七种花色苷色素中矢车菊-3-葡萄糖苷含量研究

目的:调查研究七种花色苷色素中矢车菊-3-葡萄糖苷的含量.方法:实验采用高效液相色谱法,检测条件为Ultimate(R)LP-C18(5μm,250mm ×4.6mm)色谱柱;甲酸水溶液(1∶9)∶甲醇=85∶15(v/v)梯度洗脱;流速1mL/min;柱温30℃;检测波长535nm.结果:萝卜红、甘薯红、甜菜红中不含矢车菊-3-葡萄糖苷,葡萄皮色素、欧洲越橘色素、红米红、甘蓝红中矢车菊-3-葡萄糖苷含量分别为5.09％、4.15％、10.84％、0.03％.结论:七种花色苷色素中矢车菊-3-葡萄糖苷含量存在明显差异,葡萄皮色素、欧洲越橘红色素、红米红中矢车菊-3-葡萄糖苷含量较高,为矢车菊-3-葡萄糖苷的进一步开发利用提供了可靠的理论依据.     

酒精发酵副产物对酵母菌生物的影响

探讨了乙酸、乳酸、焦糖色素及糠醛酒精发酵副产物对酵母菌生长和酒精发酵的影响。在酵母基本培养基中,加入乙酸、乳酸、焦糖色素及糠醋的量分别为0.1%、0.1%、2.0%和0.2%时,酵母细胞数减少50％。而在酵母基本培养基中同时添加乙酸、乳酸、焦糖色素及糠醛时,对酵母菌生长的抑制强度高达70％。酒精发酵的原料出酒率仅为正常发酵的50％。     

小米柠檬黄色素测定方法改进

该文报道利用高效液相色谱法快速测定小米中添加柠檬黄色素方法。首先采用温水提取小米中水溶性色素,然后以乙酸铵+甲醇(80+20)固定配比为流动相,流速为1 ml／min。在254nm波长下检测。与国标法相比,该法简便快速,方法标准偏差0．0024,添加标准回收率93．3％- 96．3％,可用于大多数粮食中合成色素测定。     

类胡萝卜素产生菌海洋红酵母培养条件优化研究

本文研究了培养条件对海洋红酵母生长的影响。结果表明:海洋红酵母生长和色素产生不需要光照,能以铵盐为主要氮源。适宜其生长的条件为:温度22-28℃,pH4.0-5.0,糖浓度35g/L,氯化钠浓度20-30g/L,种量≥7.5％。这也为反应器培养打下了基础。     

紫甘蓝色素抗氧化能力的研究

从还原能力、抗脂质过氧化和对自由基清除能力等方面对紫甘蓝色素的抗氧化能力进行了试验研究和评价，并对花色苷的含量进行了测定。结果袁明紫甘蓝色素具有一定的还原能力，对脂质过氧化、DPPH（1，1-二苯基-2-苦肼基）自由基均具有较强的抑制和清除作用，且在试验浓度范围内其最大抑制率和清除率分别为对亚油酸的抑制率为54．39％；对DPPH自由基的清除率为93．2％。表明，紫甘蓝色素作为具有抗氧化功能的天然色素，有广阔的应用前景。     

西伯利亚白刺果实花色苷的初步鉴定

以西伯利亚白刺果实为材料,利用光谱方法和色谱方法对其花色苷进行了初步鉴定。结果表明：西伯利亚白刺果实花色苷中1号色素为天竺葵色素-3-葡萄糖鼠李糖苷,3号色素为矢车菊色素-3-葡萄糖鼠李糖苷,4号色素为飞燕草色素-3-半乳糖苷。     

固相萃取-HPLC法同时测定肉制品中苋菜红、胭脂红、日落黄和诱惑红的含量

建立了利用固相萃取-高效液相色谱法同时测定肉制品中4种合成色素的检测方法.样品经乙醇、氨水和水溶液(7∶2∶1,mlm)提取后,固相萃取净化,经C18柱分离,用紫外检测器检测.结果表明:4种合成色素分离良好,加标平均回收率为66.7％～99.7％,相对标准偏差1.9％～3.6％.该方法准确度和精密度较高,可应用于测定肉制品中的合成色素.     

高效液相色谱同时检测熟肉制品中8种合成色素

建立了一种高效液相色谱法1次取样同时检测熟肉制品中8种人工合成色素的方法.采用Agilent Eclipse XDB-C 18 (4.6mm×250mm)色谱柱,流动相为甲醇-0.02mol/L乙酸铵,流速:1.0mL/min,波长210nm～800nm.结果显示线性关系良好,8种人工合成色素的RSD值均＜5％,平均回收率在85.2％～96.4％之间.     

天然美人蕉花红色素的提取及理化性质的研究

从美人蕉花中提取天然红色素的工艺条件是：以体积分数是0．1％HCI＋60％的乙醇-水溶液作提取剂，温度为70℃，时间为3h，原料与提取剂配比为1：8（g／mL）。对该色素的理化性质研究结果表明，美人蕉花红色素在pHi〈4的条件下对热的稳定性好，在此条件下加入果糖、葡萄糖、蔗糖、淀粉或Na^＋、K^＋、Mg^2＋、Ca^2＋、Al^3＋、Zn^2＋、Mn^2＋等金属离子时色素颜色不变，但Fe^3＋的存在会使该色素颜色改变。pH≥5时，色素颜色发生变化。     

天然食用植物色素山兰红的研究

由爵床科植物五指山兰(Peristophe lanceolia Nees)的嫩枝和叶提制而得的一种食用天然色素,被命名为山兰红色素。该色素属水溶性,提取得率为4～8％,pH6.8～8时最大吸收峰波长为580nm,pH3～6.4时最大吸收峰波长为480nm,颜色随pH而变化,中性色素液强日晒5小时,颜色由暗紫变为红紫。100℃加热两小时,pH4色素液变化不大,更加清澈透明,pH7色素液颜色变浅而透明,较玫瑰茄色素稳定,色价E_1cm~10％=2278(580nm),主要色素成分为天竹葵宁-3-β-葡萄糖苷。食用安全,可用于饮料,低度酒,米制品等着色。     

Elucidation of chemical structures of pink-red pigments responsible for ‘pinking’ in macerated onion (Allium cepa L.) using HPLC-DAD and tandem mass spectrometry

The chemical structures of pink-red pigments responsible for ‘pinking’ in macerated onion were tentatively elucidated using HPLC with a diode array detector and tandem mass spectrometry. All pigments were produced in conditions that approximated the natural process as closely as possible, using mixtures of onion thiosulphinates, the enzyme alliinase, and free amino acids. The isotopic distribution of protonated molecules of pink-red pigments produced from individual amino acids indicated the absence of sulphur, with the exception of pigment produced from cystine. The pigments had a basic polymethine framework containing two pyrrole rings (3,4-dimethyl-1H-pyrrole and 3,4-dimethyl-2,5-dihydro-1H-pyrrole) bridged by methines. The side chains attached to the nitrogen of the pyrrole rings were derived from the reacting amino acid. The simplest pink-red pigment, produced from glycine, was identified as 2-(2-(3-(1-(carboxymethyl)-3,4-dimethyl-1H-pyrrol-2(5H)-ylidene)prop-1-en-1-yl)-3,4-dimethyl-1H-pyrrol-1-yl)acetic acid. The pigment from alanine was identified as 2-(2-(3-(1-(carboxymethyl)-3,4-dimethyl-1H-pyrrol-2-yl)allylidene)-3,4-dimethyl-2,5-dihydro-1H-pyrrol-1-yl)propanoic acid. The chemical structures of pink-red pigments from leucine, asparagine, glutamine, tyrosine, and cystine also were determined.     

沙琪玛生产配方的优化研究

通过减少鸡蛋液,添加全蛋粉、磷脂酶A2和水溶性焦糖色素对沙琪玛生产配方进行优化研究。按照配方质量比,通过单因素和正交分析实验得到最佳配方:高筋面粉59.20%、鸡蛋液36.42%、全蛋粉1.82%、磷脂酶A20.01%和水溶性焦糖色素2.55%;通过该配方生产出沙琪玛的风味与原配方一致。     

微波法制备焦糖色素的研究

以葡萄糖和尿素为原料，利用微波独特的加热机制制备焦糖色素。探讨了工艺条件对焦糖色素色率的影响，结果显示：调节体系含水量15％、pH8．0，在中火条件下辐射14min，制得色率为93132EBC单位的焦糖色素，产品带正电荷；同时，观察了NaCl、KCl、FeCl3、CaCl2等盐的存在对焦糖色素色率的影响，研究表明：这些金属氯化物均能增加焦糖色素的色率，其中FeCl。的影响最显著，其次为NaCl；稳定性试验显示：不加盐和加入NaCl制备得到的焦糖色素耐酸性和耐盐性均良好，而加入FeCl3制备得到的焦糖色素耐酸性和耐盐性差。     

红曲橙色素的发酵制备及其在红曲红色素化学半合成中的应用

以红色红曲菌M7为菌株,采用pH 3的两步发酵法,结合结晶分离步骤,制备高纯度红曲橙色素,并以红曲橙色素和氨基酸为前体物,利用亲氨基反应在体外进行红曲红色素的化学半合成。结果显示,在该发酵条件下,所产生的色素在300 nm~600 nm范围内只有一个吸收峰,最大吸收波长为472 nm,表明该色素产物的主要成分为红曲橙色素,产量达(7.9±0.2)×10⁴U/L;结晶分离步骤能显著提高红曲橙色素的纯度,当向70%乙醇的色素提取液中加入0.5倍体积的水进行结晶分离时,每升发酵培养基可获得(0.63±0.04)g高纯度红曲橙色素晶体,含红斑红曲素和红曲玉红素两种橙色素组分,未检出桔霉素;体外亲氨基反应成功合成色氨酸和谷氨酸衍生红曲红色素,且橙色素向2种衍生红曲红色素的转化效率无显著差异。     

Identification of candidate amino acids involved in the formation of pink-red pigments in onion (Allium cepa L.) juice and separation by HPLC

The formation of pink-red pigments ("pinking") by various amino acids was investigated by reacting amino acids with compounds present in onion juice. The unknown pink-red pigments were generated and separated using high-performance liquid chromatography (HPLC) and a diode array detector (DAD) in the range of 200 to 700 nm. To generate pink-red pigments, we developed several reaction systems using garlic alliinase, purified 1-propenyl-L-cysteine sulfoxide (1-PeCSO), onion thiosulfinate, natural onion juice, and 21 free amino acids. The compound 1-PeCSO was a key compound associated with pinking in the presence of both the alliinase and amino acids. Numerous naturally occurring pink-red pigments were detected and separated from pink onion juice using the HPLC-DAD system at 515 nm. Most free amino acids, with the exceptions of histidine, serine, and cysteine, formed various pink-red pigments when reacted with onion thiosulfinate. This observation indicated that onion pinking is caused not by a single pigment, but by many. Furthermore, more than one color compound could be produced from a single amino acid; this explains, in part, why there were many pink-red compound peaks in the chromatogram of discolored natural onion juice. We presumed that the complexity of the pink-red pigments was due to the involvement of more than 21 natural amino acids as well as several derivatives of the color products produced from each amino acid. We observed that the pinking process in onion juice is very similar to that of the greening process in crushed garlic, emphasizing that both thiosulfinate from flavor precursors and free amino acids are absolutely required for the discoloration.     

红曲菌液态发酵产天然黄色素的条件优化

该实验旨在通过优化发酵条件,提高红曲黄色素的产量。该实验室前期筛选获得了1株产黄色素的菌株sjs-6,以此为试验菌株,对培养基的碳源、氮源、Mg 2+添加量、初始pH、培养温度进行了优化。并通过液质联用、核磁共振检测该红曲黄色素中的主要成分。结果表明,当麦芽糖80 g/L,(NH 4)2SO 410 g/L,MgSO 41.0 g/L,培养基初始pH值为6.0,30℃下恒温培养时黄色素的色价最高,可达508.61 U/mL,是未优化前的1.52倍。经分析鉴定,该红曲黄色素中的主要成分为红曲素Monascin,纯度为97%。该研究为天然红曲黄色素的工业化生产提供了理论依据。     

红曲霉发酵不同底物产色素的研究进展

红曲色素是由红曲霉发酵产生的天然色素。传统上红曲霉都是发酵大米生产红曲色素,近些年,随着研究的深入,小米、玉米、木薯、菠萝蜜籽等谷物及农工业废弃物都被用于红曲色素生产。文章简述了红曲色素的性质,对红曲霉发酵不同底物生产色素的研究进行了综述。     

正交优化超声辅助双水相法粗提雪菊色素

研究超声辅助正丙醇(NPA)/(NH4)2SO4双水相技术对雪菊色素的粗提工艺。以(NH4)2SO4质量分数、NPA质量分数、雪菊粉末用量、超声温度、时间及p H为考察因子,以总黄酮为指标,选择差示分光光度法测定粗提物中色素含量,并以单因素试验为基础设计正交试验优化提取工艺,发现雪菊色素主要集中于上相。在最佳水平,建立20.0 g ATPS,(NH4)2SO4质量分数29%、NPA质量分数23%,雪菊粉末用量0.08 g,调pH3,温度60℃下超声提取60 min;雪菊色素得率240.1469 mg/g,RSD为4.414%。与传统提取法相比,超声辅助NPA/(NH4)2SO4双水相粗提雪菊色素时间短、温度低、效率较高,可以实现雪菊色素粗提物的提取分离,且差示分光光度法用于雪菊色素的检测可信度较高,为雪菊色素粗提工艺提供一种新途径。     

Thermal and photochemical degradation of myoglobin pigments in relation to colour stability of sliced dry-cured Parma ham and sliced dry-cured ham produced with nitrite salt

Lipophilic and hydrophilic extracts of the red pigments from Parma ham and nitrosylated pigment of dry-cured ham produced with nitrite salt were prepared with acetone/water (75/25 v/v %) solution and aqueous phosphate buffer, respectively. The spectral characteristics differed for both the lipophilic and the hydrophilic Parma ham pigment compared with the dry-cured ham produced with nitrite salt. The red lipophilic pigment(s) extractable from Parma ham was(were) found to be very stable towards thermal degradation in acetone/water (75/25 v/v %) solution for temperatures up to 70 °C in contrast to the lipophilic pigment(s) extractable from dry-cured ham produced with nitrite salt, which was(were) found to have an energy of activation of 99 kJ/mol for thermal degradation. In contrast, quantum yields for photodegradation of the lipophilic ham pigments exposed to 366 nm (420 nm) monochromatic light were larger for Parma ham than for nitrite-cured ham [1.6×10^–5 (6.9×10^–6) versus 1.6×10^–6 (2×10^–6) mol einstein^–1] as determined for acetone/water (75/25 v/v %) solution. In agreement with these findings for the extracted lipophilic pigments, sliced Parma ham showed better colour stability than sliced dry-cured ham produced with nitrite salt, when stored in the dark at low oxygen concentration, in contrast to a faster initial discolouration for Parma ham when exposed to light, as shown for chilled storage for 35 days under retail conditions for the two products each packed at two oxygen levels (0.4 and 21%).     

Stability Modeling of Red Pigments Produced by Monascus purpureus in Submerged Cultivations with Sugarcane Bagasse

Monascus purpureus red pigments were produced in submerged cultivations employing sugarcane bagasse (SB) as carbon source in combination with various nitrogen sources. Peptone and soy protein isolate (SPI) as nitrogen sources generated the best pigment yields. NH₄Cl has not supported high pigment production. Red pigments produced using SB and SPI as growth substrates were submitted to temperature and pH stability analysis. Data from thermal pigment degradation were fitted to five mathematical models, and a first-order equation was accepted as the best one to describe color decay. Red pigments showed high stability at low temperatures (30–60 °C) and at near-neutrality pH values (6.0–8.0) when compared to that at high temperatures (above 60 °C) and at acidic pH values (4.0–5.0). Monascus pigments produced using a low-cost agroindustrial waste (SB) as carbon source could be utilized as colorants in foods and foodstuffs manufactured under mild process conditions.