In this study, leaves and stems of Talinum triangulare were sequentially extracted with phosphate buffer solution to obtain PTL and PTS (phosphate buffered extracts of T. triangulare leaves and stems), with 75% ethanol to obtained ETL and ETS (ethanol extracts of T. triangulare leaves and stems), or with 90°C boiling water to obtain WTL and WTS (water extracts of T. triangulare leaves and stems). We investigated the antioxidant activities of various T. triangulare extracts, analyzed the extracts' stimulations on human mononuclear cell (MNC) growth and secretion of cytokines (interleukin-1 beta, interferon-γ, and tumor necrosis factor-α) and nitric oxide, and then assayed their subsequent inhibitions on human leukemic U937 cell growth. Results indicated that extracts of T. triangulare showed significant antioxidant activities. Among these extracts, WTS showed the highest stimulatory effect on human MNC growth. The secretion levels of interleukin-1 beta, interferon-γ, and tumor necrosis factor-α in the conditioned medium, wherein human MNC was treated with 500 μg/mL WTS for 72 hours, were 1275, 859, and 2222 pg/mL, respectively. All conditioned media obtained from human MNCs cultured with various T. triangulare extracts showed significant inhibition against U937 cell growth of over 40%. These results suggest that T. triangulare extracts may be used in health foods for their immunomodulatory potential.
In this study, the effects of roasting camellia (Camellia oleifera Abel.) seed oils at different temperatures (65°C, 100°C, 120°C, and 140°C) on the oxidative stability and composition of the oils were investigated. The results showed that, in terms of the quality of the oils, the roasting temperature influenced the total phenolic content (which ranged from 1.64~2.45 GAE mg/g for the different oils) and total flavonoid content (which ranged from 0.36~0.45 QE mg/g for the different oils), while the fatty acid profile and tocopherol content were not influenced by the roasting temperature. We also investigated the kinetic parameters of camellia seed oil during oxidation via Rancimat (at temperatures ranging from 110~140°C). It turned out that the natural logarithms of the oxidative stability index (OSI) varied linearly with respect to temperature (R2: 0.958~0.997). This was done on the basis of the Arrhenius equation that indicates that the activation energies (Ea) for oxidative stability are 65.7~78.4 KJ/mol. Simultaneously, we found that increasing the roasting temperature could increase the antioxidant stability of Maillard reaction products in camellia seed oil. The effects of roasting include the assurance that the camellia seed oil so produced will comply with the relevant governmental health codes and standards and have a longer shelf life.
The study sought to investigate the effect of roasting temperatures on antioxidant components and oxidative stability of peanut oils. The total phenolic content, total flavonoid content, α–tocopherol content, and phytosterol content in peanut oils was influenced by roasting at temperatures of 120 °C, 140 °C, and 160 °C, while those roasting temperatures had no effect on the fatty acid profile and γ–tocopherol content of peanut oils. Roasting promotes the quality of peanut oil aroma via the Maillard reaction, particularly when it is derived from N–heterocyclic compounds (such as pyrazine and pyrrole). The oxidative stability of peanut oils was investigated using the Rancimat method, and the results show that there is a linear relationship between roasting and natural logarithm of the induction period (R2: 0.959~0.998). This was determined based on the Arrhenius equation, which indicated the activation energy (Ea) was in the range of 82.08~108.61 kJ/mol. In principal component analysis (PCA) analysis, the antioxidant stability of the increase levels of phenols released in the peanut oils was found to rise with the increment of roasting temperatures. The data obtained in this study should be confirmed as the nutritional benefits of peanut oils that will be most appealing to consumers.
1 January 2020 in International Journal of Food Properties
The health-maintaining effects of tea on the human body have been widely proven, even with the tea prepared by brewing tea leaves in cold water becoming a new choice other than hot water. In this research, quality and the antioxidant properties of the Pouchong tea infusions prepared with cold water and hot water were determined and explored their relationships under a consumer hedonic test. The results showed that the chemical components of cold tea infusions increased with increasing duration of brewing, and a maximal increment was observed during the first 2 h of brewing. All chemical components under investigation, except caffeine, were found to be higher in the cold tea infusions over 8 h as compared in the hot tea infusions. The antioxidant ability of cold tea infusion increased with increasing duration of brewing and approached the plateau after 12 hours. The chemical components showed a significantly positive correlation with the antioxidant activities (P < .01). Regarding the sensory analysis-consumer hedonic test, the cold tea infusions of 10, 12, and 14 h of brewing had the highest score in taste, the highest score in total acceptability, and the most popular in aroma, respectively.
21 December 2020 in International Journal of Food Properties
In this study, the banana flower was divided into bract and male flowers and extracted with water and ethanol, at different temperatures, and then the functionality of the obtained extract was evaluated and the bioactive compounds were analyzed. The findings showed that the banana flower with an ethanol extract of 50% and a temperature of 50°C (FE-50%-50°C) had the best DPPH radical scavenging ability and hydroxyl radical scavenging ability of 97.44% and 38.86%, respectively. Moreover, the FE-50%-50°Calso had the best reducing power. In terms of its ferrous ion chelating ability, the banana flower ethanol 50% extract at room temperature (FE-50%-RT) had the best ferrous ion chelating ability of 96.82%. The 95% ethanol extract of the banana flower was effective in inhibiting α-amylase, α-glucosidase, and lipase activity was 31.75%, 84.17%, and 70.59%, respectively. FE-50%-50°C had the highest alcohol dehydrogenase activity of 74.92%. In addition, the FE-95%-50°C had the highest content of lupeol and umbelliferone, which were 40.10 and 90.83 μg/mg, respectively.