Artificial saliva precipitation index (ASPI): An efficient evaluation method of wine astringency

Astringency is one of the most important organoleptic characteristics of red wines, and its intensity evaluation method has been the focus of research in recent years. An artificial saliva system was developed to establish an accurate and reliable evaluation method for the astringency intensity of dry red wines based on saliva precipi-tation index (SPI). To achieve this, five key protein families, which presented high reactivities and sensitivities in protein-tannin binding reactions, were selected from human whole saliva. The concentrations of the five proteins (proline-rich protein, alpha-amylase, lactoferrin, lysozyme, and albumin) and pH were optimized using response surface methodology based on the human salivary conditions to simulate the real salivary environment. The artificial saliva precipitation index method was applied to 60 commercial dry red wines and it exhibited a high correlation (CoefASPI = 0.94) with the sensory scores, indicating better performance than the traditional SPI method and other analytical approaches.

Automated summary

An accurate and reliable evaluation method for the intensity of astringency in dry red wines was developed using an artificial saliva system based on saliva precipitation index (SPI). Five key protein families with high reactivities and sensitivities in protein-tannin binding reactions were selected from human whole saliva, and their concentrations and pH were optimized to simulate the real salivary environment. The artificial saliva precipitation index method showed a high correlation (CoefASPI = 0.94) with sensory scores when applied to 60 commercial dry red wines, indicating better performance compared to traditional SPI method and other analytical approaches.