Impact of High Pressure and Pulsed Electric Fields on Bioactive Compounds and Antioxidant Activity of Orange Juice in Comparison with Traditional Thermal Processing

Abstract

Bioactive compounds (vitamin C, carotenoids, and flavanones) and DPPH* radical scavenging capacity (RSC) were measured in orange juice (OJ) subjected to different technologies. High pressure (HP) (400 MPa/40 degrees C/1 min), pulsed electric fields (PEF) (35 kVcm(-1)/750 micros), low pasteurization (LPT) (70 degrees C/30 s), high pasteurization (HPT) (90 degrees C/1 min), HPT plus freezing (HPT+F) (-38 degrees C/15 min), and freezing (F) were studied. Among the treatments assayed, even though the losses in total vitamin C were < 9%, treatments with the higher temperatures tended to show the higher decrease in the content of both forms of vitamin C. HP treatment led to an increased (P < 0.05) carotenoid release (53.88%) and vitamin A value (38.74%). PEF treatment did not modify individual or total carotenoids content. Traditional thermal treatments did not exert any effect on total carotenoid content or vitamin A value. With regard to individual carotenoid extraction, HPT and HPT+F led to different releases of carotenoids. With respect to flavanones, HP treatment led to increased (P < 0.05) naringenin (20.16%) and hesperetin (39.88%) contents, whereas PEF treatment did not modify flavanone content. In general, pasteurization and freezing process led to a diminished (P < 0.05) naringenin content (16.04%), with no modification in hesperetin. HP and PEF treatments did not modify DPPH* RSC. In the case of traditional thermal technologies, HPT treatment showed a decrease (P < 0.05) in RSC (6.56%), whereas LPT, HPT+F, and F treatments did not modify RSC. Vitamin C modulated RSC, in terms of antioxidant concentration (EC50) and kinetics (AE = 1/EC50TEC50), in the treated and untreated OJ. In summary, HP and PEF technologies were more effective than HPT treatment in preserving bioactive compounds and RSC of freshly squeezed orange juice.

EVALUATION OF EMERGING METHODS ON THE POLYPHENOL CONTENT, ANTIOXIDANT CAPACITY AND QUALITATIVE PRESENCE OF ACETOGENINS IN SOURSOP PULP (Annona muricata L.)

“…EPPs content was expressed as mg of gallic acid equivalents (GAE) 100 g-1 dry matter (DM). The method of ferric-reducing antioxidant power (FRAP) assay described by Benzie and Strain (1996), the 2-diphenyl-1-picryhydrazyl (DPPH) radical-scavenging assay described by Sánchez-Moreno et al (2005) and ABTS (2,2-Azinobis-3-ethylbenzotiazoline-6-sulfonic acid) radical scavening essay (RE et al, 1999) were used. A standard curve of Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) was employed to estimate the antioxidant capacity as µM Trolox equivalent (µMTE g -1 DM).…”

Bioactive compounds and quality parameters of natural cloudy lemon juices

“…Sanchez-Moreno et al (2005) reported that cases of thermal treated orange juice (90°C for 1 min) led to an increase in β-cryptoxanthin (19.19 %) and zeaxanthin (37.49 %) and to a decrease in lutein (23.10 %). In this study, concentrations of zeaxanthin (25.75 %), lutein (0.79 %), β-carotene (23.63 %) and β-cryptoxanthin (29.47 %) decreased in the pasteurized lemon juice (p < 0.01).…”

Influence of postharvest processing and storage on the content of phenolic acids and flavonoids in foods

“…The following list gives an enumeration of all the measures or procedures investigated: Fruit maturation [130], harvest date [126], storage [5, 126,127], cold storage [125], squeezing [5, 9], pasteurization [5,9,72,120,122], extraction [129], concentration [5], freezing [9,122], freeze-drying [127], light treatment [99], debittering [123], and irradiation [126,127].…”

“…The major flavanones discussed in the relevant publications are the aglycones (hesperetin [9, 122,124] [129,130] and didymin [5,125]) and the neohesperidose glycosides (neohesperidin [124,125], naringin [9, 99, 124 -127] and poncirin [125,127]). The alterations in flavanone glycosides during cold storage (up to 12 or 15 days at 48C) were determined in segments and juice made from grapefruits, mandarin-type fruits, tangelos and oranges [125].…”

“…A direct comparison of hot and cold pressing of grape mash revealed enhanced release of anthocyanins at elevated temperatures [122]. Significant differences in the anthocyanin content of wines were observed when carbonic maceration was applied rather than fermentation/maceration techniques using pumping-over or rotary vats.…”