Batch foam recovery of sporamin from sweet potato

The major sweet potato root protein, sporamin (which comprises about 80–90% of the total protein mass in the sweet potato) easily foams in a bubble/foam-fractionation column using air as the carrier gas. Control of that foam fractionation process is readily achieved by adjusting two variables: bulk solution pH and gas superficial velocity. Varying these parameters has an important role in the recovery of sporamin in the foam. Changes in the pH of the bulk solution can control the partitioning of sporamin in the foam phase from that in the bulk phase. A change in pH will also affect the amount of foam generated. The pH varied between 2.0 and 10.0 and the air superficial velocities (V₀) ranged between 1.5 and 4.3 cm/s. It was observed in these ranges that, as the pH increased, the total foamate volume decreased, but the foamate protein (mainly sporamin) concentration increased. On the other hand, the total foamate volume increased significantly as the air superficial velocity increased, but the foamate concentration decreased slightly. The minimum residual protein concentration occurred at pH 3.0 and V_o = 1.5 cm/s. On the other hand, the maximum protein mass recovery occurred at pH 3.0 and at V_o = 4.3 cm/s.     

改性高粱秸秆对磷酸根的吸附性能研究

将改性高粱秸秆用于磷酸根的吸附,研究了时间、酸度、温度以及改性高粱秸秆用量等因素对其吸附性能的影响。结果表明,在常温下,改性高粱秸秆对磷酸根具有良好的吸附性能,吸附时间快。改性高粱秸秆对磷酸根的吸附符合Langmuir和Freundli-ch吸附等温方程及准二级动力学方程,吸附过程以单分子层物理吸附为主。     

超声波法提取紫甘薯叶总黄酮的工艺研究

采用超声波提取法,以总黄酮含量为考察指标,利用单因素试验法对影响总黄酮提取率的因素进行了分析,然后通过正交试验确定紫甘薯叶总黄酮的最佳工艺条件。研究表明,影响紫甘薯叶总黄酮提取率的主次因素为:溶剂pH值溶剂的浓度料液比提取时间。紫甘薯叶总黄酮的最佳提取工艺为:乙醇体积分数80%,料液比1∶40(W/V),提取时间30 min,提取溶剂pH 9。在此条件下甘薯叶中总黄酮提取率为8.22%。     

Microprobing the molecular spatial distribution and structural architecture of feed‐type sorghum seed tissue (Sorghum Bicolor L.) using the synchrotron radiation infrared microspectroscopy technique

Sorghum seed (Sorghum bicolor L.) has unique degradation and fermentation behaviours compared with other cereal grains such as wheat, barley and corn. This may be related to its cell and cell‐wall architecture. The advanced synchrotron radiation infrared microspectroscopy (SR‐IMS) technique enables the study of cell or living cell biochemistry within cellular dimensions. The objective of this study was to use the SR‐IMS imaging technique to microprobe molecular spatial distribution and cell architecture of the sorghum seed tissue comprehensively. High‐density mapping was carried out using SR‐IMS on beamline U2B at the National Synchrotron Light Source (Brookhaven National Laboratory, NY, USA). Molecular images were systematically recorded from the outside to the inside of the seed tissue under various chemical functional groups and their ratios [peaks at ～1725 (carbonyl C=O ester), 1650 (amide I), 1657 (protein secondary structure α‐helix), 1628 (protein secondary structure β‐sheet), 1550 (amide II), 1515 (aromatic compounds of lignin), 1428, 1371, 1245 (cellulosic compounds in plant seed tissue), 1025 (non‐structural CHO, starch granules), 1246 (cellulosic material), 1160 (CHO), 1150 (CHO), 1080 (CHO), 930 (CHO), 860 (CHO), 3350 (OH and NH stretching), 2960 (CH₃ anti‐symmetric), 2929 (CH₂ anti‐symmetric), 2877 (CH₃ symmetric) and 2848 cm^?1 (CH₂ asymmetric)]. The relative protein secondary structure α‐helix to β‐sheet ratio image, protein amide I to starch granule ratio image, and anti‐symmetric CH₃ to CH₂ ratio image were also investigated within the intact sorghum seed tissue. The results showed unique cell architecture, and the molecular spatial distribution and intensity in the sorghum seed tissue (which were analyzed through microprobe molecular imaging) were generated using SR‐IMS. This imaging technique and methodology has high potential and could be used for scientists to develop specific cereal grain varieties with targeted food and feed quality, and can also be used to monitor the degree of grain maturity, grain damage, the fate of organic contaminants and the effect of chemical treatment on plant and grain seeds.     

高粱籽粒中多酚类物质的傅立叶变换近红外光谱分析

利用高效液相色谱(HPLC)法测定高粱籽粒中阿魏酸、原儿茶醛和花青素的含量,比色法测定总酚、总黄酮、缩合单宁的含量;运用偏最小二乘法建立NIR光谱与HPLC法和比色法分析值之间的多元校正模型,预测高粱籽粒中主要酚类物质的含量.结果表明,各成分近红外预测值与实测值之间的校正模型相关系数(R)、内部交叉验证均方差(RMSECV)、最佳主因子数分别为:总酚0.9737, 0.288, 4;总黄酮0.9660, 0.00671, 8;缩合单宁0.9558, 0.0289, 6;阿魏酸0.9818, 0.0391, 6;原儿茶醛0.9979, 0.0118, 5;花青素0.9977, 0.0523, 4;预测相对偏差(RSEP)分别为:总酚6.99%、总黄酮4.54%、 缩合单宁7.13%、阿魏酸2.68%、原儿茶醛5.46%、 花青素5.81%.结果表明,模型对样品NIR的预测值与其相应的化学值有较好的相关性,此模型可用来预测高粱籽粒中的各酚类物质的含量,在高粱优质育种和品质分析中具有广泛的应用价值.     

Hβ分子筛催化甜高粱秆汁转化制呋喃类化合物

以γ-丁内酯为溶剂,研究了Hβ分子筛催化富含蔗糖、葡萄糖和果糖的甜高粱秆汁转化制呋喃类化合物（5-羟甲基糠醛或糠醛）的性能。结果表明,甜高粱秆汁在Hβ分子筛上主要转化为5-羟甲基糠醛,而含糖量相同的模型甜高粱秆汁在相同的反应条件下,主要产物却是糠醛。²⁷Al 固体核磁结果表明,甜高粱秆汁中的微量碱性金属钾等能与Hβ分子筛发生离子交换,导致Hβ分子筛上六配位铝转变为四配位铝;因为六碳糖生成糠醛需要Hβ分子筛上具备合适的铝配位环境,而离子交换引起铝配位状态的变化,导致了甜高粱秆汁在Hβ分子筛上的主要产物是5-羟甲基糠醛。     

Evaluation of Anthocyanin Profile and Color in Sweet Cherry Wine: Effect of Sinapic Acid and Grape Tannins during Aging

Cherries are rich in bioactive phenolic compounds and are often fermented into cherry wines. The degradation of anthocyanins during storage will cause color deterioration. The study aimed to utilize sinapic acid and grape tannins in cherry wine to maintain a high fraction in the colored forms of anthocyanins, in order to maximize the color intensity, the latter being associated with good product quality. The effects on the anthocyanin profile and on color parameters of copigments, utilizing spectral measurement combined with UPLC-MS quantitative analysis, have been evaluated in sweet cherry wines. The copigmentation effect of sinapic acid and grape tannin was accompanied by the bathochromic shift and the hyperchromic effect, which lead to an increase in color intensity (lower L*, higher a* and b*). During the aging process, sinapic and grape tannin increased the content of pyranoanthocyanins in cherry wine, especially the addition of sinapic acid makes the cherry wine generate 10-syringyl-pyranocyanidin-3-rutinoside. These results demonstrate that sinapic acid is suitable for adding before alcohol fermentation, while grape tannins can be added before aging.     

快速毛细管气相色谱用于香料混合物的分析

通过GC Method Translation软件转化分析条件,建立了快速毛细管GC分析香料混合物的方法,并将该方法用于甜橙油(植物精油)和烟用香精的分析。结果表明,在保持相同分离效果的前提下,香料混合物样品、甜橙油和烟用香精的分析时间分别由76 min,91 min和52 min缩短至6.87 min,8.62 min和4.95 min。     

Triterpenoid Saponins from the Cultivar “Green Elf” of Pittosporum tenuifolium

Four oleanane-type glycosides were isolated from a horticultural cultivar “Green Elf” of the endemic Pittosporum tenuifolium (Pittosporaceae) from New Zealand: three acylated barringtogenol C glycosides from the leaves, with two previously undescribed 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, 3-O-β-d-galactopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and the known 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C (Eryngioside L). From the roots, the known 3-O-β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyloleanolic acid (Sandrosaponin X) was identified. Their structures were elucidated by spectroscopic methods including 1D- and 2D-NMR experiments and mass spectrometry (ESI-MS). According to their structural similarities with gymnemic acids, the inhibitory activities on the sweet taste TAS1R2/TAS1R3 receptor of an aqueous ethanolic extract of the leaves and roots, a crude saponin mixture, 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and Eryngioside L were evaluated.     

甜高粱茎秆生产燃料乙醇

本文对甜高粱茎秆原料的贮藏、汁液液态发酵、茎秆直接粉碎固态发酵以及榨汁后剩余的秆渣预处理同步糖化发酵4个方面的研究情况进行了综述,重点论述了甜高粱茎秆生产燃料乙醇的瓶颈问题即原料的贮藏和秆渣木质纤维素预处理技术.提出了一种更经济合理的甜高粱茎秆生产燃料乙醇工艺流程.