Analysis of composition and source of the key aroma compounds in stir-fried pepper tallow.

Stir-fried pepper tallow is widely used in cooking due to its special flavor, particularly in hot-pot dishes. However, the composition and source of the key aroma compounds in stir-fried pepper tallow are poorly understood, resulting in uneven quality. Here, the key aroma compounds were screened using flavor dilution factors (FD) and odor activity values (OAVs). A total of 41 odorants compounds were identified. Of these, 20 compounds with FD ≥ 8 were aroma-active compounds. Furthermore, among these 20 compounds, 15 with OAVs ≥ 1were the key aroma-active compounds and most of these (13 out of 15 odorants) were produced from pepper. Glycosides in pepper are the precursors of the most of these key aroma compounds. It may be possible to improve the flavor quality of stir-fried pepper tallow by hydrolyzing glycosides. These findings should help to establish a standard to assess and improve the quality of stir-fried pepper tallow.

Modular design of centrifugal microfluidic system and its application in nucleic acid screening.

Modular integration of functional components on the chip and increasement in control accuracy through real-time alteration in the force direction of droplets is an effective way to optimize centrifugal microfluidic systems and realize passive components, compact modules, and high-throughput control. Conventional centrifugal microfluidic chips are mainly driven and controlled by centrifugal force and Euler force. The control valves are easily affected by machining precision, making the control unstable. In this study, a novel centrifugal microfluidic system is introduced to improve the freedom and accuracy of chip control while facilitating the design and addition of passive functional components. Furthermore, we modularize the centrifugal microfluidic chip to greatly shorten the period of design and optimization cycle and achieve chip reusability and multi-threaded control. Finally, to verify the feasibility of the modular centrifugal microfluidic chip applied to high-throughput nucleic acid screening, we test the nucleic acid purification and detection colorimetric reactions based on the modular centrifugal microfluidic chip. Among them, Chelex-100 is used to realize the purification of nucleic acid in cell lysate, and the purified solution can realize amplification in the PCR instrument, and the nucleic acid detection results are consistent with the off-chip kit by experimental testing. The system has great flexibility and stability under the acceptable purity of nucleic acid, which indicates that the platform has great potential for large-scale rapid screening applications.