响应面法优化微波钝化玛咖黑芥子酶活

探讨微波处理在钝化玛咖黑芥子酶相对酶活研究中的应用。通过单因素试验考察微波强度、处理时间以及料液比3个主要因素对玛咖黑芥子酶相对酶活和芥子油苷的影响。以黑芥子酶相对酶活为响应值,进行响应面分析(response surface methodology,RSM)和优化,建立微波钝化玛咖黑芥子酶相对酶活的回归模型。结果显示：在微波强度14W/g、料液比2:1条件下处理60s,玛咖黑芥子酶相对酶活几乎完全丧失。与传统热水烫漂相比,在有效钝化黑芥子酶相对酶活的前提下,玛咖芥子油苷损失率下降28%,VC损失率下降21%,蛋白质含量无显著变化。     

玛咖浸泡酒工艺研究

为填补天然保健植物玛咖用于酒类产品加工研究方面的空白,进行玛咖浸泡酒工艺条件研究。以乙醇体积分数、液固比、时间3个因素进行响应优化,并以总生物碱和芥子油苷为指标,研究玛咖浸泡酒的最佳工艺。结果表明：玛咖浸泡酒的最佳提取工艺为乙醇体积分数55%、液固比40:1(mL/g)、存放时间145d,此条件下产品的生物碱、芥子油苷响应指标理论值分别可达0.47%和0.15%。     

微生物发酵改善菜籽粕品质的研究

采用实验室筛选的菌种混合固态发酵菜籽粕,比较菜籽粕发酵前后硫甙、粗蛋白质、菜籽肽、乳酸含量以及蛋白质体外消化率的变化.结果表明,菜籽粕中的硫甙降解率为53.4%,粗蛋白质含量从39.99%提高到45.84%,菜籽肽含量由2.48%提高到10.58%,氨基酸的组成和含量也有一定的变化和提高,蛋白质的快速体外消化率提高了1.94%,有益代谢产物乳酸的含量由1.03%提高到2.53%.     

7 种十字花科种子中黑芥子酶降解油菜籽饼粕中硫苷的产物比较分析

比较7 种十字花科植物种子中的黑芥子酶的活性,利用气相色谱-质谱法（gas chromatography-massspectrometry,GC-MS）分别测定这7 种黑芥子酶降解油菜籽饼粕中硫代葡萄糖苷（简称硫苷）的产物组分和相对含量。结果表明：7 种来源的黑芥子酶比活力存在差异（P＜0.05）,比活力由高到低依次为西兰花籽黑芥子酶（broccoli seeds myrosinase,BSm）、油菜籽黑芥子酶（rape seeds myrosinase,RPSm）、白菜籽黑芥子酶（whitecabbage seeds myrosinase,WCSm）、萝卜籽黑芥子酶（radish seeds myrosinase,RDSm）、芥蓝籽黑芥子酶（kaleseeds myrosinase,KSm）、甘蓝籽黑芥子酶（cabbage seeds myrosinase,CSm）和芥菜籽黑芥子酶（mustard seedsmyrosinase,MSm）。GC-MS比较分析7 种黑芥子酶降解油菜籽饼粕中硫苷的产物发现,RPSm降解产物有6 种,即1-丁烯基-4-异硫氰酸酯、烯丙基异硫氰酸酯、2-苯乙基异硫氰酸酯、苯丙腈、致甲状腺肿素和2,1-苯并异恶唑。CSm降解产物中1-丁烯基-4-异硫氰酸酯含量最高（33.22%）,RPSm次之,含量为32.20%,而MSm降解产物中未检测到。WCSm、KSm、MSm和CSm降解产物中检测到新组分丁基异硫氰酸酯。与RPSm降解产物相比,其他6 种黑芥子酶降解产物中恶唑类及腈类物质种类增多,有4 种恶唑类和3 种腈类,但降解产物中未检测到2,1-苯并恶唑。不同来源的黑芥子酶在相同环境下降解油菜籽饼粕中的硫苷的产物种类和相对含量存在明显差异,虽RPSm活性低于BSm,但其降解产物中恶唑类及腈类种类最少,含量最低,是较好的降解油菜籽饼粕中硫苷的酶源。     

Influence of Fermentation Conditions on Glucosinolates, Ascorbigen, and Ascorbic Acid Content in White Cabbage (Brassica oleracea var. capitata cv. Taler) Cultivated in Different Seasons

ABSTRACT:  The content of glucosinolates (GLS), ascorbigen, and ascorbic acid in white cabbage ( Brassica oleracea var. capitata cv. Taler) cultivated in different seasons (summer and winter) was determined, before and after spontaneous and starter-induced fermentation. Different salt concentrations (0.5% NaCl or 1.5% NaCl) were used for sauerkraut production. Glucoiberin, sinigrin, and glucobrassicin were dominating in raw white cabbage cultivated either in winter or summer seasons. Ascorbigen precursor, glucobrassicin, was found higher in cabbage cultivated in winter (2.54 μmol/g dw) than those grown in summer (1.83 μmol/g dw). Cabbage fermented for 7 d was found to contain only traces of some GLS irrespective of the fermentation conditions used. Ascorbigen synthesis occurred during white cabbage fermentation. Brining cabbage at low salt concentration (0.5% NaCl) improved ascorbigen content in sauerkraut after 7 d of fermentation at 25 °C. The highest ascorbigen concentration was observed in low-sodium (0.5% NaCl) sauerkraut produced from cabbage cultivated in winter submitted to either natural (109.0 μmol/100 g dw) or starter-induced fermentation (108.3 and 104.6 μmol/100 g dw in cabbages fermented by L. plantarum and L. mesenteroides , respectively). Ascorbic acid content was found higher in cabbage cultivated in summer and fermentation process led to significant reductions. Therefore, the selection of cabbages with high glucobrassicin content and the production of low-sodium sauerkrauts may provide enhanced health benefits towards prevention of chronic diseases.     

菜籽粕脱毒方法及其特点

简要概括了菜籽粕脱毒技术的研究现状,详细介绍了各种脱毒方法的机理及特点等。     

Glucosinolate profiles of international rapeseed lines (Brassica napus and Brassica campestris)

Seed samples from a range of international rapeseed lines (Brassica napus L and B campestris L) were analysed for glucosinolate content using high performance liquid chromatography (HPLC). This analytical method provided a total profile consisting of eight different glucosinolates, including those used to define the Canola standard. The data indicated that broad categories of distinct glucosinolate profiles existed among the seed lines analysed. Indole glucosinolate content, expressed as a percentage of total glucosinolate content, was higher in the low glucosinolate lines of B napus. The actual contents of all eight glucosinolates in the seed were variable, particularly gluconapin, glucobrassicanapin and progoitrin. The importance of this HPLC procedure in facilitating selection for high or low contents of individual glucosinolates is discussed.     

Drought and Subsequent Soil Flooding Affect the Growth and Metabolism of Savoy Cabbage

An important factor of current climate change is water availability, with both droughts and flooding becoming more frequent. Effects of individual stresses on plant traits are well studied, although less is known about the impacts of sequences of different stresses. We used savoy cabbage to study the consequences of control conditions (well-watered) versus continuous drought versus drought followed by soil flooding and a potential recovery phase on shoot growth and leaf metabolism. Under continuous drought, plants produced less than half of the shoot biomass compared to controls, but had a >20% higher water use efficiency. In the soil flooding treatment, plants exhibited the poorest growth performance, particularly after the “recovery” phase. The carbon-to-nitrogen ratio was at least twice as high, whereas amino acid concentrations were lowest in leaves of controls compared to stressed plants. Some glucosinolates, characteristic metabolites of Brassicales, showed lower concentrations, especially in plants of the flooding treatment. Stress-specific investment into different amino acids, many of them acting as osmolytes, as well as glucosinolates, indicate that these metabolites play distinct roles in the responses of plants to different water availability conditions. To reduce losses in crop production, we need to understand plant responses to dynamic climate change scenarios.     

Combined Effect of Intercropping and Turnip Root Fly (<Emphasis Type="Italic">Delia floralis</Emphasis>) Larval Feeding on the Glucosinolate Concentrations in Cabbage Roots and Foliage

The effects of plant competition and herbivory on glucosinolate concentrations in cabbage root and foliage were investigated in a cabbage-red clover intercropping system. Cabbage plants were grown under different competitive pressures and with varying degrees of attack by root-feeding Delia floralis larvae. Glucosinolate concentrations in cabbage were affected both by intercropping and by D. floralis density. Glucosinolate concentrations in foliage generally decreased as a response to intercropping, while the responses to insect root damage of individual glucosinolates were weaker. Root glucosinolates responded more strongly to both intercropping and egg density. Total root glucosinolate concentration decreased with clover density, but only at high egg densities. Increased egg density led to opposite reactions by the indole and aliphatic glucosinolates in roots. The responses of individual root glucosinolates to competition and root damage were complex and, on occasion, nonlinear. Reduced concentrations of several glucosinolates and the tendency towards a decrease in total concentration in cabbage foliage caused by intercropping and larval damage suggest that competing plants or plants with root herbivory do not allocate the same resources as unchallenged plants towards sustaining levels of leaf defensive compounds. This could also be true for root glucosinolate concentrations at high egg densities. In addition, the results suggest that changes occurring within a structural group of glucosinolates may be influenced by changes in a single compound, e.g., glucobrassicin (indol-3-ylmethyl) in foliage or sinigrin (2-propenyl) in roots.