scholarly journals Structural and Biological Properties of Water Soluble Polysaccharides from Lotus Leaves: Effects of Drying Techniques

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4395
Author(s):  
Wei Li ◽  
Ding-Tao Wu ◽  
Fen Li ◽  
Ren-You Gan ◽  
Yi-Chen Hu ◽  
...  
Keyword(s):  
Radical Scavenging ◽  
Biological Properties ◽  
Microwave Drying ◽  
Inhibitory Effects ◽  
Hot Air Drying ◽  
Hot Air ◽  
Drying Techniques ◽  
Ic50 Values ◽  
Lotus Leaves ◽  
Radical Scavenging Ability

In the present study, the influence of five drying techniques on the structural and biological properties of polysaccharides from lotus leaves (LLPs) was investigated. Results revealed that the yields, contents of basic chemical components, molecular weights, and molar ratios of compositional monosaccharides of LLPs varied by different drying technologies. Low molecular weight distributions were observed in polysaccharides obtained from lotus leaves by hot air drying (LLP-H), microwave drying (LLP-M), and radio frequency drying (LLP-RF), respectively. The high contents of bound polyphenolics were measured in LLP-H and LLP-M, as well as polysaccharides obtained from lotus leaves by vacuum drying (LLP-V). Furthermore, both Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectra of LLPs were similar, indicating that drying technologies did not change their basic chemical structures. Besides, all LLPs exhibited obvious biological properties, including in vitro antioxidant capacities, antiglycation activities, and inhibitory effects on α-glucosidase. Indeed, LLP-H exhibited higher 2,2-azidobisphenol (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability (IC50 values, LLP-H, 0.176 ± 0.004 mg/mL; vitamin C, 0.043 ± 0.002 mg/mL) and 2,2-diphenyl-1-(2,4,6-trinitrate phenyl) hydrazine radical scavenging ability (IC50 values, LLP-H, 0.241 ± 0.007 mg/mL; butylated hydroxytoluene, 0.366 ± 0.010 mg/mL) than others, and LLP-M exerted stronger antiglycation (IC50 values, LLP-M, 1.023 ± 0.053 mg/mL; aminoguanidine, 1.744 ± 0.080 mg/mL) and inhibitory effects on α-glucosidase (IC50 values, LLP-M, 1.90 ± 0.02 μg/mL; acarbose, 724.98 ± 16.93 μg/mL) than others. These findings indicate that both hot air drying and microwave drying can be potential drying techniques for the pre-processing of lotus leaves for industrial applications.

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

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 Drying Techniques and Storage: Do They Affect the Nutritional Value of Bee-Collected Pollen?

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4925
Author(s):  
Antonella Castagna ◽  
Giovanni Benelli ◽  
Giuseppe Conte ◽  
Cristina Sgherri ◽  
Francesca Signorini ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nutritional Value ◽  
Chemical Properties ◽  
Human Consumption ◽  
Hot Air Drying ◽  
Hot Air ◽  
Drying Techniques ◽  
Related Quality ◽  
And Storage

In this study, the effect of different drying processes (freeze-drying (FD), microwave-assisted drying (MWD) and classic hot air drying (HAD)) on the polyphenols, flavonoids, and amino acids content was investigated on bee-collected chestnut, willow and ivy pollen for human consumption. Furthermore, the pollen chemical properties were monitored after three and six months of storage, and then analyzed using a multivariate approach. Chestnut pollen was the richest source of polyphenols, flavonoids, and rutin, while ivy pollen contained the highest amount of total and free amino acids, and total and free proline. Drying and storage affected pollen chemical composition with species-dependent effects. MWD allowed the best retention of flavonoids in chestnut pollen for up to six months of storage. All drying techniques led to a depletion of flavonoids in willow pollen; however, MWD ensured the highest flavonoids content after six months. FD and MWD did not lead to flavonoids depletion in ivy pollen during storage. Additionally, storage did not affect the rutin content, which was highest in FD willow samples after six months. Notably, both FD and MWD techniques are efficient in preserving amino acids-related quality of bee pollen up to six months of storage.

scholarly journals Infrared Drying as a Quick Preparation Method for Dried Tangerine Peel

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mingyue Xu ◽  
Guifang Tian ◽  
Chengying Zhao ◽  
Aftab Ahmad ◽  
Huijuan Zhang ◽  
...  
Keyword(s):  
Radical Scavenging ◽  
Short Wave ◽  
Hot Air Drying ◽  
Time Saving ◽  
Drying Time ◽  
Infrared Drying ◽  
Sun Drying ◽  
Hot Air ◽  
Short Wave Infrared ◽  
Dpph Radical Scavenging

To establish the most convenient and effective method to dry tangerine peels, different methods (sun drying, hot-air drying, freeze drying, vacuum drying, and medium- and short-wave infrared drying) were exploited. Our results indicated that medium- and short-wave infrared drying was the best method to preserve nutraceutical components; for example, vitamin C was raised to 6.77 mg/g (D.W.) from 3.39 mg/g (sun drying). Moreover, the drying time can be shortened above 96% compared with sun drying. Importantly, the efficiency of DPPH radical scavenging was enhanced from 26.66% to 55.92%. These findings would provide a reliable and time-saving methodology to produce high-quality dried tangerine peels.

A Comparative Study of Combined Microwave Techniques for Longan (Dimocarpus longan Lour.) Drying with Hot Air or Vacuum

2017 ◽  
Vol 13 (7) ◽  
Author(s):  
Krit Apinyavisit ◽  
Adisak Nathakaranakule ◽  
Somchart Soponronnarit ◽  
Gauri S. Mittal
Keyword(s):  
Energy Efficient ◽  
Preference Score ◽  
Drying Method ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Microwave Vacuum Drying ◽  
Hot Air ◽  
Drying Techniques ◽  
Microwave Techniques

AbstractThe aim of this study is to find a better drying method to replace conventional hot air drying (HAD) in terms of faster, energy efficient and better product quality. Two alternative drying techniques, microwave combined with hot air drying (MHD) and microwave vacuum drying (MVD), are compared in this study to dry peeled and destoned longan fruit. Both MHD and MVD reduced the drying time up to 48 % and energy consumption as compared to HAD. These techniques provided lower product redness, yellowness and shrinkage but higher lightness and porous structure as compared to HAD. MVD reduced hardness and toughness of the dried product. MHD provided the highest preference score in terms of colour and shape and was as acceptable as the commercial product dried by HAD. MHD is the most suitable method for longan drying.

scholarly journals Comparative Study of the Characteristics of Oil Shale with Hot Air Drying and Microwave Drying

2012 ◽  
Vol 17 ◽  
pp. 884-891 ◽  
Author(s):  
Qing Wang ◽  
Zeng-yi Gu ◽  
Jing-ru Bai ◽  
Juan Liu ◽  
Hong-peng Liu
Keyword(s):  
Comparative Study ◽  
Oil Shale ◽  
Microwave Drying ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air

scholarly journals Impact of Different Drying Techniques on Quality Traits of Ginger (Zingiber officinale Rosc.) Rhizomes

2021 ◽  
pp. 30-37
Author(s):  
Annu Kumari ◽  
Yeluru Mohan Babu ◽  
Eggadi Ramesh ◽  
Tshering Ongchu Lepcha ◽  
Suman Tamang ◽  
...  
Keyword(s):  
Essential Oil ◽  
Fiber Content ◽  
Microwave Drying ◽  
Crude Fiber ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Air Drying ◽  
Sun Drying ◽  
Crude Fiber Content ◽  
Hot Air

Under the present investigation, ginger was produced at the instruction cum research plots of the Department of Plantation Crops and Processing, Faculty of Horticulture, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal. The experiment was laid out in a factorial CRD. The study was undertaken with four ginger varieties namely Gorubathan, Suprabha, Suruchi and Suravi to evaluate the effect of different drying methods (sun drying, hot air drying at 50OC, 60oC and 70oC and microwave drying on time required for drying to a moisture content of 8 – 10% and to chemical composition (essential oil, oleoresin content and crude fiber content) of the end product. Results shown that Gorubathan variety has the highest essential oil (2.243%) and oleoresin content (14.840%) among the four varieties in this study, highest crude fiber content (5.253%) was observed in Suprabha and highest dry recovery (25.77%) was obtained from Suravi variety. In hot air drying, with increase in temperature essential oil, oleoresin and crude fiber content in dry ginger as well as dry recovery reduced. With high dry recovery (25.77%), essential oil (2.037%) and oleoresin content (13.510%) and moderately low crude fiber content (4.637%), it can be concluded that Suravi variety is best suitable for producing dry ginger. Apart from microwave drying, sun drying can be recommended as better practice, when hygienically conducted, based on essential oil and oleoresin content.

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