title: Evaluation of the Bitterness of Traditional Chinese Medicines using an E-Tongue Coupled with a Robust Partial Least Squares Regression Method.
abstract: To accurately, safely, and efficiently evaluate the bitterness of Traditional Chinese Medicines (TCMs), a robust predictor was developed using robust partial least squares (RPLS) regression method based on data obtained from an electronic tongue (e-tongue) system. The data quality was verified by the Grubb's test. Moreover, potential outliers were detected based on both the standardized residual and score distance calculated for each sample. The performance of RPLS on the dataset before and after outlier detection was compared to other state-of-the-art methods including multivariate linear regression, least squares support vector machine, and the plain partial least squares regression. Both R² and root-mean-squares error (RMSE) of cross-validation (CV) were recorded for each model. With four latent variables, a robust RMSECV value of 0.3916 with bitterness values ranging from 0.63 to 4.78 were obtained for the RPLS model that was constructed based on the dataset including outliers. Meanwhile, the RMSECV, which was calculated using the models constructed by other methods, was larger than that of the RPLS model. After six outliers were excluded, the performance of all benchmark methods markedly improved, but the difference between the RPLS model constructed before and after outlier exclusion was negligible. In conclusion, the bitterness of TCM decoctions can be accurately evaluated with the RPLS model constructed using e-tongue data.
authors.affiliation: Institute of Clinical Pharmacy, Beijing Municipal Health Bureau, Beijing 100035, China. linzhaozhou@gmail.com.|School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China. linzhaozhou@gmail.com.
authors.forename: Zhaozhou
authors.initials: Z
authors.lastname: Lin
authors.affiliation: School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100102, China. zhangqiao@bucm.edu.cn.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000, China. liuruixin7@163.com.|The Level Three Laboratory of Chinese Traditional Medical Preparation of State Administration of TCM, Zhengzhou 450000, China. liuruixin7@163.com.|Key Laboratory of Viral Diseases Prevention and Treatment of TCM of Henan Province, Zhengzhou 450000, China. liuruixin7@163.com.
authors.forename: Ruixin
authors.initials: R
authors.lastname: Liu
authors.affiliation: School of pharmacy, Henan University of Traditional Chinese Medicine, Zhengzhou 450008, China. gaoxiaojie1990@126.com.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000, China. s.summer.lulu@live.com.|The Level Three Laboratory of Chinese Traditional Medical Preparation of State Administration of TCM, Zhengzhou 450000, China. s.summer.lulu@live.com.|Key Laboratory of Viral Diseases Prevention and Treatment of TCM of Henan Province, Zhengzhou 450000, China. s.summer.lulu@live.com.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000, China. kangby2008@163.com.|The Level Three Laboratory of Chinese Traditional Medical Preparation of State Administration of TCM, Zhengzhou 450000, China. kangby2008@163.com.|Key Laboratory of Viral Diseases Prevention and Treatment of TCM of Henan Province, Zhengzhou 450000, China. kangby2008@163.com.
authors.forename: Bingya
authors.initials: B
authors.lastname: Kang
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000, China. sjhx0@126.com.|The Level Three Laboratory of Chinese Traditional Medical Preparation of State Administration of TCM, Zhengzhou 450000, China. sjhx0@126.com.|Key Laboratory of Viral Diseases Prevention and Treatment of TCM of Henan Province, Zhengzhou 450000, China. sjhx0@126.com.
authors.forename: Junhan
authors.initials: J
authors.lastname: Shi
authors.affiliation: School of pharmacy, Henan University of Traditional Chinese Medicine, Zhengzhou 450008, China. zidan_wu@my.uri.edu.|Department of Computer Science and Statistics, University of Rhode Island, Kingston, RI 02881, USA. zidan_wu@my.uri.edu.
authors.forename: Zidan
authors.initials: Z
authors.lastname: Wu
authors.affiliation: School of pharmacy, Henan University of Traditional Chinese Medicine, Zhengzhou 450008, China. guixinjing1991@163.com.
authors.forename: Xinjing
authors.initials: X
authors.lastname: Gui
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000, China. xuelinli450000@163.com.
authors.forename: Xuelin
authors.initials: X
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D062609:Electronic Nose; D006801:Humans; D016014:Linear Models; D008516:Medicine, Chinese Traditional / Q000009:adverse effects*; D060388:Support Vector Machine; D013649:Taste
keywords: bitterness evaluation; electronic tongue; outlier detection; robust partial least squares; sensors
references.citation: Chem Rev. 2000 Jul 12;100(7):2595-626
references.pmid: 11749297
references.citation: Int J Pharm. 2012 Sep 15;434(1-2):235-42
references.pmid: 22659125
references.citation: Chem Pharm Bull (Tokyo). 2004 Aug;52(8):943-8
references.pmid: 15304986
references.citation: Anal Chim Acta. 2011 Apr 1;690(2):240-7
references.pmid: 21435482
references.citation: J Food Sci Technol. 2013 Oct;50(5):986-92
references.pmid: 24426007
references.citation: Talanta. 2014 Aug;126:46-53
references.pmid: 24881533
references.citation: Sensors (Basel). 2014;14(7):12233-55
references.pmid: 25010697
references.citation: J Pharm Sci. 2001 Dec;90(12):2042-8
references.pmid: 11745763
references.citation: Food Chem. 2012 Dec 15;135(4):2947-53
references.pmid: 22980895
references.citation: J Pharm Sci. 2007 Oct;96(10):2723-34
references.pmid: 17506509
references.citation: Talanta. 2010 Apr 15;81(1-2):88-94
references.pmid: 20188892
references.citation: Sensors (Basel). 2011;11(5):4744-66
references.pmid: 22163873
references.citation: Sensors (Basel). 2011;11(8):7799-822
references.pmid: 22164046
references.citation: Recent Pat Drug Deliv Formul. 2010 Jan;4(1):82-9
references.pmid: 19807680
references.citation: Anal Chim Acta. 2013 Dec 4;804:29-36
references.pmid: 24267060
references.citation: Evid Based Complement Alternat Med. 2015;2015:753942
references.pmid: 26366185
references.citation: Anal Chim Acta. 2010 Apr 14;665(1):15-25
references.pmid: 20381685
references.citation: Fitoterapia. 2013 Apr;86:137-43
references.pmid: 23481282
references.citation: Exp Ther Med. 2014 Jun;7(6):1696-1702
references.pmid: 24926369
references.citation: Talanta. 2011 Jul 15;85(1):569-74
references.pmid: 21645743
references.citation: Int J Pharm. 2013 Jan 30;441(1-2):121-7
references.pmid: 23247016
references.citation: Sensors (Basel). 2014;14(9):17770-85
references.pmid: 25254303