Functional Properties of Punica granatum L. Juice Clarified by Hollow Fiber Membranes

Abstract

Abstract:There is currently much interest in pomegranate juice because of the high content of phenolic compounds. Moreover, the interest in the separation of bioactive compounds from natural sources has remarkably grown. In this work, for the first time, the Punica granatum L. (pomegranate) juice-clarified by using polyvinylidene fluoride (PVDF) and polysulfone (PSU) hollow fiber (HF) membranes prepared in the laboratory-was screened for its antioxidant properties by using different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), Ferric Reducing Antioxidant Power (FRAP), and β-carotene bleaching tests, and for its potential inhibitory activity of the carbohydrate-hydrolysing enzymes, α-amylase and α-glucosidase. The effects of clarification on quality characteristics of the juice were also investigated in terms of total phenols, flavonoids, anthocyanins, and ascorbic acid. Experimental results indicated that PVDF membranes presented a lower retention towards healthy phytochemicals in comparison to PSU membranes. Accordingly, the juice clarified with PVDF membranes showed the best antioxidant activity. Moreover, the treatment with PVDF membranes produced a clarified juice with 2.9-times fold higher α-amylase inhibitory activity in comparison to PSU (IC 50 value of 75.86 vs. 221.31 µg/mL, respectively). The same trend was observed using an α-glucosidase inhibition test. These results highlight the great potential of the clarified juice as a source of functional constituents.

Antioxidant, Biochemical, and In-Life Effects of Punica granatum L. Natural Juice vs. Clarified Juice by Polyvinylidene Fluoride Membrane

“…Herein, PVDF-clarified juice showed interesting in vitro antioxidant activity, as well as beta-glucosidase inhibitory activity, in comparison to the natural juice. These results are in agreement with data from our previous study [18] and from the work of Valero et al [26] that showed as clarification processes are able to produce positive effects on the antioxidant activity despite a reduction of phenols content of pomegranate juice. Indeed, we can deduce that the higher antioxidant effects of clarified juice could be explained through the removal of the antagonism between antioxidants and other constituents.…”

“…The clarification of pomegranate juice with the PVDF membrane determined the highest protection on ROS production, according to our results obtained in vivo. This is consistent with phytochemical analysis that showed no significant retention of important antioxidant compounds in the MF juice [18], thus confirming the PVDF membrane as a useful tool for juice clarification with no negative effects on its biological activity. Moreover, the antioxidant activity of CJ seemed to be even higher than the NJ, thus suggesting that the filtration process may retain some compounds that limited such activity.…”

“…Hollow fiber (HF) membranes were prepared by a nonsolvent induced phase separation technique, as reported elsewhere [18]. The produced membranes were assembled in glass modules with a length of 20 cm and fixed at each extremity with epoxy glue.…”

Coupling Ultrafiltration-Based Processes to Concentrate Phenolic Compounds from Aqueous Goji Berry Extracts

“…de Carvalho et al [28] evaluated the performance of different polymeric MF and UF In the selected operating conditions, polyvinylidene fluoride (PVDF) HF membranes showed higher initial (75 L/m 2 h) and steady-state (43.5 L/m 2 h) permeate fluxes in comparison to polysulphone (PS) membranes (initial permeate flux of 27 L/m 2 h and steady-state permeate flux of 4.8 L/m 2 h). A similar behavior was also observed in the clarification of pomegranate juice with PVDF and PS HF membranes [27]. The PVDF membranes presented, in fact, higher permeate fluxes in comparison with PS membranes.…”

Membrane-Based Operations in the Fruit Juice Processing Industry: A Review

“…Hollow fiber membranes in PVDF and PS, produced in laboratory, have been also tested for the clarification of pomegranate juice, in order to study the effect of membrane material on the functional properties of the clarified juice [37]. Experimental results indicated that PVDF membranes presented a lower retention towards healthy compounds, including flavonoids and anthocyanins, in comparison to PS membranes.…”