Food-compatible method for the efficient extraction and stabilization of cranberry pomace polyphenols

Cranberry pomace is a byproduct of cranberry processing and is comprised of seeds, skins and stems of the cranberry fruit. While cranberry pomace contains beneficial polyphenols, including proanthocyanidins and anthocyanins, it is not a palatable source of these compounds and is typically discarded. In this study, we have developed and optimized a method to extract polyphenols from cranberry pomace using aqueous ethanol, a food grade solvent. Biochemical characterization of the pomace extract showed the presence of a broad range of polyphenols also present in cranberry juice concentrate. By co-drying cranberry pomace extract with a protein-rich food matrix, such as soy protein isolate (SPI), we have developed a method to produce a cranberry polyphenol–SPI complex (CBP-SPI) containing 10% cranberry polyphenols. Unlike dried cranberry pomace extract alone, proanthocyanidins, anthocyanins and total polyphenols were found to be highly stable at 37 °C in the CBP-SPI powder. The extraction and stabilization of cranberry pomace polyphenols using SPI provides an innovative approach for utilizing pomace in the development of novel food ingredients.     

Apple pomace as a source of dietary fiber and polyphenols and its effect on the rheological characteristics and cake making

Apple pomace, a by-product of apple juice industry, is a rich source of fibre and polyphenols. Also in view of the antioxidant property of pomace, it would play an important role in prevention of diseases. Apple pomace procured from fruit juice industry, contained 10.8% moisture, 0.5% ash and 51.1% of dietary fibre. Finely ground apple pomace was incorporated in wheat flour at 5%, 10% and 15% levels and studied for rheological characteristics. Water absorption increased significantly from 60.1% to 70.6% with increase in pomace from 0% to 15%. Dough stability decreased and mixing tolerance index increased, indicating weakening of the dough. Resistance to extension values significantly increased from 336 to 742 BU whereas extensibility values decreased from 127 to 51 mm. Amylograph studies showed decrease in peak viscosity and cold paste viscosity from 950 to 730 BU and 1760 to 970 BU respectively. Cakes were prepared from blends of wheat flour containing 0–30% apple pomace. The volume of cakes decreased from 850 to 620 cc with increase in pomace content from 0% to 30%. Cakes prepared from 25% of apple pomace had a dietary fibre content of 14.2% The total phenol content in wheat flour and apple pomace was 1.19 and 7.16 mg/g respectively where as cakes prepared from 0% and 25% apple pomace blends had 2.07 and 3.15 mg/g indicating that apple pomace can serve as a good source of both polyphenols and dietary fibre.     

Lab and pilot-scale ultrasound-assisted water extraction of polyphenols from apple pomace

Apple pomace, a residue from juice or cider production, shows high content of exploitable polyphenols. In this work, apple pomace was submitted to an Ultrasound-Assisted Extraction (UAE) in order to produce extracts rich in antioxidants. After a preliminary study, a solid/liquid ratio of 150 mg of dry material per mL was used, and optimized conditions obtained by response surface methodology for polyphenols water-extraction were 40 °C, 40 min and 0.764 W/cm². A comparison showed Total Phenolics Content (TPC) obtained by UAE was 30% higher than the content obtained by Conventional Extraction (CE)(555 and 420 mg of catechin equivalent per 100 g of dry weight, respectively) and both methods presented the same extraction kinetics. Furthermore, extracts obtained by ultrasound showed higher antioxidant activity, which was confirmed by HPLC analysis, that revealed main polyphenols were not degraded under the applied conditions. The large scale experiments of this ultrasound procedure showed a potential industrial application.     

<Emphasis Type="Italic">Aronia melanocarpa</Emphasis> phenolics and their antioxidant activity

The purpose of the present study was to evaluate small and high molecular phenolics (tannins) and antioxidant activity of Aronia melanocarpa berries, juice and pomace in order to find new potential sources of natural antioxidants. The fruits of Aronia melanocarpa Elliot were collected in the middle of October at a plantation near Wroclaw, Poland. The pomace has a much higher content of phenolics in comparision to juice and fruits. Results showed that polymeric proanthocyanins, predominantly of (−)epicatechin, are the major class of polyphenolic compounds in chokeberry, represent 66% of fruits polyphenols. The average concentration ranged from 1578.79 mg/100 g of DW for chokeberry juice up to 8191.58 mg/100 g in pomace. The concentration of phenolic acids (chlorogenic and neochlorogenic acids) in juice was higher than in pomace. Anthocyanins in Aronia melanocarpa are second phenolic compound group and represent about 25% of total polyphenols, mixture of four different cyanidin glycosides: 3-galactoside, 3-glucoside, 3-arabinoside and 3-xyloside. The higher antioxidant activity expressed as TEAC was measured in pomace >fruit >juice.     

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.     

蓝莓果渣花色苷提取工艺优化及抗氧化活性比较研究

以蓝莓干果渣为原料,酸化乙醇为溶剂,应用超声辅助法提取花色苷,利用pH示差法测定花色苷含量,通过单因素实验和响应面试验优化得出蓝莓干果渣花色苷提取工艺条件,比较相同干重的蓝莓干果渣、湿果渣采用超声辅助提取和无超声辅助工艺得到的提取液的总多酚、花色苷含量及抗氧化活性。结果表明,蓝莓干果渣最佳提取工艺为液料比(31:1)mL/g,乙醇浓度63%,pH2.6,超声功率500 W,提取时间20 min,在此条件下蓝莓果渣提取液中花色苷含量为498.84 mg/100 g。相同原料,超声辅助提取工艺提取液较无超声辅助提取工艺提取液的总多酚和花色苷含量多;相同工艺条件下,相同干重的湿果渣总多酚和花色苷含量较干果渣低,但却拥有更高的抗氧化活性。     

Enzymatic production of a soluble-fibre hydrolyzate from carrot pomace and its sugar composition

This study was conducted to determine the sugar composition of soluble dietary fibre from carrot pomace, a by-product from the carrot juice processing industry. Carrot pomace was treated with a mixture of 1% NaOH and 2% acetic acid, and the pretreated sample was hydrolyzed by edible snails crude enzyme. The supernatant portion was then treated with 85% ethanol and separated into alcohol-soluble dietary fibre (ASDF) and alcohol-insoluble dietary fibre (AIDF). AIDF increased from an initial value of 3.3 g/100 g to 41.7 g/100 g carrot pomace after 96 h of reaction. The AIDF contained rhamnose, arabinose, mannose, galactose, glucose and a small amount of xylose. Monosaccharides (glucose, fructose, galactose, arabinose), cellooligosaccharides (cellopentaose, cellotetraose, cellotriose, cellobiose), and galactooligosaccharides (galactotetraose, galactotriose) were detected in the ASDF.     

Inhibition of hemoglobin-mediated lipid oxidation in washed fish muscle by cranberry components

Fractions enriched in phenolic acids (Fraction 1), anthocyanins (Fraction 2), flavonols (Fractions 3 and 4) and proanthocyanidins (Fractions 5 and 6) were prepared from cranberry powder using Sephadex LH-20 chromatography. Fractions 2, 3, 4, and 5 had nearly equivalent reactivity in the total phenolate assay employed per mg dry weight of each fraction while Fractions 1 and 6 were less reactive. The ability of cranberry fractions to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals as well as their inhibitory effects on hemoglobin (Hb)-mediated lipid oxidation in washed cod muscle were assessed. Addition of cranberry fractions at a level of 74 μmol quercetin equivalents per kg of washed cod muscle extended the induction time of thiobarbituric acid reactive substances (TBARS) formation in the order: Fraction 1, Fraction 3, Fraction 4 > Fraction 2 > Fraction 5 > Fraction 6. This suggests that oligomeric polyphenols (e.g., proanthocyanidins) were least effective at inhibiting Hb-mediated lipid oxidation in washed cod muscle compared to the other classes of polyphenolics in cranberry. The ability of the different cranberry fractions to scavenge DPPH radicals did not reflect their relative ability to inhibit lipid oxidation in the washed cod muscle system. Quercetin was tentatively identified as a component in cranberry that was especially effective at inhibiting Hb-mediated lipid oxidation. The ability of flavonol and proanthocyanidin-enriched fractions to inhibit Hb-mediated lipid oxidation in spite of efforts to wash away the added polyphenolics prior to Hb addition indicated these classes of polyphenolics had binding affinities for insoluble components of washed cod muscle.     

Dietary fibre content and antioxidant activity of Manto Negro red grape (Vitis vinifera): pomace and stem

The general composition of two by-products of the vinification process of the Manto Negro red grape (Vitis vinifera) variety, namely pomace and stem, were determined. Both by-products present high contents of total dietary fibre (TDF), comprising three fourths of the total dry matter. The pomace had high protein (12.2%) and oil (13.5%) values and the stem large amounts of extractable polyphenols (11.6%). Due to the high fibre content, the soluble dietary fibre (SDF), insoluble dietary fibre (IDF), uronic acids (UA) and Klason lignin (KL) were analysed in both samples. Notable were the high percentage of soluble fibre (15%) in relation to the total dietary fibre for the pomace, as well as the high content of Klason lignin (KL) in both by-products, especially in the stem (31.6%). This fraction (KL) has important amounts of condensed tannins (CT) and resistant protein (RP).     

Phenolic Fractions from Muscadine Grape “Noble” Pomace can Inhibit Breast Cancer Cell MDA‐MB‐231 Better than those from European Grape “Cabernet Sauvignon” and Induce S‐Phase Arrest and Apoptosis

Tons of grape pomace which still contained a rich amount of plant polyphenols, is discarded after winemaking. Plant polyphenols have multi‐functional activities for human body. In this study, polyphenols of pomaces from Muscadinia rotundifolia “Noble” and Vitis vinifera “Cabernet Sauvignon” were extracted and fractionated, and then they were analyzed with LC‐MS and the inhibitory effects on breast cancer cells were compared. The inhibition on MDA‐MB‐231 cells of fractions from “Noble” was further evaluated. The results showed that polyphenols from 2 grape pomaces could be separated into 3 fractions, and ellagic acid and/or ellagitannins were only detected in fractions from “Noble” pomace. All 3 fractions from “Noble” pomace inhibited MDA‐MB‐231 better than MCF‐7. But fraction 2 from “Cabernet Sauvignon” inhibited MCF‐7 better while fraction 1 and fraction 3 inhibited both 2 cells similarly. Moreover, the fractions from “Noble” pomace rather than “Cabernet Sauvignon” can inhibit MDA‐MB‐231 better. Finally, fractions from “Noble” pomace can induce S‐phase arrest and apoptosis on MDA‐MB‐231. These findings suggested the extracts from grape pomace especially those from “Noble,” are potential to be utilized as health beneficial products or even anti‐breast cancer agents.     

Functional components of grape pomace: their composition,biological properties and potential applications

The roles of functional foods on human health have been realised by more and more researchers, food producers and consumers. Functional food ingredients from both plant and animal sources such as dietary fibre, soy protein isolate, whey protein isolate and omega 3 fatty acid have been widely used in functional food product development. Many fruit processing by‐products such as grape, apple and orange peels are rich in bioactive phytochemicals, dietary fibre and unsaturated fatty acids, hence have potential to serve as functional food ingredients. In this review, we summarise recent advancement of research in grape pomace (GP), the residual of grapes after wine making. The polyphenol profile of GP and their biological, antioxidant and antimicrobial activities, the stability of GP polyphenols in food system, the interaction between GP polyphenol and other food ingredients, as well as the functionalities of grape seed oil and GP fibre are covered.     

Apple pomace in gluten‐free formulations: effect on rheology and product quality

The objective of the present work was to formulate a gluten‐free (GF) baked product based on a cassava starch, rice flour and egg white mixture and enriched with apple pomace with minimum processing as source of fibre. Effects of apple pomace and water amount on batters and product quality were analysed by response surface methodology (RSM). Dynamic moduli of batters, specific volume and crumb texture were highly dependent on both apple pomace and water. Higher levels of fibre rendered less cohesive and less resilient crumbs and diminished specific volumes. A suitable balance between amounts of apple pomace and water led to products with enough specific volume and sponginess. Up to 12.5 g apple pomace and water ranging from 115 to 150 g (each 100 g mixture), specific volumes were maintained higher than 2 cm³ g^?1; if apple pomace was increased up to 20 g, water amounts higher than 140 g were necessary to obtain similar results.     

Grape Pomace as a Potential Food Fiber

Grape pomace, and insoluble and soluble dietary fiber (DF) fractions, obtained by enzymatic-gravimetric methods, were analyzed for neutral sugars, uranic acids, Klason lignin and amino acids. DF constituted 80% of dry matter, IDF was the major fraction. The main neutral sugar constituent of IDF was glucose. The major part was cellulose and the remainder, along with xylose, was a xyloglucan, which also contained fucose. Uranic acids accounted for 64% of SDF and a high amount of arabinose, galactose and mannose were also included in that fraction. Proteins were not well solubilized by the assay enzymes. During the isolation of DF fractions a considerable solubilization of polyphenols was observed. These compounds were associated with Klason lignin in the starting material. Composition of DF fractions enables grape pomace to be considered a useful fiber-rich food ingredient.     

Antioxidant and functional properties of a high dietary fibre powder from carambola (Averrhoa carambola L.) pomace

The use of carambola pomace as a raw material for the production of a high dietary fibre powder (HDFP) was investigated. A face‐centred design was used to study the effects of extraction conditions, namely water‐to‐pomace ratio, time and temperature, on both reducing sugars (RS) and total extractable polyphenols (EPP) contents of fibre concentrate. RS content decreased by increasing extraction times and water‐to‐pomace ratios, while EPP tend to diminish by increasing temperature and contact time (P < 0.01). Selected HDFPs showed an EPP content in the range of 5.0–6.1 g GAE 100 g^?1 dry basis (db), with antioxidant activities between 386.2–443.9 and 204.7–228.6 μmol Trolox equivalents g^?1 db according to FRAP and ABTS assays, respectively. HDFP obtained at 55 °C, 5 min and 2:1 water‐to‐pomace ratio exhibited the highest EPP content, total dietary fibre (84.0% db) and dietary indigestible fraction (61.3% db). This product can be considered as a potential valuable food ingredient considering their oil retention and swelling capacities.     

Composition of industrial seedless black currant pomace

The aim of the work was to characterize the basic chemical composition including polyphenols of seedless industrial dried black currant pomace from two subsequent harvest seasons, 2006 and 2007. Pomace after removing seeds was separated into three fractions: with particles smaller than 0.8 mm, 2–5 mm and greater than 5 mm. The pomace was analyzed for dry substance, protein, fat, ash, total dietary fiber (TDF), soluble solids content, acidity, organic acids, saccharides and polyphenols. In addition, the antioxidant activity of the pomace was assayed by the DPPH method. All the fractions were characterized by a high content of total dietary fiber above 63% and a low content of saccharides below 3.15% and acidity below 3.2%. The composition of polyphenol compounds of all the fractions was qualitatively determined, yet it was shown that the fraction of the pomace of 2–5 mm is characterized by the greatest content of phytocompounds, of which anthocyanins constitute about 90% of the polyphenols determined. Moreover, the presence of myricetin and quercetin glycosides as well as considerable quantities of myricetin and quercetin aglycones was found in the pomace. The pomace had a high antioxidant activity ranging from 93.3 to 126.5 μM TEAC/g. It was also found that the content of most polyphenol compounds investigated, as well as protein, ash, TDF, acidity and saccharides, was statistically dependent on the type of fraction. Disclaimer: The views and opinions expressed in this publication are purely those of the writers and may not in any circumstances be regarded as stating an official of European Commission.     

桑叶多酚的鉴定及其抗氧化、抗α-淀粉酶活性分析

目的:桑树叶片在传统医学中被用作降糖和降血压的药物,其作用机理与活性成分含量有关。评价桑叶提取物不同生物活性,包括生物活性物质含量、抗氧化活性和抗α-淀粉酶活性。方法:采用SPE（固相萃取技术）将多酚粗提液分离纯化为花色苷、非花色苷多酚和水层三个组分,采用HPLC-PDA和HPLC-ESI/MS2对桑叶中的多酚物质进行系统地定性和定量。利用DPPH（1,1-二苯基-2-三硝基苯肼自由基清除能力）、ABTS（2,2’-联氮-双（3-乙基苯并噻唑啉-6-磺酸））和FRAP（铁离子还原能力）三种方法测定不同提取物的抗氧化活性,并采用福林酚法、pH差异法和比色法测定桑叶提取物总酚、总花色苷和总原花青素含量。结果:桑叶中共鉴定出6种花色苷、42种非花色苷多酚,其中,矮牵牛素-3-葡萄糖苷和原花青素衍生物含量很高;桑叶中总酚、总花色苷和总原花青素的含量分别为14.09 mg GAE/g DW、0.17 mg C3G/g DW和17.24 μg PA2/g DW;多酚粗提液、花色苷、非花色苷多酚和水层对α-淀粉酶活性的IC₅₀（半抑制浓度）分别为8.31、13.70、0.25和12.00 mg/mL,由此看出非花色苷多酚的抗α-淀粉酶活性最高。结论:桑叶具有较强的抗氧化活性,其中花色苷显示出最高的抗氧化活性。这些数据可以为蒙古桑叶用作功能食品提供重要参考。     

Juices, Fibres and Skin Waste Extracts from White, Pink or Red-Fleshed Apple Genotypes as Potential Food Ingredients

This study measures and compares the bioactive content and appearance attributes of juices, dietary fibres (DFs) and skin wastes of three apple genotypes (white fleshed (WF), pink fleshed (PF) and red fleshed (RF)). The juices of the PF and RF apples had more appealing and stable colours and much greater total extractable polyphenol content (TEPC) (RF had the highest, 3.40 mg catechin equivalent/mL juice) and vitamin C (PF had the highest, 14.2 mg/100 mL juice), compared with the WF apple. DFs isolated from the three apples using aqueous and ethanolic methods varied in bioactive profiles as a function of genotype. The TEPC and antioxidant activity (AA) of the fibres decreased in the order of PF > RF > WF. The total DF (TDF) in the fibre obtained using the aqueous method decreased in the order of RF?>?PF?>?WF. The ethanolic method yielded higher neutral monosaccharide (NM) and slightly greater TDF contents than the aqueous method. More polyphenol species were detected in the PF fibres, especially those obtained using the aqueous method. The polyphenol content in the apple skin decreased in the order of RF > WF > PF, with PF having slightly more pectic polysaccharides. As a whole, the RF apple appeared to be the best genotype as the potential source for juice, fibre and skin waste extract (SWE) ingredients. The PF apple would be the second best genotype for juice and fibre ingredients. The skin of the RF and WF genotypes would provide a good source of polyphenols. There is potential for promoting RF and PF apple genotypes because of their excellent nutritional values. The aqueous fibre preparation method used herein containing no solvent treatment and freezing steps represents an industrial-scale cost-effective alternative to the conventional ethanolic methods used for producing DFs whilst retaining polyphenols.     

不同烹饪方式下野生蔬菜中活性成分的比较研究

本文选取马齿苋、蕨菜、椿菜和百花菜为材料,研究其在微波处理、爆炒、焯制和煮制等不同烹饪方式下的总多酚、总黄酮以及叶酸等活性成分含量的变化,并以转移率、保存率和损失率等为评价指标,通过这三种评价指标可以进行对比分析,得出不同烹饪方式下野生蔬菜中各种活性成分的变化情况。实验结果表明,爆炒后椿菜总多酚保存率最高;四种蔬菜经过微波处理后,总多酚转移率大都高于其他烹饪方式,煮制是使总多酚转移率最低的烹饪方式;煮制后,马齿苋、蕨菜、椿菜和百花菜的实际热损失率较高,蕨菜可达到43.37%,微波条件下均为负数。爆炒方式下百花菜总黄酮保存率处于最高水平,为83.14%,微波是最不利于总黄酮保存的一种烹饪方式;为保证总黄酮转移率,宜采用煮制方式;煮制后的蔬菜实际热损失率整体高于其他烹饪方式。此外,焯制方式处理后的蔬菜叶酸含量最高。由此可见,不同烹饪方式下,野生蔬菜中活性成分的变化各不相同,需要合理选择烹饪方式。     

Effects of Sodium Fertiliser on the Chemical Composition of Grass and Clover Leaves,Stems and Inflorescences

Sodium fertiliser was applied to dairy cow pasture to investigate the effects on the chemical composition of grass and clover leaves, stems and inflorescences. The effect of sodium fertiliser varied between fractions, with grass leaves and stems generally being more responsive than grass inflorescences or clover fractions. The sodium content of all fractions was already high in the control treatment, and was increased to an excessive level by sodium fertiliser in all fractions except grass stems. Grass leaves were most affected. Potassium content was reduced in grass leaves and stems, but not in other fractions. The effects on calcium and magnesium varied between fractions but the K: (Ca+Mg) ratio, the most sensitive index of susceptibility to hypomagnesaemia, was reduced in grass leaves, but increased in other fractions. DM digestibility was decreased in grass and clover leaves by sodium, probably because of the high sodium content. MAD fibre content was also increased in these fractions. Crude protein content was decreased by sodium fertiliser in grass leaves, in particular. Therefore, when applied to pasture which is naturally high in sodium, sodium fertiliser had detrimental effects on pasture macronutrient content. However, beneficial effects were still observed on mineral ratios for plant and animal nutrition. It is concluded that if sodium fertiliser increases herbage sodium concentrations above 5 g kg⁻¹ DM, improvements in mineral ratios that could affect ruminant health may be offset by reductions in the nutritive value of the herbage. It is therefore recommended that the herbage sodium concentration should be known before sodium fertiliser is applied.     

A survey of Irish fruit and vegetable waste and by-products as a source of polyphenolic antioxidants

In this study, fruit and vegetable by-product and waste sources in Ireland were tested for their antioxidant activity and polyphenol content. The highest levels of antioxidants measured by both ferric reducing antioxidant power (FRAP) and diphenyl-picrylhydrazyl (DPPH) assays, were detected in whole kiwifruit. Of the vegetable by-products, broccoli stems showed the best antioxidant potential. The level of polyphenols as assessed by the Folin–Ciocalteu Reagent (FCR) was significantly correlated with the level of polyphenols by HPLC–DAD (r = 0.93). The level of polyphenols assessed by HPLC–DAD was not significantly correlated with the antioxidant assays. Apple pomace and vegetable by-products were found to be good sources of both polyphenols and antioxidants and due to their abundance may be exploitable resources to use as food ingredients.