Microwave-assisted extraction of phenolic antioxidant compounds from peanut skins

A microwave-assisted extraction system was used to extract phenolic antioxidants from peanut skins. The effects of microwave power (10%, 50%, 90% nominal), irradiation time (30, 90, 150 s) and sample mass (1.5, 2.5, 3.5 g) on total phenolic content (TPC), ORAC (oxygen radical absorbance capacity) level and resveratrol content of peanut skin extracts (PSE) were investigated. Peanut skins were extracted with 37.5 ml of 30% ethanol (EtOH) in water. A response surface method was used to estimate optimum extraction conditions, based on TPC, ORAC level and resveratrol content. The maximum predicted TPC, under the optimised conditions (90% microwave power, 30 s irradiation time and 1.5 g skins), was 143.6 mg gallic acid equivalent (GAE)/g skins. The highest ORAC value was 2789 μmol trolox equivalents (TE)/g skins, which occurred at 90% power, 150 s and 1.5 g of skins. Resveratrol was identified in PSE by LC–MS–MS analysis.     

Potential use of phenolic antioxidants on peanut to control growth and aflatoxin B1 accumulation by Aspergillus flavus and Aspergillus parasiticus

Food‐grade antioxidants: butylated hydroxyanisole (BHA), propyl paraben (PP) and butylated hydroxytoluene (BHT) (10 and 20 mmol g^?1) and all the mixtures of these chemicals were tested for inhibitory activity on the growth of and aflatoxin B₁ (AFB₁) accumulation by Aspergillus parasiticus and A. flavus on irradiated (7 kGy) peanut grains. Also, the influence of these treatments was evaluated in different water conditions (0.982, 0.955, 0.937a_w) at 11 and 35 days of incubation at 28 °C. Water activity (a_w) affected the fungal growth, no fungal development was observed at the highest stress water condition (0.937a_w). Butylated hydroxyanisole at 10 mmol g^?1 level and all the mixtures with PP and/or BHT were significantly effective (P = 0.05) in increasing lag phase and reducing growth rate and colony forming units per gram of peanut of both Aspergillus section Flavi strains and AFB₁ accumulation. The application of BHA at concentrations of 20 mmol g^?1 alone or with PP and/or BHT totally inhibited fungal growth at 11 and 35 days of incubation. The results suggest that the addition of these chemical mixtures on peanut grains at low levels has potential to impact synergically on the control of Aspergillus section Flavi. Copyright © 2007 Society of Chemical Industry     

超声波辅助提取野桂花蜜中多酚的工艺优化

为确定野桂花蜜中多酚化合物提取的最佳工艺参数,以野桂花蜜为主要原料,采用响应面优化野桂花蜜中多酚化合物的超声波辅助提取工艺。在单因素试验的基础上,以超声波时间、超声波温度、料液比、溶剂浓度为自变量,以多酚化合物得率为响应值,进行试验设计,研究自变量与响应值之间的关系。结果表明:优化得出的最佳工艺条件为溶剂浓度62%,料液比1︰10(m︰V),超声波时间21 min,超声波温度54℃。该工艺条件下多酚得率为68.27mg/10g。     

花生红衣补血口服液的研制

贫血是世界公共性营养卫生问题之一,近几年越来越得到人们的重视,以四粒红花生红衣、大枣、木耳为主要原料,根据中医配伍原则,研制出一种具有补血功能的口服液。通过响应面分析确定了最佳配方为:花生红衣提取液0.04%、红枣浓缩汁49%、木耳浓缩汁25%、甜蜜素0.15%、柠檬酸0.03%,其感官得分为92.3分。并对口服液的稳定性进行了研究,结果表明花生红衣补血口服液的热稳定和光稳定性都比较好,在常温下保质期可达2年。     

Note on utilisation of peanut seed testa

Peanut testae (skins, seed coats) are an extremely low value by‐product of peanut‐blanching operations. Their commercial value is $12–20 per ton and their limited use is only as a minor component of cattle feed. Based on world in‐shell peanut production of 29.1 million tons in 1999/2000 and an average skin content of 2.6%, world production of peanut skins can be estimated at over 750 000 tons annually. Research performed to find new uses for peanut skins demonstrated that up to 35% of the oil in the skins can be recovered. In some cases the oil can be a new potential source of behenic and lignoceric acids, which are used in body‐building formulations and as ingredients in shampoos. After removal of the oil the skins were useful for making brandy, liqueur and tea. Peanut skin oil extraction followed by tannin extraction also produces a protein‐enriched product that could find application in mixed feeds for cattle consumption at higher concentrations relative to existing practice. A simple technique was also offered to use the skins in finishing decorative panels. Published in 2003 for SCI by John Wiley & Sons, Ltd.     

Optimization and economic evaluation of pressurized liquid extraction of phenolic compounds from jabuticaba skins

The optimization of the extraction of anthocyanins and other phenolic compounds from jabuticaba skins, a promising Brazilian source of these compounds, was studied using pressurized liquid extraction (PLE). An optimization study was performed using ethanol as a solvent and with extraction pressure (5-10 MPa), temperature (313-393 K) and static extraction time (3-15 min) as independent variables. The optimum PLE conditions for all response variables were estimated; however, PLE conditions resulting in the highest recovery of anthocyanins (5 MPa, 553 K and 9 min of static extraction time) were chosen for comparison with a conventional low-pressure solvent extraction (LPSE). The attributes compared were yield, content of anthocyanins and phenolic compounds and economic feasibility. Similar extraction yields were obtained by LPSE and PLE under optimized conditions; however 2.15 and 1.66-fold more anthocyanins and total phenolic compounds, respectively, were extracted using PLE, while the cost of manufacturing (COM) obtained for the PLE extract was 40-fold lower.     

酶解辅助超声法提取花生红衣原花青素的工艺研究

本试验以花生红衣为原料,纤维素酶辅助超声波提取花生红衣中原花青素,采用单因素和正交试验研究了纤维素酶添加量、料液比、提取温度和提取时间对原花青素得率的影响,并分析其体外抗氧化活性。结果表明:最佳工艺条件为纤维素酶添加量为0.3%,料液比1∶20(m/v),提取时间40 min,提取温度55℃,原花青素得率为10.97%,原花青素提取物对DPPH自由基具有较强的清除作用。     

压榨对酿酒葡萄皮渣酚类物质提取及抗氧化活性的影响

酿酒葡萄皮渣（皮和籽）生物活性物质含量丰富,具有很高的再加工利用价值。对鲜葡萄皮渣进行压榨处理后再干燥,研究压榨对皮渣的酚类物质提取及抗氧化活性的影响。结果表明：压榨处理可以快速降低葡萄皮渣水分含量,缩短干燥时间、提高可溶性膳食纤维提取率。压榨葡萄皮总酚、原花青素的提取量均有所增加,其含量分别为19.56 mg/g和22.64 mg/g。压榨葡萄皮的抗氧化能力高于未压榨葡萄皮,其DPPH、ABTS及羟自由基清除率分别为62.90%、70.18%和41.09%,铁氰化钾还原能力及金属离子螯合能力分别为0.23%和21.33%。压榨籽和皮籽混合物的酚类物质和抗氧化活性则明显降低。抗氧化活性与总酚、原花青素存在显著的相关关系（P＜0.01）。     

莲房多酚提取工艺优化及其抗氧化活性研究

在单因素实验的基础上,通过正交实验优化了热回流提取莲房多酚的工艺,并通过测定其清除ABTS+自由基、DPPH自由基、OH自由基的能力,还原力,亚铁离子螯合活性及对大鼠脑匀浆脂质过氧化的影响,对莲房多酚的抗氧化活性进行综合研究。结果表明,热回流提取莲房多酚的最佳工艺参数为:乙醇浓度50%,料液比1∶25,提取温度80℃,提取时间为2h,最优条件下的得率是5.23%。莲房多酚的体外抗氧化实验表明莲房多酚对DPPH自由基、ABTS+自由基、OH自由基有很强的清除能力,对亚铁离子的螯合活性和还原力均较强,并能显著抑制大鼠脑匀浆脂质过氧化。本研究表明在该优化工艺下提取的莲房多酚具有较强的抗氧化活性。      

不同纯度花生红衣原花青素的制备工艺研究

研究了AB-8大孔吸附树脂分离纯化得到不同纯度花生红衣原花青素的制备工艺,并对产物进行了HPLC-MS分析鉴定。结果表明:最佳分离纯化条件为上样流速0.5 m L/min、洗脱流速1.0 m L/min、洗脱液20%和40%乙醇溶液,解吸后得到的原花青素纯度分别为98.7%和86.2%;此外,不同的收集方式也可得到不同纯度的原花青素;经AB-8大孔吸附树脂分离得到的纯化物均为低聚体原花青素,20%乙醇纯化物的主要成分为A型原花青素二聚体和A型原花青素三聚体,40%乙醇纯化物的主要成分为A型原花青素二聚体和A型原花青素四聚体。     

超声波辅助提取小麦麸皮酚基木聚糖的研究

以小麦麸皮为原料,研究了超声波超声功率、超声时间、碱液质量分数、碱提时间、碱提温度对小麦麸皮中水溶性酚基木聚糖和总酚基木聚糖得率的影响,同时分析了小麦麸皮水溶性酚基木聚糖的抗氧化特性和总酚含量.结果表明,小麦麸皮中酚基木聚糖提取的最佳工艺条件是超声功率300 W,超声时间30 min,碱液质量分数2％,碱提时间2h,碱提温度55℃,在此条件下,酚基木聚糖得率为38.73％,水溶性酚基木聚糖得率为29.05％.对提取的麸皮水溶性酚基木聚糖的抗氧化性的研究表明,水溶性酚基木聚糖对羟自由基有明显的清除作用,并呈现明显的量效关系.水溶性酚基木聚糖的总酚含量为12.27mg/g.     

Minimizing the Negative Flavor Attributes and Evaluating Consumer Acceptance of Chocolate Fortified with Peanut Skin Extracts

In recent years, there has been increased interest in antioxidant‐rich products by consumers wanting to enhance the health benefits of their diet. Chocolate has been identified as a natural source of antioxidant compounds, which resulted in the development of polyphenol‐enriched chocolate products that are now available commercially. This study investigated the use of phenolic compounds extracted from peanut skins as a novel antioxidant source for the enrichment of milk chocolate. The extracts were encapsulated with maltodextrin to lessen their bitterness. Antioxidant potential of the encapsulated peanut skin extracts was evaluated by the 2,2‐diphenyl‐1‐picrylhydrazl radical quenching assay. Encapsulated peanut skins were found to have a corrected Trolox equivalency of 31.1 μmol/g of chocolate up to 0.8% (w/w). To produce a product with an antioxidant content similar to that of dark chocolate yet which maintained the milder flavor of milk chocolate, the best estimate threshold of encapsulated peanut skin extract in chocolate was 0.9 % (w/w) based on the standard method (American Society of Testing Materials; ASTM E‐679). Consumer liking of milk chocolate enhanced by adding subthreshold (0.8 % (w/w)) inclusion levels of encapsulated peanut skin extract was found to be at parity with milk chocolate as a control.     

Pre-bottling use of dehydrated waste grape skins to improve colour,phenolic and aroma composition of red wines

Different dehydrated waste grape skins from the juice industry were added into aged and young red wines as an innovative way of compensating for colour loss before bottling. After addition of grape skins, colour intensity of wines increased a mean 11% and a maximum of 31% with predominance of the red component. Total polyphenols mean increase was 10% with a maximum value of 20%. Analysis of low molecular weight phenolic compounds by HPLC–DAD showed a significant (p < 0.05) content increase of the bioactive compounds gallic acid, (+)-catechin, (−)-epicatechin, and (E)-resveratrol. Anthocyanins content also increased at an average of 50 mg/l. The volatile profile of wines analysed by SBSE–GC–MS was only moderately influenced by the treatments. Mixtures of dehydrated waste grape skins were useful to improve the colour and polyphenol profile of red wines, considering them a useful tool for correcting colour loss before bottling.