Pressing Effects on Yield, Quality, and Nutraceutical Content of Juice, Seeds, and Skins from Black Beauty and Sunbelt Grapes

ABSTRACT: The effects of hot and cold (nonheated) pressing on yield, quality components, and nutraceutical content of juice, grapes, and press fractions (seeds and skins) from Black Beauty ( Vitis rotundifolia ) and Sunbelt ( Vitis labruscana L.) grape cultivars were evaluated. Heating the must before pressing increased juice yield, titratable acidity, red color, brown/yellow pigments, and darkness and decreased the press fraction yield and juice pH in both cultivars. Sunbelt juice from the heated must had the highest yield (786 L/metric ton), red color, brown/yellow pigments, and darkness. Black Beauty nonheated must had the largest press fraction (43%) but the lowest red color, brown/yellow pigments, and darkness in the juice. The juice generally had less total phenolics, total anthocyanins, and oxygen radical absorbance capacity (ORAC) than the whole grapes. The juice from heated Black Beauty and Sunbelt musts had the highest total phenolics (1354 and 1937 mg/L, respectively) and anthocyanins (414 and 513 mg/L, respectively). Although the data for seeds and skins are on a dry basis, the press fractions had higher levels of phenolics and ORAC than the whole grapes and juice. The dried seeds had more phenolics and less anthocyanins than the skins. The highest total phenolic level (95338 mg/kg) equivalents and ORAC level (1100 μmol trolox/g) was in Black Beauty seeds from nonheated must. The skins of nonheated Sunbelt had the highest anthocyanins (11889 mg/kg). Because the press fractions of both cultivars had high ORAC values and total phenolic levels, products with nutraceutical benefits could be developed.     

Antioxidant potentials of buntan pumelo (Citrus grandis Osbeck) and its ethanolic and acetified fermentation products

The antioxidant potentials of buntan pumelo (Citrus grandis Osbeck) and its fermented products were determined. The essential oil from peel had higher total phenolic (214 mM) and flavonoid (134 mg QE/g of dried material) contents than those of different solvent extracts from fruit pulp. In addition, DPPH free radical-scavenging activity and ferric-reducing antioxidant power values determined for the essential oil were 26.1 ± 1.2% and 2.3 ± 0.3 mM, respectively, which were significantly higher than those of various fruit pulp extracts. The ethanol-fermented products of pumelo juice had higher total phenolic and flavonoid contents than those of fresh juice. For maintenance of the substantial antioxidant properties of pumelo products, ethanol-fermented juice rather than fresh or acetate-fermented juice is recommended. Through correlation analysis, the phenolic compounds in the fermented pumelo products were found to be the major contributors to the free radical-scavenging activity and ferric-reducing power.     

3 种梨果实发育过程中酚类物质及其抗氧化能力分析

为进一步了解新疆主要栽培品种梨生长发育期果实酚类物质和抗氧化能力的变化规律,选取‘库尔勒香梨’‘早酥梨’及其杂交后代‘新梨7号’果实为试材,对其总酚、总黄酮、酚类物质含量以及1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力和2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）阳离子自由基清除能力进行分析。结果表明：3 种梨果实总酚含量、总黄酮含量、DPPH自由基清除能力在整个生长发育过程中总体呈逐渐降低的变化趋势,ABTS阳离子自由基清除能力呈先降低后升高再降低的变化趋势,花后50 d‘早酥梨’果实中总酚和总黄酮含量、DPPH自由基清除能力最高,分别达23.10、32.25 mg/g和29.12 μmol/g;花后80 d,‘早酥梨’果实ABTS阳离子自由基清除能力最高,达80.74 μmol/g。不同生长发育期同品种梨果实的酚类物质含量均存在明显差异,果实中的熊果苷、儿茶素、绿原酸、表儿茶素、槲皮葡萄糖苷、山柰酚-3-O-葡萄糖苷含量总体逐渐降低,其中熊果苷含量最高,平均值为5 797.82 μg/g,其次是绿原酸含量,平均值为1 781.02 μg/g。梨果实中总黄酮、总酚、熊果苷、儿茶素、绿原酸、表儿茶素含量与DPPH自由基清除能力呈极显著正相关（P＜0.01）。3 种梨幼果期（花后50 d）酚类物质及抗氧化能力较高,‘早酥梨’总酚含量、总黄酮含量、DPPH自由基清除能力和ABTS阳离子自由基清除能力均比‘库尔勒香梨’和‘新梨7号’高。     

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.     

Contents of phenolics and flavonoids and antioxidant activities in skin, pulp, and seeds of miracle fruit

Miracle Fruit (Synsepalum dulificum) has been studied because of its unique taste modifying properties. This study investigated contents of phenolics, flavonoids, and antioxidant activities in skin, pulp, and seeds of Miracle Fruit. The free phenolic content in skin was almost 3 times of that in pulp and 4 times of that in seeds. Skin contributed 43.96% of free phenolic compounds with 15.91% of freeze-dried solids due to its high phenolic content. As the trend observed for phenolic content, the free flavonoid content in the skin was tremendously higher than that in the seed and pulp. The skin contributed about 52% of total flavonoid with 15.91% of dried solids. On other hand, the differences in the bound phenolic contents were not so distinct among the 3 components. The free antioxidant activities in skin and pulp were comparable, and were significantly higher than that in seeds. Although the antioxidant activities in seeds was considerably lower than that in skin, 49.45% free antioxidant activity, 76.41% bound antioxidant activity, and 58.56% of total antioxidant activity were contributed by seeds due to about 66% of solid of total solids. In general, the results of antioxidant activities using sequential methods were higher than that using direct method. This study suggests that Miracle Fruit is a good source not only for flavor and color, and also antioxidant activity for functional food applications.     

蒸汽爆破预处理对籽粒苋籽实抗氧化能力的影响

实验选取汽爆压力0.3、0.6、0.9、1.2、1.5 MPa,汽爆时间10、20、30、60、120 s,对籽粒苋籽实进行预处理。分别测定汽爆前后各组样品的总酚、总黄酮含量,并通过测定其对DPPH、ABTS+自由基的清除率、铁离子还原能力来衡量各组样品的抗氧化能力,旨在探讨蒸汽爆破对籽粒苋籽实总酚、总黄酮和抗氧化能力的影响。结果表明:经过汽爆处理,籽粒苋籽实总酚、总黄酮含量和抗氧化能力显著提高(p<0.5)。0.6 MPa、60 s是最佳处理条件,此时总酚、总黄酮含量分别为未汽爆组的5.3倍和7.3倍,DPPH、ABTS+自由基清除率、铁离子还原能力分别是未汽爆组的4.6、3.8和11.6倍。蒸汽爆破是一种高效、无污染的前处理方式,为籽粒苋籽实的后续开发奠定基础。     

Effect of Fermentation Time on the Phenolic,Flavonoid and Vitamin C Contents and Antioxidant Activities of Okra (Abelmoschus esculentus) Seeds

The objective of this study was to evaluate the effect of fermentation on the phenolic, vitamin C and total flavonoid contents and antioxidant properties of okra seed. The okra seeds were removed from the pod of matured and fibrous okra that cannot be easily cut with kitchen knife, and was allowed to undergo chance fermentation for 120 h. Samples were taken for antioxidant analysis at 24 h, 72 h and 120 h, respectively. The aqueous extracts of fermented and unfermented okra seeds were obtained and subsequently used for the analysis. The phenolic, vitamin C and total flavonoid contents and the antioxidant properties (ferric reducing antioxidant power (FRAP) and 1, 1-diphenyl-2 picrylhydrazyl (DPPH) free radical-scavenging ability) of the extracts were determined. The results revealed that fermented okra seeds had significantly (p < 0.05) higher phenolic content, vitamin C, total flavonoid and non-flavonoid contents and showed greater antioxidant activities than unfermented okra seed. Okra seeds fermented for 24 h exhibited the highest ferric reducing antioxidant power of 980 mgAAE/100 g and the least IC₅₀ of 2.27 mg/ ml for DPPH free radical-scavenging ability than the others. Okra seeds fermented for 24 hours had significantly (p < 0.05) higher antioxidant activities. The product from fermented okra seeds could be used for the production of functional foods.     

Improving the Extraction of Juice and Anthocyanins from Blueberry Fruits and Their By-products by Application of Pulsed Electric Fields

Pulsed electric field (PEF) treatments (1–10 kJ/kg at 3 kV/cm) were applied before pressing of blueberry fruits to improve the yield and quality of expressed juice as well as the recovery of anthocyanins from blueberry by-products (press cake) via solid–liquid extraction. A PEF pre-treatment at 1 kJ/kg was sufficient to significantly increase the juice yield (by 32%) with respect to the untreated sample. Higher energy input (10 kJ/kg) was most favorable for the largest increment of anthocyanin content (55%) and antioxidant capacity (36 and 41%, determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assay, respectively) in juice. Extracts obtained from the press cake of PEF-treated blueberries at 10 kJ/kg possessed an anthocyanin content (75%) and antioxidant capacity (71 and 109%, determined by FRAP and DPPH assay, respectively) higher than that of the extracts obtained from non-treated berries press cake. HPLC analyses revealed the major classes of the detected anthocyanins as glycosides of delphinidin, cyanidin, petunidin, peonidin, and malvidin, and no significant degradation of individual anthocyanins due to PEF application was observed. The present PEF pre-treatment could be a promising approach to facilitate efficient extraction of juice and antioxidants especially anthocyanins from blueberry and their by-products.     

Effects of Chitosan,Calcium Chloride,and Pullulan Coating Treatments on Antioxidant Activity in Pear cv. “Huang guan” During Storage

Effects of different calcium chloride, chitosan and pullulan coating treatments on antioxidant activity of “Huang guan” pears (Pyrus pyrifolia Nakai) during storage have been studied. Total phenolic content, phenolic composition, total flavonoid content, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH), 2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant potential (FRAP)) were determined in peel and pulp tissues over 210 days. Coating treatments slowed decrease of total phenolic and flavonoid contents, chlorogenic acid, arbutin, catechin and caffeic acid, SOD and CAT activities, and total antioxidant activity. However, POD activity was inhibited. The antioxidant content in the peel was higher than in the pulp. Of the coatings, chitosan was the most effective, but overall, all coatings may be useful to extend shelf-life, maintain quality and control decline of antioxidant activity in pear.     

The occurrence and characterisation of phenolic compounds in Camelina sativa seed, cake and oil

In this study, the antioxidant activities of Camelina sativa methanolic extracts were evaluated by different chemical assays: reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH·) assay, the β-carotene bleaching method and the metal chelating activity assay. An LC-MS profiling method was used for a comprehensive study of the phenolic compounds and their representation in camelina seeds, cake and oil. For this purpose, 4-vinyl derivatives of hydroxycinnamic acids were synthesized by thermal decarboxylation of the corresponding phenolic acids and sinapine was isolated from kale (Brassica oleracea) applying a new method and confirmed by NMR. The results revealed that besides the total phenolic content and antioxidant activity, seeds and cake also possess a similar phenolic profile. In addition to sinapine and 4-vinyl derivatives, other antioxidants were successfully identified: ellagic acid, protocatechuic acid, p-hydroxybenzoic acid, sinapic acid, salicylic acid, catechin, rutin, quercetin and quercetin glucoside. Since after oil pressing most of the phenolic compounds remain in the seed residues, only a few compounds were identified in the oil. Camelina cake was found to have the best reducing power and radical scavenging activity, whereas camelina oil, with a relatively low phenolic content, exhibited the highest iron-chelating capacity and the best inhibitory action against β-carotene discolouration in an emulsified system.     

云南特色豆类的酚类含量及其抗氧化活性

采用分光光度计法,对云南产的8种特色豆类的酚类含量及其抗氧化活性进行研究。结果表明:雀蛋豆的黄酮质量分数最高,为0.55%,丽江大花豆、保山透心绿蚕豆和保山大绿豆提取液中的总酚质量分数相对较高,均达到0.25%。雀蛋豆提取液的总还原力最高,而昆明白花豆最低。剑川荷包豆对DPPH·的清除率仅为52.28%,其他豆类品种对DPPH·的清除率较高,均在69%以上。剑川荷包豆和丽江大花豆2个品种对·OH都有很好的清除效果。相关性分析得出8种豆类的总黄酮含量与抗氧化之间没有显著性相关关系(P0.05),而且总酚含量与自由基清除率之间也没有显著性相关关系(P0.05),但总酚含量与总还原力之间具有极显著相关关系(P0.01)。云南产的8种特色豆类酚类含量较高,抗氧化活性较强,经常食用对人类健康有促进作用。     

储藏温度对荔枝果汁中酚类物质含量及抗氧化能力的影响

以经UHT杀菌的荔枝果汁为原料,分析5周内在4、25、37℃3个储藏温度下荔枝果汁中总酚含量、总黄酮含量及FRAP和ABTS抗氧化能力的变化。结果显示,随着储藏时间的延长,在4、25、37℃储藏温度下荔枝果汁中总酚含量与抗氧化能力均呈现显著下降趋势(p<0.05);总酚含量受储藏时间影响更显著(p<0.05),总黄酮含量受温度影响更显著(p<0.05),抗氧化能力则同时受储藏时间(p<0.05)和温度(p<0.05)的影响。由此表明不同储藏条件对荔枝果汁中酚类物质含量存在显著影响,低温及短时储藏有利于保持荔枝果汁中酚类物质含量及其抗氧化活性。     

Evaluation of free radical-scavenging properties of commercial grape phenol extracts by a fast colorimetric method

Three commercial extracts of grape phenols (seeds, skin, whole) were used in this study. Each extract was divided by HPLC into five fractions of different polarities, and their free radical-scavenging activities were measured using the DPD (N,N-diethyl-p-phenylenediamine) colorimetric method. Total phenol contents were determined using the Folin-Ciocalteu method to assess their contribution to the antiradical activity. The results showed that there was good correlation between total phenolic compound contents and free radical-scavenging activities of the different grape extracts. Moreover, the seed extract presented the most important free radical-scavenging properties (138 USP/mg extract), whereas the whole extract presented the lowest free radical-scavenging capacity (80.5 USP/mg extract). However, the free radical-scavenging properties, reported on the basis of content of phenolic compounds in each extract, showed that the free radical-scavenging activities of seed and whole extracts were not significantly different (171 versus 162 USP/mg phenol). In addition, free radical-scavenging activities of fractions from seed and skin extracts decreased as their polarities decreased.     

Antioxidant and antiradical properties of cranberry juice and extracts

The antioxidant capacities of cranberry juice and three extracts isolated from frozen cranberries containing anthocyanins, water-soluble and apolar phenolic compounds, were evaluated at pH 2.5 and 7, respectively. The free radical-scavenging (FRS) and the lipid peroxidation inhibition (LPI) activities of each samples, and extracts, were studied using the N,N-diethyl-p-phenylenediamine (DPD) decoloration test and the thiobarbituric acid reactive substances (TBARS) assay, respectively. The cranberry phenols displayed good free radical-scavenging properties, but were less efficient at inhibiting the peroxidation of lipids. Of all the samples tested, the water-soluble phenolic compounds showed the greatest free radical-scavenging (68.2 mmol TE/mg phenol) and antioxidant (13.4 mmol TE phenol) activities. The polarity of the phenols, the pH of the medium and the juice process had a great influence on the antioxidant activities. The phenols isolated from cranberries with an aqueous solvent have greater antioxidant properties than those extracted with an organic solvent mixture. The antioxidant activity of the cranberry samples adjusted at pH 2.5 was greater than those adjusted at pH 7. Compared to the cranberry extracts, the juice exhibited a much lower antioxidant activity, especially when compared with the extract containing water-soluble compounds which the extraction conditions were similar to those used to obtain the juice.     

Antioxidant and antiinflammation capacities of some pear cultivars

Abstract: Five commercial pear cultivars were investigated for total phenolics and flavonoids contents, the main phenolic compounds, and their antioxidant and antiinflammation capacities. Four in vitro oxidant and 2 in vivo antiinflammation models were used to evaluate the pharmacological activities of the different pears. The main phenolic compounds were determined by high‐performance liquid chromatography with diode‐array detector, which result indicated that gallic acid ranged from 5.23 to 10.72 μg/g, catechin from 0.41 to 28.83 μg/g, chlorogenic acid from 485.11 to 837.03 μg/g, caffeic acid from 0 to 1.16 μg/g, epicatechin from 6.73 to 131.49 μg/g, and rutin from 0.92 to 104.64 μg/g. The total antioxidant capacity was in descending order: Shuijing > Fengshui > Xuehua > Ya > Xiang pear, which was consistent with the total phenol and flavonoid contents. Thus, the antioxidant capacity of pears may be attributed to their high contents of phenolics and flavonoids. However, the antiinflammation activity was in decreasing order: Xuehua > Xiang > Ya > Fengshui > Shuijing pear, which indicates that compounds other than antioxidants may be responsible for the antiinflammation effect. Practical Application: The importance on antioxidant activities of phenolic compounds in foods and vegetables as natural antioxidants has reached a new high in recent years. In this study, the total phenol and flavonoid contents, and the antioxidant and antiinflammation activities of 5 different types of commercial pears in China were investigated, which may be the experimental basis for the further development and utilization of the pears.     

Potential of nanofiltration for the concentration of bioactive compounds from watermelon juice

The aim of this study was to evaluate the potential of nanofiltration for the concentration of bioactive compounds of watermelon juice. Lipophilic and hydrophilic antioxidant activities were determined through two assays, ferric reducing antioxidant power and DPPH. The content of lycopene, flavonoids and total phenolic in the concentrate samples increased with the increase in the volume reduction factor. Volume reduction factor of three showed the best performance of concentration, generating the highest values for lycopene, flavonoid and total phenolic contents. Average permeation flux was 2.3 L h^?1 m^?2, with continuous extraction of the concentrate at a volumetric reduction ratio of three. Lycopene showed the highest rejection coefficient (0.99), followed by flavonoids (0.96) and total phenolic content (0.65). The hydrophilic antioxidant activity values in both assays were higher than the lipophilic antioxidant activity values. A highly significant correlation was noted between the contents of flavonoids, phenolic compounds, ascorbic acid, and lycopene and their antioxidant potential in both lipophilic and hydrophilic fractions.     

Physico-chemical characteristics of juice extracted by blender and mechanical press from pomegranate cultivars grown in Georgia

Pomegranate juice is consumed widely for its possible health benefits. The aril juice from 15 pomegranate cultivars grown in Georgia were analysed for juice yield based on fresh weight (FW) and physico-chemical properties, using blender and mechanical press extraction. Blender had a higher juice yield (42.04% FW) compared to mechanical press (38.05% FW). Total phenolics and antioxidant capacity was determined by Folin–Ciocalteau method and ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays, respectively. Total monomeric anthocyanins were determined by pH differential method and RP-HPLC. The major anthocyanin was delphinidin 3-glucoside. High negative and significant (p ? 0.05) correlations were found between pH and titratable acidity (TA). The total soluble solids content (TSS) averaged 15.59 in blender and 14.94 °Brix in mechanical press. Chemical analysis of juice showed significant differences among cultivars and extraction methods. Overall, blender was more efficient than mechanical press juice extraction.     

Effect of milling time on antioxidant compounds and activities of methanol extracts of sorghum [Sorghum bicolor (L.) Moench]

Antioxidant compounds and activities of methanol extracts of sorghum for different milling times were investigated. Total polyphenol, flavonoid, and tannin contents were measured using spectrophotometric methods. Methanol extracts were also evaluated for antioxidant activities based on DPPH and ABTS radical-scavenging activities. As milling rates increased, milling recovery and a value decreased, while L and b values increased. The extraction yield, antioxidant compound contents, and antioxidant activities of sorghum grain decreased with increasing milling rates. Methanol extracts from sorghum bran generally showed higher antioxidant activities than extracts from sorghum grain. The antioxidant content was higher in sorghum bran extracts than in grain extracts. A significant (p<0.05) correlation was observed between free radical-scavenging activity and the content of polyphenolic compounds. Sorghum bran exhibited antioxidant activities that may have important health benefits.     

Enhancement of antioxidant activity,total phenolic and flavonoid content of black soybeans by solid state fermentation with Bacillus subtilis BCRC 14715

In the present study, a solid state fermentation of black soybeans with Bacillus subtilis BCRC 14715 was performed. The effect of fermentation on the changes of total phenolic and flavonoid content and antioxidant activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, and Fe²⁺-chelating ability exerted by various solvent (water, 80% methanol, 80% ethanol, 80% acetone) extracts of black soybeans was examined. It was found that fermentation enhanced the total phenolic and flavonoid content as well as antioxidant activity of the black soybean extract. Among the various extracts examined, the acetone extract of fermented black soybeans showed the highest total phenolic and flavonoid content. The acetone extract and the methanol extract of fermented black soybeans showed the highest DPPH free radical-scavenging effect and Fe²⁺-chelating ability, respectively. Analysis of extraction yields showed that the active principle associated with the DPPH radical-scavenging effect was most efficiently extracted from black soybeans using water, regardless of fermentation. Water and methanol effectively extract the Fe²⁺-chelating principles from non-fermented and fermented black soybeans, respectively.     

Antioxidant activity of grape products and characterization of components by electrospray ionization mass spectrometry

Grapes are known for their health benefits and high antioxidant activity due to phenolic content. Our work provides metabolic fingerprints of three grape products, namely grape juice (GJ), grape juice concentrate (GJC) and grape skin extract powder (GSE). Using direct infusion electrospray ionization mass spectrometry (ESI–MS) and evaluating the relationship between total lphenolic content and antioxidant activity, it is possible to compare which product has the best effectiveness. Fingerprints of GJC and GSE showed similar characteristic distributions of resveratrol and pterostilbene in relatively significant abundances. GJC provided higher antioxidant activity/phenolic ratio; therefore, the identified phenolic compounds from GJC may offer enhanced antioxidant potential when compared to the other two samples (GJ and GSE).