Ginger (Zingiber officinale Roscoe.) starch is a waste product generated during the extraction of bioactive compounds from ginger. This study aimed to treat ginger starch with different freeze–thaw cycles and explore the effect on the functional components, physicochemical properties, and structural properties of ginger starch. The results of the study showed that as the number of freeze–thaw cycles increased, the content of resistant starch, amylose, total starch, and recrystallization in ginger starch increased significantly (p < 0.05). Freeze-dried ginger starch exhibited a C-type crystal structure in the X-ray diffraction pattern. The Fourier-transform infrared spectroscopy results also showed that the value of A_1047/1022 increased, indicating that the freeze–thaw cycle would increase the degree of starch recrystallization. In terms of physical and chemical properties, compared with gelatinized starch, freeze–thawed starch had low swelling power, high solubility, low peak viscosity and breakdown, indicating higher thermal stability. In conclusion, freeze–thaw treatment can promote the formation of resistant starch from ginger starch and reduce starch hydrolysis, reflecting the potential of low–GI foods. We hope that ginger starch can be used as a raw material for new applications in functional foods.

This study investigated the dynamics of aroma compounds in different locations of tea leaves at various stages of the Oolong tea-making process via metabolomics analysis and ribonucleic acid (RNA) gene transcriptome analysis of metabolism-related enzymes. In addition, this study focused on examining the composition and metabolic synthesis pathways of milk flavor compounds during the processing of Jin Xuan Oolong tea. This study showed that a total of 57 aroma compounds were identified, whereas the abundance of the heat map showed a decreasing abundance of these compounds from the first leaves to the stems. The milky aroma compounds were divided into two groups based on changes during the leaf-stirring process (shaking). Specifically, hexanal, 1-octen-3-ol, and trans-2-decanal decreased throughout this process. In contrast, heptanal, limonene, and jasmone increased, producing Oolong tea with a milky fragrance. Moreover, the results of this study on gene expressions of metabolic enzymes and fatty acid contents indicated the milky flavor compounds were derived from fatty acid metabolism. Therefore, this study provides theoretical support and information on the knowledge of Oolong tea processing, which potentially allows the tea industry to improve the quality of the tea to bring this fantastic flavor to consumers.

Black garlic has many beneficial effects, and it has a less spicy flavor. However, its aging conditions and related products still need to be further investigated. The present study aims to analyze the beneficial effects under different processing conditions and utilize high-pressure processing (HPP) in the production of black garlic jam. The highest antioxidant activities, including the DPPH scavenging, total antioxidant capacity, and reducing power (86.23%, 88.44%, and A₇₀₀ = 2.48, respectively), were observed in black garlic that had been aged for 30 days. Similarly, the highest total phenols and flavonoids were observed in black garlic that had been aged for 30 days (76.86 GAE/g dw and 13.28 mg RE/g dw, respectively). The reducing sugar in black garlic was significantly increased to about 380 (mg GE/g dw) after 20 days of aging. The free amino acids in black garlic were decreased time-dependently to about 0.2 mg leucine/g dw after 30 days of aging. For the browning indexes of black garlic, the uncolored intermediate and browning products were increased in a time-dependent manner and reached a plateau at day 30. Another intermediate product in the Maillard reaction, 5-hydroxymethylfurfural (5-HMF), was observed in concentrations that increased to 1.81 and 3.04 (mg/g dw) at day 30 and 40, respectively. Furthermore, the black garlic jam made by HPP was analyzed for its texture and sensory acceptance, showing that a 1:1.5:2 ratio of black garlic/water/sugar was the most preferred and was classified as “still acceptable”. Our study suggests suitable processing conditions for black garlic and outlines the prominent beneficial effects after 30 days of aging. These results could be further applied in HPP jam production and increase the diversity of black garlic products.

Methylglyoxal (MG) is the primary precursor of advanced glycation end products involved in the pathogenesis of inflammation and diabetes. A previous study in our laboratory found anti-inflammatory and anti-hyperglycemic effects of the polyphenol vescalagin (VES) in rats with MG-induced carbohydrate metabolic disorder. The present study further investigated the occurrence of inflammation in pancreatic β-cells in MG-induced diabetic rats and the mechanism by which VES prevents it. The results showed that VES downregulates the protein expression levels of advanced glycation end product receptors and CCAAT/enhancer binding protein-β and upregulates the protein expression levels of pancreatic duodenal homeobox-1, nuclear factor erythroid 2-related factor 2 and glyoxalase I from the pancreatic cells. The results also revealed that VES elevates glutathione and antioxidant enzyme contents and then downregulates c-Jun N-terminal kinase and p38 mitogen-activated protein kinases pathways to protect pancreatic β-cells in MG-administered rats.

Methylglyoxal (MG) is a highly reactive dicarbonyl aldehyde and a major precursor of advanced glycation end products that result in oxidative stress. Graptopetalum paraguayense E. Walther (WGP) is a herbal medicine of Taiwan with the hepatoprotective property. The aim of this study was to investigate the protective effects of the water extract of WGP on MG-induced liver damage in a rat model. The results showed that WGP lowered the total cholesterol level and the low-density lipoprotein cholesterol level. WGP could help normalize the MG level. The amelioration of inflammatory factors such as transformation growth factor-β1 was observed in the WGP treatment group. In another animal model, a high-fructose diet (HFD) was used to induce intestinal dysfunction in C57BL/6 mice. The results indicated that the HFD induction resulted in intestinal dysbiosis, including inflammation, microflora imbalances, and reductions in tight-junction proteins. However, both WGP and its active compound gallic acid could improve intestine function. According to the above, WGP can improve hyperlipidemia in the liver, inhibit inflammatory cytokine production, and regulate intestinal flora in mice, as well as enhance the intestinal barrier. These findings provide a basis for the development of health products.