A practical application of front-face synchronous fluorescence spectroscopy to rapid, simultaneous and non-destructive determination of piperine and multiple adulterants in ground black and white pepper (Piper nigrum L.). (May 2023)

• Record Type: Journal Article
• Authors: Liu, Zhao-Xi; Xiong, Shu-Rui; Tang, Shu-Hua; Wang, Ying; Tan, Jin
• Is Part Of: Food research international. Volume 167(2023)
• Publication Date: 2023-05
• Subjects: Pepper adulteration -- Front-face fluorescence -- Synchronous fluorescence -- Partial least square -- Papaya seed -- Food fraud; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2023.112654
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Front-face fluorescence of ground black and white pepper is observed. Their emissions are distinct from those of several possible adulterants. Piperine in pepper and tryptophan in adulterants yield the distinction. Simultaneous detection of multiple adulterants in ground pepper is feasible. Rapid and non-destructive analysis of piperine is achieved as well. Abstract: Based on the distinct fluorescence of piperine and tryptophan, and their different profiles in pepper and several possible adulterants, front-face synchronous fluorescence spectroscopy (FFSFS) was applied for the fast and non-invasive authentication of ground black pepper adulterated with papaya seed powder and buckwheat flour, and ground white pepper adulterated with whole wheat and maize flours. For either single adulterant or dual adulterants in the range of 10–40% w/w, prediction models were constructed based on the combination of unfolded total synchronous fluorescence spectra and partial least square (PLS) regression, and were validated by both five-fold cross-validation and external validation. The built PLS2 models produced suitable results, with most of the determination coefficients of prediction ( R p 2 ) greater than 0.8, the root mean square error of prediction (RMSEP) < 5% and residual predictive deviation (RPD) greater than 2. The limits of detection (LODs) were 11.1, 5.5, 10.6 and 12.0% for papaya seed powder, buckwheat, whole wheat and maize flours, respectively. Most relative prediction errors for simulated blind samples were within ± 30%. Besides, piperine in ground black and white pepper was also determined with acceptable PLS results.