◽  
Andrea Mahn

This work studied the effect of drum-rotation frequency, drum temperature, and water-to-pulp ratio in a double-drum drier on the content of sulforaphane, glucoraphanin, total phenolic compounds, ascorbic acid, and antioxidant activity of broccoli pulp through a multilevel factorial design with one replicate. Drum-drying conditions did not significantly affect sulforaphane content, unlike glucoraphanin, however the poor adherence of broccoli pulp resulted in a final product with undefined shape and heterogeneous color. On the other hand, antioxidant activity was unevenly affected by drying conditions; however, drum-rotation frequency affected it in the same way that phenolic compounds and ascorbic acid, showing a concordant behavior. The ascorbic acid content decreased significantly after drying, and it was highly dependent on the experimental factors, resulting in a regression model that explained 90% of its variability. Drum-rotation frequency of 5 Hz, drum temperature of 125 °C, and water-to-pulp ratio of 0.25 resulted in an apparent increase of sulforaphane and phenolic compounds content of 13.7% and 47.6%, respectively. Drum drying has great potential to fabricate dehydrated broccoli-based foods with functional properties. Besides, since drum drying has low investment and operation costs, it represents a very attractive option for the industrialization of broccoli derivatives.


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 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.


2019 ◽  
Author(s):  
anni faridah

Brown seaweed known as one of the source of the hydrocolloid (alginate) that is useful as thickener in food processing. Moreover, it also contains many beneficial compounds such as sulphated polysaccharides, phlorotannins, peptides, natural pigments, polyphenols, vitaminswhich can be developed as antioxidant, anticervix-tumor, hepatoprotector, and anti-diabetes. The use of wild brown seaweed which obtained from the coast of Nirwana in West Sumatera as an additive ingredient for jelly candy as a functional food was studied. Water extract of brown seaweed was added with various concentrations as much as 5%, 10%, and 15%. Sensory analysis was conducted for evaluating the product acceptance. Total phenolic compounds, antioxidant activity, the content in carbohydrate, fat, protein, ash, moisture were measure for determined the quality of most acceptable jelly candy. The most acceptable jelly candy was the product with 15 % addition of brown seaweed extract. The addition of brown seaweed extract improved the functionality of candy jelly that indicated by increasing of total phenolic compound, antioxidant activity, the content of carbohydrate, fat, protein and ash. The utilization of wild brown seaweed at the coast of Nirwana in West Sumatera is promising in developing of diversity functional food such as jelly candy and others product.


2019 ◽  
Vol 37 (No. 5) ◽  
pp. 359-365
Author(s):  
Ivo Soural ◽  
Petr Šnurkovič ◽  
Monika Bieniasz

Eight less-known juices are characterised and contents are monitored of selected substances and nutritional parameters. 100% juices were produced of Aloe Vera, Aronia, Blackcurrant, Black elder, Cranberry, Malpighia, Pomegranate and Seaberry by pressing, including the flesh. Total phenolic compounds (TPC) and ascorbic acid (AA) content were analysed as other parameters. The juices were measured on total antioxidant capacity (TAC) as the content of trolox, where the highest levels were found for Malpighia 63.2 mM, when the value was significantly different (P < 0.05) compared with all the other juices, while Aloe Vera had lowest levels with 0.4 mM. The Aronia juice possessed the highest level of TPC (8297 mg of GAE/l). TAC levels very well corresponded with TPC levels while AA content actually did not correlate with TAC values. In addition to the objective analysis, the juices were subjected to a sensory evaluation. Blackcurrant presents an attractive product from the sensorial aspect as well as in terms of the nutritional value.


Author(s):  
Esther Vidal Cascales ◽  
José María Ros García

Quince fruit and two industrial derivates (pulp and jam) were characterized from physicochemical, nutritional and microbiological viewpoint. Quinces were collected at maturity (September) in Murcia (Spain). Quinces were converted at a processing factory in pulp (intermediate product) and, in the same factory, this pulp was transformed in jam. The pH, soluble solids, acidity, color, moisture, water activity, total phenolic compounds, antioxidant activity, vitamin C and flavonoids were measured for all samples, while for microbiological analysis was only used quince jam. There were significant differences among quince fruit, industrial pulp and commercial jam. Processing caused pH, moisture and water activity decrease, while soluble solids increase. Total phenolic compounds and antioxidant activity increased in the pulp and in the jam. The effect of cooking and storage was a decrease of vitamin C and flavonoids in the jam. Quince jam presented a total number of molds and yeasts lower than 2 log cfu/g. Although the production parameters affect to the quality of the quince jam, it is a sensory attractive food with healthy properties.


2017 ◽  
Vol 38 (4) ◽  
pp. 1853 ◽  
Author(s):  
Lorena Mendes Rodrigues ◽  
Diene France de Souza ◽  
Elisângela Aparecida da Silva ◽  
Thais Odete de Oliveira ◽  
Juliana Pinto de Lima

Brazil is the third largest producer of fresh fruits in the world. Among fruits, berries such as strawberry, blueberry and blackberry can be highlighted for the benefits they provide to the body, owing to their presence of bioactive compound content. The phenolic compounds, especially anthocyanins and ascorbic acid, are examples of bioactive compounds that mainly function in the body as antioxidants. However, the processing steps that lead to the generation of derivatives from these fruits, are damaging to these compounds, often leading to their loss. Thus, the aim of this study was to physically and chemically characterize fresh berries (strawberry, blueberry and blackberry) and their jams, and also to quantify and to evaluate the antioxidant activity of bioactive compounds in berries and their jams. The following parameters were analyzed: moisture, ash, pH, titratable acidity, soluble solids, and color. The levels of total phenolic compounds, total anthocyanins, ascorbic acid content and antioxidant activity were measured. We concluded that there were significant differences in the chemical composition of berries and jams. There was also a significant loss of bioactive compounds due to processing, nevertheless these jams remain good sources of bioactive compounds, and are still considered important to promote some favorable health effects.


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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