Grape seed removal: effect on phenolics,chromatic and organoleptic characteristics of red wine

Winemakers are interested in wines with low bitterness and astringency, and therefore, there is a preference for a higher presence of skin proanthocyanidins in wines. However, the information regarding the effect of reducing or eliminating seed proanthocyanidins from the must or fermenting wine on the characteristics of finished wines is scarce. For this reason, we elaborated a wine using Monastrell grapes from which the seeds had been removed and compared it with a control wine (CW) made from intact grapes. The anthocyanin and proanthocyanidin concentration and profile, and the chromatic and sensory characteristics were studied. The absence of seed proanthocyanidins did not affect anthocyanin concentration, although the proanthocyanidin concentration was 40% lower than in the CW. The copigmentation (CA) study showed that both wines had a similar extent of CA phenomena although colour intensity was higher when seed proanthocyanidins were present. The panellist evaluated the wines elaborated without seeds as being fruitier, less astringent and with an overall higher quality.     

高效液相色谱-质谱联用法测定薏苡仁药材中黄曲霉毒素

目的建立高效液相色谱-质谱联用法(high performance liquid chromatography-masss pectrometer,HPLC-MS)测定薏苡仁中药饮片中黄曲霉毒素B_1、B_2、G_1、G_2的方法,并对比不同产地薏苡仁中黄曲霉毒素含量。方法样品经过免疫亲合柱处理后,采用HPLC-MS进行测定。分析柱为C18柱(50 mm×2.1 mm, 1.8μm),流动相为10 mmol/L醋酸铵溶液-甲醇溶液,梯度洗脱,流速为0.3 mL/min,柱温为25℃。结果黄曲霉毒素B_1在0.26～10.4ng/mL浓度范围内与峰面积值均呈现良好的线性关系(r~2=0.9995),平均加样回收率为75.4%～123.9%,黄曲霉毒素B2在0.0875～3.5 ng/mL浓度范围内与峰面积值均呈现良好的线性关系(r~2=0.9996),平均加样回收率为71.1%～124.2%,黄曲霉毒素G_1在0.295～11.89 ng/mL浓度范围内与峰面积值均呈现良好的线性关系(r~2=0.9995),平均加样回收率为78.9%～112.2%,黄曲霉毒素G2在0.1475～5.9 ng/mL浓度范围内与峰面积值均呈现良好的线性关系(r~2=0.9992),平均加样回收率为73.8%～123.9%。结论该方法准确、可靠、专属性强,通过精确化合物离子监测,可准确的测定薏苡仁中黄曲霉毒素含量。     

Plasma Behavior in a High‐Temperature Noble Gas Plasma Disk‐Shaped MHD Power Generator

R‐θ two‐dimensional numerical simulations have been carried out to clarify the plasma behavior in a high‐temperature noble gas plasma disk‐shaped magnetohydrodynamic (MHD) generator. At low inlet total temperature and high load resistance, the plasma has spiral structure which is similar to the nonuniform structure under the weak noble gas ionization condition in a seed‐plasma MHD generator. As seen in a linear‐shaped Faraday‐type MHD generator, the plasma becomes stable with increase in the inlet total temperature because the coulomb collision of electrons becomes dominant. Even at low inlet total temperature, the ionization instability can be suppressed for low load resistance, because the relatively low electron temperature due to less Joule heating makes the ionization relaxation time longer than plasma residential time.     

山桐子产业在我国的开发利用情况

山桐子作为优良的木本油料树种,近年来受到越来越多的关注。论述了山桐子产业在我国的开发利用情况,主要包括山桐子国家扶持政策、良种选育、人工栽培、山桐子油食用安全性、山桐子油加工工艺及深加工应用情况,以期为山桐子产业的发展提供参考。     

Ultrasound-assisted extraction of oil from Moringa oleifera Lam. seed using various solvents

The present research analyzes the extraction of oil from Moringa oleifera Lam. seed using ultrasound-assisted extraction (UAE) technique under different operating conditions such as temperature, solvent type, and time. Three factors with three levels Box-Behnken response surface design was employed to optimize and investigate the effect of process variables on the response (oil yield). The independent variables showed significant effect on the extraction process. Interactive effects of the extraction process variables were analyzed by Pareto analysis of variance (ANOVA), and second-order polynomial model was used to plot the 3D response surface plot. Optimum extraction conditions for the maximizing the extraction yield of oil (59%) was found to be: temperature of 35°C, solvent type of 2, and time of 20 min. FT-IR was used to analysis the oil. From the results, it can be concluded that the UAE is the effective technique to extract the oil from Moringa oleifera Lam. seed.     

Characterization of the Chemical Composition of Chinese Moringa oleifera Seed Oil

This work focused on physicochemical property assaying, fatty acid composition, triacylglycerol (TAG) profiles, and unsaponifiable matter composition of the Chinese Moringa oleifera seed oil. The results indicated that there was no significant difference in approximate nutritional components between M. oleifera seeds from China and India, while variations in the mineral element contents are significant. Both the Soxhlet extraction method and the aqueous enzymatic extraction method were adopted to extract oil from Chinese M. oleifera seeds. Oil yield obtained using the Soxhlet extraction method was higher than that obtained using the aqueous enzymatic extraction method. While both the iodine value and unsaponifiable matter content of the aqueous enzymatic extracted oil were a little higher than that of the Soxhlet extracted oil. Both oils possess a very low acid value and peroxide value, suggesting their good quality as edible oil. Fatty acid composition results indicated that this oil was especially high in oleic acid. Characterization of the TAG composition was achieved by a two-dimensional high-performance liquid chromatography (HPLC) coupling of nonaqueous reverse-phase and silver ion HPLC with the atmospheric pressure chemical ionization mass spectrometry method. A total of 22 TAG including 16 regioisomers were determined. Composition results of unsaponifiable matters revealed that this oil possesses a number of phytosterols, in which β-sitosterol and stigmasterol are most predominant.     

青海糖茶藨籽油脂肪酸及不皂化物成分分析研究

研究糖茶藨籽油的脂肪酸和不皂化物成分。采用气相色谱-质谱联用法对糖茶藨籽油脂肪酸和不皂化物成分进行分析和鉴定。结果表明:糖茶藨籽油中共鉴定出13种脂肪酸,不饱和脂肪酸占(86.88±0.53)%,其中主要的不饱和脂肪酸为亚油酸、亚麻酸和油酸,相对含量分别为(29.06±1.08)%、(25.85±0.79)%和(19.08±0.76)%;糖茶藨籽油的不皂化物以植物甾醇和萜类化合物为主,其中植醇含量最高,达(40.42±2.54)%,其次为β-谷甾醇。