The Detection of Substitution Adulteration of Paprika with Spent Paprika by the Application of Molecular Spectroscopy Tools

Abstract

The spice paprika (Capsicum annuum and frutescens) is used in a wide variety of cooking methods as well as seasonings and sauces. The oil, paprika oleoresin, is a valuable product; however, once removed from paprika, the remaining spent product can be used to adulterate paprika. Near-infrared (NIR) and Fourier transform infrared (FTIR) were the platforms selected for the development of methods to detect paprika adulteration in conjunction with chemometrics. Orthogonal partial least squares discriminant analysis (OPLS-DA), a supervised technique, was used to develop the chemometric models, and the measurement of fit (R2) and measurement of prediction (Q2) values were 0.853 and 0.819, respectively, for the NIR method and 0.943 and 0.898 respectively for the FTIR method. An external validation set was tested against the model, and a receiver operating curve (ROC) was created. The area under the curve (AUC) for both methods was highly accurate at 0.951 (NIR) and 0.907 (FTIR). The levels of adulteration with 100% correct classification were 50–90% (NIR) and 40–90% (FTIR). Sudan I dye is a commonly used adulterant in paprika; however, in this study it was found that this dye had no effect on the outcome of the result for spent material adulteration.

Relationships between amylopectin internal molecular structure and physicochemical properties of starch

“…Some of the adulterants used in spices are corn starch, fruit seeds, peanuts, almond, and buckwheat (Galvin-King et al, 2020). The most concerning problems of spices adulteration are its health effects.…”

Botanical Ingredient Forensics: Detection of Attempts to Deceive Commonly Used Analytical Methods for Authenticating Herbal Dietary and Food Ingredients and Supplements

“…Another way to deceive macroscopic identification is the sale of cut or powdered plant materials from which the valuable constituents have been removed. Such adulteration is known for spice plants such as black pepper, cinnamon ( Cinnamomum verum and other Cinnamomum species, Lauraceae) bark, ginger ( Zingiber officinale , Zingiberaceae), or paprika ( Capsicum annuum , Solanaceae) . This type of adulteration may be detected by organoleptic assessment, predominantly by the absence or changes in the expected color, texture, aroma, or taste, microscopically through the observation of ruptured cell walls indicative of pre-extraction, or quantitative analysis of the compounds of interest, e.g., using HPLC-UV/vis or GC-FID.…”

Detection and Quantitation of Adulterated Paprika Samples Using Second-Order HPLC-FLD Fingerprints and Chemometrics

“…Owing to its particular taste (sweet and spicy), flavor, and high coloring capacity, paprika can be used as a food additive, acting as both a natural colorant and a flavoring agent [ 3 ]. In China, paprika is widely used in a wide variety of cooking methods for both flavor and color [ 4 ]. Moreover, it is also well-known to be a good source of micronutrients (minerals and vitamins) and bioactive compounds such as capsaicinoids, carotenoids, and phenolic and polyphenolic compounds [ 5 ].…”