The Use of Microwave and Pulsed Electric Field as a Pretreatment Step in Ultrasonic Extraction of Polyphenols from Defatted Hemp Seed Cake (Cannabis sativa) Using Response Surface Methodology

The use of microwave and pulsed electric field (PEF) processing to optimize polyphenol extraction from defatted hemp seed cake in mixed solvent of methanol, acetone and water (MAW, 7:7:6 v/v/v) was investigated using the Box-Behnken response surface method. A variables combination for microwave processing of time, microwave power and liquid to solid (L:S) ratio and for PEF (ethanol concentration, time, frequency and voltage) were used in the investigation. Following microwave or PEF treatments, the polyphenols were extracted from the samples under ultrasound with fixed variables (200 W of ultrasonic power, water bath of 70 °C and 20 min of extraction time). The measured responses were total phenolics (TP), total flavonoids (TF), DPPH˙ scavenging activity and ferric reducing/antioxidant power (FRAP). The optimum variables combination for microwave processing (5 min treatment time, L:S ratio of 6, 700 W power and volume 30 mL) and PEF-assisted extraction (voltage (30 V), frequency (30 Hz), ethanol concentration (10 %) and time (10 s)) resulted in maximum yields in all measured responses. The results suggest that microwave processing and PEF can be integrated in processing defatted hemp seed cake to enhance polyphenol extraction and maximize the yield.     

Reutilization of mango byproducts: study of the effect of extraction solvent and temperature on their antioxidant properties

Mango biowastes, obtained after processing, contain large amounts of compounds with antioxidant activity that can be reused to reduce their environmental impact. The present study evaluates the effect of solvent (methanol, ethanol, acetone, water, methanol:water [1:1], ethanol:water [1:1], and acetone:water [1:1]), and temperature (25, 50, and 75 °C) on the efficiency of the extraction of antioxidants from mango peel and seed. Among the factors optimized, extraction solvent was the most important. The solvents that best obtained extracts with high antioxidant capacity were methanol, methanol:water, ethanol:water, and acetone:water (β-carotene test, antioxidant activity coefficient 173 to 926; thiobarbituric acid reactive substances test, inhibition ratio 15% to 89%; 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid ABTS(·+); and 2,2-diphenyl-1-picrylhydrazyl DPPH· scavenging, 7 to 22 and 8 to 28 g trolox equivalent antioxidant capacity [TE] per 100 g mango biowaste on a dry matter basis [DW]). Similarly, the flavonoid (0.21 to 1.4 g (+)-catechin equivalents per 100 g DW), tannin (3.8 to 14 g tannic acid equivalents per 100 g DW), and proanthocyanidin (0.23 to 7.8 g leucoanthocyanidin equivalents per 100 g DW) content was highest in the peel extracts obtained with methanol, ethanol:water, or acetone:water and in the seed extracts obtained with methanol or acetone:water. From the perspective of food security, it is advisable to choose ethanol (which also has a notable antioxidant content), ethanol:water, or acetone:water, as they are all solvents that can be used in compliance with good manufacturing practice. In general, increasing temperature improves the capacity of the extracts obtained from mango peel and seed to inhibit lipid peroxidation; however, its effect on the extraction of phytochemical compounds or on the capacity of the extracts to scavenge free radicals was negligible in comparison to that of the solvent. PRACTICAL APPLICATION: There are many antioxidant compounds in mango peel and seed, and they could be used as a natural and very inexpensive alternative to synthetic food additives. However, the conditions in which the antioxidants are extracted must be optimized. This work proves that conditions such as extraction solvent or temperature have a crucial impact on obtaining extracts rich in antioxidants from mango biowastes.     

Antibacterial and antioxidant activities of grape (Vitis vinifera) seed extracts

Grape seeds were powdered and the fatty material was extracted in a Soxhlet extractor with petroleum ether (60–80 °C) for 6 h. The defatted powder was extracted with acetone:water:acetic acid (90:9.5:0.5) and methanol:water:acetic acid (90:9.5:0.5) for 8 h each separately. The extracts were concentrated under vacuum to obtain crude extracts, which were analyzed by high performance liquid chromatography with UV detection at 280 nm. Monomeric procyanidin was found to be the major compound being at 48 and 40% in acetone:water:acetic acid (90:9.5:0.5) and methanol:water:acetic acid (90:9.5:0.5) extracts, respectively. These extracts were tested for antibacterial activity by pour plate method against Bacillus cereus, Bacillus coagulans, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. It was found that, Gram-positive bacteria were completely inhibited at 850–1000 ppm, while Gram-negative bacteria were inhibited at 1250–1500 ppm concentration. Radical-scavenging activity of grape seed extracts of acetone:water:acetic acid (90:9.5:0.5) and methanol:water:acetic acid (90:9.5:0.5) were compared with BHA at 25 and 50 ppm concentrations by HPLC method using 1, 1-diphenyl-2-picrylhydrazyl (DPPH). The antioxidant capacities of grape seed extracts were determined by the formation of phosphomolybdenum complex method. It was found that acetone:water:acetic acid (90:9.5:0.5) extract was better radical scavenger than methanol:water:acetic acid (90:9.5:0.5) extract.     

Optimization of Extraction of Bioactive Compounds from Black Carrot Using Response Surface Methodology (RSM)

In this study, optimum conditions for the extraction of black carrot anthocyanins were determined by response surface methodology. Central composite design of extraction factors (pH 2.5–6.5, temperature 4–72 °C, solvent/solid ratio 5:1–25:1 v/w, ethanol/water ratio 0:100–100:0?v/v) was generated as two replicates. Total phenolic content, total monomeric anthocyanin content, polymeric color, total antioxidant activity, and anthocyanin composition determined by high-performance liquid chromatography were used as responses. Except for color analysis, higher temperature, solid/solvent ratio, and ethanol concentration were observed to increase the extraction yield. However, polymeric color results were found to have minimum values at lower pH and solid/solvent ratio, lower or moderate temperature, and higher ethanol concentration. Optimum extraction conditions were found as follows: 50 °C, pH 3.5, solvent solid ratio 10:1 (v/w), and ethanol/water ratio 75:25 (v/v) when all responses were considered. The validation of the optimum conditions for black carrot extraction was performed at specified values.     

阴香花中原花青素的提取工艺

优化阴香花中原花青素的提取工艺。以经冷冻干燥、粉碎与80 目过筛的阴香花粉末为供试物料,丙酮- 乙醇混合提取,提取液以铁盐催化显色,测定反应体系的吸光度。在提取溶剂体积分数、pH值、料液比、温度 及时间单因素试验基础上进行正交试验优化提取条件。结果表明：以体积分数70%的混合液（70%丙酮-70%乙醇 （3∶2））为提取溶剂、pH 2、料液比1∶7.5（g/mL）、提取温度50 ℃、提取时间2 h提取阴香花原花青素的效果为 佳,以此参数条件下提取3 次原花青素的提取率为95.37%、得率为9.02%。丙酮是阴香花原花青素提取的有效溶 剂,采用优化提取条件可有效的提取阴香花原花青素。     

溶剂法提取柠檬种籽油脂的研究

以丙酮做提取剂,用索氏抽提法提取柠檬籽油,并对其提取条件进行了研究和优化.首先通过单因素试验,对水浴温度、提取时间、料液比3个因素分别进行研究,确定了各因素对柠檬籽油得率的影响趋势.在此基础上,用正交试验优化得出最佳提取条件是:温度为85℃,时间为3.5h,物料比是1∶10,得到柠檬籽的出油率为36.03％;对出油率影响的主次关系为:料液比＞提取时间＞水浴温度.柠檬籽油为淡黄色液体,具有较好的香味.此提取方法稳定可靠,能为柠檬籽油的提取提供参考.     

Antioxidant activity of extracts from Gevuina avellana and Rosa rubiginosa defatted seeds

Chilean hazelnuts (Gevuina avellana Mol) and mosqueta rose (Rosa aff. Rubiginosa L.) meals were extracted with methanol, ethanol, acidified water, acetone, butanol, diethyl ether and ethyl acetate. Ethanol and methanol extracted the highest amount of soluble substances from both seed meals. The highest concentration of total polyphenols was found in the ethanolic extracts, although that of acetone from R. rubiginosa presented similar values. The antioxidant activity of the extracts evaluated by the β-carotene assay and with as hydrogen radical scavenging ability showed that the activity of the butanol and methanol extracts from G. avellana was comparable to those of synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The 2,2,-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging activity of the G. avellana methanol, ethanol and water extracts was 2–3 times lower than those of BHT and BHA, respectively. The activity of R. rubiginosa extracts ranged from that of BHT for the water extracts to 80% inhibition in respect to control achieved with the ethanol extracts.     

Extraction optimization of a hydrocolloid extract from cress seed (Lepidium sativum) using response surface methodology

Extraction conditions for maximum values of yield, viscosity and minimum protein content of hydrocolloid extract from Lepidium sativum seed were investigated using response surface methodology. A Central Composite Face Design (CCFD) with four independent variables: temperature (25–85 °C); pH (3–10); extraction time (10–25 min) and water to seed ratio (10:1–80:1) was used to study the response variables (yield, viscosity and protein content). Data analysis showed that all the variables significantly (p < 0.05) affected the extraction yield and viscosity, whereas the effect of water to seed ratio on protein content was not significant (p > 0.05). Applying a desirability function method the optimum parameters were: extraction temperature 35 °C, pH 10, water to seed ratio of 30:1 and an extraction time of 15 min. At this optimum point, apparent viscosity, yield and protein content were 0.2 Pa s, 6.46% and 0.57%, respectively. The experimental values were very close to the predicted values and were not statistically different (p > 0.05).     

Pressurized green liquid extraction of betalains and phenolic compounds from Opuntia stricta var. Dillenii whole fruit: Process optimization and biological activities of green extracts

The Opuntia Stricta var. Dillenii's prickly pears are an underutilized fruits, which provide a great source of betalains (mainly, betacyanins) and phenolic compounds (phenolic acids and flavonoids) that could play an important role in health-promotion. This study focuses on the optimization of process for the green extraction of betalains and phenolic compounds from Opuntia stricta var. Dillenii's whole fruits by Pressurized liquid extraction (PLE), using a response surface methodology (RSM) by a central composite design (CCD) in order to obtain rich extracts in betalains and phenolic compounds with the similar profile of the original one found in O. dillenii fruits (avoiding any degradation of these compounds during the extraction process) with proven biological activities. For PLE optimization, the ethanol volume in water (0–100%, v/v) and the temperature (25–65°C) were selected as independent variables. The identification and quantification of the individual bioactive compounds of the obtained green extracts were done by HPLC-DAD-ESI/MS and HPLC-DAD-ESI/QTOF and their biological activities were determined by in vitro tests, as: the antioxidant activity by the ORAC method and the anti-inflammatory activity by the hyaluronidase inhibition method. Ethanol volume in water (%, v/v) was the variable with most significant (p ≤ 0.05) effect in the target responses (bioactive content and biological activities). The best results were obtained at 50% ethanol in water (v/v) and 25°C temperature (run 10) obtaining extracts with betalains as 2.34 ± 0.18 mg of betanin/g dry weight, 2.51 ± 0.04 mg of 5′´-O-E-sinapoyl-2′-apyosil-phyllocactin/g dry weight, 2.32 ± 0.19 mg of neobetanin/g dry weight and phenolic compounds, 2.08 ± 0.07 mg of piscicid acid/g dry weight and 0.25 ± 0.02 mg of isorhamnetin glucoxyl-rhamnosyl-pentoside (IG2) /g dry weight. The betalain and phenolic profile of the PLE extracts was quite similar to the profile from the conventional extraction, but PLE extraction process enhanced the extraction of some bioactives as neobetanin (39%) andpiscidic acid (124%). All employed PLE process CCD combinations significantly upgrade the in vitro biological activities (antioxidant and anti-inflammatory) of the Opuntia stricta var. Dillenii's PLE green extracts.     

响应面法优化沙苑子中黄酮类化合物超声辅助提取工艺

为了获得沙苑子黄酮类化合物的最佳提取工艺参数,选取液料比、超声温度、沙苑子粒度、超声时间作为实验因素,以提取物的吸光度为响应值,采用响应面实验设计法对工艺参数进行优化。结果表明：沙苑子黄酮类丙酮提取物在323nm处有最大吸光值;60%丙酮为最佳提取剂;最佳工艺参数为粒度120目,超声温度50℃,超声时间60min,液料比40：1（mL/g）,粗提率为16.19%。环境扫描电镜显示,超声处理后沙苑子粉的表面出现了蜂窝状形貌图,从而促使胞内物质溶出,提高了提取率。     

A Fast Determination of Chlorophylls in Barley Grass Juice Powder Using HPLC Fused-Core Column Technology and HPTLC

This work presents a novel approach to qualitative and quantitative evaluation of chlorophyll content in food supplement using simple and fast separation techniques (high performance liquid chromatography (HPLC) and high performance thin layer chromatography (HPTLC)). For the first time, an Ascentis® Express C-18 HPLC column (100?×?4.6 mm; 2.7 μm), based on fused-core particles, was utilised for the analysis of chlorophyll a and chlorophyll b in green young barley grass juice powder extracts. The mobile phase was composed of methanol, water and ethyl acetate of 40:10:50 (v/v/v) at a flow rate of 1.5 mL/min. Chlorophylls were separated in time less than 6 min. The extraction procedure was optimised by using of 90 % of acetone in water, and the method was validated. The method precision was found in the range of 1.15–2.85 %, and the method recovery was established at three concentration levels. Calibration graphs were linear in the range of 0.75–25.5 mg/L, with correlation coefficients r ²?=?0.99958 for chlorophyll a and r ²?=?0.99961 for chlorophyll b. The comparative HPTLC fingerprint analysis of three samples from different continents showed only slight qualitative differences between the particular samples. The results demonstrated that the proposed methods can be used as fast and powerful techniques for the characterisation of barley juice extracts in quality control.     

Optimization of extraction process of crude polysaccharides from boat-fruited sterculia seeds by response surface methodology

Response surface methodology (RSM) was applied to optimize the extraction of crude polysaccharides from boat-fruited sterculia seeds. A central composite design was used for experimental design and analysis of the results to obtain the optimal extraction conditions. Extraction temperature, pH, extraction time and water to seed ratio were found to have a significant influence on the yield and purity of the extracted crude polysaccharides, while the three other factors except the water to seed ratio also significantly affected the relative viscosity. Based on the RSM analysis, optimum conditions were: temperature 60–65 °C, time 2.3–3.1 h, pH at 7.0 and water to seed ratio at 75:1. Under the optimized conditions, the experimental values were in close agreement with values predicted by the model. The crude polysaccharides prepared under optimum conditions contained 58.2% total carbohydrates (including uronic acids), 20% proteins, 9% moisture and 4.5% ash. The crude polysaccharides consisted of glucose (22.6%), rhamnose (10.0%), arabinose (7.9%), galactose (5.0%), xylose (0.8%) and galacturonic acid (11.8%).     

Utilisation Potential of Feijoa Fruit Wastes as Ingredients for Functional Foods

Feijoa fruits have high antioxidant activity as they contain significant concentrations of polyphenols (PPs), carotenoids and vitamins. This study evaluates the colour, pH, total soluble solids (TSS), pectin fibre content, total extractable PP content (TEPC) and total antioxidant activity of the extracts generated from the fruit wastes (primarily skin and some flesh) remaining after feijoa flesh consumption. Extractions were conducted at room temperature and 50 °C using accelerated solvent extraction technology and different extraction media [water, acidified water (containing citric acid, pH?3.5), and 30, 50 and 80 % (v/v) aqueous ethanol solutions]. Results show that the composition and properties of the extracts depend on the extraction media and, to a lesser extent, on the extraction temperature. The 80 % ethanolic extract was bright green in colour. The water and acidified water extracts showed more browning than the ethanolic extracts, suggesting possible detrimental sensory impacts for food applications. The TSS decreased in the order of 80, 50 and 30 % ethanolic and water extracts. The 50 % ethanolic extract had the highest TEPC and antioxidant activity at both extraction temperatures, which was supported by high performance liquid chromatography analyses. The extracts produced with solutions containing less ethanol, especially water extracts, had higher pectin contents. The UA content of the extract produced using water alone was the highest (5.56 % as GalA) at 20 °C, whilst that produced using 30 % ethanol solution was the highest (3.90 % as GalA) at 50 °C. Higher extraction temperature (50 °C) resulted in lower pectin contents. These results demonstrate the potential of feijoa waste extracts, especially 50 and 80 % ethanolic extracts, as ingredients for functional food applications.     

Factors affecting sample extraction in the liquid chromatographic determination of organic acids in papaya and pineapple

A solvent extraction method was developed for the extraction of organic acids (oxalic, citric, tartaric, L-malic, quinic, succinic and fumaric acids) in papaya and pineapple. Central composite design “2ⁿ + star” was used in order to optimise the following extraction parameters: number of extractions, composition of the extractant mixture, extraction time and extraction temperature. Optimal conditions for extraction were determined by experimental design using response surface methodology. The results suggest that the extractant composition is statistically the most significant factor and that the optimum values for the variables are: three (number de extractions), water as extractant, 60 min (extraction time) and 65 °C (extraction temperature). The separation and determination of the organic acids was carried out by liquid chromatography with UV–Vis detection.     

Residues of grape (Vitis vinifera L.) seed oil production as a valuable source of phenolic antioxidants

Phenolic compounds of seven grape seed samples originating from mechanical seed oil extraction were identified and quantified by HPLC–DAD before (intact seeds) and after (press residue) the oil recovery process. Total amounts of all identified compounds ranged from 4.81 (‘Cabernet Mitos’) to 19.12 g/kg (‘Schwarzriesling’) of defatted dry matter (DM; ‘Schwarzriesling’) for integral grape seeds, whereas their content in the press residues ranged from 2.80 (‘Cabernet Mitos’) to 13.76 g/kg of defatted DM (‘Spätburgunder’). This is the first study presenting comprehensive data on the contents of individual phenolic compounds comprising all polyphenolic subclasses of press residues from grape seed oil production also covering the determination of the antioxidant activities of each subclass (Folin–Ciocalteu, FRAP and TEAC assays). Additionally, the effects of different solvents on the yields of phenolic compounds were determined. Maximum yields were obtained using methanol/0.1% HCl (v:v), water [75 °C] and a mixture of ethanol and water [3:1; v:v], respectively, whereas pure ethanol resulted in poor polyphenol extraction. The results of the present study confirm the press residues of grape seed oil production still to be a rich source of polyphenolics with strong antioxidant activity.     

Simultaneous Determination of Nine Plant Growth Regulators in Navel Oranges by Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry

A new and reliable method for the simultaneous determination of nine plant growth regulators in navel oranges was developed by liquid chromatography-triple quadrupole tandem mass (QqQ LC/MS). Extraction was performed by acetone and ethyl acetate (v/v, 1:2) with microwave-assisted extraction technique. Cleanup of extracts was performed with dispersive-solid phase extraction (d-SPE) using active carbon as the sorbent. The identification of each analyte was established by chromatographic retention time, analyte-specific fragmentation patterns, and relative peak area ratios of precursor/production pairs. Under the optimized conditions, the average recoveries (six replicates), except for methyl naphthacetate, were in the range of 61.0–109.4 % and limits of detection ranging from 0.01 to 162.2 μg kg^?1. The results demonstrated that the developed QqQ LC/MS, extraction and purification method is highly effective for analyzing trace amounts of target plant growth regulators (PGRs) in navel orange samples.     

USE OF A MODIFIED UREA GEL ISOELECTRIC FOCUSING METHOD FOR SPECIES IDENTIFICATION OF RAW OR BOILED WHITE,PINK, AND ROCK SHRIMP1

Isoelectric focusing (IEF) polyacrylamide gel containing an 80% pH 4–6.5 and 20% pH 3–10 ampholyte mixture greatly improved protein banding pattern for species identification of water extracts of raw pink, white and rock shrimp compared with the system using only the pH 3–10 range ampholyte. Identification of a specific species in mixture samples was achieved by the detection of water-extractable shrimp specific protein bands present in the gel. Sodium dodecyl sulfate (SDS) was a better protein extractant than water for cooked shrimp. Both water and SDS extracts of cooked shrimp showed specific protein banding patterns and improved resolution for species identification.     

Optimization of Processing Parameters for the Preparation of Flounder Frame Protein Product

Flounder frame was used as a raw material for the preparation of protein product. Processing parameters were evaluated using both fresh and frozen ground frames. The results indicate the following optima: (1) pH of extraction medium, ii; (2) extraction time, 60 min; (3) volume to weight ratio, 10: 1; (4) extraction temperature, 23°C. Isoelectric precipitation was conducted at pH 5 using KCI or H₃PO₄. Results indicate that NaOH was more effective than Ca(OH)₂ in solubilizing frame protein at pH 11. Ground frozen flounder frames gave a 10% decrease in protein extractability when compared to fresh frames using NaOH as the extractant and a 22% decrease when Ca(OH)₂ was employed as the extractant. Approximately 70% of the protein is recovered using the NaOH-HCI system.     

五味子果籽中木脂素与原花青素的RCO辅助优化提取的研究

研究旨在采用随机质心映射法(Random-Centroid Optimization,RCO)对五味子果籽中木脂素与原花青素进行辅助优化提取。以总木脂素含量、总原花青素含量、DPPH自由基清除率以及得率等4个指标作为提取目标,从提取液乙醇溶液中乙醇的浓度、溶液的pH、提取的液料比以及提取时间等4个影响因素考察最佳提取条件。结果显示,以总木脂素含量为提取目标的最佳提取条件为:乙醇溶液中乙醇的浓度为75%、溶液的pH为4.8、提取的液料比为9:1、时间为4.0h,其中乙醇溶液中乙醇的浓度对总木脂素含量的影响最为显著;以总原花青素含量为提取目标的最佳提取条件为:乙醇溶液中乙醇的浓度为65%、溶液的pH为5.2、提取的液料比为9:1、时间为8.0h,其中溶液的pH对总原花青素含量的影响最为显著。以总木脂素和总花青素含量为提取目标得到的提取物具有较强的抗氧化性。