Quality Characterization of Waste Olive Cake During Hot Air Drying: Nutritional Aspects and Antioxidant Activity

2012 ◽  
Vol 6 (5) ◽  
pp. 1207-1217 ◽  
Author(s):  
Elsa Uribe ◽  
Roberto Lemus-Mondaca ◽  
Antonio Vega-Gálvez ◽  
Lorena A. López ◽  
Karina Pereira ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Olive Cake ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

Determination of Antioxidant Activity of Edible Calendula Flowers by Hot-air Drying Time

2018 ◽  
Vol 26 (4) ◽  
pp. 202-208
Author(s):  
Sang Im Oh ◽  
Seo Young Kim ◽  
Ja Hee Lee ◽  
Ae Kyung Lee
Keyword(s):  
Antioxidant Activity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Hot Air

scholarly journals The Effect of Different Extraction Protocols on Brassica oleracea var. acephala Antioxidant Activity, Bioactive Compounds, and Sugar Profile

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1792
Author(s):  
Nikola Major ◽  
Bernard Prekalj ◽  
Josipa Perković ◽  
Dean Ban ◽  
Zoran Užila ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Freeze Drying ◽  
High Energy ◽  
Total Phenolic ◽  
Glucosinolate Content ◽  
Aqueous Methanol ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Sugar Profile

The extraction of glucosinolates in boiling aqueous methanol from freeze dried leaf tissues is the most common method for myrosinase inactivation but can be hazardous because of methanol toxicity. Although freeze drying is the best dehydration method in terms of nutritional quality preservation, the main drawbacks are a limited sample quantity that can be processed simultaneously, a long processing time, and high energy consumption. Therefore, the aim of this study is to evaluate the effects of applying high temperature for myrosinase inactivation via hot air drying prior to the extraction step, as well as the effects of cold aqueous methanol extraction on total antioxidant activity, total glucosinolates, total phenolic content, and sugar profile in 36 landraces of kale. The results from our study indicate that cold aqueous methanol can be used instead of boiling aqueous methanol with no adverse effects on total glucosinolate content. Our results also show that hot air drying, compared to freeze drying, followed by cold extraction has an adverse effect on antioxidant activity measured by DPPH radical scavenging, total glucosinolate content, as well as on the content of all investigated sugars.

scholarly journals Effect of Dehydration on Several Physico-Chemical Properties and the Antioxidant Activity of Leeks (Allium porrum L.)

2011 ◽  
Vol 39 (1) ◽  
pp. 144 ◽  
Author(s):  
Mehmet OZGUR ◽  
Arzu AKPINAR-BAYIZIT ◽  
Tulay OZCAN ◽  
Lutfiye YILMAZ-ERSAN
Keyword(s):  
Antioxidant Activity ◽  
Dry Matter ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Allium Porrum ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Physico Chemical

This study investigated the changes in some physico-chemical properties and variations in antioxidant compounds of leeks (cv. ‘Inegol-92’) caused by the drying process. The dry matter and ash contents of the fresh leek samples were 8.06 and 0.58 g 100 g-1, respectively. The pH of the fresh leek samples was 6.02, and the titritable acidity in terms of citric acid was 0.14%. As expected, application of hot-air drying significantly increased the dry matter and ash values due to removal of water from the leek slices. The rehydration ratio of dried leeks at 45°C was 5.41, and the coefficient of rehydration was 0.47. The contents of chlorophyll a and b were higher in the dried leeks than in the fresh leeks. The dehydrated leeks showed a high total color difference (?E=12.53) mainly due to the effect of temperature on heat-sensitive compounds. As expected, both fresh and dried leek samples exhibited antioxidant activity with fresh leeks showing a higher capacity of antioxidant activity. Drying the leeks resulted in some ascorbic acid loss. Fresh leeks had much higher phenolic values (26.33 mg rutin eq 100 g DM-1) than the dehydrated samples. The antioxidant capacity of leeks was decreased by more than 50% during the drying process. Although being the most applied method of thermal dehydration, hot air drying causes the degradation of sensitive components, which results in significant losses in sensorial and physico-chemical properties of the dried products.

Viscoelastic Characterization of Microwave Drying Nature Rubber

2011 ◽  
Vol 291-294 ◽  
pp. 1344-1350
Author(s):  
Fu Quan Zhang ◽  
Yong Zhou Wang ◽  
Mei Chen ◽  
Mao Fang Huang
Keyword(s):  
Rheological Behavior ◽  
Viscoelastic Properties ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Drying Technology

Nature rubber (NR) is neither completely viscous nor elastic in nature, but viscoelastic in their properties. In the experiment, we used two types of equipments named rubber process analyzer (RPA) 2000 and mooney viscometer to characterize the viscoelastic properties of NR dried by microwave and hot-air, respectively. In present research, RPA tests on uncured NR dried by different methods were carried out using frequency and strain sweeps, and Mooney viscometer was detected using the big rotor at 100°C. The results showed that microwave drying has not influenced the viscoelastic properties of NR greatly, without changing the profiles of its rheological behavior. Compared with hot-air drying, the properties of NR dried by microwave improved significantly. As a new application, microwave drying technology offered an alternative way to the drying of NR.

Effects of ozone application and hot-air drying on orange peel: moisture diffusion, oil yield, and antioxidant activity

2020 ◽  
Vol 123 ◽  
pp. 80-89
Author(s):  
Taise Raquel Bechlin ◽  
Suian José Granella ◽  
Divair Christ ◽  
Silvia Renata M. Coelho ◽  
Carlos Henrique de O. Paz
Keyword(s):  
Antioxidant Activity ◽  
Orange Peel ◽  
Moisture Diffusion ◽  
Oil Yield ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

scholarly journals Effects of Drying Techniques on Murtilla Fruit Polyphenols and Antioxidant Activity

2014 ◽  
Vol 3 (5) ◽  
pp. 73 ◽  
Author(s):  
Susana Alfaro ◽  
Ana Mutis ◽  
Andres Quiroz ◽  
Ivette Seguel ◽  
Erick Scheuermann
Keyword(s):  
Antioxidant Activity ◽  
Freeze Drying ◽  
Anthocyanin Content ◽  
Hot Air Drying ◽  
Air Drying ◽  
Total Anthocyanin ◽  
Hot Air ◽  
Freeze Dried ◽  
Dried Fruit ◽  
Fruit Preservation

<p>‘Murtilla’ (<em>Ugni molinae</em> Turcz) is a native Chilean species that belongs to the Myrtaceae family. It produces a small, globular fruit with pleasant flavor and recognized antioxidant activity. Convective hot-air and freeze drying are important techniques for fruit preservation, but their effect on murtilla fruit polyphenols and antioxidant activity has not yet been studied simultaneously. The objective of this study was to compare the effect of convective hot-air drying at 65 and 80 ºC and freeze drying on total polyphenol content (TPC), total anthocyanin content (TAC), polyphenols and anthocyanins of the Red Pearl-INIA variety of fresh murtilla fruits as measured by HPLC and antioxidant activity (DPPH and ABTS). The freeze dried fruit retained higher values for TPC (2192.4 mg/100 g d.w.), TAC (13.4 mg/100 g d.w.), polyphenols (79.02 mg/100 g d.w. by HPLC) and anthocyanins (0.188 mg/100 g d.w. by HPLC) than the murtilla dried by convective hot-air at both 65 and 80 ºC. The application of all treatments showed a positive increase in the DPPH (2945.4 to 3677.6 ?mol TE/100 g d.w.) and ABTS (2664.8 to 3397.2 ?mol TE/100 g d.w.) antioxidant activity of the dried murtilla compared to the DPPH (2111.1 ?mol TE/100 g d.w.) and ABTS (2247.8 ?mol TE/100 g d.w.) of the fresh fruit. Freeze drying was the best technique for the retention of polyphenols and antioxidant activity from the fresh murtilla fruit. Therefore, freeze drying is recommended over convective hot-air drying at 65 and 80 ºC when these bioactive compounds need to be preserved.</p>

Improving Nutritional Value of Dried Blueberries (Vaccinium corymbosum L.) Combining Microwave-Vacuum, Hot-Air Drying and Freeze Drying Technologies

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Esteban I Mejia-Meza ◽  
Jaime A. Yanez ◽  
Neal M. Davies ◽  
Barbara Rasco ◽  
Frank Younce ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Nutritional Value ◽  
Freeze Drying ◽  
Vaccinium Corymbosum ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Total Polyphenols ◽  
Air Drying ◽  
Hot Air ◽  
Freeze Dried

Blueberries (Vaccinium corymbosum L.) were dried combining microwave-vacuum, hot-air drying and freeze drying technologies to retain their nutritional value. Polyphenol retention, total polyphenols, anthocyanins, and antioxidant activity were evaluated in dried blueberries. Glycoside compounds for ellagic acid, quercetin, and kaempferol exhibited a higher retention than phloridzin, and R- and S-naringin in dried blueberries following dehydration. Freeze and HA-MIVAC® dried blueberries had a higher retention of total polyphenols and anthocyanins. Freeze dried blueberries had higher antioxidant activity, followed by the combination of HA-MIVAC®, MIVAC® and HA drying methods. FD, HA-MIVAC® and MIVAC® treated blueberries had a higher retention of individual polyphenols than HA treated blueberries, indicating that the nutritional properties of berries may be retained to a greater extent when these processes are employed.

Characterization of hot-air drying and infrared drying of spearmint (Mentha spicata L.) leaves

2016 ◽  
Vol 10 (3) ◽  
pp. 466-473 ◽  
Author(s):  
Mohammad Nozad ◽  
Mehdi Khojastehpour ◽  
Mohammad Tabasizadeh ◽  
Majid Azizi ◽  
Seyed-Hassan Miraei Ashtiani ◽  
...  
Keyword(s):  
Hot Air Drying ◽  
Mentha Spicata ◽  
Air Drying ◽  
Infrared Drying ◽  
Hot Air
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