Composition and antioxidant activity of raisin extracts obtained from various solvents

Experiments were conducted to determine if the contents of phenolics and browning reaction products and antioxidant activity of raisin extracts were closely dependent on the extraction solvent. Enhanced extraction yields were obtained from solvent containing higher water concentrations. However, total phenolic content (TPC) was highest for extracts obtained from solvent to water ratios of 60:40 (v/v), whereby the extract obtained from ethanol:water (60:40, v/v) had the highest TPC of 375 mg gallic acid equivalents (GAE)/100 g extract. HMF content was highest in extracts obtained from 60% solvent, regardless of solvent type. The extract obtained from 60% methanol had the highest HMF content at 199 μg/g extract. Although the 60% solvents provided extract with high antioxidant components, the antioxidant activity of raisin extracts obtained from 80:20 (v/v) solvent/water was significantly higher than other raisin extracts obtained from different solvent concentrations. Phenolic acids, HMF, and low-molecular-weight flavonoids were responsible for the antioxidant activity, but not the high-molecular-weight flavonoids.     

Effects of catechin on the phenolic content and antioxidant properties of low‐fat cheese

The effect of (+)‐catechin on total phenolic content (TPC) and antioxidant properties in low‐fat hard cheese were examined over a 90‐day ripening period at 8 °C. Antioxidant activity (AA) in cheese was measured by ferric reducing antioxidant power, oxygen radical absorbance capacity (ORAC) and 2,2‐diphenyl‐1‐picrylhydrazyl assays and compared with TPC. Catechin retention coefficients in cheese curds were in the range of 0.63–0.75 and decreased the pH of cheese without affecting protein, fat or moisture content. Both TPC and AA increased during the 90‐day ripening period. Oxygen radical absorbance capacity was the most suitable technique for evaluating AA in cheese due to the high correlation with TPC and suitability in both lipophilic and hydrophilic systems.     

Antioxidant and tyrosinase inhibitory activities of different parts of oriental cherry (Prunus serrulata var. spontanea)

Six different parts (branch, flesh, flower, fruit, leaf, and seed) of oriental cherry (Prunus serrulata var. spontanea) were extracted with ethanol or water, then total phenol content (TPC), antioxidant activity, and tyrosinase inhibitory activity of the extracts were evaluated. The ethanol extracts showed higher TPC and antioxidant activity than the water extracts regardless of parts. The ethanol extracts of leaf as well as branch possessed superior TPC and antioxidant activity. The highest tyrosinase inhibitory activity was found in ethanol extract of leaf. There was no dramatic difference of tyrosinase inhibitory activities according to parts of cherry. The results suggest that leaf and branch of oriental cherry could be a candidate for antioxidant and anti-whitening materials in food or cosmetic industries.     

Antimicrobial and Antioxidant Activities of Cichorium Intybus Root Extract Using Orthogonal Matrix Design

Solvent, impregnation time, sonication repetitions, and ultrasonic power were important factors in the process of ultrasound‐assisted extraction from chicory (Cichorium intybus) root, while there were no studies about optimizing these 4 factors for extract yield, total phenolic content (TPC), antioxidant, antibacterial, and antifungal activity of the extracts using orthogonal matrix design. The present research demonstrated that the solvent composition played a significant role in the improving extract yield, TPC, antioxidant, and antibacterial activities. The other 3 factors had inequable effect on different purposes, ultrasonic power could improve TPC and antioxidant activity, but long time of extraction lowered antioxidant activity. The TPC increased from 22.34 to 27.87 mg GAE (gallic acid equivalents)/100 g (dry extracts) with increasing solvent polarity. The half inhibition concentration (IC_50, μg/mL) of the radical scavenging activity of the chicory extracts ranged from 281.00 to 983.33 μg/mL. The content of caffeoylquinic acids of root extract, which was extracted by the optimal combination was 0.104%. Several extracts displayed antibacterial activities against Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, Bacillus subtilis, and Salmonella typhi, while Penicillium sp. and Aspergillus sp. resisted against all the extracts. Combination of 70% ethanol v/v, 24‐h impregnation time, 3 sonication rounds, and 300‐W ultrasonic input power was found to be the optimal combination for the chicory extract yield, TPC, antioxidant activity, and antibacterial activity.     

Jabuticaba (Myrciaria cauliflora) Seeds: Chemical Characterization and Extraction of Antioxidant and Antimicrobial Compounds

This study was aimed to assess the effect of time and temperature on the extraction of antioxidant compounds from jabuticaba seeds (Myrciaria cauliflora cv. Sabará), to optimize the solvent proportion (water, ethyl alcohol, and propanone), and to characterize the extract according to the chemical composition, antioxidant, and antimicrobial properties. Proximal composition, total phenolic content (TPC), antioxidant, and antimicrobial activities were analyzed. The optimized solvent ratio of 60% water and 40% propanone provided a mean TPC of 8.65 g GAE/100 g seeds and the antioxidant activity toward 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) was 82.79% ± 0.50%. Time and temperature parameters did not influence the yield of TPC. The gross seed extract was partially purified and both exhibited a high antioxidant activity and antimicrobial potential toward Gram‐positive and Gram‐negative bacteria. The purified jabuticaba seed lyophilized extract contained a higher (P < 0.05) TPC, o‐diphenols, flavonols, and antioxidant activity measured by the DPPH assay and total reducing capacity as compared to the gross lyophilized extract. Electrospray ionization coupled with tandem mass spectrometry (ESI‐MS/MS) data showed the presence of ellagitannins and ellagic acid in the extracts, which are probably the responsible for the antimicrobial and antioxidant activities.     

阿拉伯胶/白色玫瑰茄提取物复合涂膜对低温贮藏蓝莓保鲜效果的影响

为改善低温贮藏蓝莓果实易于腐败的问题,探讨一种可以改善蓝莓贮藏品质的保鲜处理方法。实验以‘兔眼’蓝莓品种为试材,在（4.0±0.5）℃、相对湿度75%的贮藏条件下,采用100 mg/mL阿拉伯胶＋体积分数1.5%甘油（M1）、100 mg/mL阿拉伯胶＋体积分数1.5%甘油＋体积分数1.5%白色玫瑰茄提取物（white roselle extract,WRE）（M2）、100 mg/mL阿拉伯胶＋体积分数1.5%甘油＋体积分数2.5% WRE（M3）3 种可食性涂膜液对蓝莓样品进行涂膜处理,通过分析果实理化性质、抗氧化酶活力和抗氧化物质含量等指标的变化,探讨复合涂膜对低温贮藏蓝莓保鲜效果的影响。结果表明：在低温贮藏的条件下,阿拉伯胶复合涂膜可以显著减缓蓝莓果实质量损失、降低腐烂率和延缓硬度降低（P＜0.05）,并能维持果实较高的总酚、花色苷含量和较好的感官品质,显著抑制多酚氧化酶（polyphenol oxidase ,PPO）活力和降低果实表面褐变程度（P＜0.05）;且M3涂膜剂在抑制低温贮藏蓝莓果实PPO活力、维持果实总酚和花色苷含量、改善感官品质方面具有最佳效果。综合分析各项指标可得出,M3涂膜剂对低温贮藏蓝莓的保鲜效果最好。     

Enhancing antioxidant availability in wheat grains from plants grown under seawater stress in response to microalgae extract treatments

BACKGROUND: The present study was designed to investigate the enhanced antioxidant capacity of whole grains from wheat plants grown under seawater stress in response to microalgae extract treatment. RESULTS: The total carotenoid (TCAR), tocopherol (TOC), phenolic (TPC), and protein (PC) contents in whole grains of wheat plants irrigated with 10% and 20% (v/v) seawater (SW) in response to water extracts of microalgae Spirulina maxima (SME) and Chlorella ellipsoida (CEE) as well as exogenous plant growth enhancers of ascorbic acid and benzyladenine treatments were measured. The results showed that the levels of enhanced TCAR (range 0.08–0.14 g kg^?1), TOC (range 0.05–0.12 g kg^?1), TPC (range 0.80–2.96 g kg^?1) and PC (range 93.4–137.9 g kg^?1) in wheat grains of plants irrigated with 10% and 20% SW were significantly increased in response to SME and CEE treatments. Evaluation of antioxidant activity of ethanolic extracts of grains of SW‐stressed plants indicated that DPPH and TBAS radical scavenging activity was significantly increased in response to SME and CEE treatments and coincided with the increase in levels of antioxidant compounds present in each extract. The electrophoretic profiles of the grains of proteins of treated samples exhibited quite different patterns from those in control samples. CONCLUSION: The results suggest that the application of algal extracts to wheat plants irrigated with SW is useful for improvement of salinity tolerance. This effect can be triggered by the stimulation of antioxidant components and protein content. Copyright © 2009 Society of Chemical Industry     

正交试验优化复凝聚法制备液体香精微胶囊工艺

为将液体香精加工成缓释性固体粉末香精,以明胶和海藻酸钠为壁材,用复凝聚法制备液体香精微胶囊,以包埋率为评价指标,研究了不同因素对微胶囊制备效果的影响,通过正交试验优化工艺条件。结果表明,壁材为质量分数1%明胶溶液与0.5%海藻酸钠溶液按3∶1的质量比混合、液体香精与壁材质量比1∶1、复凝pH 4.0～4.5条件下,平均包埋率达92.80%,对包埋率影响最大的因素为两壁材的比例。用石油醚浸提,与同类固体粉末香精对比考察,验证了所包埋的微胶囊具有较好的缓释效果。     

Isolation of probiotic bacteria from turmeric (Curcuma longa Linn.) and its application in enriched beverages

The purpose of this study is to obtain lactic acid bacteria (LAB) from fresh turmeric rhizomes that could be used as starter culture with the ability to ferment turmeric and to investigate its influence on total phenolic content (TPC) and antioxidant activity. Three LAB strains, namely Enterococcus faecium, Lactococcus lactis subsp. lactis, and Lactobacillus plantarum, were isolated from turmeric rhizomes. These microorganisms showed similar characteristics as probiotic organisms. The TPC of fermented turmeric beverages was measured using the Folin–Denis reagent method, while the antioxidant activity assays were quantified by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ferric reducing antioxidant power assay. This study confirms that bacteria isolated from turmeric can be used as starter. Moreover, fermentation time and LAB lead to dominant amount of TPC and that they have high levels of antioxidant activities.     

Antioxidant and antimicrobial properties of Thai propolis extracted using ethanol aqueous solution

The potential of using propolis collected from Thailand as a natural antioxidant and antimicrobial agent for food applications was investigated. The propolis extract was prepared by using different ethanol aqueous solutions, including 30%, 40%, 50% and 70%. Total phenolic content (TPC), phenolic compound and antioxidant activity of the propolis were determined using Folin–Ciocalteau method, high performance liquid chromatography (HPLC) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity, respectively. The antimicrobial ability was tested against Staphylococcus aureus (TISTR 118), Salmonella enteritidis (DMST 17368), Escherichia coli (TISTR 780) and Pseudomonas aeruginosa (ATCC 27853) using disc diffusion technique. The major phenolic compounds found in Thai propolis were rutin, quercetin and naringin. The TPC and DPPH radical scavenging activity increased with increasing ethanol concentration in the solvent. Propolis extract showed antimicrobial activity, in terms of inhibitory zone for S. aureus and limited growth underneath paper discs, against all tested bacteria.     

Factors influencing antioxidant activities and total phenolic content of guava leaf extract

The aim of this study is to investigate the influence of certain factors on the yield, antioxidant activity (AA) and total phenolic content (TPC) of guava leaf extract. The effects of pretreatment of leaf sample prior to extract, extraction method, and the leaf age were investigated. Folin-Ciocalteau was used to determine the TPC. Trolox equivalent antioxidant capacity (TEAC) and equilibrium concentration (EC) were used for evaluation of AA. Results indicated that ultrasonication is the most suitable method for guava leaf extraction as it yielded the extract with the significantly highest TPC and AA. Blanching followed by ice water cooling (BCD) was suggested for the pretreatment process of guava leaves. The study of leaf maturity demonstrated that the highest activity was from the young leaves. Hot water was the best solvent to extract the active principles. The extract of BCD pretreated young leaves, extracted by hot water exhibited the highest TPC and AA with the TEAC and EC values of 24.30 ± 0.50 and 20.41 ± 0.67 mM/mg, respectively. These values are 1.88 and 8.72 times higher than the synthetic antioxidant butylated hydroxy toluene (BHT) and 1.75 and 1.21 times higher than vitamin E, respectively. It was concluded that pretreatment and drying process, method of extraction and leaf maturity played important roles on the bioactive compounds and their antioxidant power of guava leaf extract.     

Impact of different solvents on the recovery of bioactive compounds and antioxidant properties from lemon (<Emphasis Type="Italic">Citrus limon</Emphasis> L.) pomace waste

The effects of different solvents on the recovery of (i) extractable solids (ES), (ii) total phenolic compounds (TPC), (iii) total flavonoid content (TFC), (iv) vitamin C, and (v) antioxidant activity from lemon pomace waste were investigated. The results revealed that solvents significantly affected the recovery of ES, TPC, TFC, and antioxidant properties. Absolute methanol and 50% acetone resulted in the highest extraction yields of TPC, whereas absolute methanol resulted in the highest extraction of TFC, and water had the highest recovery of vitamin C. 50% ethanol, and 50% acetone had higher extraction yields for TPC, and TFC, as well as higher antioxidant activity compared with their absolute solvents and water. TPC and TFC were shown to be the major components contributing to the antioxidant activity of lemon pomace.     

Effects of mashing on total phenolic contents and antioxidant activities of malts and worts

Effects of mashing on total phenolic contents (TPC), radical‐scavenging activity, reducing power and metal chelating activity of malts and corresponding worts were clarified in this study. Results showed that there were significant variations in TPC and antioxidant activity across malts and worts. An 8.8% of increase in TPC was observed during the early stage of mashing, accompanied by an increase in antioxidant activity. However, 2.6% of decrease in TPC and inconsistent changes in antioxidant activity were found during the mashing at higher temperature. Overall, mashing resulted in 6.0% and >10.0% of increases in TPC and antioxidant activity, respectively. Moreover, Pearson correlation analysis revealed that there were good correlations (ranging from 0.622 to 0.735, P < 0.01) between TPC and antioxidant activity of malts and worts. Additionally, mashing resulted in more positive correlations between TPC and antioxidant activity, emphasising the key role of malt phenolic compounds for wort antioxidant activity.     

Optimization of phenolic compound recovery and antioxidant activity of light and dark dried fig (Ficus carica L.) varieties

The optimum conditions for extraction of total phenolic contents (TPC) and for enhancing the antioxidant activity from light and dark dried figs were determined. The effects of the solvent nature (acetone, ethanol, methanol, or water), solvent concentration (20–80%), acetic acid concentration (0–2%), extraction temperature (25–70°C), extraction time (0.5–4 h), sample to solvent ratio (1/25–1/100), and number of extractions (1, 2, and 3) were determined. The TPC was used to identify antioxidant compounds. 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used to evaluate antioxidant activity. All extraction parameters had significant effects (p<0.05) on the TPC and the antioxidant activities. The best conditions were obtained with double extraction using 60% acetone without acidification, at 40°C for 120 min, and with a 1/75 solid to solvent ratio. These conditions resulted in TPC concentrations of 469.46 (light variety) and 399.79 mg of gallic acid (GAE)/100 g (dark variety), and antioxidant activities of 96.47 and 102.28 mg of GAE/100 g, respectively.     

Color,Phenolics, and Antioxidant Activity of Blackberry (Rubus glaucus Benth.), Blueberry (Vaccinium floribundum Kunth.), and Apple Wines from Ecuador

Seventy wines were produced in Ecuador under different processing conditions with local fruits: Andean blackberries (Rubus glaucus Benth.) and blueberries (Vaccinium floribundum Kunth.) and Golden Reinette apples. Wines were evaluated for antioxidant activity (AA) using the radical scavenging capacity (DPPH) method, total phenolic content (TPC) using the Folin–Ciocalteu method, total monomeric anthocyanins (TMAs) using the pH differential test, and color parameters using VIS‐spectrophotometry. For blackberry wines, ellagitannins and anthocyanins were also analyzed using high‐performance liquid chromatography with diode‐array detection (HPLC‐DAD). Apples wines (n = 40) had the lowest TPC (608 ± 86 mg/L) and AA (2.1 ± 0.3 mM Trolox). Blueberry wines (n = 12) had high TPC (1086 ± 194 mg/L) and moderate AA (5.4 ± 0.8 mM) but very low TMA (8 ± 3 mg/L), with a color evolved toward yellow and blue shades. Blackberry wines (n = 10) had the highest TPC (1265 ± 91 mg/L) and AA (12 ± 1 mM). Ellagitannins were the major phenolics (1172 ± 115 mg/L) and correlated well with AA (r = 0.88). Within anthocyanins (TMA 73 ± 16 mg/L), cyanidin‐3‐rutinoside (62%) and cyanidin‐3‐glucoside (15%) were predominant. Wines obtained by cofermentation of apples and blackberries (n = 8) showed intermediate characteristics (TPC 999 ± 83 mg/L, AA 6.2 ± 0.7 mM, TMA 35 ± 22 mg/L) between the blackberry and blueberry wines. The results suggest that the Andean berries, particularly R. glaucus, are suitable raw materials to produce wines with an in vitro antioxidant capacity that is comparable to red grape wines.     

Encapsulation of the phenolic compounds of the blackberry (Rubus fruticosus)

Microencapsulated phenolic extracts of blackberry (PE) were obtained by lyophilization in matrixes of β-cyclodextrin (β-CDS), chitosan (C), xanthan (X) and hydrogel (H). The encapsulation was confirmed by Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA); their antioxidant activity, controlled release of phenolics and efficiency of encapsulation were determined. However, coated chitosan and xanthan only showed the characteristic shape. In fact, encapsulation efficiency depended on the phenolic compound and the encapsulated coating used; gallic acid and epicatechin were predominantly in microcapsules coated with β-cyclodextrin and xanthan. The highest antioxidant activity in microcapsules coated with β-cyclodextrin (84.43 ± 3.5%) and xanthan (90.75 ± 0.09%) was related to the equitable presence of encapsulated phenolic compounds. The controlled release of phenolic extract capsules was influenced by coating, solvent and pH.     

Effects of inlet air temperature and spray rate of coating solution on quality attributes of turmeric extract coated rice using top-spray fluidized bed coating technique

The addition of natural antioxidants onto white rice kernel can improve its functionality. Curcuminoids that present in turmeric rhizomes possess high antioxidant activity and heat stability. The objective of this study was to investigate the effects of inlet air temperatures and spray rates of turmeric extract solution on quality attributes of the turmeric extract coated rice (TCR) using the top-spray fluidized bed coating technique. The experimental results have shown that inlet air temperature and spray rate of coating solution strongly affected the final moisture content and percentage of fissured kernel of TCR. Almost all of TCR kernels in the bed cracked when their final moisture content was lower than 11.8% wet basis. However, the head coated rice yield of fissured TCR slightly decreased from that of white rice. The color of TCR was uniform over the entire surface. Texture of cooked TCR insignificantly changed from that of uncoated sample. Increasing spray rate provided higher both total phenolic content (TPC) and total antioxidant capacity (TAC) whilst increasing inlet temperature yielded lower TPC but it did not affect TAC. Retentions of TPC and TAC of TCR after cooking remained higher than 90%.     

Polyphenols content and antioxidant activity of Ghure (unripe grape) marc extract: influence of extraction time,temperature and solvent type

The objective of this study was to optimise the temperature (25–50 °C), time (1–24 h) and the solvent ratio (ethanol/water, 0–100%) for the phenolic compounds extraction of Ghure marc (unripe grape) using response surface methodology. The central composite design (CCD) generated satisfactory models for the optimisation of process variables. The results revealed that the ratio (X₃) was the most significant parameter on total phenolic content (TPC) and antioxidant activity [% 2‐diphenyl‐1‐picrylhydrazyl (DPPH)], and there was a significant correlation between TPC and antioxidant activity. The optimal conditions for temperature and time were 44.93 °C and 19.34 h, respectively, and the ratio of ethanol to water was 70.08, which verified with carrying out confirmatory experiments. Under this condition, TPC and %DPPH were 388.79 mg GAE per 100 g and 91.01, respectively. The results of this study revealed that the Ghure marc can be used as a low‐cost source of natural antioxidant in food.     

Antioxidant Extraction from Mustard (Brassica juncea) Seed Meal Using High‐Intensity Ultrasound

Brassicaceae oilseeds provide feedstocks for the biofuels industry, but value‐added coproducts are necessary to supply financial incentives for increased production. Our objective was to use high‐intensity ultrasound to optimize extraction of antioxidants from mustard (Brassica juncea) seed meal. The ultrasound‐assisted extraction (UAE) variables included temperature, solvent‐to‐material ratio, sonication duration, and EtOH concentration. Extracts were analyzed for total phenolics content (TPC), antioxidant activity, and sinapine content. Conventional extraction using water and 70% EtOH (v/v) at 80 °C for 3×30 min yielded 7.83 ± 0.07 and 8.81 ± 0.17 mg sinapic acid equivalents (SAE)/g meal, respectively. UAE extraction at 40 °C for 30 min yielded similar phenolics content (8.85 ± 0.33 mg SAE/g meal) as conventional hot ethanolic extraction, but required less time and lower temperature. The highest TPC (13.79 ± 0.38 mg SAE/g meal) was in the 7‐d aqueous extracts. Sonicated solutions of pure sinapine and sinapic acid showed 1st‐order reaction kinetics with greater degradation of isolated compounds than those present in extracts. Sinapine contained in extracts showed insignificant (P < 0.05) degradation after 30 min of sonication. Our research indicates that ultrasound treatment can assist the extraction of antioxidants from B. juncea meal by reducing both the temperature and time requirement without significant degradation of the primary antioxidants present.     

The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp

BACKGROUND: This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin–Ciocalteu reaction, and TAA using the ABTS radical reaction. RESULTS: The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L^?1 (P?0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L^?1 (P?0.05) for the conventional pulp. CONCLUSION: TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level. Copyright © 2012 Society of Chemical Industry