Multi-Frequency Ultrasonic Extraction of Anthocyanins from Blueberry Pomace and Evaluation of Its Antioxidant Activity.

BACKGROUND: A large amount of blueberry pomace is discarded and wasted. OBJECTIVE: To make full use of blueberry pomace and extract anthocyanins. METHOD: Multi-frequency ultrasound was used to extract anthocyanins from blueberry pomace. The effects of different extraction conditions on the anthocyanin yields were studied. The antioxidant activity of anthocyanins was evaluated, and the main anthocyanin components were identified by HPLC-electrospray ionization (ESI)-MS/MS. RESULTS: The optimal anthocyanin extraction conditions were as follows: dual-frequency ultrasound of 40 + 80 kHz, ultrasonic power of 350 W, extraction temperature of 50°C, and extraction time of 40 min. Compared with single frequency (25 kHz) and tri-frequency ultrasound (25 + 40 + 80 kHz), the anthocyanin yield with dual-frequency ultrasound increased by 15.26% and 5.45% respectively. Furthermore, the antioxidant activities (DPPH, hydroxyl radical scavenging ability, and reducing power) of anthocyanins extracted with dual-frequency ultrasound were all higher than those without ultrasound. Seven kinds of anthocyanins were identified by HPLC-ESI-MS/MS. CONCLUSIONS: Dual-frequency ultrasound had a higher extraction yield than single frequency ultrasound, tri-frequency ultrasound, and no ultrasound. HIGHLIGHTS: Dual-frequency ultrasonic technology provides an effective approach for improving the extraction yield of anthocyanins from blueberry pomace.

[The change and significance of the cardiopulmonary exercise test parameters in patients with obstructive sleep apnea-hypopnea syndrome].

OBJECTIVE: To investigate the change of exercise cardiopulmonary function in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: Thirty OSAHS patients and 18 normal healthy adults (control group) were studied by cardiopulmonary exercise test (CPET). The results including maximal oxygen uptake percent predicted (Vo(2)max% predicted), oxygen uptake to work rate (Vo(2)/WR), oxygen pulse percent predicted (Vo(2)/HRmax% predicted), anaerobic threshold to maximal oxygen uptake (AT/Vo(2)max), breathing reserve (V(E)max/MVV) and ventilatory equivalents for carbon dioxide (V(E)/V(CO2)) were compared between two groups. RESULTS: The levels of Vo(2)max% predicted, AT/Vo(2)max, Vo(2)/HRmax% predicted, Vo(2)/WR, and V(E)max/MVV in the OSAHS group [(83 +/- 5)%, (44 +/- 6)%, (79 +/- 5)%, (9.3 +/- 0.6) ml.min(-1).W(-1), (73 +/- 8)%] were lower than those in the control group [(88 +/- 5)%, (49 +/- 6)%, (83 +/- 4)%, (10.9 +/- 2.3) ml.min(-1).W(-1), (79 +/- 9)%, all P < 0.05]. The levels of V(E)/V(CO2) in the OSAHS group (29 +/- 3) was higher than the control group (26 +/- 3, P < 0.05). In the OSAHS group Vo(2)max% predicted, Vo(2)/HRmax% predicted, Vo(2)/WR AT/Vo(2)max and V(E)max/MVV correlated negatively with apnea-hypopnea index (AHI, r = -0.52, -0.62, -0.59, -0.37, -0.66, P < 0.05). Vo(2)max% predicted, Vo(2)/HRmax% predicted, Vo(2)/WR, AT/Vo(2)max and V(E)max/MVV correlated with lowest oxygen saturation (LSaO(2), r = 0.60, 0.63, 0.64, 0.40, 0.59, P < 0.05). V(E)/V(CO2) correlated with AHI (r = 0.57, P < 0.01) and correlated negatively with LSaO(2) (r = -0.62, P < 0.01). CONCLUSIONS: The cardiac output of patients with OSAHS can not meet the demand of hard exercise. At the same time, there is more significant ventilation-perfusion disturbance in OSAHS patients than normal subjects. The patients' exercise cardiopulmonary function has been compromised although there are no symptoms.