Deciphering Flavor Characteristics and Brand Differences of Braised Sauce Used for Guilin Rice Noodles

Guilin rice noodles (GRN) are the most representative delicious food of the world-famous tourist city of Guilin. The braised sauce is the soul of GRN and also a commercial secret, which few people know much about. This study employed multi-platform flavor analysis methods, including E-nose, E-tongue, GC-IMS, HS-SPME-GC-MS, high-performance liquid chromatography (HPLC), recombination and omission experiment, and chemometrics, to delve into the flavor characteristics and discrimination of the braised sauce from six original renowned brands of GRN. The results showed that the characteristic odorants and their concentration ranges were as follows: anethole (10,073.36-77,218.90 µg/kg), eugenol (1520.80-15,518.71 µg/kg), estragole (898.58-17,161.72 µg/kg), limonene (7.34-1221.63 µg/kg), geraniol (9.67-882.31 µg/kg), and ethyl p-methoxycinnamate (112.73-867.76 µg/kg), which imparted the odors of clove, fennel, fruity aroma, sweet, and herbal fragrance. The key tastants and their concentration ranges were listed below: glutamic acid (10.23-28.90 mg/g), aspartic acid (1.09-2.36 mg/g), alanine (0.67-2.27 mg/g), valine (0.41-0.96 mg/g), histidine (0.69-1.36 mg/g), and inosine monophosphate (318.41-596.80 mg/kg), which mainly present umami and sweet tastes. A total of 28 discriminative odorants and 5 discriminative tastants were screened out, and a discrimination model for different brands of the braised sauce was constructed. The findings provide a reference for formulating quality standards, offer guidance for consumers in brand selection, and are of great significance for the publicity and promotion of GRN.