Supplementing white maize masa with anthocyanins: Effects on masa rheology and on the in vitro digestibility and hardness of tortillas

The aim of this work was to supplement masa made from nixtamalized white maize flour (NWMF) with anthocyanins (0.0, 0.03, 0.06 and 0.12 g/100 g of masa), and to evaluate the effects on the rheological properties of the masa and on color, staling, in vitro digestibility, and hardness of tortillas. Tortilla baking reduced the content of anthocyanins by about 10%. The color parameters of the tortillas added with anthocyanins was similar to that of tortillas made with blue maize. Attenuated total reflection ATR-FTIR spectra showed that the 1022/1047 peak ratio increased, indicative that retrogradation increased with storage time, but the ratio was significantly lower for tortillas with added anthocyanins than without them, and lower for higher anthocyanins concentration. Freshly made tortillas added with anthocyanins exhibited lower ready digestible (about 35%) and slowly digestible (about 20%), but higher resistant (about 45%) starch fractions. Tortillas with 0.12 g of anthocyanins showed significantly lower hardness than the control tortillas (without added anthocyanins). Both previous mentioned effects can be associated with retrogradation, which on turn could be linked to anthocyanins-starch complexes and inhibition of amylolytic enzymes.     

超声波辅助提取蓝莓果渣中花色苷的工艺研究

目的:确定超声波辅助提取蓝莓果渣中花色苷的最佳工艺。方法:采用正交试验确定超声波辅助提取蓝莓花色苷的最佳工艺条件。结果:超声波辅助提取蓝莓果渣中花色苷的最佳工艺条件为提取剂为酸性乙醇,固液比1∶60(g/mL),超声波功率350W,萃取时间40min,提取温度75℃。在此条件下,确定的蓝莓果渣花色苷含量3.122mg/g。结论:超声波辅助提取技术对充分利用蓝莓资源获取高附加值的花色苷是可行的。     

Effects of artificial light sources on accumulation of phytochemical contents in hydroponic lettuce

Lettuce is grown in different parts of the world and it is beneficial for health. Light condition is one of the most important environmental factor in regulating growth, development, and phytochemical accumulation in lettuce, particularly when lettuce is produced in a hydroponic system. Due to advances in technologies, artificial light sources have become increasingly capable of providing appropriate quality, intensity, and photoperiod of light in hydroponic lettuce production. This review highlights the progress of current research on the effects of artificial light regulation on growth and phytochemical accumulation in lettuce produced in hydroponic systems.     

红豆越橘花色苷的分离及功能性研究

采用活性跟踪的方法分离纯化野生红豆越橘提取物,并将有效组分进行抗癌细胞增殖活性测定。首先采用大孔吸附树脂X-5富集分离红豆越橘丙酮提取物,多酚含量和ABTS抗氧化做指标确定乙醇梯度洗脱有效组分,并命名为LB-1、LB-2、LB-3、LB-4,其总洗脱物命名为LB-MIX。用MTT法检测以上5个组分抗结肠癌HT29、卵巢癌Hela、肺癌A549和肝癌HepG-2细胞增殖活性,并选用环磷酰胺做阳性对照。结果显示,LB-MIX具有较好的抑制几株癌细胞的增殖活性。     

蓝莓的营养保健价值与栽培条件

蓝莓是近几年来从国外引进的新兴的小浆果,它的营养价值和保健价值正被越来越多的人所认识,其消费群体也从高端人群向大众延伸扩散。该文介绍了蓝莓的营养组成和它的保健功效,同时列举了蓝莓栽培3个最基本的条件。     

Effect of curing at different temperatures on biochemical composition of onion (Allium cepa L.) skin from three freshly cured and cold stored UK-grown onion cultivars

Onions are cured in order to form a complete, dry, outer skin which reduces water loss and suppresses incidence of disease, and can promote a darker skin finish. Currently in the UK, standard curing practises for onions involves heating at 28 °C for six weeks (65–75% RH), however, reducing curing temperatures may help to reduce energy usage. There is little empirical data on the effects of curing temperature on flavonol concentration in the skin of brown onions and on flavonol and anthocyanin concentration in the skin of red onions. Therefore, the aim of this study was to elucidate the compounds responsible for the change in onion skin colour when cured at different temperatures.Brown cvs. Sherpa and Wellington, and red onions cv. Red Baron, were cured at 20, 24 or 28 °C for six weeks. Replicated skin samples were analysed immediately after curing and after seven months cold storage at 1 ± 0.5 °C. Measurement of objective colour showed that skin of cvs. Sherpa and Wellington was darker and had a lower hue angle (H°) immediately after being cured at 28 °C compared to 20 °C. In contrast, skin of cv. Red Baron had a higher H° but no change in lightness (L*) when cured at 28 °C compared to 20 °C. Fructose, sucrose and glucose concentrations were analysed as they are thought to play a role in regulating the synthesis of flavonols and anthocyanins, both coloured compounds found in onion skin; however no significant correlations were found between colour data and sugar concentrations. Flavonols were measured in the skin of all cvs. and anthocyanins in the skin of cv. Red Baron. Quercetin glucoside and anthocyanin concentrations in the skin of onions cv. Red Baron immediately after curing were higher in those cured at 20 °C. Total flavonols and total anthocyanins were negatively correlated with H° in the skin of onions cv. Red Baron, but there was no similar correlation between total flavonols and H° for onion cvs. Sherpa and Wellington. This suggests that anthocyanins and flavonols may play a major role in varying skin colour of red onions cv. Red Baron cured at different temperatures; however, the difference between curing temperatures may not have been sufficient to represent a correlation between darkening of cvs. Sherpa and Wellington and flavonol concentration. Further investigation is therefore required to fully elucidate the compounds responsible for colour changes observed in brown onions.     

紫黑色作物花色苷实验室定量检测方法研究

为了寻求快速、经济地测定自然界中紫黑色作物总花色苷含量的方法,利用酸性乙醇对黑元麦、茄子、葡萄3种不同作物进行花色苷提取,并采用pH示差法和差减法2种不同的实验室方法对3种样品总花色苷含量进行留样分析再测定。结果表明,黑元麦、葡萄采用pH示差法和差减法这2种测定方法的结果精确度和准确性没有显著性差异,且样品进行留样再检测时发现,2种样品测定结果之差的绝对值均小于测定结果质量不确定度,可以说明黑元麦、葡萄花色苷实验室定量检测pH示差法和差减法均适用。茄子采用pH示差法测定值相对标准偏差为2.20%,精确度明显好于差减法;从质控图看,茄子检出值出现1次连续4个点上升的情况,说明茄子皮利用差减法测定结果准确性差;从留样再检测结果可以看出,利用差减法测定2次结果之差的绝对值为0.023 mg/g,小于测定结果质量不确定度0.011 mg/g,说明茄子花色苷pH示差法检测结果可信赖,差减法检测存在问题。     

风箱果叶色变化及呈色机理研究

为研究风箱果叶片不同生长发育过程中叶色变化及呈色机理的问题,以风箱果、‘金叶’风箱果、‘紫叶’风箱果为材料,对其叶片从幼嫩到成熟转变过程5 个生长阶段的叶部特征和叶色变化进行比较研究,并采用徒手切片法观察叶片中色素空间分布。结果表明,随着3 种风箱果的生长,叶片面积均呈逐渐增大的趋势,‘紫叶’风箱果叶面积最大;3 种风箱果叶绿素a 含量、叶绿素b 含量、叶绿素/类胡萝卜素均呈现逐渐升高的趋势,风箱果不同生长阶段叶绿素a 含量、叶绿素b 含量均显著高于‘紫叶’风箱果和‘金叶’风箱果;3 种风箱果叶片色素均主要分布于栅栏组织内,在海绵组织和表皮细胞分布较少。上述结果明确了风箱果叶片在生长发育过程中的叶部特征和叶色表现,为其科学合理应用提供了理论依据。     

枣果皮色素物质的初步研究（摘要）

[目的]鉴定枣果皮色素物质的成分。分别提取‘鲁北冬枣’、‘辣椒枣’、‘成武冬枣’和‘大白铃’果皮中的色素物质,并利用HPLC-MS技术进行色素物质的成分鉴定。[方法]在4个枣品种中均可检测到8种黄烷醇类物质,4～5种黄酮醇类物质,未检测到花色苷类物质。各类物质在不同品种中含量有所不同,其中‘大白铃’中含量最多,黄烷醇类物质和黄酮醇类物质含量分别为11和1.78mg/g,约为其他品种含量的1倍。槲皮素3-芸香苷是枣果皮中主要的黄酮醇类物质。[结论]为进一步研究枣果皮转红机制提供理论基础。     

植物花色苷及其生物活性的研究进展

花色苷是一种广泛存在的水溶性植物色素,是植物靓丽颜色的来源。本文对花色苷的颜色和稳定性受到其结构、pH、温度和酶等因素的影响及其所具有的抗氧化、抗癌及其它生物活性进行了综述。