Antioxidant activity improvement of identified pine nut peptides by pulsed electric field (PEF) and the mechanism exploration

LWT ◽  
2017 ◽  
Vol 75 ◽  
pp. 366-372 ◽  
Author(s):  
Songyi Lin ◽  
Rong Liang ◽  
Peiyu Xue ◽  
Shuyu Zhang ◽  
Zeyu Liu ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Electric Field ◽  
Pulsed Electric Field ◽  
Pine Nut

scholarly journals Quality stability and sensory attributes of apple juice processed by thermosonication, pulsed electric field and thermal processing

2016 ◽  
Vol 23 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Alifdalino Sulaiman ◽  
Mohammed Farid ◽  
Filipa VM Silva
Keyword(s):  
Antioxidant Activity ◽  
Electric Field ◽  
Sensory Analysis ◽  
Thermal Processing ◽  
Apple Juice ◽  
Treatment Time ◽  
Pulsed Electric Field ◽  
Color Difference ◽  
Soluble Solids ◽  
Total Color Difference

Worldwide, apple juice is the second most popular juice, after orange juice. It is susceptible to enzymatic browning spoilage by polyphenoloxidase, an endogenous enzyme. In this study, Royal Gala apple juice was treated by thermosonication (TS: 1.3 W/mL, 58 ℃, 10 min), pulsed electric field (PEF: 24.8 kV/cm, 60 pulses, 169 µs treatment time, 53.8 ℃) and heat (75 ℃, 20 min) and stored at 3.0 ℃ and 20.0 ℃ for 30 days. A sensory analysis was carried out after processing. The polyphenoloxidase activity, antioxidant activity and total color difference of the apple juice were determined before and after processing and during storage. The sensory analysis revealed that thermosonication and pulsed electric field juices tasted differently from the thermally treated juice. Apart from the pulsed electric field apple juice stored at room temperature, the processed juice was stable during storage, since the pH and soluble solids remained constant and fermentation was not observed. Polyphenoloxidase did not reactivate during storage. Along storage, the juices’ antioxidant activity decreased and total color difference increased (up to 6.8). While the antioxidant activity increased from 86 to 103% with thermosonication and was retained after pulsed electric field, thermal processing reduced it to 67%. The processing increased the total color difference slightly. No differences in the total color difference of the juices processed by the three methods were registered after storage. Thermosonication and pulsed electric field could possibly be a better alternative to thermal preservation of apple juice, but refrigerated storage is recommended for pulsed electric field apple juice.

Optimizing extraction of berberine and antioxidant compounds from barberry by maceration and pulsed electric field-assisted methods

2020 ◽  
pp. 1-16 ◽  
Author(s):  
Mozhdeh Sarraf ◽  
Adel Beig-babaei ◽  
Sara Naji-Tabasi
Keyword(s):  
Antioxidant Activity ◽  
Optimum Condition ◽  
Electric Field ◽  
Ethanol Concentration ◽  
Pulsed Electric Field ◽  
Antioxidant Compounds ◽  
Good Source ◽  
Valuable Compounds ◽  
Central Composite ◽  
Different Parts

BACKGROUND: Barberry is a valuable plant, which is useful in the treatment of different diseases. There are valuable compounds in different parts of barberry that are pruned per year and discarded as waste. OBJECTIVE: In this study, the amount of berberine, phenolic compounds and antioxidant activity of barberry fruits, leaves, and stems of different barberry species (B.integerrima and B.thunbergii) were investigated. METHODS: Central composite design of response surface methodology (RSM) were used in this study to investigate the extraction variables (time: 2–24 h, temperature: 24–70°C and ethanol concentration: 50–90%) in the extraction of berberine from the stem of B.integrrima. The responses used as criteria were the amount of berberine, scavenging radical DPPH, and polyphenol. Also, pulsed electric field-assisted (PEF) was applied as a pretreatment (Pulse strengths of 250, 1000 and 1250 Vcm–1; Pulse numbers (n) of 50 and 100; frequency (f) of 1 Hz) and then the extraction was conducted in optimum condition. PEF increased significantly the amount of berberine. RESULTS: The stem of B.integrrima had the most amounts of antioxidant activity and berberine content, and it was selected for more investigation. The optimum condition in the maceration method was: 90% of ethanol, 70°C, and 3.36 h (141.6 min). According to the result of PEF method, the best condition for extraction of berberine from barberry stems was 1000 Vcm–1 and n = 100. CONCLUSIONS: The results demonstrated that the extract of B.integrrima stem is a good source of berberine, antioxidant, and has the potential to be applied in various industries.

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