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By the combined use of metabolomics, flavoromics, and rapid electronic sensory detection technology, this study identified and analyzed the differences in flavor quality of six coffees. The results suggested that 2,6-dimethylpyrazine, 2-ethylhexan-1-ol, acetoin, isovaleric acid, and methyl valerate could be employed as aroma markers to distinguish coffees with different degrees of roasting. Additionally, 48 compounds, including guanine, tryptophan-alanine, crotonic acid, and 1-methyladenosine, were found to be the metabolic difference indicators to distinguish coffee powder from different geographical origins and their mixed samples. The major taste compounds of lightly roasted coffee were 1,4-D-xylose, alanine, isoleucine, and phenylalanine. Maltotriose was found to be a major compound in moderately roasted coffee, which also contained a lesser amount of inosine. The combination of electronic nose and electronic tongue detection with principal component analysis (PCA) could be used for rapid classification and variety identification of coffee. These results provide a theoretical basis and technical support for the production of coffee as well as a reference for establishing standards to evaluate the flavor and quality of coffee.

Due to its significant physiological effects, a sulfated polysaccharide has been considered an important nutrient of sea cucumber, but its metabolism in vivo is still unclear. The present study investigated the metabolism of a sea cucumber sulfated polysaccharide (SCSP) in rats and its influence on the metabolite profiles. The quantification by HPLC-MS/MS revealed that the blood level of SCSP achieved a maximum of 54.0 ± 4.8 μg/mL at 2 h after gavage, almost no SCSP was excreted through urine, and 55.4 ± 29.8% of SCSP was eliminated through feces within 24 h. These results prove the utilization of SCSP by gut microbiota, and a further microbiota sequencing analysis indicated that the SCSP utilization in the gut was positively correlated with Muribaculaceae and Clostridia_UCG-014. In addition, the non-targeted metabolomic analysis demonstrated the significant effects of SCSP administration on the metabolite profiles of blood, urine, and feces. It is worth noting that the SCSP supplement decreased palmitic acid, stearic acid, and oleic acid in blood and urine while increasing stearic acid, linoleic acid, and γ-linolenic acid in feces, suggesting the inhibition of fat absorption and the enhancement of fat excretion by SCSP, respectively. The present study shed light on the metabolism in vivo and the influence on the fat metabolism of SCSP. [ABSTRACT FROM AUTHOR]

Low-temperature deposition manufacturing has attracted much attention as a novel printing method, bringing new opportunities and directions for the development of biological 3D printing and complex-shaped food printing. In this article, we investigated the rheological and printing properties of gelatin solution and conducted numerical simulation and experimental research on the low-temperature extrusion process of gelatin solution. The velocity, local shear rate, viscosity, and pressure distribution of the material in the extrusion process were calculated using Comsol software. The effects of the initial temperature, inlet velocity, and print head diameter of the material on the flow field distribution and printing quality were explored. The results show that: (1) the fluidity and mechanical properties of gelatin solution vary with its concentration; (2) the initial temperature of material, inlet velocity, and print head diameter all have varying degrees of influence on the distribution of the flow field; (3) the concentration change of the material mainly affects the pressure distribution in the flow channel; (4) the greater the inlet velocity, the greater the velocity and shear rate in the flow field and the higher the temperature of the material in the outlet section; and (5) the higher the initial temperature of the gel, the lower the viscosity in the flow field. This article is of great reference value for the low-temperature 3D printing of colloidal materials that are difficult to form at room temperature. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the freshness of ice stored rainbow trout by bioelectrical impedance measurements. Rigor mortis, ATP‐related components, K‐value, and hardness of rainbow trout muscle during storage were monitored along with impedance. The results showed that the progress of rigor mortis was accompanied by an increase in impedance. Impedance kept decreasing even in rigor state, and during the gradual resolution of rigor mortis with impedance change upon storage of fish was biphasic (r = −0.944, p <.01). Thus, when impedance decreased close to the lowest value, K‐value was only about 61.57 ± 0.52%, but still exhibited a high pertinence (r = −0.959, p <.01). A gradual decrease of the hardness of fish muscle upon storage of fish showed a close correlation (r = 0.981, p <.01) with impedance decrease. These results suggested that the impedance measurement has a great potential for predicting the freshness of the rainbow trout during ice storage. [ABSTRACT FROM AUTHOR]