Stability of Chokeberry Bioactive Polyphenols during Juice Processing and Stabilization of a Polyphenol-Rich Material from the By-Product

Abstract

Chokeberries (Aronia melanocarpa) are nowadays believed to exhibit potential cardioprotective and antidiabetic effects principally due to their high content in bioactive phenolic compounds. The stability of the phenolic compounds was studied during different stages of a juice production line and a method for the valorization of pomace was evaluated. Samples were taken from a commercial juice production plant, extracted and analyzed for phenolic constituents and antioxidant potential. Prototypes of functional food ingredients were produced from the pomace by wet milling and micro-milling. Alongside juice processing, the contents of phenolic berry constituents did not vary to a great extent and the overall antioxidant activity increased by about 34%. A high quality juice and a by-product still rich in polyphenols resulted from the process. The phenolic compounds content and the overall antioxidant activity remained stable when milling and micro-milling the pomace. During coarse milling, extractability of total phenolic compounds increased significantly (40% to 50%). Nanosized materials with averaged particle sizes (x 50,0 ) of about 90 nm were obtained by micro-milling. These materials showed significantly enhanced extractability of total phenolic compounds (25%) and total phenolic acid (30%), as well as antioxidant activity (35%), with unchanged contents of total procyanidins and anthocyanins contents. OPEN ACCESSAgriculture 2012, 2 245

Comparison of in vitro anti-lipase and antioxidant activities, and composition of commercial chokeberry juices

“…Nevertheless, chokeberry juice contains several classes of phenolic compounds which in combination might differently affect the lipase activity due to the different interaction between them as well as with other juice components. The results of qualitative and quantitative analyses of low molecular phenolic compounds by UPLC-MS and HPLC methods allowed to conclude that all most active juices had the same phenolic profile (Table 3), which was in accordance with the data published [9,34]. The major low molecular phenolic compounds of chokeberry juice were chlorogenic acids such as 3-and 5-O-caffeoylquinic acid.…”

“…The mean size of proanthocyanidin molecules described by their mDP in the chokeberry juices tested was very diverse and ranged from 12 to 52, while for two more efficient juices was >40 (Table 2). For comparison, the mDP value for chokeberry juice obtained from heated fruits followed by decantation of raw juice was 24 [34]. The very high mDP values obtained in this study for juice brands 1 and 2 may indicate lack of enzyme treatment of chokeberry mash during fruit processing as well as decantation or filtration process of raw juice.…”

“…Among chokeberry phenolic constituents, in particular, anthocyanins were extensively degraded (losses 93 %) during juice processing, while levels of hydroxycinnamic acids decreased by 37 %, proanthocyanins by 45 %, and flavonols by 48 % [33]. On the other hand, Mayer-Miebach et al [34] demonstrated high stability of phenolic compounds during chokeberries processing without enzyme treatment of mash.…”

“…The very high mDP values obtained in this study for juice brands 1 and 2 may indicate lack of enzyme treatment of chokeberry mash during fruit processing as well as decantation or filtration process of raw juice. The mDP of proanthocyanidins occurring in chokeberry fruit was determined as 59 [36] or in the acetone fruit extract as 19 [34]. The published studies have shown that anti-lipase activity of proanthocyanidins depends upon the degree of polymerization and more potent effect was observed for higher DP [27,37].…”

Biological activity of Aronia melanocarpa antioxidants pre-screening in intervention study design

“…The total phenolics contents of CCJ and FCJ were similar (p = 0.79), showing that processes included in the production of the commercial juice (pectinase treatment, filtration) did not influence the phenolics of the juice. The obtained results were in accordance with the results of Mayer-Miebach et al 17 The contents of total phenolics in WCE and MCE, expressed as mg GAE per g of WECE dry weight (DW), were 4 and 2.5 times lower, respectively, than phenollics content in the juices, calculated on DW. It could be concluded that the phenolics present in 100 mL of juice could be provided with at least 35 g of the investigated extract, indicating that the extraction process should be further optimized and/or prioritizing juice as the optimal source of chokeberry phenolics in future clinical studies.…”