Optimising germinated conditions to enhance yield of resveratrol content in peanut sprout using response surface methodology

Peanut sprout has associated with enhance the content of a nonflavonoids known as resveratrol, which influences a variety of functions including against cancer, cardiovascular and delaying ageing. Peanut from Liaoning province of China was used as a material to accumulate resveratrol during germination. The individual effects of soaking temperature and time as well as germination temperature, time and humidity on resveratrol accumulation in 5 days germinated peanut were investigated. Then, based on Box–Behnken design, interactive effects of the germination parameters were evaluated by response surface methodology. The optimum conditions were as follows: soaking temperature at 35 °C, soaking time at 8 h, germination temperature at 29 °C, germination humidity at 90%, and germination time at 5 day. Under the optimum condition, resveratrol content reached 32.87 μg g^?1, which was almost 9.78 times higher than that in the peanut which did not germinate.     

响应面优化花生芽中白藜芦醇提取工艺

为提高花生芽中白藜芦醇(Res)提取率,此次试验优化了超声波-纤维素酶法联用提取花生芽中白藜芦醇的工艺。在单因素试验的基础上,进行了响应面优化试验,分析了酶的添加量、料液比和超声波处理温度、时间4个因素对白藜芦醇提取量的影响。结果表明:花生芽中白藜芦醇最优提取工艺为花生芽粉1.000 g,酶添加量7 mg,超声波处理温度50℃,超声波处理时间35 min,料液比1︰35(g/mL)。在此条件下,花生芽中白藜芦醇最大提取率为0.8239mg/g,约是传统乙醇回流法提取率的4.4倍。超声波辅助纤维素酶提取能有效地提高花生芽中白藜芦醇的提取率。     

超声提取花生根中白藜芦醇的工艺研究

以乙醇溶液为溶剂,对超声提取花生根中白藜芦醇的工艺进行了研究。首先,建立了白藜芦醇含量测定的紫外分光光度法。然后,以白藜芦醇的提取率为考察指标,考察了不同乙醇浓度、提取时间、提取温度、料液比对花生根中白藜芦醇提取工艺的影响。通过单因素试验和正交试验确定了最佳超声提取条件:乙醇溶液浓度为80%,提取时间为40min,提取温度为50℃,料液比为m(花生根质量,g):υ(乙醇溶液体积,ml)=1:10。此时白藜芦醇得率为0.192‰。     

花生种衣活性成分提取工艺参数优化

花生种衣富含黄酮类化合物、原花色素和白藜芦醇等多酚活性物质.本研究以花生种衣为原料,通过单因素试验考察乙醇浓度、水浴温度、提取时间和料液比对花生种衣中多酚物质提取效果影响,并通过响应面法对提取多酚工艺加以优化;结果表明,提取多酚最佳工艺条件为:乙醇体积分数55％、料液比1:20、水浴温度60℃、提取时间2h,在此条件下...     

花生发芽过程中基础成分变化及白藜芦醇的诱导富集

以8种花生种子为原料,探究发芽4 d过程中各品种花生发芽率、芽长、基础成分和白藜芦醇含量的变化,并优选出3个品种(花育22、花育25和花育50),分别采用低温、超声、紫外、添加诱导剂苯丙氨酸和水杨酸对白藜芦醇进行富集。结果表明,发芽过程中,各品种发芽率和芽长呈现不同程度的增长,营养成分也发生改变,水分、游离氨基酸均显著增加,粗脂肪、可溶性蛋白总体均显著下降,灰分、粗蛋白和总糖的含量总体上不发生变化,活性成分白藜芦醇的含量也显著增加,最高达144.72 μg/100 g。此外,进一步通过对比3个品种发芽2 d时各诱导处理组与对照组白藜芦醇的含量可知,超声、紫外以及添加苯丙氨酸的处理对发芽过程中白藜芦醇均有显著的富集作用。     

Effects of roasting on phenolics composition and antioxidant activity of peanut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.) kernel flour

The effects of roasting on the phenolics composition and antioxidant activity of peanut (Arachis hypogaea L.) kernel flour were appraised. Peanut kernel flour, with and without skin, were roasted at 160 °C for 10, 20, 30, 40 and 50 min. The resultant changes in the antioxidant activity of roasted peanut kernel flour were assessed by the determinations of total phenolics, 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging capacity, percent inhibition of linoleic acid oxidation and thiobarbituric acid test and compared with those of unroasted kernel flour. It was observed that roasting significantly (p < 0.05) increased the antioxidant activity of the peanut kernel flour. HPLC analysis revealed the detection of three phenolic acids (p-hydroxybenzoic, chlorogenic, p-coumaric), two flavonols (quercetin, kaempferol), and a stilbene (resveratrol) both in the roasted and unroasted samples. In peanut kernel flour without skin, the contents of the phenolics increased in the initial roasting phase, however, decreased gradually in the later phase (>20 min of roasting time). In contrast, over the course of heating, the amounts of phenolics were noted to be slightly increased in the peanut kernel flour with skin; the most significant (p < 0.05) increase occurred in the concentration of p-coumaric acid and quercetin at 30, 40, and 50 min of roasting. The results of this study reveal that optimum roasting time should be sought to enhancing the antioxidant capacity and phenolics concentration in peanut kernel flour.     

Effects of soaking and aeration treatment on γ-aminobutyric acid accumulation in germinated soybean (<Emphasis Type="Italic">Glycine max</Emphasis> L.)

Effects of soaking temperature, soaking time, opportunity of aeration treatment, culture temperature, pH value, and air flow rate on γ-aminobutyric acid (GABA) accumulation during germination of soybean (Glycine max (L.) Merr.) were investigated in this study. The objective of this study was to optimize the culture conditions of GABA production in germinated soybeans. Results showed that soaking at 30 °C for 4 h was found to be the most effective soaking ways that made soybean seeds have sufficient moisture, satisfactory germination, and GABA accumulation. The suitable stress opportunity was dark culture for 2 days with distilled water and then hypoxia stress in aerated culture medium for 2 days in a dark incubator at 30 °C. Under these conditions, the maximum GABA content (2.24 mg/g DW) was 3.5 times higher than the initial sample of aeration treatment (0 h) and 12.5 times higher than the raw material. Correlation analysis also revealed that GABA accumulation was significantly correlated to the corresponding physiochemical indexes (p < 0.01). Box-Behnken experimental analysis showed that the optimal condition with aeration treatment for GABA accumulation in germinated soybean was at a temperature of 30.5 °C, a pH value of 4.1, and an air flow rate of 0.9 L/min; the predicted highest GABA yield was 2.60 mg/g DW, which was 15.2 times higher than raw seeds. Analysis of variance and confirmatory trials for the regression model suggested that the model can quite exactly predict GABA accumulation in soybean during germination.     

发芽花生生产工艺、发芽过程中营养成分变化及加工利用研究进展

发芽花生因风味独特、口感脆嫩、富含白藜芦醇,具有抗氧化、抗肥胖、降血脂等多种功能作用而备受关注。本文综述了发芽花生的生产工艺,比较了不同花生品种原料对发芽花生中白藜芦醇含量的影响,系统分析了花生发芽过程中营养成分的变化规律,详细阐述了国内外发芽花生在食品中的加工利用现状及应用前景,在现有研究基础上,对现阶段存在的问题进行了分析展望,以期推动发芽花生产业健康快速发展,同时为发芽花生深入研究提供理论基础,供科研工作者进行参考。     

Optimization of extraction conditions for improving solubility of peanut protein concentrates by response surface methodology

By ethanol precipitation and physical separation procedures, the peanut protein concentrate (PPC) was isolated from defatted peanut flour (DPF) and the extraction times were determined as twice. The effects of liquid-to-solid ratio, ethanol concentration and reaction temperature on the solubility of PPC were studied for the primary extraction and the later two factors were studied for the second extraction by response surface methodology (RSM). The results showed that for both of the second-order models, the coefficient determination (R²) was good and a liquid-to-solid ratio of 11.79: 1 (v/w), an ethanol concentration of 85 mL/100 mL, an extract temperature of 36.35 °C for the primary extraction and a corresponding list of variables of 8:1 (v/w), 97.50 mL/100 mL and 38.40 °C for the secondary extraction were found to be optimal for the protein extraction from defatted peanut flour. By means of additional experiments, the adequacy of the model was confirmed.     

超声波辅助SDS反胶束前萃花生蛋白研究

采用SDS(十二烷基磺酸钠)/异辛烷―正辛醇反胶束体系萃取花生蛋白,并采用超声波辅助萃取,主要研究全脂花生粉加入量、缓冲溶液pH值、萃取时间、萃取温度、超声波功率、KCl浓度、SDS浓度、Wo对蛋白萃取率影响。设计正交实验优化萃取工艺,结果表明,最优前萃工艺条件为:花生粉加入量0.015 g/mL、缓冲溶液pH值9、萃取时间40 min、萃取温度35℃、超声波功率270 W、KCl浓度0.25 mol/L、SDS浓度0.07 g/mL、Wo为24;在此条件下,花生蛋白萃取率为89.62%±1.15%。     

超声辅助提取花生粕中植酸工艺优化

用响应面法研究超声波辅助提取花生粕中植酸的最佳工艺,考察超声温度、超声时间、超声功率、液料比和盐酸浓度5 个因素对植酸提取率的影响。经响应面优化的超声波辅助提取植酸的优化工艺条件：超声温度40℃、超声时间24min、超声功率72W、液料比11:1(mL/g)、盐酸浓度0.01mol/L,此时提取率为1.48%,与模型预测值1.44% 相差不到3%。实验结果说明超声波方法可较好地应用于花生粕中植酸的提取,同时得到一个能较好预测实验结果的提取模型方程。     

Effect of time and temperature on bioactive compounds in germinated Brazilian soybean cultivar BRS 258

The objective was to determine the effect of time and temperature on the concentration of bioactive compounds during germination of Brazilian soybean cultivar BRS 258. The concentration of bioactive compounds was optimized using Response Surface Methodology, with a 2² central composite rotational design and germination time and temperature as independent variables. Germination was carried out in a germination chamber, using paper in trays containing 500 g of seeds. Germination temperature and time modified the concentrations of bioactive compounds within the ranges studied. An increase in germination time at 25 °C decreased the concentration of Bowman–Birk inhibitor, lectin and lipoxygenase. After 63 h of germination, a temperature increase from 20 °C to 30 °C resulted in a decrease of lipoxygenase activity by 22.5%. Optimal increases in the concentrations of isoflavone aglycones (daidzein and genistein) and saponin glycosides were observed with a 63 h germination time at 30 °C. Both germination time and temperature had an influence on the composition and concentration of bioactive compounds in germinated soybean flour. Equations determined can be used to predict concentrations of bioactive compounds in germinated soybeans in relation to climate changes and thus optimize their potential use in human health and nutrition.     

Accumulation of γ-aminobutyric acid in germinated soybean (<Emphasis Type="Italic">Glycine max</Emphasis> L.) in relation to glutamate decarboxylase and diamine oxidase activity induced by additives under hypoxia

High levels of γ-aminobutyric acid (GABA) accumulate in plant tissues under various stresses and exogenous additives. The purpose of this research is to provide an effective finding that can prove a rapid accumulation of GABA in germinated soybean (Glycine max L.) in response to different additives under hypoxia. Hypoxia-induced GABA accumulation in soybean embryo resulted in part from polyamine oxidation. Response to different concentration of glutamate (Glu), pyridoxal phosphate, arginine, CuCl₂, NaCl, and CaCl₂, a significant difference including GABA accumulation, changes of Glutamate decarboxylase (GAD), and Diamine oxidase activity (DAO) activity in germinated soybean under hypoxia occurred (p < 0.05) and the maximum accumulation of GABA were 4.07, 3.02, 3.50, 3.26, 4.00, and 3.30 g kg⁻¹ DW respectively, which were significantly higher than those germinated soybean under normal culture (CK) and hypoxia culture (CK₀) (p < 0.05). The GAD and DAO have different distributions in cotyledon and embryo of germinated soybean, and the enzyme activity mainly located in embryo of germinated soybean. Germinated soybean is a good resource of GABA-rich food. Different additives have significant effects on GABA production, among which Glu and NaCl are ideal material for GABA accumulation.     

Accumulating mechanism of γ‐aminobutyric acid in soybean (Glycine max L.) during germination

γ‐aminobutyric acid (GABA) has been found accumulating significantly in soybean seeds during germination. However, the mechanism of the accumulating process is not clear. Therefore, gene expression, enzyme activity and metabolites associated with GABA shunt in ZH 13 soybean during germination were analysed in this paper. GABA content in 5‐day germinated soybean was 0.26 ± 0.016 mg g^?1 DW, which was equivalent to six times concentration of original soybean. The GAD activity has a positive effect on the accumulation of GABA, as well as the GABA‐T activity was found to play a significant role in the degradation of GABA. The expression levels of GmGAD and GmGABA‐T may affect the GABA content by regulating the respective enzyme activities. In conclusion, upregulation of GAD and downregulation of GABA‐T may cause the accumulation of GABA.     

响应面法优化发芽豇豆积累γ-氨基丁酸工艺条件的研究

以豇豆为原料,利用发芽过程积累γ-氨基丁酸。通过单因素及响应面试验研究浸泡温度和时间、发芽温度和时间等因素对γ-氨基丁酸积累量的影响,确定豇豆最佳发芽工艺参数。结果表明:在浸泡温度34℃和浸泡时间25h、发芽温度33℃和发芽时间24h的条件下,豇豆中γ-氨基丁酸的含量达到203.53mg/100g,是未发芽豇豆中γ-氨基丁酸的7.48倍。同时建立浸泡温度和时间、发芽温度和时间与γ-氨基丁酸含量之间的二次多项式模型,该模型可以很好地预测豇豆在发芽过程中的γ-氨基丁酸含量。     

白藜芦醇提取工艺的研究

本研究探讨了虎杖中白藜芦醇的提取工艺和稳定性。在虎杖中,白藜芦醇对光、干热、湿热和氧化剂均敏感;通过实验得出回流、超声、固定床连续提取的提取率分别0.201%、0.423%、0.513%;同时利用正交设计得出固定床连续提取的最佳工艺为溶剂为30%乙醇,固定床连续提取速度为8ml/min·kg,浸泡时间为12h,溶剂用量为8倍量。     

The effect and mechanism of ultrasonic treatment on the postharvest texture of shiitake mushrooms (Lentinula edodes)

Fresh shiitake mushrooms (Lentinula edodes) are prone to texture softening and quality decline during storage. We investigated the effects of prestorage ultrasonic treatment on the textural changes of the mushrooms during storage. We monitored physiological parameters, such as respiration intensity, weight loss, cell wall composition and resistance‐related enzymes activity. The hardness of the ultrasonic‐treated (40 kHz, 80 W L^?1, 20 min) mushrooms after 12 days of storage (0.461 N) was significantly higher than the untreated control group (0.286 N). The weight loss and respiration intensity of the ultrasonic‐treated group were significantly lower, whereas the cell wall contents, including glucan and chitin, were significantly higher. The ultrasonic‐treated mushrooms also had higher phenylalanine ammonia lyase, superoxide dismutase and catalase activities. Thus, ultrasound preserves the texture of mushrooms by reducing metabolic rate, maintaining cell wall compositions, activating the activity of SOD and maintaining the activity of PAL and CAT.     

Improvement in sprouted wheat flour functionality: effect of time,temperature and elicitation

This study was aimed at optimising conditions of wheat germination (temperature, time of sprouting and elicitation) to improve its phenolics content, antioxidative capacity and nutritional quality. Total phenolics and antioxidant potential were improved most effectively after 4 days of sprouting at 20 °C. The highest reducing ability and the ability to quench free radicals (1.24 mg Trolox equivalent (TE) g^?1 d.m. and 0.38 mg TE g ^?1 d.m., respectively) were determined for 4‐day‐old control and willow + yeast elicited sprouts germinated at 20 °C. The kinetics of starch and protein mobilisation were affected by sprouting conditions. The highest protein digestibility was found for 2‐day‐old sprouts germinated at 20 °C, whereas the lowest for 4‐day‐old sprouts germinated at 25 °C. Starch was more effectively mobilised during germination at 25 °C. Sprouting conditions were found to effectively modify the quality of sprouts. A key role was ascribed to time and temperature of sprouting, whereas the effect of elicitation was marginal.     

Kinetics of Acid Hydrolysis of Defatted Peanut Flour

The kinetics of hydrolysis of defatted peanut flour as affected by treatment at 100, 110 and 120°C in 3N and 5N HCl were determined. Rates of hydrolysis of protein and destruction of reducing sugars were rapid at 120°C and in 5N HCl. About 90% of total amino acids were released after 4 hr. The overall rate of reaction followed second-order kinetics as monitored by the generation of free amino acids over time. This relationship was reliable for all acid and temperature treatment conditions when the extent of hydrolysis was less than 80%. The rate of hydrolysis of peanut protein was about 2.2 times faster for every 10°C increase. Hydrolysis in 3N HCl was about 2.3 times faster than in 3N HCl at the same temperature. The activation energy was =24 kcal mol^?1. The rate of liberation of individual amino acids with respect to temperature and HCl concentration, however, varied.     

白藜芦醇共轭亚油酸酯凝胶油的制备及表征

以花生油为基料油,利用9c,11t-共轭亚油酸酯化改性白藜芦醇,并与蜂蜡复配制备白藜芦醇共轭亚油酸酯凝胶油,探讨蜂蜡与白藜芦醇共轭亚油酸酯添加量、蜂蜡与白藜芦醇共轭亚油酸酯质量比、加热温度、加热时间和冷却温度对白藜芦醇共轭亚油酸酯凝胶油持油性的影响,并对其基本理化性能、热性能、组成成分进行表征。结果表明：蜂蜡与白藜芦醇共轭亚油酸酯添加量12%、蜂蜡与白藜芦醇共轭亚油酸酯质量比7∶3、加热温度70 ℃、加热时间20 min、冷却温度4 ℃,白藜芦醇共轭亚油酸酯凝胶油的持油性最高可达98.6%;与蜂蜡凝胶油相比黏度降低30%、亮度降低、减少了α型晶体,并发现白藜芦醇共轭亚油酸酯凝胶油无反式脂肪酸生成。