With the growing demand for high-throughput analyses that can detect diverse molecules with varying physicochemical properties in shorter times, researchers are increasingly focused on developing or modifying analytical methods. This is particularly relevant in the food, pharmaceutical/nutraceutical, cosmetic, agricultural, and environmental industries. This study aimed to modify, establish, and validate a high-performance liquid chromatography method with ultraviolet detection (HPLC-UV) for the simultaneous determination of disodium guanylate (GMP) and disodium inosinate (IMP) in mushrooms, using Hericium erinaceus as a model. These compounds are natural flavour enhancers that contribute to the umami taste, boost savoury flavour, and improve the palatability of mushroom-based dishes. Their presence in mushrooms also supports sodium reduction in recipes, making them valuable for healthier meal preparation. The optimal chromatographic conditions were determined using isocratic elution with a mobile phase composed of phosphate buffer, acetonitrile, and methanol in varying concentrations and pH levels. Flow rates and column temperatures were systematically tested. GMP and IMP were extracted from samples using deionized water, 0.1 M HCl, and 6 % acetic acid. Separation was carried out on a Kromasil 100-5-C18 column (4.6 × 250 mm; Sigma-Aldrich), with detection at 254 nm. The method showed excellent linearity (R² = 0.9989 for GMP and 0.9958 for IMP), low relative standard deviation (RSD: 1.07 % for GMP and 2.16 % for IMP), and good sensitivity, with LODs of 3.61 ppm (GMP) and 7.30 ppm (IMP) and LOQs of 10.93 ppm and 22.12 ppm, respectively. Recovery rates ranged from 91.4 % to 95.0 %, with RSDs below 5 %, indicating high accuracy and precision. Quantitative results revealed that H. erinaceus contains more IMP than GMP, contributing significantly to its umami profile. The validated method offers high precision, accuracy, and adaptability for other mushrooms and umami-rich foods. It is suitable for quality control, flavour enhancement, and nutritional profiling in the food industry-particularly in the development of natural flavouring agents. This method enables accurate quantification of umami-enhancing nucleotides, supporting flavour standardization, product formulation, and compliance with food labelling standards. It can also aid in shelf-life studies and thermal process optimization. Ultimately, this study advances natural flavour science by offering a robust method for analyzing GMP and IMP in H. erinaceus.
Ketemepi et al. (Wed,) studied this question.