紫薯醋发酵工艺优化及品质分析

采用单因素结合响应面法优化紫薯醋酸发酵条件,同时发酵得到紫薯醋和紫薯色素回添醋,并对2种醋和紫薯原料的品种指标进行测定及比较。优化后的紫薯醋酸发酵条件为发酵时间11 d、初始酒度7.35%vol、装液量28%,此条件下,总酸含量为6.92 g/100g。与原发酵工艺相比,紫薯色素回添醋除总糖和维生素含量较低外,其总酸、总酯、总多酚、总黄酮、花青素含量和抗氧化能力均显著优于紫薯醋(P<0.05)。与紫薯原料中的活性成分相比,紫薯醋中总多酚、总黄酮、花青素含量较原料分别损失75.59%、63.63%和72.75%,采用新发酵工艺可使损失率分别降低10.34%、15.61%和42.93%。挥发性成分分析显示2种紫薯醋中鉴定出的挥发性成分的化合物数量相差不大,种类却有较大差异。同时,紫薯花青素的提取过程会导致一些对醋品香气有贡献的化合物损失。     

DPPH法测定紫红薯提取物清除自由基的能力

通过DPPH法测定紫红薯色素抗氧化、清除自由基的能力.试验表明,随着紫红薯色素浓度的增大,其抗氧化能力也相应提高.与VC和芦丁比较,紫红薯色素抗氧化、除自由基能力低于VC,但略高于芦丁.紫红薯色素清除DPPH自由基的半抑制量为163 mg/mL,其清除自由基能力AE为0.006 1.     

Phenolic content and antioxidant capacity of Philippine sweet potato (Ipomoea batatas) varieties

The study established baseline data on the total phenolic content and antioxidant activities of five sweet potato (Ipomoea batatas) varieties grown in the Philippines including Dakol, Emelda, Haponita, PSBSP and Violet. Phenolic content ranged from 192.7 to 1159.0 mg gallic acid equivalent (GAE) /100 g dry sample. Antioxidant activities were highest for Dakol, with an EC₅₀ value of 0.7 ± 0.2 mg/mL for DPPH radical scavenging activity, 2.5 ± 0.5 mg/mL for reducing power, and 2.4 ± 0.3 mg/mL for iron-chelating ability, on a dry basis. However, Haponita had the best inhibitory action on linoleic acid oxidation at 99.4 ± 0.9%. Methanolic sweet potato extracts had higher radical scavenging activity, reducing power and oxidation inhibition than α-tocopherol and higher iron-chelating capacity than ethylenediamine tetraacetic acid (EDTA). Significant (∗P < 0.05) negative correlation was observed between total phenolic content and the EC₅₀ for DPPH radical scavenging activity (R = −0.826), reducing power (R = −0.876) and iron-chelating capacity (R = -0.800).     

甘薯水溶性紫色素清除DPPH自由基活性研究

从紫A4甘薯果肉及皮中分别提取水溶性紫色素,测定其黄酮含量并研究了其清除DPPH自由基的动力学性质,并与BHA、BHT比较其抗氧化能力。结果表明:紫A4甘薯皮中比果肉中含有更多的黄酮,分别为107.7mg/kg;135.6mg/kg;并且其清除DPPH自由基速度更快,而果肉提取色素抗氧化能力最强(ARP为4.76),两者抗氧化能力堪与BHA、BHT相媲美。     

Flavonoid content of several vegetables and their antioxidant activity

Several vegetables were selected to study their flavonoid contents and antioxidant activities. The results showed that both green and purple leaves of sweet potatoes (185.01 and 426.82 mg kg⁻¹ respectively) and the outer leaves of onion (264.03 mg kg⁻¹) possessed higher amounts of flavonoids, and more than 85% of free radical scavenging activities were evaluated by using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), superoxide and hydroxyl radicals. In addition, green leaves of sweet potatoes and the outer leaves of onion showed higher reducing power and higher antioxidant activity in a linoleic acid system as compared to cabbage, spinach, potato and crown daisy. Blanching of green leaves of sweet potatoes for 30–60 s retained more flavonoids and higher free radical scavenging activities as compared to more than 1 min of blanching. The storage test showed that green leaves of sweet potatoes stored at 4–10 °C maintained better quality than those stored at room temperature. © 2000 Society of Chemical Industry     

不同品种紫薯抗氧化物质及体外抗氧化活性比较

为比较福建产区主栽紫薯抗氧化物质成分含量及其体外抗氧化活性,对7个不同品种紫薯中总酚、总黄酮、总花色苷及花青素组分进行了分析,并测定其清除自由基活性。结果表明:福宁紫3号紫薯中所含抗氧化活性成分如总酚、总黄酮、总花色苷和花青素的含量均为最高。通过高效液相色谱法分析测定紫薯中含有的花青素单体主要为飞燕草色素、芍药色素和矢车菊色素,不同品种紫薯中花青素组成及含量表现出的一定的差异性。福宁紫3号紫薯表现出较强的自由基清除活性,0.5 mg·L-1紫薯鲜样提取液DPPH自由基、OH自由基及ABTS清除率分别达到88.4%、49.1%、90.1%。 相对于其他品种,福宁紫3号紫薯在抗氧化活性成分含量及体外抗氧化活性方面表现最佳。     

Antioxidant activity of vinegar melanoidins

Melanoidins, the brown polymers formed through Maillard reaction during vinegar process, are one of major high-molecular-weight fractions of vinegar. In this study the antioxidant activity of high-molecular-weight fractions (MW > 3500 Da) separated from ethanol-supernatant extraction of concentrated Zhenjiang aromatic vinegar was evaluated by different in vitro tests: the DPPH radical scavenging activity, the reducing power, total phenolic content, and the inhibitory effect on hydroxyl radical. Each individual fraction was found to have antioxidant activity in all the model systems tested. The high-molecular-weight fractions of vinegar (MW > 3500 Da) were separated into different fractions by DEAE-Sepharose fast flow. The fractions eluted by 0.2 mol/L NaCl and 0.3 mol/L NaCl with higher phenolic content have stronger DPPH radical scavenging activity and reducing power. Antioxidant activity in hydroxyl radical system was not correlated with phenolic content. Two phases which have stronger effects on Maillard reaction products (MRPs) in production process were examined. Decoction, storing and aging may affect vinegar’s antioxidant activity. The present results support the concept that melanoidins formed during vinegar production process may have health promotion activity.     

三种甘薯发酵酒抗氧化特性研究

通过测定渝紫263、紫薯王以及豫薯王三种甘薯发酵酒中理化指标和酚类物质含量,以及对铁离子还原能力、DPPH自由基清除能力、羟基自由基清除能力,研究了3种甘薯发酵酒的抗氧化特性。结果显示,三种甘薯发酵酒总酚含量分别为247.5 mg/L、200.5 mg/L、63.5 mg/L,渝紫263发酵酒和紫薯王发酵酒的各项酚类物质含量及铁离子还原能力、DPPH自由基清除能力均明显高于豫薯王发酵酒,且三种甘薯发酵酒的羟基自由基清除均明显高于对照组VC。表明三种甘薯发酵酒均具有较强的抗氧化特性。     

Physicochemical and functional characteristics of a novel fermented pepper (Capsiccum annuum L.) leaves-based beverage using lactic acid bacteria

Two lactic acid bacteria (LAB), Lactobacillus homohiochii JBCC 25 and L. homohiochii JBCC 46, were isolated from a naturally fermented vinegar beverage. Fermented pepper leaves beverage (FPLB-3) which indicated good assessment based on a sensory evaluation test was prepared using the mixed strains. The prepared FPLB-3 showed enhanced functional aspects based on γ-aminobutyric acid (23.6 mg%), total polyphenol (2,828.2 gallic acid equivalents μg/g), and flavonoid contents (2,008.8 catechin equivalents μg/g). Moreover, FPLB-3 showed significantly stronger scavenging activities for the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (84.6%) and superoxide radical (90.8%) and outstanding inhibitory activity against α-glucosidase of 65.9% at 50 mg/mL compared to the raw material. Based on the results, the newly developed FPLB using Wongi-1 pepper leaves and Lactobacillus is expected to be a novel functional food with natural antioxidant and antidiabetic capacities.     

不同发酵剂对红枣果酒发酵品质的影响

选取4种不同的发酵剂（帝伯仕LA DELICIEUSE活性干酵母（LA-D）、安琪酵母、清香型酒曲和薯曲）分别对红枣进行发酵,通过对感官评分、酒精度、色度以及发酵过程中营养成分含量变化和抗氧化活性等指标进行比较,筛选出一种性能较优的发酵剂。结果表明,LA-D酵母发酵酒的色泽透亮,为琥珀色,苦味较小,枣香味浓郁,感官评分达88.5分,酒精度为10.6%vol;在发酵第12天,VC含量为213.37 mg/100 mL、总黄酮含量为3.49 mg/mL、氨基酸态氮含量为933.3 mg/100 mL,均高于其他三种酵母发酵酒,总多酚含量为0.212 mg/mL,仅次于清香型酒曲发酵酒。枣酒的抗氧化性实验结果表明,在发酵末期,LA-D酵母发酵酒的还原力、羟基、超氧阴离子、DPPH自由基清除率分别为2.425、77.38%、88.75%、92.8%。通过以上实验,分析得出LA-D酵母是最适合红枣果酒发酵的酵母。     

不同熟化方式对速冻熟紫薯品质的影响

为深入研究冻前不同熟化方式对速冻熟紫薯品质的影响,本实验以‘紫罗兰’紫薯为原料,采用蒸制、微波制和烤制3种熟化方式处理速冻熟紫薯,并对挥发性成分、色泽、微观结构、花色苷含量和抗氧化活性等进行分析。结果表明,不同熟化方式能够引起速冻熟紫薯中挥发性风味物质的重新分布,提供更多的芳香气味和独特的风味。熟化处理使速冻熟紫薯内组织结构发生变化,使其更易于消化,同时不同熟化处理紫薯花色苷含量也有显著差异,其中蒸制熟紫薯达4.12 mg/g,与鲜紫薯（3.36 mg/g）相比显著提高（P<0.05）。经液相色谱串联质谱（liquid chromatography tandem mass spectrometry,LC-MS/MS）分析鉴定出的紫薯花色苷共有六大类,主要是芍药色素和矢车菊素,蒸制熟紫薯中芍药花素占比最大,达到总量的84.12%,较好地保留了紫薯营养成分和色泽。此外,熟化处理还提高了速冻熟紫薯中花色苷在胃肠消化过程中的释放量,进而显著提高了其抗氧化活性（1,1-二苯基-2-三硝基苯肼自由基清除率、2,2-联氮基双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率和O2-·清除率）,...     

Antioxidant capacity of japchae,Korean stir-fried sweet potato noodles with vegetables

Antioxidant capacities of japchae, a Korean traditional food were investigated. Japchae showed concentration dependent radical scavenging abilities with half maximal inhibitory concentration values (IC₅₀) of 0.68 and 1.36 mg/mL from DPPH and ABTS assays, respectively. Positive correlations were observed between radical scavenging effects and the contents of total polyphenol (TPC), retinol, β-carotene, and ascorbic acid. Lipid peroxidation was inhibited by japchae with IC₅₀ values of 1.49 and 1.40 mg/mL based on ferric thiocyanate (FTC) and thiobarbituric acid reactive substances (TBARS) assays, respectively.     

挤压重组紫薯米工艺优化 及其抗氧化活性研究

以籼米为主要原料,并添加紫薯粉制备挤压重组紫薯米。主要选取紫薯粉添加量、挤压温度、物料水分含量3个试验因素,以花色苷含量、质构品质和感官评分作为综合指标,进行单因素及响应面优化试验。获得最佳工艺参数为:紫薯粉添加量为10%、挤压温度为80 ℃、水分含量为26%。该工艺条件下获得的挤压重组紫薯米呈现亮紫色,且综合得分最高为71.08±0.79分。体外抗氧化活性试验结果表明,挤压重组紫薯米对DPPH和ABTS的清除率分别为86.71%、87.55%,显示其良好的抗氧化特性。     

Evaluation of reducing power and radical scavenging activities of water and ethanol extracts from sumac (Rhus coriaria L.)

The purpose of this study was to determine the reducing power, metal chelating, and radical scavenging capabilities of water and ethanol extracts of sumac (Rhus coriaria L.), comparatively. The water and ethanol extracts of sumac were evaluated for their radical scavenging activities by means of the DPPH and DMPD assays. Water extract of sumac (R. coriaria L.) scavenged radicals effectively with EC₅₀ values of 36.4 ??g/ml for DPPH free radical and 44.7 ??g/ml for DMPD cation radical. Similarly, the total reducing power of water extract was found higher than ethanol extract in both potassium ferricyanide reduction (FRAP) and cupric ions reduction capacity methods (CUPRAC). 2,2′-Bipyridine was used to determine the metal chelating activity and the result of water extract was found higher than ethanol extract. Total phenolic and total flavonoid contents of both extracts were studied as well. The values of water extract were found to be higher than that of ethanol extract. The present study found that water extracts of sumac (R. coriaria L.) have effective antioxidant and radical scavenging activities as compared to ethanol extracts.     

镇江香醋抗氧化活性成分来源分析

文中研究了镇江香醋生产过程中抗氧化性成分酚类、黄酮类化合物含量及DPPH自由基清除活性的变化,并分析了总酚、总黄酮与DPPH自由基清除活性的相关性。研究表明,在醋酸发酵阶段,镇江香醋总酚含量及总黄酮含量开始明显增加。露底封醅阶段和煎煮过程对镇江香醋DPPH自由基清除作用有较明显的影响。总酚含量与总黄酮含量与DPPH自由基清除活性有较高的相关性,相关系数分别为0 9334和0 935 3。     

Potato juice fermented with Lactobacillus casei as a probiotic functional beverage

This study was conducted to evaluate probiotic potato juice as a potential substrate for the production of Lactobacillus casei, and the change in the functionality of potato juice was monitored during fermentation. L. casei grew well in potato juice without nutrient supplementation, and lactic acid bacteria of fermented ‘Haryoung’ juice reached 1.7×10⁹ CFU/mL after a 48 h fermentation. DPPH radical scavenging activities of the potato juices decreased after a 72 h fermentation, but fermented colored potato juice still maintained >50% radical scavenging activity. The survival rate of L. casei fermented in’ Haryoung’ juice was 89.0% after exposure to an acidic condition, and L. casei in all fermented potato juice samples showed the ability (50–85%) to survive in the presence of bile. These results suggest that fermented potato juice might serve as a probiotic functional beverage for vegetarians or consumers who are allergic to dairy products.     

In Vitro Antioxidant Effects of Flavonoids of Sweet Potato Vines

Flavonoids of sweet potato vines (FSPV) were examined for their antioxidant effects in vitro. The scavenging capacities of FSPV on 1,1-diphenyl 2-picrylhydrazyl (DPPH), superoxide anion radical, and hydroxyl radical were measured, and their antioxidant activity in a linoleic acid model system was studied using thiobarbituric acid (TBA) method. The results showed that FSPV had a strong scavenging effect on DPPH. Their scavenging activity on superoxide radicals was stronger than that of rutin, and the scavenging activity on hydroxyl radical was higher than that of rutin and vitamin C. Moreover, FSPV had strong antioxidant activities in the linoleic acid model system.     

茶多酚红薯粉条的研制及其抗氧化活性评价

本文考察了茶多酚的添加量和添加时机对红薯粉条断条率、碘蓝值、感官品质、质构特性的影响,并以面条为对照,探讨了粉条对茶多酚分别在干燥常温贮藏和鲜湿冷冻贮藏条件下的保留率和自由基清除率的影响效果。结果发现,糊化前添加茶多酚所制红薯粉条品质普遍优于糊化后添加,茶多酚在粉条中的最适添加量为每100 g红薯淀粉中添加0.15 g。经60 d贮藏后,干燥常温贮藏条件下粉条中茶多酚的保留率为60.73%,自由基清除率降幅为16.29%;鲜湿冷冻贮藏条件下粉条中茶多酚的保留率为71.54%,自由基清除率降幅为10.38%。而且,粉条对两种贮藏条件下的茶多酚含量及活性保护作用均明显优于面条。     

蜂巢醋液态发酵工艺及其抗氧化活性研究

研究首次将蜂巢引入食醋的液态发酵工艺,优化获得了蜂巢醋液态发酵的最佳工艺条件:起始糖度5.33%,酵母活化液0.10%,酒精度5.0%,醋酸发酵温度35℃。在此条件下制备的蜂巢醋由于发酵原料和菌种单一,在可溶性固形物、总糖、香气、滋味等方面低于传统固态发酵产品,而在色泽、体态和风味典型性等方面较优。此外,该蜂巢醋DPPH自由基清除能力(33.29%)和总抗氧化能力(2252.63mmol·g-1)均显著低于固态发酵(66.25%,5092.63mmol·g-1)产品,这主要归因于和固态发酵峰巢醋总黄酮和总多酚(0.71%,2.33%)相比,液态发酵蜂巢醋总黄酮和总多酚含量(0.38%,1.20%)较低。     

Effects of genotype and treatment on the antioxidant activity of sweet potato in Taiwan

Six genotypes of sweet potato commercially available in Taiwan, including TNG57, TNG66, TNG68, TYY1, RP and WP, were used as samples in this study of the effects of steaming and kneading with pre-steaming treatments on the antioxidant components and antioxidant properties of methanolic extracts. Steam treatment increased the total phenols contents of all genotypes (2–13 times), flavonoids content of RP (1.3 times) and anthocyanins contents of RP and WP (5–6 times). Steam treatment also increased the reducing power and scavenging DPPH radical effect of sweet potato flours. For the methanolic extracts of steamed and kneaded flours, reducing powers were 0.02–1.70 at 5.0 mg ml⁻¹ and the scavenging effects on DPPH radicals were 19–92% at 2.5 mg ml⁻¹. Both showed the order of RP > WP > TYY1 and TNG66 > TNG57 and TNG68. However, the chelating effect of the six genotypes at 1.0 mg ml⁻¹ ranged from 50% to 73%. Contents of total phenols, flavonoids, and anthocyanins of sweet potato flours were significantly positively correlated with the reducing power and scavenging DPPH radical effects. After steaming and kneading treatments, RP showed the highest increase in the contents of total phenols, flavonoids and anthocyanins among the six genotypes studied.