Effects of carboxymethyl cellulose/pectin coating combined with ultrasound pretreatment before drying on quality of turmeric (Curcuma longa L.)

Nan-Nan An; Nan Shang; Wei-Qiao Lv; Dong Li; Li-Jun Wang; Yong Wang

doi:10.1016/j.ijbiomac.2022.01.021

Effects of carboxymethyl cellulose/pectin coating combined with ultrasound pretreatment before drying on quality of turmeric (Curcuma longa L.)

Int J Biol Macromol. 2022 Mar 31:202:354-365. doi: 10.1016/j.ijbiomac.2022.01.021. Epub 2022 Jan 13.

Authors

Nan-Nan An¹, Nan Shang¹, Wei-Qiao Lv¹, Dong Li², Li-Jun Wang³, Yong Wang⁴

Affiliations

¹ College of Engineering, Beijing Advanced Innovation Center for Food Nutrition and Human Health, National Energy R & D Center for Non-food Biomass, China Agricultural University, P. O. Box 50, 17 Qinghua Donglu, Beijing 100083, China.
² College of Engineering, Beijing Advanced Innovation Center for Food Nutrition and Human Health, National Energy R & D Center for Non-food Biomass, China Agricultural University, P. O. Box 50, 17 Qinghua Donglu, Beijing 100083, China. Electronic address: dongli@cau.edu.cn.
³ College of Food Science and Nutritional Engineering, Beijing Key Laboratory of Functional Food from Plant Resources, China Agricultural University, Beijing, China. Electronic address: wlj@cau.edu.cn.
⁴ School of Chemical Engineering, UNSW, Sydney, NSW 2052, Australia.

PMID: 35033525
DOI: 10.1016/j.ijbiomac.2022.01.021

Abstract

Turmeric is an herb with multiple bioactive substances and health benefits. Drying is one of the most important steps of its processing and sales. In order to obtain high-quality turmeric products, we used five different pretreatment methods to treat turmeric prior to pulse-spouted microwave vacuum drying (PSMVD), including carboxymethyl cellulose coating (CMC), pectin coating (P), ultrasound (US) and their combination (CMCUS or PUS). The effect of different pretreatments on the drying kinetics, quality attributes and microstructure of turmeric were evaluated. Results showed that the US pretreatment had the shortest drying time (60 min), while coating treatment did not significantly affect drying rate. Dried turmeric with coating pretreatment had lower rehydration ratio and water adsorption capacity compared with individual ultrasound treatment. Carboxymethyl cellulose coating protected bioactive substances better than pectin coating. Moreover, CMCUS pretreatment showed significantly lower total color change, higher curcumin content, total phenols and flavonoid content as well as antioxidant capacity in all dried samples. Microstructure observation showed that the polysaccharide coating covering the surface of turmeric might reduce the degradation of bioactive compounds. Therefore, the CMCUS pretreatment before PSMVD of turmeric was recommended due to the efficiency and quality protections.

Keywords: Drying; Pretreatment; Turmeric.

MeSH terms

Carboxymethylcellulose Sodium*
Curcuma* / chemistry
Desiccation / methods
Pectins
Phenols

Substances

Phenols
Pectins
Carboxymethylcellulose Sodium