High‐pressure processing at increased temperatures provides enhanced removal of indigenous microbial contamination in beet/carrot juice without damaging the bioactive components

Abstract

In this study, an optimised high hydrostatic pressure process (600 MPa, 15 min, 55 and 65 °C) caused elimination of microbial levels in beetroot/carrot juice (80:20 v/v, pH 4.0) after 28 days of storage (4 °C) (psychrotrophic bacteria, yeast and mould counts below the limit of detection = 0 log cfu mL À1 ). Room temperature (20 °C) was insufficient for the complete elimination of psychrotrophic bacteria (0.9-2.0 log cfu mL À1 after 7-28 days of storage). No significant (P < 0.05) changes in the polyphenol content were observed (1.11 AE 0.13 in control vs. 1.13 AE 0.13 mg gallic acid mL À1 in samples treated at 65 °C). No significant (P < 0.05) changes in the antioxidant, antiradical activity and biological properties of the highpressure processing (HPP)-treated juice were observed in the studies involving CCD 841 CoTr and HT29 cell lines. The HPLC-MS analysis confirmed increase in isobetalain, decarboxybetalain and betalain content (by 100%, 14% and 10%) and loss of vulgaxanthin I (by 65%) after HPP at 65 °C. The innovative character of this paper stems from the comprehensive quality assessment (especially experiments involving cell lines) of high-quality, safe beetroot-carrot juice that retains a major part of its bioactive compounds.

Can Bioactive Compounds in Beetroot/Carrot Juice Have a Neuroprotective Effect? Morphological Studies of Neurons Immunoreactive to Calretinin of the Rat Hippocampus after Exposure to Cadmium

“…In our previous paper [ 22 ], we presented the composition of BCJ (using high-resolution, qualitative, and quantitative HPLC-ESIQTOF- MS) and identified the main bioactive components present (betanin, isobetanin, vulgaxanthin I and II, indicaxanthin, neobetanin, dexarboxyneobetanin, and decarboxybetanin). The juice showed significant total polyphenolic content, high antioxidant activity (tested using three experimental models), and positive effects towards human colon epithelial normal and cancer cells [ 22 ], so it was a promising research material in the context of the presented work.…”

“…In our previous paper [ 22 ], we presented the composition of BCJ (using high-resolution, qualitative, and quantitative HPLC-ESIQTOF- MS) and identified the main bioactive components present (betanin, isobetanin, vulgaxanthin I and II, indicaxanthin, neobetanin, dexarboxyneobetanin, and decarboxybetanin). The juice showed significant total polyphenolic content, high antioxidant activity (tested using three experimental models), and positive effects towards human colon epithelial normal and cancer cells [ 22 ], so it was a promising research material in the context of the presented work. In the present work, we tested the ability of the juice to decrease the activity of acetyl- and butyrylcholinesterase and we report that the activity towards both enzymes was high (equal to donepezil applied at the concentration of 0.05 ± 0.00 µg/mL and 0.09 ± 0.01 µg/mL, respectively).…”

“…In our previous paper, we showed that beetroot/carrot juice was a rich source of bioactive compounds (mainly polyphenols, nitric pigments, and saponins). The juice revealed strong antioxidant activity, as confirmed using three experimental in vitro methods [ 22 ]. It has been reported before (e.g., in [ 3 ]), that Cd 2+ can contribute to the development of Alzheimer’s disease.…”

“…The beetroot/carrot juice (BCJ) was prepared essentially as described in our previous work [ 22 ]. In short, freshly pressed juices were obtained from thoroughly washed vegetables (Opolski beetroot and Nantejska carrot; in tap water), using an Angel 750 low-pressure screw press (Angel Co. Ltd., Naarden, The Netherlands).…”

“…The composition of the juice, as well as its total polyphenolic content and antioxidant activity were given in our previous work [ 22 ]. The anticholinesterase activity of BCJ (against acetyl- and butyrylcholinesterase) was studied as described by Studzińska-Sroka et al [ 23 ] using juice prepared as described above and not otherwise processed in any way prior to analysis.…”