Effects of steam‐microwave blanching and different drying processes on drying characteristics and quality attributes of Thunbergia laurifolia Linn. leaves

BACKGROUND Dried Thunbergia laurifolia leaves are usually prepared using tray drying, resulting in products that have lost substantial amounts of bioactive compounds and antioxidant activity. The maturity of the raw material, blanching techniques and drying methods were investigated in order to sele...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the science of food and agriculture 2017-08, Vol.97 (10), p.3211-3219
Main Authors: Phahom, Traiphop, Phoungchandang, Singhanat, Kerr, William L
Format: Article
Language:English
Subjects:
Acanthaceae - chemistry
antioxidant activity
Antioxidants
Antioxidants - analysis
Bioactive compounds
Biocompatibility
Blanching
Caffeic acid
Dehumidification
Desiccation
desorption
diffusivity
Drying
drying models
drying temperature
Flavonoids - analysis
Food Preservation - methods
heat
Heat exchangers
Leaves
maturity
Microwaves
Moisture
Plant Leaves - chemistry
Quality management
Quercetin
raw materials
Steam - analysis
steam‐microwave blanching
Temperature effects
Thunbergia
Thunbergia laurifolia leaves
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:BACKGROUND Dried Thunbergia laurifolia leaves are usually prepared using tray drying, resulting in products that have lost substantial amounts of bioactive compounds and antioxidant activity. The maturity of the raw material, blanching techniques and drying methods were investigated in order to select the best condition to produce high qualities of dried T. laurifolia leaves. RESULTS The 1st stage of maturity was selected and steam‐microwave blanching (SMB) for 4 min was adequate for blanching leading to the maximum recovery of bioactive compounds. The modified Halsey model was the best desorption isotherm model. A new drying model proposed in this study was the best to fit the drying curves as compared to five common drying models. Moisture diffusivities were increased with the increase of drying temperature when combining SMB and heat pump‐dehumidified drying. Microwave heat pump‐dehumidified drying (MHPD) provided the shortest drying time, high specific moisture extraction rate (SMER) and could reduce drying time by 67.5% and increase caffeic acid and quercetin by 51.24% and 60.89%, respectively. CONCLUSION MHPD was found to be the best drying method and provided the highest antioxidant activity and bioactive compounds content, high SMER and short drying time. © 2016 Society of Chemical Industry
ISSN:0022-5142
1097-0010
DOI:10.1002/jsfa.8167