Influence of high-intensity pulsed electric field processing on lipoxygenase and β-glucosidase activities in strawberry juice

Impact of high-intensity pulsed electric field variables affecting peroxidase and lipoxygenase activities of watermelon juice

“…also found that bipolar treatments induced the highest LOX inactivation (54%) when applying 40 kV/cm for 57 ms to tomato juice. In contrast to our results, Aguiló -Aguayo, Sobrino-Ló pez, et al (2008) observed that LOX activity in strawberry juice was more reduced in monopolar mode than in bipolar mode, irrespective of the frequency and pulse width applied. However, less than a 10% of the initial activity of a suspension of LOX soybean in distilled water was reported to be inactivated when applying a monopolar treatment at 30 kV/cm for 40 ms (Van Loey et al, 2002).…”

“…In accordance with our results, other studies about HIPEF-treated juices showed that a high LOX activity remained after HIPEF processing. Thus, reported a RA LOX of 46% after treating tomato juice with 2.0-ms bipolar pulses of 40 kV/cm for 57 ms. An 80% reduction of LOX activity was observed by Min, Min, and Zhang (1995) when tomato juice LOX was exposed to HIPEF at 35 kV/cm for 50 s or 60 s at 30 C. In strawberry juice, a reduction in the initial LOX activity up to a residual level of 55% was achieved when applying 4.0-ms monopolar pulses at 150 Hz (Aguiló -Aguayo, Sobrino-Ló pez, et al, 2008). In contrast, LOX activity in soymilk was largely inactivated, -up to a 12% of the activity in the non-treated juice-, after treating at 42 kV/cm for 1036 ms applying bipolar 2-ms pulses at 400 Hz (Li, Chen, Liu, & Chen, 2008).…”

“…Few studies have been conducted evaluating the effects of these parameters on POD and LOX (Aguiló -Aguayo, Odriozola-Serrano, Quintao-Teixeira, & Martín-Belloso, 2008;Aguiló -Aguayo, Sobrino-Ló pez, Soliva-Fortuny, & Martín-Belloso, 2008) and particularly, no information is currently available about the effect of HIPEF processing on enzymes from watermelon juice. Fundamental knowledge is essential to compare the sensitivity of different enzymes from diverse sources under similar treatment conditions.…”

Effect of thermal and non thermal processing technologies on the bioactive content of exotic fruits and their products: Review of recent advances

“…In cases where PEF has induced a loss of anthocyanins this is probably due to a direct impact of the treatment on these compounds and to the partial inactivation of enzymes (β-glucosidase, peroxidase (POD) and polyphenoloxidase (PPO)) that is induced by PEF processing. Aguiló-Aguayo et al (2008) reported an increase in the activity of β-glucosidase in strawberry juice, which can explain the corresponding degradation of anthocyanin following PEF treatment at 35 kV/cm for 1000 μs at 50 Hz. The total phenolic content of a blend of orange, kiwi, pineapple juice and soymilk was not affected by PEF treatments conducted at 35 kV/cm, 4 μs bipolar pulses at a frequency of 200 Hz for a total treatment time of 800 μs and 1400 μs.…”

The Effects of Non-Thermal Technologies on Phytochemicals

“…Pelargonidin-3-glucoside and pelargonidine-3-rutinoside content and, in turn, total anthocyanins of strawberry juices, depleted with storage time after PEF (35 kV/cm for 1,700 µs in bipolar 4-µs pulses at 100 Hz) and thermal treatments (90ºC for 60 or 30 s) (Odriozola-Serrano et al, 2008b) (Figure 1). Changes in anthocyanins content throughout storage of PEF-treated juices were associated to the presence of residual enzyme activities such as -glucosidase (Aguiló-Aguayo et al, 2008). HP treatment at ambient temperature has been reported to have minimal effects on the anthocyanins content of various food products (Oey et al, 2008).…”