scholarly journals Influence of drying technique on physicochemical properties of bimodal meso-macropore structure of silica support

2018 ◽  
Author(s):  
Chalida Niamnuy ◽  
Noppadol Panchan ◽  
Thanaphat Chukeaw ◽  
Anusorn Seubsai ◽  
Sakamon Devahastin ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Sol Gel ◽  
Porous Silica ◽  
Textural Properties ◽  
Microwave Drying ◽  
Silica Support ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Macropore Structure

Drying process directly affect in structure of the silica support for catalysts. Therefore, we herein prepared bimodal meso-macropore structure of silica by sol-gel method and investigated the silica support obtained from various drying techniques, namely, hot air drying (HA), microwave drying(MW)and freeze drying (FD)by means of BET and BJH N2-sorption, and SEM. The results showed a significant effect of drying technique on the textural properties of the dried bimodal porous silica support. In addition, it was found that freeze drying could enhance surface area of silica support with higher than 500 m2/g. Keywords: bimodal meso-macropore structure silica support: drying technology: freeze drying: hot air drying: microwave drying

Drying Behaviour and Change in Colour and Textural Properties of Mushroom During Drying

2012 ◽  
Vol 8 (1) ◽  
Author(s):  
Tarsem Chand Mittal ◽  
Sajeev Rattan Sharma ◽  
Jarnail Singh Muker ◽  
Satish Kumar Gupta
Keyword(s):  
Textural Properties ◽  
Microwave Drying ◽  
Drying Methods ◽  
Button Mushroom ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Drying Behavior ◽  
L Value ◽  
Drying Behaviour

Button mushroom in the form of whole and slices were dried using convective hot air drying and microwave drying methods. Main objectives were to study the drying behavior and change in colour and textural properties. To get moisture content of 0.08 g/g, hot air drying at 600C took 463 minutes and 350 minutes for whole and sliced mushroom respectively whereas these times were just 9 minutes and 8.5 minutes when the microwave oven was run at 60% of its maximum power (1350 W). The convective hot air drying process can be put into two falling rate periods. The decrease in brightness (indicated by L-value) in dried samples was about 44% as compared to the fresh ones. The variation within the differently dried samples was not much. Hardness was lowest (<2>N) in fresh samples and was highest (>5.5 N) in microwave dried samples with hot air dried samples in between. For most of the samples, the springiness were between 0.4 and 0.6 except for hot air dried sliced samples where it was 0.9. Except in hot air dried samples, the change in cohesiveness was not much. Adhesiveness was found in fresh mushroom only..

scholarly journals STUDY OF PHYSICOCHEMICAL PROPERTIES OF CAPSICUM POWDER BY DIFFERENT DRYING TECHNIQUES

2021 ◽  
Vol 10 (4) ◽  
pp. 3110-3114
Author(s):  
Madhumita Saha
Keyword(s):  
Bulk Density ◽  
Freeze Drying ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Hot Air ◽  
Drying Techniques ◽  
Peroxidase Enzyme ◽  
Density Values

The objective of this study was to analyse the effects of phytochemical parameter, physical parameter, color, and sensory analysis in green capsicum by different drying processes (microwave, freeze, and hot air drying). Results showed an increase in microwave output power (600W), decreased drying time, moisture content, Chroma, and bulk density values. The Freeze drying process significantly improved the lightness of dried capsicum. Due to take less time for the Microwave drying technique, phytochemical parameters are intact in capsicum; on the other side, color degradation has been occurred due to the Maillard reaction (L*=29.34±0.08, a*=6.98±0.09,b*=15.36±0.10). Bulk density (0.335±0.01) and dispersibility (40±2.00%) were highest in Microwave drying powder. The capsaicin content of dried capsicum was higher than the fresh capsicum sample, but compared to the different drying techniques, the Microwave drying sample has higher capsaicin content than the Hot air drying and Freeze-drying samples. The lower capsaicin content in fresh capsicum may occur due to the catalytic activity of the peroxidase enzyme. The capsaicin content of all dried capsicum varied between 1.91±0.05 and 3.31±0.16 mg/100 g. In this research, the Microwave drying powder of capsicum was the best product for its highest antioxidant content and other physical properties.

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 Osmotic Dehydration Combined with Freeze-drying of Apple Cubes and Comparison with Microwave Drying and Hot Air Drying

2018 ◽  
Vol 2 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Fernanda Rosa Assis ◽  
◽  
Rui Manuel Santos Costa de Morais ◽  
Alcina Maria Miranda Bernardo de Morais ◽  
◽  
...  
Keyword(s):  
Freeze Drying ◽  
Osmotic Dehydration ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

scholarly journals Determining the Effect of Pre-Treatment in Rice Noodle Quality Subjected to Dehydration through Hierarchical Scoring

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1309
Author(s):  
Muhammad Heikal Ismail ◽  
Hii Ching Lik ◽  
Winny Routray ◽  
Meng Wai Woo
Keyword(s):  
Heat Pump ◽  
Freeze Drying ◽  
Oil Content ◽  
Hot Air Drying ◽  
Air Drying ◽  
Starch Gelatinization ◽  
Hot Air ◽  
Heat Pump Drying ◽  
Pre Treatment ◽  
Noodle Quality

Fresh rice noodle was usually coated in a large amount of oil to avoid stickiness and extend the shelf life. Pre-treatment has been applied to reduce the quantity of oil in rice noodle. In this research, the pre-treatment and temperature effect on the rice noodle quality subjected to hot air drying, heat pump drying, and freeze drying was investigated. Texture, color, oil content, and starch gelatinization of the dried noodle was further evaluated. Results revealed that there were significant differences (p < 0.05%) in texture, color, oil content, and starch gelatinization in rice noodle subjected to pre-treatment. Furthermore, the texture, color, oil content, and starch gelatinization demonstrated a significant difference (p < 0.05%) in freeze drying rather than hot air drying and heat pump drying. The findings indicate that the qualitative features of the dehydrated noodle are synergistic to pretreatment and drying temperature. Despite superior quality shown by freeze drying, the hierarchical scoring has proven that rice noodle undergoing hot air drying at 30 °C to produce comparable quality attributes. The hierarchical scoring can be a useful tool in quality determination for the food industry.

scholarly journals Supercritical CO2 Extraction of Phytocompounds from Olive Pomace Subjected to Different Drying Methods

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 598
Author(s):  
Graziana Difonzo ◽  
Antonella Aresta ◽  
Pietro Cotugno ◽  
Roberta Ragni ◽  
Giacomo Squeo ◽  
...  
Keyword(s):  
Olive Oil ◽  
Freeze Drying ◽  
Oil Production ◽  
Production Costs ◽  
Drying Methods ◽  
Olive Pomace ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Pharmaceutical Industries

Olive pomace is a semisolid by-product of olive oil production and represents a valuable source of functional phytocompounds. The valorization of agro-food chain by-products represents a key factor in reducing production costs, providing benefits related to their reuse. On this ground, we herein investigate extraction methods with supercritical carbon dioxide (SC-CO2) of functional phytocompounds from olive pomace samples subjected to two different drying methods, i.e., freeze drying and hot-air drying. Olive pomace was produced using the two most common industrial olive oil production processes, one based on the two-phase (2P) decanter and one based on the three-phase (3P) decanter. Our results show that freeze drying more efficiently preserves phytocompounds such as α-tocopherol, carotenoids, chlorophylls, and polyphenols, whereas hot-air drying does not compromise the β-sitosterol content and the extraction of squalene is not dependent on the drying method used. Moreover, higher amounts of α-tocopherol and polyphenols were extracted from 2P olive pomace, while β-sitosterol, chlorophylls, and carotenoids were more concentrated in 3P olive pomace. Finally, tocopherol and pigment/polyphenol fractions exerted antioxidant activity in vitro and in accelerated oxidative conditions. These results highlight the potential of olive pomace to be upcycled by extracting from it, with green methods, functional phytocompounds for reuse in food and pharmaceutical industries.

Effects of drying methods on color retention and chlorophyll of celery (ApiumgraveolensL.), spinach (Spinacia oleraceaL.), Malabar spinach (Basella albaL.)

2020 ◽  
pp. 53-61
Author(s):  
Dat Q Tran
Keyword(s):  
Microwave Drying ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Color Retention ◽  
Hot Air ◽  
Drying Techniques ◽  
Dried Vegetables

Dried vegetables are considered convenient for storage, transportation and preservation. The different drying techniques could influence the quality of resulting products. This study aimed to evaluate the effects of three distinguish drying methods as hot-air drying, foam-mat drying and microwave drying on the color retention and chlorophyll of green vegetables powder. Fresh spinach(Spinacia oleraceaL.), celery (Apium graveolensL.), Malabar spinach (Basella albaL.) were dried by different methods: hot air at 60oC, foam-mat at 60oC and microwave at 270 W until the samples reached approximately 9% of moisture content (wb). The drying time of the dried samples by microwave, foam-mat and hot-air method were 60, 210 and 240 min, respectively. Foam-mat dried vegetables were found to have the best quality in terms of color and the residual chlorophyll content. The findings suggest that foam-mat drying is promising in dried vegetable processing

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