## 1 Introduction  
Meat and meat products are high-quality sources of essential amino acids, protein, and many other nutritional compounds in human diets [1]. However, meat is susceptible to suffering adulteration, and incidences of commercial meat adulteration like mislabeling, undeclared ingredient additions, and species substitution are common [2]. Nowadays, consumers are paying more and more attention to meat authenticity and demanding higher protection from fraudulent meats. Therefore, rapid, reliable, and effective identification methods are urgently needed in the meat industry to provide efficient management for regulators and accurate information for consumers. Compared to red meat, chicken meat is always considered as one of the most popular foods globally due to its affordability, low fat, and high protein content [3]. Poultry consumption hasincreased steadily in the last decade [4]. To date, several adulteration phenomena related to chicken meat have increased in China, such as water-injected or gel-injected chicken [5]. In particular, the injection of gel (carrageenan is most commonly used) is used to cover up water that is injected, which can help to hold more water and gain more weight to make profits. In addition, some unscrupulous chicken steak wholesalers used restructured meat by splicing minced chicken scraps together with hydrocolloids including carrageenan instead of intact chicken meat [6]. These arbitrary behaviors on one hand violate the interests and rights of consumers and on the other hand seriously increase their health risks, although the addition of carrageenan within permissible limits can improve the textural and rheological characteristics that are related to consumers' sensory acceptance [7]. At present, there is still no particular method to discover injected carrageenan except by the naked eyes, however this transparent material is difficult to distinguish visually. Minced meat, which is one of the most versatile products, is a major ingredient in hamburgers, meatballs, patties, etc. Moreover, it removes the morphological characteristics of muscles, which makes it more difficult to identify adulteration by sight. Thus, the detection of adulterants has always been a challenge in the poultry industry, especially the identification of carrageenan adulteration in minced chicken meat. Near-infrared (NIR) spectroscopy, as a rapid, non-destructive, and efficient tool for electrochemical analysis, has been recognized as effective in meat adulteration detection [8; 9; 10]. However, spectroscopic assessments, with their relatively small point-source measurements, are not fully representative of the whole specimen, which may cause measuring error. In addition, spatial information of the adulteration cannot be provided by this conventional spectroscopic method. Recently, hyperspectral imaging (HSI), through integrating spectroscopic and computer vision techniques into one system to simultaneously capture spectral and spatial information of the tested object, has been widely used in detecting food quality and safety [11]. Different from titration, the colorimetric method, or chromatographic analyses, HSI overcomes disadvantages such as being tedious, time-consuming, and having destructive processes. In particular, HSI with chemometrics is nowadays gaining in importance for detecting meat adulteration, and some works have been successfully conducted including pork adulteration in lamb [12], horsemeat in beef [13; 14], pork in beef [15; 16], chicken in beef [17], and gelatin in drawn [18]. However, specifically, the utilization of HSI for estimating carrageenan adulteration in chicken meat is scarce. It was also noted that the majority of studies only used reflectance (R) spectra as inputs, however, absorbance (A) and Kubelka-Munck (KM) spectra are also effective as candidate spectral units in evaluating meat quality using HSI [17; 19; 20]. To improve the precision for detecting adulteration, comparing the performance of R, A, and KM spectra is also desirable.