Effects of different antioxidants combined with high hydrostatic pressure on the color and anthocyanin retention of a blueberry juice blend during storage.

Blueberry juice has been found to undergo severe browning after treatment and cold storage, such as processing by high hydrostatic pressure (HHP) at 550 MPa/10 min/25 °C followed storage at 4 °C for 4 days. This browning may be due to the degradation of anthocyanin (AC) in the berries. Therefore, in this study, gallic acid (GA), ferulic acid (FA), ascorbic acid (VC), citric acid (CA), tea polyphenol (TP) and α-tocopherol (VE) were compared to determine their ability to improve the stability of the AC in HHP-treated blueberry juice. The juice was combined with the six abovementioned antioxidants at different concentrations, then treated by HHP at 550 MPa/10 min/25 °C and stored at 4 °C for 20 days. Thereafter, the pH levels, degrees °Brix, color parameters, total AC content and polyphenol oxidase (PPO) activity of the blueberry juice blend were measured and compared. Gallic acid at 2 g/L was found to be the most effective antioxidant to protect against AC degradation. After storage at 4 °C for 20 days, the AC content of the juice with no added antioxidants had decreased by 62.27% with a PPO relative activity of 50.78%, while the AC content of juice supplemented with 2 g/L GA had decreased by 13.42% with a PPO relative activity of 28.13%. The results of this study, thus, suggest that GA can stabilize the structure of AC in blueberry juice and reduce PPO activity, which may be beneficial in guiding the production of blueberry juice with high AC retention.

Impaired pre-attentive change detection in major depressive disorder patients revealed by auditory mismatch negativity.

Patients with major depressive disorder (MDD) show deficits in cognitive functions. However, the neural mechanisms underlying the pre-attentive information processing in MDD patients are poorly understood. The present study investigated whether MDD patients have impairments in pre-attentive information processing indexed by auditory mismatch negativity (MMN). The deviant-standard reverse oddball paradigm was used to obtain the memory-comparison-based duration auditory MMN in 24 MDD patients and 24 healthy control subjects. Over the frontal-central area, MDD patients exhibited decreased MMN amplitudes only for the increment condition (150-ms MMN), whereas the temporal MMN did not differ between MDD patients and healthy subjects, regardless of the increment or decrement (50-ms MMN) condition. The MMN amplitudes were not correlated with depression symptoms. In addition, the peak latency of MMN amplitudes was longer in the MDD patients than the control subjects. These data indicate that pre-attentive information processing is impaired in MDD patients. This dysfunction may represent a trait of MDD patients rather than a state-dependent phenomenon.