High-moisture extrusion technology should be considered one of the best choices for producing plant-based meat substitutes with the rich fibrous structure offered by real animal meat products.  Unfortunately, the extrusion process has been seen as a “black box” with limited information about what occurs inside, causing serious obstacles in developing meat substitutes.  This study designed a high-moisture extrusion process and developed 10 new plant-based meat substitutes comparable to the fibrous structure of real animal meat.  The study used the Feature-Augmented Principal Component Analysis (FA-PCA) method to visualize and understand the whole extrusion process in three ways systematically and accurately.  It established six sets of mathematical models of the high-moisture extrusion process based on 8 000 pieces of data, including five types of parameters.  The FA-PCA method improved the R² values significantly compared with the PCA method.  The Way 3 was the best to predict product quality (Z), demonstrating that the gradually molecular conformational changes (Yⁿ´) were critical in controlling the final quality of the plant-based meat substitutes.  Moreover, the first visualization platform software for the high-moisture extrusion process has been established to clearly show the “black box” by combining the virtual simulation technology.  Through the software, some practice work such as equipment installation, parameter adjustment, equipment disassembly, and data prediction can be easily achieved.

The function of the 3 040 bp sequence at the upstream translation starting site (ATG) of the ZAG2 gene, isolated from the maize genome, was studied. The sequence analysis showed that the sequence contained a typical class C MADS-box gene regulatory element. The 5´ UTR region of the gene contains a 1 299-bp intron that might have important regulatory functions. To study the sequence function, deletion derivatives of promoter-reporter (uidA) gene fusions were generated and transformed into tobaccos. The GUS staining and fluorescence quantification results showed that the GUS activity was detected only in the third and fourth whorl floral organs of the transgenic tobaccos under driving the promoter including the first intron, while detected in all the organs and was stronger under driving the promoter without the first intron. However, the GUS activity was just detected in one whorl of the fourth or third floral organs under driving of the 35S promoter. These results suggested that the first intron of the ZAG2 gene contains functional regulatory elements, which turned out to be important for gene expression in the heterologous systems. Moreover, the GUS activity was decreased when the reporter gene driven by the promoters with 5´-deletions, respectively, from -1 606 to -951 and -951 to -426 nts, which indicates that positive regulatory elements are present in these two sequence stretches.