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Passiflora edulis, commonly known as passion fruit, is a popular all‐weather fruit eaten fresh or processed. Its shells, which currently are mostly discarded as waste and hurt the environment, account for more than half of the passion fruit. The shells contain gamma‐aminobutyric acid (GABA) which is the main inhibitory neurotransmitter and has many proven medical values such as antidepressant, anti‐anxiety, etc. Many studies have shown that GABA production in plants can be significantly increased by reverse stress. Taking Tainong 1 as a typical passion fruit cultivar, this study explored the optimal anoxic vacuum treatment for increasing the GABA content of passion fruit shells. The content increased to 2139.25 ± 26.69 mg/100 g on day 4 of chill storage after vacuum packing (63.68% higher than the control). The activities of glutamate decarboxylase (GAD) and diamine oxidase (DAO) were significantly higher in the vacuum‐treated group than in the control group after 4 days of vacuum‐chill storage. On day 5 of vacuum‐chill storage, the activities of all measured enzymes decreased except for the increase of GABA transaminase (GABA‐T), which was accompanied by a decrease in GABA content. Vacuum treatment and subsequent chill storage increased the content of GABA, thereby increasing functional value of passion fruit shells. [ABSTRACT FROM AUTHOR]

BACKGROUND This study investigated the effects of high‐pressure processing (HPP) on the glycaemic index (GI) of atemoya puree (AP) in rats. Sprague–Dawley rats were fed with unprocessed and high‐pressure processed atemoya puree (HPP‐AP), and the GIs for the unprocessed AP and HPP‐AP were calculated from changes in blood glucose concentrations within 2 h after meals. The physicochemical properties of AP were analysed to understand the mechanism affecting its GI. RESULTS: The results showed that HPP (600 MPa for 15 min) could delay increase in postprandial blood glucose levels, decrease the peak value of postprandial blood glucose by 76.1%, and significantly decrease the GI of AP to 49.8 in the experimental group compared to 65.4 in the control group. HPP did not exert a significant effect on the glucose and pectin contents of AP, but it increased the viscosity of the puree and its dietary fibre content and delayed the time of peak glucose response. In the analysis of enzymes of the puree, we found that HPP significantly decreased the activities of sucrose invertase, pectin methylesterase and polygalacturonase, thereby decreasing the rate of glucose generation in the puree and stabilizing the pectin structure, which decreased the absorption of glucose by the small intestine, thus decreasing the GI value. CONCLUSION: Our findings suggest that HPP technology could effectively delay increase in postprandial blood glucose levels and decrease the GI value of AP, thus having a potential application in developing atemoya puree products with low GI. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the in vitro anti-inflammatory properties of the shake extract ( SE) and the high pressure-assisted extract ( PE) of the mycelia of Grifola frondosa in a lipopolysaccharide-stimulated RAW 264.7 macrophage model. The content of total polysaccharides and β-glucans of PE at 600 MPa ( PE-600) was 41.2 and 6.2 mg g−1 dry weight, respectively, which were significantly higher than SE extracts. The results showed that treatment with 500 μg mL−1 of PE by 600 MPa ( PE-600) did not reduce RAW 264.7 cell viability but did significantly inhibit the production of LPS-induced NO, PGE2 and intracellular ROS. The PE-600 inhibited the activation of NF- kB and then reduced the production of LPS-induced TNF-α, IL-6 and IL-1β in a dose-dependent manner. Thus, the PE could be used as an alternative extraction method for improving the extraction efficacy of G. frondosa and serve as an alternative source of anti-inflammatory agents. [ABSTRACT FROM AUTHOR]