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.

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.

Freeze-Drying Investigations of Antlers

2012 ◽  
Vol 195-196 ◽  
pp. 441-446
Author(s):  
Jun Liu ◽  
Shi Wei Zhang ◽  
Zhi Jun Zhang
Keyword(s):  
Freeze Drying ◽  
Eutectic Temperature ◽  
Tissue Structure ◽  
Chemical Compositions ◽  
Drying Method ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Freeze Dried

In this paper, the vacuum freeze-drying experiments of both antler slices and whole antlers are reported in details. The moisture content and the eutectic temperature of antler were measured. A 22 h process curve of antler slice freeze drying was obtained. The freeze drying process of whole antler was also investigated. The microscopic tissue structure was observed and chemical compositions were analyzed for those freeze-dried whole antlers in comparison with the traditional water boiling and hot air drying method. More nutrients were retained for freeze drying in addition to the better physical properties than traditional drying.

scholarly journals Comparative Study of the Effects of Drying Methods on Antioxidant Activity of Dried Strawberry (Fragaria Var. Camarosa)

2013 ◽  
Vol 2 (2) ◽  
pp. 92 ◽  
Author(s):  
Maritza Alonzo-Macías ◽  
Anaberta Cardador-Martínez ◽  
Sabah Mounir ◽  
Gerardo Montejano-Gaitán ◽  
Karim Allaf
Keyword(s):  
Antioxidant Activity ◽  
Steam Pressure ◽  
Saturated Steam ◽  
Drying Methods ◽  
Anthocyanin Content ◽  
Flavonoid Content ◽  
Hot Air Drying ◽  
Total Anthocyanin ◽  
Hot Air ◽  
Instant Controlled Pressure Drop

<p>Hot air drying (HAD), freeze-drying (FD), and swell-drying (SD, coupling instant controlled pressure drop, DIC, to standard hot air) were applied to strawberries (<em>Fragaria</em> var. Camarosa). The total phenol, total flavonoid, and total anthocyanin contentswere evaluated versusthe drying methods. The correlations between the bioactive compounds and antioxidant activity were investigated. The obtained results showed that the differences in phenol levels were no quite comparing the three drying techniques; however, great variations were reported for anthocyanin and flavonoid content.</p> A strong correlation between the antioxidant activity and anthocyanin content was found in SD strawberries. Also, it was observed that saturated steam pressure (P) of DIC texturing operation, had a significant effect on the studied parameters compared to the thermal holding time (t). The optimum conditions of DIC were P = 0.35 MPa for t = 10 s to obtain the highest levels of phenols, flavonoids, and anthocyanins, as well as antioxidant activity.

scholarly journals Effect of Blanching on Enzyme Inactivation, Physicochemical Attributes and Antioxidant Capacity of Hot-Air Dried Pomegranate (Punica granatum L.) Arils (cv. Wonderful)

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 25
Author(s):  
Adegoke Olusesan Adetoro ◽  
Umezuruike Linus Opara ◽  
Olaniyi Amos Fawole
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Punica Granatum ◽  
Enzyme Inactivation ◽  
Soluble Solids ◽  
Anthocyanin Content ◽  
Hot Air Drying ◽  
Air Drying ◽  
Total Anthocyanin ◽  
Hot Air

Blanch-assisted hot-air drying of pomegranate arils with blanching treatments 90 °C for 30 s, 100 °C for 60 s, and unblanched (control) arils were investigated. Effects of blanching on enzyme inactivation (polyphenol oxidase and peroxidse), colour, texture, and other qualities of dried arils were discussed. The hot-air drying conditions were 60 °C, 19.6% relative humidity, and 1.0 m s−1 air velocity. Results showed that blanching reduced enzyme activity by 76% and 68% for blanched arils treated at 90 °C for 30 s and 100 °C for 60 s, respectively, compared to unblanched arils. With regard to the total colour difference (TCD), unblanched arils were 20.9% and 16.6% higher than blanched arils treated at 90 °C for 30 s and 100 °C for 60 s, respectively. Furthermore, the total soluble solids (TSS) for unblanched aril increased significantly from 16.1 to 24.9 °Brix after drying, followed by arils treated at 90 °C for 30 s and 100 °C for 60 s (21.4; 18.5 °Brix), respectively. Among the blanching treatments, dried arils treated at 90 °C for 30 s had the highest total anthocyanin content (28.6 mg C3gE/g DM), followed by 100 °C for 60 s (24.8 mg C3gE/g DM). Similarly, dried arils treated at 90 °C for 30 s had the highest radical scavenging activity (RSA) (32.1 mM TE/g DM) while the least was observed with unblanched arils (17.0 mM TE/g DM). Overall, the blanching treatment was more effective to maintain the quality attributes of pomegranate dried arils.

scholarly journals Influence of Various Drying Conditions on Phytochemical Compounds and Antioxidant Activity of Carrot Peel

Beverages ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 80 ◽  
Author(s):  
Van Nguyen ◽  
Minh Le
Keyword(s):  
Antioxidant Activity ◽  
Optimal Condition ◽  
Freeze Drying ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Air Drying ◽  
Food Industries ◽  
Hot Air ◽  
Phytochemical Compounds ◽  
Drying Conditions

(1) Background: Drying is an important process in the research of bioactive compounds. The aim of this study was to identify an optimal condition to dry carrot peel. (2) Methods: In this study, various drying conditions including hot-air (50 °C and 100 °C), vacuum (50 °C and 100 °C), microwave (600 W and 1200 W) and freeze dying (−45 °C) were applied, and the phytochemical yield and antioxidant activity of carrot peel were then assessed. (3) Results: The results showed that the highest amount of phytochemical compounds was achieved by microwave drying at 1200 W, followed by microwave drying at 600 W and freeze drying at −45 °C. In contrast, hot-air drying resulted in the lowest level of phytochemical compounds. Regarding the antioxidant activity of carrot peel, microwave drying at 1200 W was an optimal condition as it possessed the best antioxidant activity whereas hot-air, vacuum and freeze drying were not effective methods for retaining antioxidant activity. (4) Conclusions: Based on the results obtained from this study, microwave drying at 1200 W is recommended to dry carrot peel for potential application in the nutraceutical, beverage and/or functional food industries.

scholarly journals Physicochemical Properties of Red Beetroot and Quince Fruit Extracts Instant Beverage Powder: Effect of Drying Method and Maltodextrin Concentration

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Marziyeh Hajiaghaei ◽  
Akram Sharifi
Keyword(s):  
Antioxidant Activity ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Drying Method ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Freeze Dried ◽  
Optimum Sample

In this study, production of instant beverage powder by the foam-mat drying method (foam-mat freeze- and hot-air drying) from red beetroot, quince fruit, and cinnamon extracts without and with maltodextrin (MD) (0%, 10%, 20%, and 30%) were investigated. The results showed that an increase in the MD level has led to a decrease in the moisture content of powders. Drying method and MD concentration had a significant effect on rehydration time, color, and total phenolic content ( p ≤ 0.05 ). Foam-mat hot-air-dried powder containing 20% MD had a good flowability. According to the statistical analysis, MD content had a more significant effect on the antioxidant activity of powders than the drying method ( p ≤ 0.05 ). The total phenolic content of foam-mat hot-air-dried powders was higher than that of foam-mat freeze-dried powders. Based on the results, the produced powder containing 20% MD via foam-mat hot-air drying (60°C) was the optimum sample.

scholarly journals Effect of Hot-Air and Freeze-Drying on the Quality Attributes of Dried Pomegranate (Punica granatum L.) Arils During Long-Term Cold Storage of Whole Fruit

Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 493
Author(s):  
Adegoke Olusesan Adetoro ◽  
Umezuruike Linus Opara ◽  
Olaniyi Amos Fawole
Keyword(s):  
Cold Storage ◽  
Freeze Drying ◽  
Radical Scavenging ◽  
Storage Period ◽  
Total Phenolic ◽  
Anthocyanin Content ◽  
Total Anthocyanin ◽  
Hot Air ◽  
Freeze Dried

This study investigated the effect of hot-air and freeze-drying on the physicochemical, phytochemical and antioxidant capacity of dried pomegranate arils during long-term cold storage (7 ± 0.3 °C, with 92 ± 3% relative humidity) of whole fruit over a single experiment. Extracted arils were processed at monthly intervals during 12 weeks of cold storage of whole fruit. After the 12-week storage period, hot-air and freeze-dried arils showed the least (3.02) and highest (23.6) total colour difference (TCD), respectively. Hot-air dried arils also contained 46% more total soluble solids (TSS) than freeze-dried arils. During the storage of pomegranate fruit, total phenolic content (TPC) steadily increased from 20.9 to 23.9 mg GAE/100 mL and total anthocyanin content (TAC) increased from 6.91 to 8.77 mg C3gE /100 mL. Similarly, an increase in TPC and TAC were observed for hot-air (9.3%; 13%) and freeze-dried arils (5%; 5%), respectively. However, the radical scavenging activity (RSA) reduced by 8.5 and 17.4% for hot-air and freeze-dried arils, respectively, after 12 weeks of cold storage. Overall, the parameters such as colour, TPC and TAC as well as the lower degradation in RSA stability during storage showed distinct differences in quality when using the freeze-drying method, which is, therefore, recommended.

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