Antioxidant synergism between fruit juice and <Emphasis Type="Italic">α</Emphasis>-tocopherol. A comparison between high phenolic black chokeberry (<Emphasis Type="Italic">Aronia melanocarpa</Emphasis>) and high ascorbic blackcurrant (<Emphasis Type="Italic">Ribes nigrum</Emphasis>)

Black chokeberry juice (Aronia melanocarpa, Elliot), blackcurrant juice (Ribes nigrum, Ben Lomond) and α-tocopherol were found to protect phosphatidyl choline against oxidation in a peroxidating liposome system as evidenced by lag phases for formation of conjugated dienes. When present together, black chokeberry juice and α-tocopherol showed a clear synergistic effect on the length of the lag phase, while effects of blackcurrant juice and α-tocopherol were additive. The concentration of total phenolics in black chokeberry juice was six times higher than in blackcurrant juice (gallic acid equivalents). Ascorbic acid corresponded to 1% of total phenolics in black chokeberry juice and 10% in blackcurrant juice. Based on the length of the lag phase, the phenolics present in black chokeberry were on an average, twice efficient as scavengers of lipid peroxyl radicals as phenolics in blackcurrant. Black chokeberry was by HPLC analysis of peroxidating liposomes, in contrast to blackcurrant, found to protect α-tocopherol efficiently against oxidation to the end of the lag phase. The phenolics present in black chokeberry juice were concluded to be more efficient in regenerating or protecting α-tocopherol than ascorbic acid or the phenolics in blackcurrant. As for the phenolics, this was further evidenced by ranking of their radical scavenging activity as studied by ESR-spectroscopy.     

Phenolic Composition,Radical Scavenging Activity and an Approach for Authentication of Aronia melanocarpa Berries,Juice, and Pomace

Aronia melanocarpa is a rich source of phenolic compounds like anthocyanins, chlorogenic acids, quercetin derivatives, and proanthocyanidins possessing strong antioxidative potential. The consumption of A. melanocarpa is actually increasing because of the known bioactivity of its phenolic constituents. A. melanocarpa extracts are used as natural colorants and nutraceuticals. Several attempts of adulteration of aronia products have already been reported. In this study, we investigated changes in phenolic composition from berry to juice by HPLC‐PDA, and HPLC‐ESI‐MSⁿ analyses as well as fingerprint profiles for authentication of commercially available aronia products in order to detect possible adulteration. Additionally, the radical scavenging activity of aronia products was determined by using the TEAC (Trolox® equivalent antioxidant capacity) assay. Aronia pomace, a valuable by‐product of juice production, showed the highest phenolic content and possessed the highest radical scavenging activity.     

Bioavailability and Antioxidant Activity of Black Chokeberry (Aronia melanocarpa) Polyphenols: in vitro and in vivo Evidences and Possible Mechanisms of Action: A Review

Abstract: Black chokeberry (Aronia melanocarpa) is a distinctive berry with a high content of polyphenol compounds and possesses one of the highest in vitro antioxidant activities among fruits. The bioavailability of aronia polyphenols seems to be low, but there is ample evidence for chokeberry health benefits including antidiabetic, cardioprotective, hepatoprotective, antimutagenic, and anticarcinogenic effects. This review presents the available information for the bioavailability and antioxidant activity of chokeberry polyphenols and explains the possible mechanisms of action in vivo in the prevention and treatment of oxidative stress‐related diseases. The review shows the available data for chokeberry antioxidant activity in vitro, in isolated cells and cell lines, and in vivo, in both human subjects and animals. It is evident that in vivo antioxidant action of chokeberry extends far beyond radical scavenging and includes suppression of reactive oxygen and nitrogen species formation, inhibition of prooxidant enzymes, restoration of antioxidant enzymes, and probably cellular signaling to regulate the level of antioxidant compounds and enzymes. The original contribution of this work is that it compiles the available information up to date and outlines the gaps and future directions in the assessment of chokeberry antioxidant action in vivo.     

黑果腺肋花楸在体外模拟消化过程中酚类物质及抗氧化性的变化规律

本研究探讨了体外胃肠道消化模拟对黑果腺肋花楸中酚类物质的含量及抗氧化活性的影响,采用福林酚法和硝酸铝显色法测定黑果腺肋花楸消化前后总酚和总黄酮的含量。通过DPPH?和ABTS+自由基清除能力来验证胃肠消化处理对黑果腺肋花楸抗氧化活性的影响。实验结果表明：在模拟体外消化过程中,黑果腺肋花楸的多酚和黄酮含量表现出不同的变化趋势。其中,黑果腺肋花楸多酚在胃消化模拟过程中稳定性较好,黄酮含量显著增加（p<0.05）,DPPH?和ABTS+自由基清除能力均无显著性变化（p>0.05）;在模拟肠液消化过程中,多酚和黄酮含量显著增加,分别是提高了1.33、1.38倍（p<0.05）,DPPH?和ABTS+自由基清除率分别降低了36.84%和8.55%。胃肠道中胃蛋白酶、胃酸、胰蛋白酶对黑果腺肋花楸中多酚和黄酮的释放有一定的促进作用,但胰蛋白酶会降低果实的抗氧化能力,这可能与有机酸的分解有关。本研究结果为黑果腺肋花楸天然产品的开发及应用提供科学依据。     

Comparative Analysis of the Antioxidant Capacity of Selected Fruit Juices and Nectars: Chokeberry Juice as a Rich Source of Polyphenols

The bioactive compounds, and hence the antioxidant capacity, of fruit juice are affected by a given type of juice and fruit processing conditions. In this study, some polyphenol-rich juices and nectars were compared, considering the manufacturing conditions (Stage I). Organic chokeberry juice was determined to possess the highest antioxidant capacity, which was 4- to 10-fold higher than in other popular juices. Subsequently, this juice was analyzed for selected flavonoids (flavanols, flavonols, flavones) and phenolic acids (Stage II). The results showed that chokeberry juice was a rich source of chlorogenic and neochlorogenic acids. The high total content of polyphenols and high antioxidant capacity encourage further clinical research on chokeberry juice, in the context of cardiovascular diseases prophylaxis.     

Determination of Carotenoids in Fruits of Rosa sp. (Rosa Canina and Rosa Rugosa) and of Chokeberry (Aronia Melanocarpa)

Carotenoid composition of fruits of two Rosa species (Rosa canina and Rosa rugosa) and of chokeberry (Aronia melanocarpa) was studied by high performance liquid chromatography. Nine carotenoids were determined: three carotenes (lycopene, ζ-carotene, β-carotene) and six xanthophylls (neoxanthin, trans-violaxanthin, cis-violaxan-thin, 5,6-epoxylutein, lutein, β-cryptoxanthin). This high number of compounds classified these fruits among those with the greatest variety of carotenoid pigments. Quantitatively large differences occurred in the carotenoid composition of the three fruits. Rosa hips contained the highest concentrations of total carotenoids, which were mainly comprised of lycopene and βcarotene. Conversely, total xanthophylls were low. In contrast to Rosa, fruits of Aronia were lower in total carotenoids while xanthophylls composed a higher proportion.     

Effect of pectinase treatment on extraction of antioxidant phenols from pomace,for the production of puree-enriched cloudy apple juices

Effects of pomace maceration on yield, turbidity, cloud stability, composition of phenolics, antioxidant activity and colour properties were studied, to evaluate the potential applicability of enzyme preparations in puree-enriched cloudy apple juice production. The yield of mixed juice and puree from pomace obtained in the enzymatic processing of apple ranged from 92.3% to 95.3%, significantly higher than the yield from the control without enzymatic pomace treatment (81.8%). Higher turbidity was obtained upon pomace treatment with Pectinex XXL and Pectinex Ultra SPL enzymes. The total content of phenolic compounds in apple pomace was higher than in raw juices (1520 mg/kg and 441 mg/L, respectively). The total polyphenol yields were higher in juices treated with Pectinex AFP L-4, Pectinex Yield Mash and Pectinex XXL, as compared to the control treatment. During 6 months of storage, a significant change was observed in the content of polyphenols, especially in procyanidin fractions.     

RP-HPLC-DAD Determination of Phenolics in Industrial Apple Pomace

Processing of apple fruits for juice/cider production generates large volume of pomace at industrial scale. This biomass (cell wall material and pulp tissues) is rich in array of nutrients, especially dietary fiber and polyphenols. Apple fruits confront various processing conditions at industrial level, influencing the biochemical composition of generated pomace, including its phenolic profile. In present study, a simple, fast and reproducible reversed-phase high-performance liquid chromatography method using diode array detector was developed and validated for separation of different phenolics present in industrial apple pomace. The present method showed reliable and reproducible intraday (0.2–4.0 % RSD) and interday (3.7–8.1 % RSD) precision with limits of detection and quantification values in range of 0.14–0.58 and 0.48–1.95 μg ml^?1, respectively, for all the phenolics. Different solvent-mediated extraction of dried pomace powder was also performed to evaluate its total antioxidant potential using standard spectrophotometric assays. The major phenolics found in industrial apple pomace extracts were quercetin (1.4–10.3 μg mg^?1), phloretin (1.1–9.3 μg mg^?1) and phloridzin (0.62–2.0 μg mg^?1).     

Impact of processing and storage on the phenolic profiles and contents of pomegranate (Punica granatum L.) juices

Juices were obtained on pilot-plant scale from untreated, steamed and peeled pomegranate fruits (Punica granatum L.), respectively, by applying increasing pressures and various juice treatments, i.e., enzymatic treatment, filtration, clarification and pasteurization, to determine the influence of process technology on the phenolic profiles and contents of the juices. Polyphenols were characterized and quantified by HPLC-DAD-ESI/MSⁿ, and total phenolics and antioxidant capacity of the juices were determined by Folin–Ciocalteu, FRAP and TEAC assays, respectively. The total amounts of anthocyanins and colorless phenolics in the juices significantly differed depending on the applied technology. Highest phenolic recoveries were obtained from steamed fruits without further treatment. In contrast, lowest phenolic contents were determined in the juices produced from peeled fruits, i.e., the isolated seeds with adherent arils. With increasing pressures, polyphenol recoveries were enhanced, whereas juice treatments such as microfiltration and fining lowered phenolic contents of the juices. Furthermore, the amounts of individual phenolics were determined by HPLC-DAD with ellagitannins dominating the phenolic profiles. Juices solely produced from the edible parts of pomegranate exhibited lower amounts of ellagitannins compared with the juices from entire fruits. In contrast, the former juices were characterized by the highest amounts of gallotannins, hydroxybenzoic acids, hydroxycinnamic acids and dihydroflavonols. These results were consistent with the astringency of the juices. Additionally, storage experiments were performed at 4 °C and 20 °C in the dark and 20 °C under light exposure, revealing significant pigment degradation and concomitant color loss, especially at elevated temperatures and upon illumination, whereas the contents of non-anthocyanin phenolics and antioxidant capacity remained virtually unchanged throughout storage.     

Stability of polyphenols in chokeberry (Aronia melanocarpa) subjected to in vitro gastric and pancreatic digestion

Berries and red fruits are dietary sources of polyphenols with reported health benefits. As part of the diet, polyphenols are ingested as complex mixtures immersed in a food matrix which is digested in the gut. Epithelial cells lining the gut are regularly exposed to these digested mixtures. To understand the effects of dietary polyphenols on human gut health it is essential to determine their stability and fate in the lumen. In this work, we investigated the effects of an in vitro gastric and pancreatic digestion on the stability and composition of the major polyphenols in chokeberry juice. Digestion was carried out with a mixture of pepsin-HCl for 2 h, followed by a 2 h incubation with pancreatin and bile salts at 37 °C with shaking, in the absence of light and under N₂. After digestion, the chokeberry samples were acidified, filtered and HPLC-DAD/HPLC–MS–MS analysed to determine the content of total soluble recovered phenolics. Gastric digestion had no substantial effect on any of the major phenolic compounds in chokeberry, namely anthocyanins, flavan-3-ols, flavonols and caffeic acid derivatives. However, these compounds were significantly altered during the pancreatic digestion and this effect was more marked for anthocyanins (approximately 43% was lost during the 2 h treatment with pancreatin). Flavonols and flavan-3-ols decreased by 26% and 19%, respectively. Neochlorogenic acid decreased by 28% whereas chlorogenic acid was increased by 24%. In vitro digestion of standard phenolic compounds, representing each of the groups of phenolics in chokeberry, confirmed some of the observed changes. Interactions with the digestive enzymes were not responsible for the observed losses which were mostly due to the chemical conditions during pancreatic digestion. Our results, in accordance with previously published results, show that dietary polyphenols are highly sensitive to the mild alkaline conditions in the small intestine and that a good proportion of these compounds can be transformed into other unknown and/or undetected structural forms with different chemical properties and, consequently, different bioaccessibility, bioavailability and biological activity.     

New food ingredients from broccoli by-products: physical,chemical and technological properties

Broccoli stems and leaves examined were rich in protein (23.2%, dry weight), fibre (36.5%, dry weight) and polyphenols (11.4 mg gallic acid equivalents g⁻¹). Chlorogenic acid, neochlorogenic acid and quinic acid were the major phenolics found. Broccoli by-products have potential to be developed as differentiated food ingredients by separation. On a dry basis, the pomace and washed pomace fractions were enriched in fibre and had higher water-holding but lower water solubility and emulsifying capacity compared to juice and supernatant from washed pomace, which were enriched in protein. The juice and supernatant had higher polyphenol content and higher antioxidant activity, suggesting that polyphenols were the major contributors to antioxidant activity. For convenience of use, the products may be supplied as packaged powdered ingredients, but this was practical only for broccoli stems and leaves and pomaces as these powders had higher glass transition temperatures than the juice and supernatant fractions.     

Effect of Blanching and Drying Temperature on Polyphenolic Compound Stability and Antioxidant Capacity of Apple Pomace

The effects of blanching and drying treatments on stability, physical properties, and antioxidant activity of apple pomace polyphenols were evaluated. Blanched and unblanched apples were extracted, and the pomace was dried in a cabinet dryer at a speed of 3 m/s at 50 °C, 60 °C, 70 °C, and 80 °C. The color, total phenolics, flavonoids, individual polyphenolic compounds, anthocyanins, and total antioxidant activity were analyzed. The blanching process caused a major retention in color, total polyphenolic content, and total flavonoid content for fresh apple pomace when compared with fresh unblanched pomace. Drying of either fresh blanched or fresh unblanched pomace caused a significant reduction (P < 0.05) in total polyphenol and flavonoid content leading to a reduction in the total antioxidant activity. When compared with the unblanched treatment, drying the blanched pomace at 80 °C resulted in a product with significant amounts of total phenolics, flavonoids, and antioxidant activity. The individual phenolic compounds were significantly increased (P < 0.05) in blanched pomace that was not dried when compared with unblanched samples. Drying blanched apple pomace did not cause a significant change in the concentration of individual polyphenolic compounds, but drying unblanched apple pomace caused a reduction in the concentrations of epicatechin and caffeic acid, with an important reduction in p-coumaric acid at temperatures higher than 60 °C. However, the drying process caused a significant reduction in the antioxidant capacity. Therefore, a combination of blanching and drying processes for apple pomace results in a product that maintains antioxidant capacity.     

Chokeberries (Aronia melanocarpa) and Their Products as a Possible Means for the Prevention and Treatment of Noncommunicable Diseases and Unfavorable Health Effects Due to Exposure to Xenobiotics

Aronia melanocarpa berries (chokeberries) constitute a very rich source of numerous substances exerting a beneficial impact on health, including mainly polyphenols (proanthocyanidins, anthocyanins, flavonoids, and phenolic acids), possessing antioxidative, anti‐inflammatory, antiviral, anticancer, antiatherosclerotic, hypotensive, antiplatelet, and antidiabetic properties. Thus, the consumption of products made from chokeberries is of vital importance for health maintenance and protection. Nowadays, due to the growing prevalence of noncommunicable diseases and ubiquitous human exposure to numerous man‐made and naturally occurring toxic substances, some of which are dangerous even at low amounts, it is very important to look for effective means of health protection. An important role in this regard may be played by A. melanocarpa berries; however, up to now the attention of scientists, nutritionists, and health practitioners has been focused mainly on the effectiveness of chokeberry products in the prevention and treatment of noncommunicable diseases, while only little attention has been paid to the possibility of their use to counteract the adverse health effects of exposure to xenobiotics. That is why in this review article the main interest has been focused on the possibility of using chokeberries in the protection against unfavorable health effects caused by the action of substances to which humans may be exposed environmentally and/or occupationally. The available experimental data indicate that not only the fruit but also the leaves of A. melanocarpa and their products may be effective means for prevention and treatment of the effects of toxic action of some xenobiotics in humans; however, further studies on this subject are necessary.     

The effect of addition of chokeberry, flowering quince fruits and rhubarb juice to strawberry jams on their polyphenol content, antioxidant activity and colour

The aim of the study was to establish whether the addition of berries (flowering quince, chokeberry) and rhubarb juice during jam processing improves its colour and enriches jams in polyphenol compounds other than those found in strawberries. The sum of phenolic compounds determined by HPLC was distributed in a wide concentration range depending on the cultivar. Jams prepared from Elkat cultivar had 27% more total phenolic compounds than jams prepared from Senga Sengana. The following compounds were identified in jams prepared from strawberries: p-coumaric, ferulic and ellagic acids, quercetin, kaempferol, anthocyanins, (+)-catechin, (−)-epicatechin and proanthocyanidins. Proanthocyanidins and ellagic acid are the major polyphenol compounds of all strawberries jams. The Elkat cultivar (47.34 mg/100 g) contained higher amounts of proanthocyanidins compared to Senga Sengana (29.95 mg/100 g). The addition of 10% of flowering quince and chokeberry to jams during their preparation resulted in the increase in the content of phenolic components in final products, especially for proanthocyanidins. The highest level of total polyphenols (P < 0.05) was found in strawberry mixed with chokeberry, 237.82 mg/100 g for Senga Sengana and 260.61 mg/100 g for Elkat. There has been a marked increase of proanthocyanidins content (5.4 and 4.0 times) in jams made from Senga Sengana and Elkat cultivars mixed with chokeberry. However, the addition of rhubarb juice did not increase the content of polyphenol in Senga Sengana jam (not statistically significant). Antioxidant activity of strawberry jam was determined by 2,2′azinobis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH) and ferric reducing/antioxidant power methods (FRAP). The antioxidant activity of this mixed jam was more than two times higher (P < 0.05) than control sample of strawberry jam. Rhubarb juice had high effect on L* (lightness) value in case of all strawberry varieties. The redness (a*), and yellowness (b*) were significantly different in jams with supplement. Strawberry jam with chokeberries had smaller L* value than control and other samples, and the lowest a* and b* values. This variation could be due to the nature of the pigments in these fruit cultivars and the content of anthocyanins which resulted in more reddish colour.     

Composition of Sugars,Organic Acids,and Total Phenolics in 25 Wild or Cultivated Berry Species

Abstract: Sugars, organic acids, and total phenolic content in fruit of 25 wild and cultivated berry species were identified and quantified with high‐performance liquid chromatograph. The composition of sugars, organic acids, and total phenolic compounds in various species of Vaccinium, Rubus, Ribes, and Fragaria genus was evaluated. Additonally, total phenolics of less known berry species of the Morus, Amelanchier, Sorbus, Sambucus, Rosa, Lycium, Actinidia, and Aronia genus were determined in wild growing as well as in cultivated fruits. Significant differences in the concentration of sugars and organic acids were detected among the berry species. Glucose and fructose were the most abundant sugars in berry fruits and the major organic acids were malic and citric acid. However, in kiwi fruit, sucrose represented as much as 71.9% of total sugars. Sorbitol has been detected and quantified in chokeberry, rowanberry, and eastern shadbush fruit. The highest content of total analyzed sugars was determined in rowanberry fruit, followed by dog rose, eastern shadbush, hardy kiwifruit, American cranberry, chokeberry, and jostaberry fruit. Rowanberry stands out as the fruit with the highest content of total analyzed organic acids, followed by jostaberry, lingonberry, red gooseberry, hardy kiwifruit, and black currant. The berries of white gooseberry, black currant, red currant, and white currant had the lowest sugar/organic acid ratio and were thus perceptively the sourest species analyzed. On the other hand, the species with highest sugar/organic acid ratio were goji berry, eastern shadbush, black mulberry, and wild grown blackberry. The highest amounts of total phenols were quantified in chokeberry fruit. Wild strawberry, raspberry, and blackberry had 2‐ to 5‐fold more total phenolics compared to cultivated plants. Practical Application: The fruit of analyzed berry species contained different levels of sugars, organic acids, and total phenolics. Moreover, it has been demonstrated that wild grown species generally contain more phenolics than cultivated ones. This information is interesting for nutritionists as well as berry growers and breeders who can promote the cultivation of species and new cultivars with higher phenolic content.     

Antioxidant activity,anthocyanins, and phenolics of rabbiteye blueberry (Vaccinium ashei) by-products as affected by fermentation

Basic blueberry processing includes juice processing or winemaking. By-products obtained from the juice and wine industry can be a source of new value-added products such as phenolic antioxidant supplements or ingredients for food processing. The phenolic compositions of products and by-products (pomaces) depend mainly on processing techniques such as duration of skin contact, crushing, pressing, and others. The present study was to evaluate the effects of fermentation type on retention of total anthocyanins, total phenolics, and antioxidant activity of blueberry by-products. Total phenolics (TPH), total anthocyanins (ACY), antioxidant activities (β-carotene bleaching assay and ferric thiocyanate assay), and antiradical activity (DPPH radical-scavenging assay) of rabbiteye blueberry (Vaccinium ashei) by-products (juice, wine, and vinegar pomaces) were determined. The wine pomace (WP) had higher TPH, antioxidant activities and antiradical activity. Vinegar pomace (VP) had the lowest ACY, TPH, antiradical activity, and antioxidant activities. The results indicate that the antioxidant and antiradical activities of blueberry by-products were not significantly affected by the wine making process. Acetification significantly decreased TPH, ACY, antioxidant activities, and antiradical activity. However, VP still maintained an important phenolics concentration and antioxidant activity.     

Fatty acid composition and phenolic antioxidants of winemaking pomace powder

The fatty acid composition, phenolic constituents and contents, and antioxidant activities of two varieties (‘Cabernet Sauvignon’ and ‘Royal Rouge’) of grape pomace powder from the winemaking industry were examined. Large proportions of polysaturated fatty acids (PUFA), ranging from 60.9% to 64.4%, high ratios of PUFA/SFA, ranging from 2.80 to 3.11, and high ratios of n−6/n−3, ranging from 20.8 to 36.9, were found in both varieties. Five classes of lipids were separated with thin-layer chromatography and identified as polar lipids (PL), sterols (ST), free fatty acids (FFA), triglycerides (TG) and cholesteryl esters (CE). TG showed the highest PUFA contents (64.4% and 66.2%) and n−6/n−3 ratios (70.7 and 55.1), while CE showed the lowest values of PUFA (33.2% and 26.5%). High contents of phenolics and anthocyanins, which contribute to considerably strong antioxidant activity, were found in both varieties. Grape pomace contains considerably high amounts of phenolics, a large proportion of which are anthocyanin pigments (52% of ‘Cabernet Sauvignon’ and 63% of ‘Royal Rouge’). The HPLC analysis of phenolic compounds showed that catechin, epicatechin, epicatechin gallate, and gallic acid were major constituents. Antioxidant properties of grape pomace extract significantly varied with variety and appeared to be dependent upon the contents of phenolics. In addition, from the point of nutrition, “Royal Rouge’ had better benefits because of its lower n−6/n−3 ratio, higher contents of phenolic antioxidants and anthocyanin, and higher antioxidant activity than ‘Cabernet Sauvignon’.     

Comparative study of phenolic content and antioxidant activity of strawberry puree,clear, and cloudy juices

The aim of this study was to determine the concentrations of phenolic compounds and their antioxidant activity in different kinds of juice: clear, cloudy, and puree which were made from three different strawberry cultivars (Elkat, Kent, and Senga Sengana). The anthocyanins, p-coumaric acid, ellagic acid, quercetin, keampferol derivatives, (+)-catechin, proanthocyanidins content and degree of proanthocyanidin polymerization, were determined both in the fresh and after 6 months of storage at 4 and 30 °C. Freshly produced juices contained higher amounts of phenolics, especially of anthocyanins and proanthocyanidins, than those stored for 6 months at 4 and 30 °C. The processing of the clear juice showed the higher loss of all phenolic compounds. The antioxidant capacity was the smallest for clear, and the highest for the puree juices. This was assessed by measurements made with different antioxidant activity assays: ABTS and FRAP. The puree of strawberry juice had significantly higher levels of the phenolic compounds and showed more antioxidant activity than the clear and cloudy juices, before and after storage in all strawberry cultivars.     

Effect of vacuum‐drying,hot air‐drying and freeze‐drying on polyphenols and antioxidant capacity of lemon (Citrus limon) pomace aqueous extracts

The aim of this study was to investigate the effect of freeze‐drying, hot air‐drying and vacuum‐drying at 70, 90 and 110 °C, on dried lemon pomace polyphenols and antioxidant capacity. The total phenolic content and antioxidant capacity were higher in lemon pomace dried by hot air or under vacuum than those dried by freeze‐drying and increased as the temperature increased. The highest total flavonoid content was recorded in the pomace dried under vacuum at 70 and 90 °C. Lemon pomace dried by freeze‐drying had the highest neohesperidin content, whereas pomace dried under vacuum at 70 °C had the highest rutin and p‐coumaric acid content. The highest gallic acid content was recorded in the pomace dried by hot air at 110 °C. The results of this study indicate that drying technique should be carefully selected according to the bioactive compounds aimed to be extracted.     

Changes of bioactive components in berry seed oils during supercritical CO2 extraction

The objective of the work was to elucidate the chemical composition of fractions of oil extracts obtained during the supercritical extraction on a semi‐industrial scale from strawberry (Fragaria x ananassa Duch.), chokeberry [Aronia melanocarpa (Michx.)], and raspberry (Rubus idaeus L.) seeds from industrial press cake. The oil extracts differed in terms of their content of bioactive components: carotenoids, tocopherols, chlorophylls, and fatty acids. Raspberry seed oil was the richest source of tocopherols (620.1–2166.7 mg kg^?1) and α‐linolenic acid (above 37%). Chokeberry seed oil had the highest content of linoleic acid (above 70%), and α‐tocopherol (166.0–1104.8 mg kg^?1). Strawberry oil was characterized by the highest content of chlorophylls and α‐linolenic acid (above 30%). It was showed that the oil fraction collected at the beginning of extraction is characterized by a high acid value, which requires purification steps to be used for food purposes.

Practical applications

Strawberry, raspberry, and chokeberry by‐products left over from the production of concentrated juice are a valuable source of oils rich in n‐3 and n‐6 polyunsaturated fatty acids, tocopherols, and carotenoids. The research showed that the fractionation of extracts in the course of supercritical extraction leads to oils with varying amounts of different bioactive compounds, and thus to products with potentially wide applications. Seeds oils have high potential utility as a source of unconventional oil for cosmetic and pharmaceutical sectors and biodiesel. Their targeted utilization may be exploited for economic, environmental and health benefits.