Rapid determination of geographical authenticity and pungency intensity of the red Sichuan pepper (Zanthoxylum bungeanum) using differential pulse voltammetry and machine learning algorithms

The development of an analytical method for assessing pungency intensity and determining geographical origins is crucial for evaluating the quality of visually similar Zanthoxylum bungeanum pericarp (PZB). This study analyzed 210 PZB samples from 14 origins across China, focusing on origin adulteration identification and pungency intensity using a combination of differential pulse voltammetry (DPV) and machine learning algorithms. The artificial neural network (ANN) and K-nearest neighbor (KNN) algorithms provided the highest accuracy in origin identification (100 %) and adulteration detection (97.9 %) respectively. Moreover, the ANN excelled in predicting pungency intensity (R2 = 0.918). Assessment via feature importance analysis of DPV features revealed that segments of polyphenols (0.34-0.52 V and 1.0-1.2 V) and alkylamides (1.0-1.2 V) contributed significantly to the PZB pungency intensity. These findings highlight the potential of DPV as a reliable method for assessing the quality of PZB, and offer a promising solution for ensuring the geographical authenticity of this important crop.

Dynamic Zanthoxylum pungency characteristics and their correlation with sanshool composition and chemical structure

Huajiao (Zanthoxylum) from different regions varies in pungency features. The objective of this study was to explore the reasons for the differences. Temporal check-all-that-apply (TCATA) and time-intensity (TI)) were used to determine time-related pungency features of huajiao and sanshools. The compositions of sanshools in huajiao were measured by high-performance liquid chromatograph (HPLC). TI results revealed that hydroxy-γ-sanshool tingling and numbing duration (1332.00 ± 50.91 and 1020.00 ± 61.19 s, respectively) were about twice that of hydroxy-α-sanshool (720.00 ± 25.92 and 584.00 ± 22.63 s, respectively). Tingling and numbing were not perceived by hydroxy-β-sanshool and hydroxy-γ-isosanshool. HPLC results showed that HαSS was the main component of huajiao sanshools, representing 71.06 % to 92.90 %. TCATA results revealed the pungency sensations appearance sequence: tingling, salivating, cooling, and burning appeared first, followed by vibrating, and numbing was perceived last. These findings revealed the relationship between the compositions of sanshool and the pungency features of huajiao.

Sensory characterization of Baijiu pungency by combined time-intensity (TI) and temporal dominance of sensations (TDS)

Pungency is increasingly being recognized as an important factor of overall sensory quality, palatability, and consumer preference of distilled spirits. The characterization of pungency is necessary to evaluate the potential sensory quality of distilled spirits. In this study, the temporal profiles of pungency of Baijiu with different aging times were evaluated using time-intensity (TI) and temporal dominance of sensations (TDS) methods, considering both pungency intensity and pungency sub-qualities. TI results indicated significant differences in release rate of pungency during Baijiu consumption. Compared to young Baijiu, old Baijiu tend to show higher release rate of pungency, the areas under the curve and duration of pungency were significantly decreased in old Baijiu. The TDS results showed significant differences in the combination of dominant sub-qualities, as well as in the maximum dominance rates and the dominant duration of sub-qualities among Baijiu. The young Baijiu were mainly characterized by the dominant sub-qualities of "burning" and "numbing", whereas for old Baijiu, "burning", "prickle", and "drying" were dominant. The application of TI and TDS provided dynamic and temporal profiles of pungency to fully characterize pungency differences of distilled beverages.