Evaluation of Loquat Jam Quality at Different Cooking Times Based on Physicochemical Parameters, GC-IMS and Intelligent Senses

Abstract

The study compared and analyzed the quality of loquat jam with different cooking times through physicochemical parameters, headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) and intelligent senses. The results showed that with the prolongation of the cooking time, the color of loquat jam slowly deepened, the energy significantly increased, the adhesiveness, gumminess, hardness and chewiness enhanced, the free amino acid content increased from 22.40 to 65.18 mg/g. The organic acid content increased from 1.64 to 9.82 mg/g. Forty-seven volatile flavor compounds were identified in five types of loquat jam using HS-GC-IMS, among which the relative content of aldehydes was sharply higher than that of other chemical substances, playing an important role in the flavor formation of loquat jam. LJ0, LJ1 and LJ2 had higher aldehyde content, followed by LJ3 and LJ4 had the lowest aldehyde content. The orthogonal partial least squares-discriminant analysis (OPLS-DA) screened 15 marker compounds that could distinguish five types of loquat jam. The E-nose results showed a significant difference in olfactory sense between loquat jam cooked for 100 and 120 min. The E-tongue results corroborated the results of free amino acids (FAAs) and organic acids, indicating that the gustatory sense of loquat jam changed significantly when the cooking time reached 120 min. The results provided a basis for further research on the relationship between the cooking process and quality characteristics of loquat jam.

Characterization of flavor and taste profile of different radish (Raphanus Sativus L.) varieties by headspace-gas chromatography-ion mobility spectrometry (GC/IMS) and E-nose/tongue

“…3 A, B). Oxalic acid, with a low threshold value of 0.504 mg/g, is identified as the primary contributor to the sour taste in radishes due to its high intensity of sour perception ( Qiao et al, 2024 ). As the previous study reported, oxalic acid is the major organic acid in raw radish and maintained one of the highest concentrations even across fermentation ( Gutiérrez & Perez, 2004 ; Y.…”

“…Referring to Qiao et al (2024) , The contents of free amino acids (FAAs) were measured as follows: the radish was homogenized (the mass ratio of radish to ultra-pure water was 1:1) using a wall breaker, then 20 g homogenate was added in 10 mL of 7% sulfosalicylic acid, and ultrasonic was carried out at 40 °C for 40 min. The mixture was centrifuged at 12,000 rpm for 10 min.…”

Quality Assessment of Loquat under Different Preservation Methods Based on Physicochemical Indicators, GC–MS and Intelligent Senses

“…After picking loquat, complex physicochemical changes will occur in the storage process, and preservation methods on its quality characteristics have a great impact. Therefore, appropriate preservation methods can reduce the changes in loquat quality brought about by prolonged storage time [10].…”