萝卜苗中异硫氰酸盐的动态变化及体外抗氧化活性

测定不同生长时期的6种萝卜苗(长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗、抚顺红萝卜苗及满堂红萝卜苗)正己烷提取物的总异硫氰酸盐和4-methylthio-3-butenyl isothiocyanate (MTBITC)含量,分别用FRAP法、ABTS法、抗超氧阴离子自由基(O2－ ·)和抗羟自由基( ·OH)能力4种方法测定提取物的体外抗氧化性能。结果显示：萝卜苗中MTBITC含量占总异硫氰酸盐的80%以上;5～10d的萝卜苗中含有较高的MTBITC含量;同生长期的苗中,长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗的MTBITC含量比抚顺红萝卜苗和满堂红萝卜苗高。长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗4种萝卜苗的抗氧化性能与MTBITC含量呈正相关。而满堂红和抚顺红萝卜苗中MTBITC含量较低,但却表现出较强的抗氧化性能。     

西兰花种子发芽过程中生理活性物质含量的变化

以西兰花种子为试材,测定不同品种西兰花种子中萝卜硫苷和萝卜硫素含量,分析选取的种子在发芽过程中抗坏血酸、总酚、花色苷、萝卜硫苷、黑芥子酶活性和萝卜硫素含量的变化。结果表明,10种西兰花种子中萝卜硫苷和萝卜硫素含量差异显著,两者在LX5种子中含量最高,分别为134.06μmol/g DW和11.37 mg/g DW,且硫苷水解的产物中萝卜硫素的含量最高。LX5中,抗坏血酸在发芽过程中逐渐生成,发芽4 d时高达127.49mg/100 g FW,随后逐渐下降;总酚在发芽过程中逐渐下降,发芽5 d时其含量下降42.14%;花色苷含量与抗坏血酸含量变化趋势基本一致;萝卜硫苷和萝卜硫素含量在发芽过程中呈下降趋势;黑芥子酶活性在0~3 d无显著变化,随后逐渐增强。     

外源蔗糖对萝卜幼苗品质及代谢酶活性的影响

以“满堂红”品种的萝卜为材料,探究不同质量浓度的外源蔗糖喷洒处理对不同生长天数的萝卜幼苗营养品质（花青素、叶绿素、类胡萝卜素、总酚和芥子油苷等含量）及代谢酶（过氧化物酶（peroxidase,POD）和苯丙氨酸解氨酶（phenylalanine ammonialyase,PAL））活性的影响。结果表明：对于生长3、5 d和7 d的萝卜幼苗,0.4 g/100 mL和0.6 g/100 mL蔗糖处理均能够显著提高其花青素、叶绿素、类胡萝卜素、总酚、芥子油苷含量及POD、PAL活性（P＜0.05）,而0.2 g/100 mL蔗糖处理对其营养物质含量及抗氧化性的影响不显著（P＞0.05）;0.4 g/100 mL和0.6 g/100 mL蔗糖处理在改善其营养价值方面的差别不大。因此,在农业生产中,可采用质量浓度0.4 g/100 mL蔗糖喷洒处理萝卜幼苗来提高其营养价值。     

黑豆发芽过程中成分的变化

探究黑豆在发芽过程中营养成分的变化。在20℃发芽7 d对黑豆中各营养成分发芽前后含量进行测定。未发芽前黑豆中几乎不含VC,发芽后VC逐渐增加;黑豆干种子中不含有叶绿素,发芽5 d后叶绿素急剧增加;异黄酮在发芽过程中逐渐增加,在发芽第6天达到最大值为0.39 g/100 g;蛋白质的含量由发芽前36 g/100 g先下降至34.56g/100 g,后又上升至39.56 g/100 g;多酚的含量出现2个峰值,第4天达到最大值182 mg/100 g,必需氨基酸总量不断增加;黑豆在发芽过程中γ-氨基丁酸(GABA)的含量呈持续上升的趋势。黑豆经过发芽培育在发芽5~6 d食用对人体更有益。     

绿豆萌发期蛋白质和维生素C含量及营养价值

绿豆种子萌发过程中蛋白质和VC含量会发生变化。紫外吸收法和2,6-二氯酚靛酚滴定法分别是测定蛋白质和VC含量的常用方法。采用这2种方法测定了绿豆不同萌发期蛋白质和VC含量变化,结果为,萌发1 d时,蛋白质与VC含量分别为0.964 mg/g和0.325 mg/g,2 d时为0.746 mg/g和0.223 mg/g,3 d时为0.629 mg/g和0.157 mg/g,4 d时为0.711 mg/g和0.170 mg/g,5 d时为0.695 mg/g和0.132 mg/g。因此,随萌发时间延长蛋白质含量先下降后略微升高,VC含量下降。     

大豆发芽过程中营养成分变化规律的研究

通过对大豆发芽过程中营养成分含量变化进行分析,结果表明脂肪和总糖含量随时间的延长而下降,而蛋白质、还原糖、VC和异黄酮含量在发芽后均较未发芽时增加。其中VC的含量增加最多,到第7天时候,每100 g的大豆芽中含有9.7 mg的VC。大豆在发芽1 d时,蛋白质的含量有所下降,随后缓慢增加,第7天的蛋白质含量比未发芽前增加了11%。还原糖含量在其发芽的过程中平稳地上升,在第7天的时候达到9.38 g/100 g,比未发芽前增加了2.32倍。异黄酮含量在发芽4 d时达到最大值0.51 g/100 g,以后平缓。     

发芽处理对蚕豆主要营养成分与抗营养因子的影响

研究发芽处理对启豆2号蚕豆主要营养成分与抗营养因子含量的影响。对蚕豆发芽前后蛋白质、脂肪、淀粉、VC、氨基酸、植酸和单宁含量测定。结果表明：蚕豆在发芽1d时可溶性蛋白质含量显著增加,随后逐渐下降;粗脂肪和淀粉含量均呈下降趋势;发芽2d时VC含量显著增加,达到最大58.65mg/100g,随后逐渐下降,5d后VC含量仍高于未发芽的;发芽后1～2d蚕豆的氨基酸含量略有增加;发芽1d抗营养因子植酸含量下降了33.55%,随后平缓;发芽1d蚕豆的单宁含量增加到462.70mg/100g,2～3d增加比较平稳,5d急剧增加至1306.10mg/100g。可推知,将启豆2号蚕豆发芽1～2d的作为食用及加工的较佳时期。     

山毛豆发芽过程中营养成分的变化

对山毛豆发芽过程中营养成分含量的变化进行分析。结果表明:脂肪和还原糖含量随时间的延长而下降,而蛋白质、VC和异黄酮含量在发芽后均较未发芽时增加。其中VC的含量增加最多,从第4天到第5天增幅达到了200%,蛋白质含量在发芽初期持续上升,第4天的时候达到最大值349.1 mg/g,还原糖含量在第4天时达到最大值64.1 mg/g,以后又逐渐减少,到了第9天下降至46.1 mg/g。脂肪的含量在1-4 d下降得较快,在第4天的时候下降幅度达到24.48%。总糖含量在第2天下降幅度达28.92%。第9天下降至6.82%,比发芽前减少38.56%。异黄酮含量在发芽4 d时达到最大7.8 mg/g,以后有缓慢下降。     

燕麦发芽过程中营养成分变化

为了探究燕麦发芽过程中主营养成分的变化,对燕麦在20℃发芽8 d过程中主要营养成分的变化进行测定。结果表明:燕麦发芽过程中,游离氨基酸、还原糖、磷脂在发芽4 d时含量最高,分别为250 mg/100g、5.3 mg/g、10.2 g/100g;蛋白质、生物碱在发芽6 d时最多,为20.5%、54.6 mg/100g;总酚发芽7 d时最高,为1.73 mg/g;维生素C在8 d时含量高达31.2 mg/g。燕麦发芽后主要营养物质在4~6 d营养价值最高,为最佳使用时间。     

6 种东北地区红树莓果渣提取物的抗氧化活性差异

以东北地区6 种红树莓果实加工后的果渣提取物为实验材料,研究其总酚、总黄酮、原花青素、花色苷含量和体外抗氧化活性的差异。结果表明：宝石红果渣提取物中总酚、总黄酮和原花青素含量最高,分别为14.18、3.71、15.28 mg/g;哈瑞太兹果渣提取物中花色苷含量最高,为0.68 mg/g;菲尔杜德和野生果果渣提取物的总还原能力与VC接近;除哈瑞太兹外,其他品种红树莓果渣提取物对（1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基和2,2’-二氮-双（3-乙基苯并噻唑-6-磺酸）二铵盐自由基（2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical,ABTS+·）的清除率均大于VC。相关性分析结果表明红树莓果渣提取物的总还原能力与总黄酮、原花青素含量的相关性较大;对DPPH自由基的清除率与原花青素、花色苷含量的相关性较大;而对ABTS＋·的清除率与总酚和总黄酮含量的相关性较大。在6 个红树莓品种中,菲尔杜德和野生果果渣提取物具有较强的抗氧化活性。     

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。     

Time dependence of bioactive compounds and antioxidant capacity during germination of different cultivars of broccoli and radish seeds

Optimisation of the germination process of different cultivars of broccoli (Brassica oleracea var. italica cv. Lucky, cv. Tiburon and cv. Belstar) and radish (Raphanus sativus cv. Rebel and cv. Bolide) seeds in relation to the content of glucosinolates (GLS), vitamin C and total antioxidant capacity was carried out in order to maximise the health-promoting properties of Brassica sprouts. The content of total and individual GLS varied between species, among cultivars, and germination time. Glucoraphanin in broccoli and glucoraphenin in radish were the predominant GLS in raw seeds (61–77 and 63–129 μmol/g DM, respectively) and, although their content decreased during germination, they were maintained in rather large proportions in sprouts. Vitamin C was not detected in raw seeds and its content increased sharply in broccoli and radish sprouts (162–350 and 84–113 mg/100 g DM, respectively). Raw brassica seeds are an excellent source of antioxidant capacity (64–90 and 103–162 μmol Trolox/g DM in broccoli and radish, respectively) and germination led to a sharp increase. Germination of broccoli cv. Belstar and radish cv. Rebel for 4 days provided the largest glucoraphanin and glucoraphenin content, respectively, and also brought about large amounts of vitamin C and antioxidant capacity.     

Effect of salt stress on phenolic compounds,glucosinolates, myrosinase and antioxidant activity in radish sprouts

The germination, growth, total phenolics, glucosinolate, myrosinase and antioxidant activity of radish sprouts germinated under 0 (control), 10, 50 and 100 mM of NaCl were investigated. The glucoraphasatin (4-methylthio-3-butenyl-glucosinolate), total glucosinolate and total phenolic contents of 5- and 7-day-old sprouts treated with 10 and 50 mM of NaCl were significantly decreased. However, the antioxidant activity of sprouts treated with 10 and 50 mM of NaCl was not affected. The glucoraphasatin and total glucosinolate contents of 5- and 7-day-old sprouts, total phenolic contents of 3- and 5-day-old sprouts were significantly increased and myrosinase activities of 3- and 5-day-old sprouts were inhibited, although the germination was dramatically inhibited by 100 mM of NaCl treatment. These results indicated that salt stress (100 mM of NaCl treatment) could improve the nutritional value of radish sprouts, and germination of sprouts under adequate salt stress could be one useful way to enhance health-promoting compounds of plant food.     

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.     

小白菜硝酸盐含量与光照度及氮代谢关键酶的相关性

采用土培实验研究不同品种小白菜（低富集硝酸盐小白菜品种“揭农四号春白菜”（JN4）、高富集硝酸盐小白菜品种“香港特选奶白菜”（HKTX））硝酸盐含量与光合系统参数及植物-土壤氮代谢关键酶的相关性。结果表明：随着光照度的增加,小白菜生物量总体呈增加趋势。与3 000 lx处理组相比较,光照度增加到6 000 lx和12 000 lx时,“HKTX”和“JN4”的地上部分干质量增加了10.51%～28.09%。随着光照度的增加,小白菜叶片硝酸盐含量显著降低。与3 000 lx处理组相比较,光照度增加到6 000 lx和12 000 lx时,“HKTX”和“JN4”的叶片硝酸盐含量降低了22.27%～43.32%,叶柄硝酸盐含量降低了8.21%～31.40%。两个供试品种小白菜叶片硝酸盐含量与净光合速率（Pn）成极显著负相关,相关系数分别为－0.686和－0.833（P＜0.01）;叶片硝酸还原酶活力与硝酸盐含量成显著负相关,相关系数分别为－0.719和－0.696（P＜0.05）;叶片、叶柄硝酸盐含量与土壤硝态氮含量成显著正相关,相关系数分别为0.692、0.726、0.676和0.796（P＜0.05）;土壤硝态氮含量与硝酸还原酶活性成极显著负相关,相关系数分别为－0.826和－0.832（P＜0.01）。     

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。     

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%。     

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。     

Effects of Nonthermal Plasma Treatment on Decontamination and Sprouting of Radish (<Emphasis Type="Italic">Raphanus sativus</Emphasis> L.) Seeds

Sprout-related foodborne disease outbreaks are increasingly becoming a concern for food safety. The primary sources of microbial contamination in ready-to-eat sprouts are contaminated seeds, which are improperly disinfected prior to sprouting. In recent years, the application of nonthermal plasmas for seed decontamination is increasingly being investigated as a substitute to regular pre-germination treatments. The present study was intended to evaluate the potentiality of corona discharge plasma jet (CDPJ) for decontaminating microorganisms on radish seeds and to determine the plasma exposure effects on the seed germination as well as physicochemical properties of sprouts grown from the CDPJ-treated seeds. Microbial contaminants, namely, aerobic bacteria, Bacillus cereus, Escherichia coli, Salmonella spp., and molds and yeast were detected in the seeds. All the microorganisms found in the seed samples were reduced in the range of 1.2–2.1 log CFU/g upon treatment using the CDPJ for 3 min. Pseudo-first-order kinetics provides the best fit to the microbial inactivation patterns. The plasma seed treatment for up to 2 min showed beneficial effects on seed germination rate and growth of seedlings. Compared to untreated controls, sprouts grown from the CDPJ-treated seeds exhibited no significant changes in the levels of moisture (mean range 85.45–87.51%), reducing sugars (0.547–0.550%), total phenolic content (6.14–6.29 μg GAL/g), and DPPH radical scavenging activity (78.03–78.60%). Sensory characteristics of radish sprouts grown from the plasma-treated (up to 2 min) seeds were not significantly different from controls. In conclusion, the CDPJ treatment of radish seeds for 2 min not only decreased the seed microbial counts but also led to the improvement of their germination rate and seedling growth, without negatively affecting the physicochemical and sensory properties of their corresponding sprouts.