Daily Variation in Glucosinolate Concentrations in the Leaves and Roots of Cabbage Seedlings in Two Constant Temperature Regimes

Limited information is available on the glucosinolate variation within the Brassica plant and the relationship between the pattern and concentration of glucosinolates in the aerial parts and the roots has received little attention. Early studies carried out under field conditions have shown that glucosinolate levels may vary considerably throughout a 24 h period. The purpose of the present study was to show whether, under controlled conditions, temperature was a factor in glucosinolate variation and to determine whether such variation might be due to translocation of glucosinolates between the aerial parts of the plant and its roots. Cabbage seedlings were maintained at 20 and 30°C over 2 days and leaves and roots sampled at 02:00 h, 06:00 h, 10:00 h, 14:00 h, 18:00 h and 22:00 h. The glucosinolates 2-propenyl- and 3-methylsulphinylpropyl- with an average of 261 and 167 μmol 100 g^-1 DW, respectively, were the two main glucosinolates in the aerial part of the plant whilst in the roots 1-methoxyindol-3-ylmethyl-, 2-phenylethyl- and 3-methylsulphinylpropyl, with 495, 495 and 385 μmol 100 g^-1 DW respectively, showed the highest average concentrations. Total and individual glucosinolates in the roots and in the aerial part of the plant showed the highest concentrations in the dark cycle, at 02:00 h and 22:00 h, respectively, whilst the lowest levels were during the light cycle, mainly at 18:00 h. The results suggest that temperature was not a major factor in the short-term variation in glucosinolate levels. Although there was a very high significant difference between the total glucosinolate levels in the aerial part of the plant (581 μmol 100 g^-1 DW) and roots (2124 μmol 100 g^-1 DW), the results of the present study do not support the concept of translocation between aerial part and roots, suggesting that other factors may be involved. © 1997 SCI.     

Glucosinolate content of Brassica vegetables-Chinese cabbages Pe-tsai (Brassica pekinensis) and Pak-choi (Brassica chinensis)

The glucosinolate content of 19 cultivars of pe-tsai and three cultivars of pak-choi Chinese cabbage (Brassica pekinensis Lour) Rupr and (Brassica chinensis L, respectively) has been determined using high performance liquid chromatography. The levels of total glucosinolates were 0.097-0.337 g kg^?1 fresh weight (mean 0.198) in pe-tsai and 0.39-0.704 g kg^?1 (mean 0.534) in pak-choi. The main components present were (2-hydroxybut-3-enyl-progoitrin), but-3-enyl- (gluconapin), 5-methylsulphinylpentyl- (glucoalyssin) and pent-4-enyl (glucobrassicanapin) glucosinolates, respectively. In comparison with other UK brassicas and American cultivars of Chinese cabbage, both the UK-grown pak-choi and pe-tsai are low in glucosinolates.     

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.     

鲜切紫甘蓝中花青苷和硫代葡萄糖苷在贮藏过程中的变化

采用高效液相色谱和液相色谱-质谱联用技术,对紫甘蓝（Brassica oleracea L. ssp. capitata f. rubra）中花青苷、硫代葡萄糖苷（简称硫苷）成分和含量进行鉴定和分析,并对低温（8±1）℃条件下经鲜切处理的紫甘蓝中花青苷和硫苷在货架期内（7 d）的变化情况进行研究。结果表明：紫甘蓝中存在11 种不同矢车菊花青苷,矢车菊-3-阿魏酰-槐糖苷-5-葡萄糖苷作为紫甘蓝中最主要的花青苷,在贮藏过程中的损失量占总花青苷损失量的55.51%,其占总量比例也在贮藏7 d后由35.12%下降至30.60%;紫甘蓝中存在10 种硫苷（由6 种脂肪族硫苷、3 种吲哚族硫苷和1 种芳香族硫苷组成）,以4-戊烯基硫苷和3-丁烯基硫苷为主,贮藏7 d后,二者损失率均为7%左右,损失量相加却达总花青苷损失量的50.07%,而所占比例相加也由71.68%上升到74.33%。     

硒硫互作对白菜芽苗菜硫代葡萄糖苷含量及抗氧化性的影响

为探讨硒硫互作对白菜芽苗菜硫代葡萄糖苷(以下简称硫苷)含量及抗氧化性的影响,以白菜种子为实验材料,通过4 mmol/L ZnSO₄溶液单独喷施、50μmol/L和100μmol/L的Na₂Se O₃溶液单独喷施以及二者联合喷施,分析白菜芽苗菜主要生理生化指标、抗氧化能力及硫苷含量等变化规律。结果表明,单独施用Zn SO₄溶液对白菜芽苗菜造成了生长胁迫,而单独施用Na₂Se O₃溶液可增加芽长和单株平均质量;Na₂SeO₃溶液联合ZnSO₄溶液喷施处理可以有效缓解单独施用ZnSO₄溶液对白菜芽苗菜生长发育的抑制作用。同时,相较于对照(喷施去离子水),经过ZnSO₄溶液联合Na₂SeO₃溶液喷施处理后,白菜芽苗菜硒元素含量及总硫苷含量均显著提高(P<0.05),其中ZnSO₄溶液联...     

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.     

Changes of Mineral Concentrations in Serra Cheese during Ripening and Throughout the Cheesemaking Season

Seasonal changes of the ash content and mineral concentrations in Serra cheese were studied over a typical 35-day ripening period. Statistically significant differences (at the 5% level) exist between the ash content and the concentrations of Na, K, Ca, P, Mg and Zn in cheeses during ripening. The highest concentrations of Na was obtained in cheese ripened for 7 days, whereas the concentrations of K, Ca, P, Ng and Zn decreased significantly during ripening. For 35-day-old cheeses, concentrations of Na, K and Cu were lowest and concentration of P was highest for cheeses manufactured in May. The concentration of Ca was lowest for cheeses manufactured in February. On average, the most concentrated minerals (in g kg^-1 of total solids, TS) in 35-day-old Serra cheese were Na (18·56), Ca (9·70) and P (7·92) and, at a lower level, K (1·70) and Mg (0·96). Only trace levels (in mg kg_TS^-1) of Zn (94·33), Cu (2·26) and Mn (1·25) were detected. A high mineral nutrition quality was thus ascribed to 35-day-old Serra cheese based on the average nutritional densities: 4·8 for Ca, 4·0 for P, 1·1 for Mg, 3·4 for Na, 2·4 for Zn, 0·4 for Cu, 0·2 for Mn and 0·2 for K. © 1997 SCI     

Glucosinolate and folate content in sprouted broccoli seeds

HPLC analysis of broccoli seeds and laboratory-grown broccoli sprouts revealed that three aliphatic glucosinolates (glucoraphanin, glucoiberin and glucoerucin) and a group of indol-glucosinolates including 4-hydroxy-glucobrassicin are preformed in the seeds. In the early stage of sprouting a reduction (approx. 20%) of the aliphatic glucosinolates was measured. During further growing, until day 8, and subsequent cold storage up to the 12th day the amounts of the aliphatic glucosinolates levelled off. While 4-hydroxy-glucobrassicin declined continuously, three minor indole-derivatives increased steadily, but remained at a comparatively low level. Besides glucosinolates, folates were quantified in broccoli sprouts by stable isotope dilution assays (SIDAs). During germination, the contents of total folates increased to 72 μg/100 g fresh mass and 546 μg/100 g dry mass on the 4th day, which was equivalent, respectively, to a 3-fold and a 24-fold increase in the seed’s content. Thereafter, total folates decreased again to 13 μg/100 g fresh mass until the 8th day of germination and remained at this low level. The folate pattern measured by SIDA revealed 5-methyltetrahydrofolate as the predominant vitamer at each stage.     

甘蓝苗生长过程中主要生理生化变化

以“新夏50”和“紫红钻”两种甘蓝种子为试材,研究了芽苗生长过程中芽长、呼吸速率、含水量、硫苷含量、异硫氰酸盐含量、多酚含量、抗坏血酸含量等主要的生理生化变化。结果表明：两种甘蓝在发芽过程中芽长、呼吸速率和含水量逐渐升高,“新夏50”的生长速率较“紫红钻”快;硫苷和总酚含量在种子中含量最高,随发芽时间延长均逐渐下降。“新夏50”和“紫红钻”芽苗中的异硫氰酸盐含量均在发芽1 d后达到最高水平,之后异硫氰酸盐含量缓慢下降至较低水平;而黑芥子酶活性则分别在第3天和第1天达到最高。两种甘蓝种子中未检测到抗坏血酸,随着种子发芽其含量先上升后下降。     

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。     

Rapeseed Meals,Methimazole, Thiocyanate and Iodine Affect Growth and Thyroid. Investigations into Glucosinolate Tolerance in the Pig

In two factorial experiments with a total of 81 growing pigs, the effects of antithyroid compounds and rapeseed meal (RSM) diets differing in glucosino-late content were tested without or with supplementary iodine. In Experiment 1, a 4×3 factorial arrangement was used to investigate the effects of antithyroid compound inclusion and supplementary iodine. Pigs received a grain–soya bean meal diet (control) or this diet with 250 mg kg^-1 methimazole (MMI), 1000 mg kg^-1 thiocyanate (SCN^- as KSCN) or 80 g kg^-1 high glucosinolate RSM (9·5 mmol glucosinolates kg^-1), each diet supplemented without or with iodine; 0, 125 μg kg^-1 (requirement) or 500 μg kg^-1. In Experiment 2, a 5×3 factorial arrangement was used to study the effects of dietary glucosinolate content and iodine supplementation. Pigs received a grain–soya bean meal diet or four diets with 160 g kg^-1 RSM differing in glucosinolate content (0·6, 2·4, 6 or 19 mmol kg^-1 diet), each diet supplemented with iodine: 62·5 μg kg^-1, 125 μg kg^-1 (requirement) or 250 μg kg^-1. Irrespective of the iodine dosage, MMI suppressed production of thyroxine and resulted in goitre, myxoedema and cretinism. SCN^- induced clinical hypothyroidism when there was no supple-mental iodine. Despite high iodine supplementation, glucosinolate load (19 mmol kg^-1 diet) decreased growth, feed intake, iodine store of the thyroid and serum concentration of thyroid hormone and resulted in goitre formation. In the case of diets with ⩽6 mmol glucosinolates kg^-1, iodine prevented antithyroid effects. However, more iodine was required by these pigs than by control animals to a high T₄ serum concentration. The lowest glucosinolate level tested (0·6 mmol kg^-1 diet) yielded the same thyroid hormone status and thyroid weight as the control, however, the iodine content of thyroid gland was decreased. In conclusion, iodine administration prevents the effects of a low glucosinolate intake only, by overcoming the depressed thyroxine released of the thyroid, resulting in regression of goitre. © 1997 SCI.     

甘蓝不同部位及加工对硫代葡萄糖苷组分和含量的影响

采用高效液相色谱法对甘蓝内叶、外叶、漂烫及真空干燥后的硫苷含量进行了成分鉴定及组分分析.结果表明,甘蓝内叶与外叶的组分相同,通过HPLC-ESI-MS共鉴定出5种脂肪族硫苷(3-甲基硫氧丙基GS,2-羟基-3-丁烯基GS,2-丙烯基GS,3-丁烯基GS,4-戊烯基GS)和1种吲哚族硫苷(3-吲哚基甲基GS),甘蓝中主要硫苷成分为2-羟基-3-丁烯基GS,2-丙烯基GS,3-吲哚基甲基GS及3-甲基硫氧丙基GS,内叶和外叶中硫苷含量分别为1 972 μg/g干重和1 941 μg/g干重,漂烫和真空干燥后硫苷的保存率分别为87.7％和37.4％.     

不同时期鲳鱼冷藏期间优势腐败菌的多样性变化

目的：比较分析不同时期冷藏鲳鱼（Pampus argenteus）贮藏期间的感官品质、pH值、微生物指标与主要微生物菌群的变化规律。方法：冷藏（4±1） ℃条件下,以感官评定、pH值与菌落总数为品质评价指标,采用聚合酶链式反应（polymerase chain reaction,PCR）扩增结合生理生化鉴定法分别对冬、春两个时期的鲳鱼进行优势腐败菌的变化规律研究。将经细菌培养与分离纯化得到单菌落按其形态特征进行分类,再通过生理生化鉴定与革兰氏染色,初步得到菌落种类,对单菌落进行DNA提取与PCR扩增并测序。结果：冬季样品获得12 种菌株,春季样品获得9 种菌株。贮藏末期时,冬季样品中优势腐败菌的种类与比例分别为嗜冷杆菌（Psychrobacter spp.）21.51%、草莓假单胞菌（Pseudomonas fragi）16.13%、荧光假单胞菌（Pseudomonas fluorescens）52.68%与热杀索丝菌（Brochothrix thermosphacta）9.68%;春季样品为草莓假单胞菌（Pseudomonas fragi）8.62%、荧光假单胞菌（Pseudomonas fluorescens）64.66%与腐败希瓦氏菌（Shewanella putrefaciens）26.72%。结论：冬、春时期中冷藏鲳鱼贮藏期间优势腐败菌的种类基本一致,以革兰氏阴性菌为主,但在细菌种类与比例上存在差异,冬季样品的微生物种类较春季丰富。贮藏期间,随着荧光假单胞菌所占比例的增加,使腐败希瓦氏菌的生长受到明显抑制。     

结球甘蓝不同品种及部位中主要生物活性物质含量比较

对春大将、帕特、汉城和春优4种结球甘蓝(Brassica oleracea var.capitata L.)以及帕特甘蓝的不同部位中硫代葡萄糖苷、异硫氰酸盐(isothiocyanate,ITCs)、总酚和抗坏血酸等主要生物活性物质含量进行比较。结果表明:各品种中脂肪族硫苷含量均最高。其中帕特甘蓝中总硫苷、脂肪族硫苷均高于其他3个品种,且其不同部位中总硫苷含量以外部叶为最高,而中部叶中含量最低。帕特甘蓝中ITCs和总酚含量最高,汉城甘蓝中抗坏血酸含量高于其他3个品种;春大将甘蓝中黑芥子酶(myrosinase,MYR)活性最高,帕特和春优甘蓝中其活性差异不显著,汉城甘蓝中最低。帕特甘蓝中ITCs和抗坏血酸含量以外部叶为最高,总酚含量则在内部叶中最高,MYR活性在中部叶和内部叶中显著高于外部叶。可见,帕特甘蓝可作为功能性食品的原料加以开发利用。     

Sensory Properties of Frozen Herring (Clupea harengus) from Different Catch Seasons and Locations

Freezing of herring (Clupea harengus) for human consumption is increasing in the Nordic herring industry, either onboard the fishing vessels or right after landing. The quality of frozen herring as a raw material does not only depend on the frozen storage conditions applied, but also on compositional features, something which in turn can vary with season and catching ground. To unravel the link between biological variations, basic muscle composition, and sensory properties of frozen herring, a unique herring raw material was caught by commercial fishing vessels at three locations: around Iceland, outside the Norwegian coast, and in Kattegat/Skagerrak. The samplings were done according to a specific scheme and conducted over several seasons and 2 years. The herring was converted into butterfly fillets, packed in cardboard boxes, frozen, and then stored at -20 °C or -80 °C for up to 18 mo. The sensory quality was characterized by objective sensory profiling. It was shown that two generalized sensory variables could be defined from a principal component analysis of the sensory data. Except for the expected pronounced effect from storage time, the most distinct variation followed the lipid content, which in turn varied with season. An unexpected conclusion was that catching location only had a minor affect on the changes in sensory quality of herring during frozen storage. Knowledge about how season and catching location affect herring during frozen storage will be useful for optimizing the utilization of herring for frozen storage for human consumption. Practical Application: The results of this study constitute important information for the herring processing industry when handling raw materials with different geographical and seasonal history. The reported information on a highly equal sensory quality of geographically diverse raw materials will give consumers and retailers valuable knowledge on the changes in eating quality to expect after long-term frozen storage under conditions similar to household freezers or refrigerated counters in supermarkets.     

萝卜苗发芽过程中营养物质的动态变化

通过测定抚顺红与盛丰白萝卜苗中芥子油苷、花青素、VC、总酚含量以及抗氧化能力,探究萝卜种子在发芽过程中营养物质的动态变化。结果表明：除盛丰白幼苗中4-甲硫基-3-丁烯基硫代芥子油苷的含量随着发芽过程而增加外,抚顺红与盛丰白萝卜苗中其余种类的芥子油苷含量均逐渐下降。抚顺红与盛丰白幼苗生长5 d后总酚含量较萝卜种子中分别下降61.62%和43.93%,之后2 d的含量变化趋于稳定。抚顺红与盛丰白萝卜种子中均未检测到VC,但随着发芽过程的进行,生长7 d的幼苗中VC含量分别增加至65.81 mg/100 g和52.48 mg/100 g。     

红色LED光照下上海青采后硫代葡萄糖苷代谢的变化

为研究发光二极管（Light-Emitting Diodes,LED）处理对上海青采后硫代葡萄糖苷（简称硫苷）代谢的作用机理,该研究首先采用不同颜色和光密度的光照处理上海青,得出6.5 μmol/(m2•s)的红色LED光照处理可显著抑制上海青中叶绿素降解,延缓其黄化。在此基础上,研究了6.5 μmol/(m2•s)红色LED光照处理对贮藏期间上海青中硫苷代谢相关物质及基因表达水平的影响。结果表明,上海青叶柄中总硫苷和异硫氰酸酯含量分别为叶片的2.72倍和1.32倍;红色LED光照处理可显著上调上海青叶柄中脂肪族合成关键基因MYB28、CYP83A1、GSTF11等的表达水平,从而促进叶柄中主要硫苷物质3-丁烯基硫苷等的合成;由此,上海青叶柄中总硫苷含量在贮藏4~8 d期间为对照组的1.62~1.99倍;同时,该处理提升了上海青叶柄的黑芥子酶活性,从而促进了总异硫氰酸酯的积累,且在贮藏4~8 d期间,对照组上海青叶柄的总异硫氰酸酯含量为红光处理组的77.43%~91.98%。综上,红色LED光照处理通过调控硫苷合成关键基因和黑芥子酶活性来延缓上海青中硫苷物质和异硫氰酸酯的流失。     

Glucosinolates in etiolated sprouts of sea-kale (Crambe maritima L)

Sea-kale, a long-forgotten vegetable, could make a resurgence due to its culinary attractiveness. Unfortunately, as with most cruciferous plants, its quality may be reduced owing to the presence of glucosinolates, mainly known for their antinutritional properties. The aim of this study was to evaluate the actual amount of these compounds found in edible sea-kale sprouts, using qualitative and quantitative analysis by liquid chromatography carried out after treatment by freezing, blanching and cooking. Before treatment, the quantity of glucosinolates, of which more than 80% is represented by epi-progoitrin, was found between 5.4 and 7.3 μmol g^?1 of fresh matter. In this study, freezing then thawing causes a nearly complete decomposition of glucosinolates into nonidentified compounds which are most probably 5-vinyloxazolidine-2-thionc and nitrites. Cooking for 4 min (blanching) brings about through leaching, a nearly 30% reduction. A greater decrease (76%) can be obtained with a cooking time of 20 min. The amount of glucosinolates found in sea-kale was compared with that of other commonly used cruciferous vegetables and there appears to be practically no risk when consumed on a monthly basis. At present sea-kale remains a desired vegetable in gastronomical dishes.     

菜籽饼粕中硫甙及其降解物分析中存在的问题

阐述了菜籽饼粕中硫甙的降解途径和各种毒素的存在形式,并指出目前分析测定硫甙、噁唑烷硫酮、异硫氰酸酯、腈类和硫氰酸酯等毒素中存在的一些问题,以期为今后的研究提供参考。