天然色素研究与应用

天然色素不但具有呈色作用,并兼有营养、保健等功能,对人体健康起着重要保护作用。该文主要论谜天然色素特点与特性、分类、性质与作用、应用与开发。     

Stability and use of natural colours in foods Red beet powder, copper chlorophyll powder and cochineal

Three natural pigments – red beet powder, chlorophyll powder (in the form of a copper complex) and aqueous cochineal – were examined in order to understand better their behaviour or colouring ability in different model systems. All were heat labile but red beet colour in particular was rapidly degraded above about 14°C. Cochineal proved the most stable of the three colours. All were adversely affected by changes in pH and a reduction in water activity gave a corresponding increase in stability for each colour. Light was similarly shown to cause degradation of the natural colours. The colours were used in food products and shown to have certain applications with regard to the colour of jam and restoring the colour of peas after blanching.     

Consumer exposures to anthocyanins from colour additives,colouring foodstuffs and from natural occurrence in foods

Anthocyanins are responsible for the red/blue colour of grapes, currants, and other fruits and vegetables. They may also be extracted for use as colour additives (E163) or concentrated for use as colouring foods. Consumer exposures have been assessed using data on natural occurrence, use levels and frequencies from food manufacturers and European food consumption data. Intakes from natural occurrence can be up to 4 mg kg bw^?1 day^?1 at the mean and up to 17 mg kg bw^?1 day^?1 for children who are high level consumers of red/black berries and small fruits. High-level intakes for children from food colour and colouring food applications lie in the range 0.3–6.3 mg kg bw^?1 day^?1 and for adults at 0.6–2.8 mg kg bw^?1 day^?1. Exposures from food colour use and colouring foods separately or combined are therefore lower than those from natural occurrence in foods.     

Colloidal approach to prepare colour blends from colourants with different solubility profiles

Food colouring plays a vital and a determining role in the processing and the manufacturing of food products because the appearance of products is critical for attracting consumers and influencing their food choices. However, factors such as legislative restrictions, limited number of approved colourants and the processing, formulation and stability issues of the natural colourants severely limits the application of food colouring in actual product formats. Hence, finding alternatives to the currently utilised formulation practises, represents an important area of research. Here, we report a simple colloidal approach to prepare colour blends by co-incorporating colourants with contrasting aqueous solubility profiles in composite colloidal particles. Curcumin and indigocarmine were selected as water insoluble and water soluble food-grade colourants respectively and incorporated in the colloidal particles prepared from food protein-zein. Composite particles obtained by loading of curcumin and indigocarmine (at different ratios) had mean particle size ranging from 76 to 300 nm. The spherical shape of the colloidal particles was confirmed using transmission electron microscopy and the colloidal dispersions were further characterised using UV–Vis and fluorescence spectroscopy. The incorporation of colourants in colloidal particles led to the generation of different shade of colour in yellow–green–blue range. The encapsulation also led to the stabilization of individual pigments against photodegradation. Such composite colloidal particles could potentially serve as an approach for developing tuneable colouring system for food and nutraceutical applications.     

一株银杏内生真菌红色素稳定性的研究

真菌色素是一个极具应用潜力的食用色素来源。一株从银杏枝条分离的内生真菌SX01,能产生大量的红色素,经鉴定该菌属于产紫青霉（Penicillium purpurogenum）。该菌在PDA液体培养基中静置培养后,经过离心、过滤可得到红色素,该色素为水溶性色素。通过分析红色素特征吸光值的变化,研究了光照、pH、温度、金属离子对该红色素稳定性的影响。结果表明,色素溶液对温度和光照较为敏感,色素在温度〈60℃的稳定性较高,但当温度上升至80℃以上后,色素稳定性较差。色素对光照较为敏感,长时间光照可以使色素色价大幅度下降,影响色素品质。该色素对pH是稳定的,色素提取液在pH10时色价甚至有所增高。金属离子对该色素稳定性影响较小,Zn2+有一定的增色效果,Cu2+、Al3几乎无影响,Fe2+和Fe3+对其有不良影响。     

红枣红色素的研究进展

随着食品工业的迅猛发展,食品添加剂在人们生活中发挥的作用日益显著。近年来,食品安全屡遭质疑,人们对食用色素也提出了更高的要求,相较于大多数具有致癌风险的合成色素,取自天然、无污染的植物色素更受到人们的青睐。枣红色素是一种提取自红枣果皮的天然色素资源,但开发和利用这一天然色素资源还存在许多问题。本文就色素组成、性质、药理活性、提取和精制方法及深加工技术进行了介绍,综述了近年来红枣红色素在提取、加工和应用方面的研究概况。分析表明,红枣红色素原料来源丰富,提取方便,是一种值得深度开发的性能优异的天然色素资源,但在色素结构鉴定、高效低能耗提取方法开发和产品干燥制粉等方面目前开展的工作较少,文末就此对枣红色素的研究进行了展望。     

Microbiological denitrification of red beet juice

The purpose of study was the determination of optimal conditions for red beet juice denitrification by Paracoccus denitrificans bacteria as well as the evaluation of the usefulness of microbiologically treated juice for the production of a natural colouring preparation for foods. Total reduction of nitrates was found during bacterial culturing at 25 and 30 °C, at an initial pH of 7.0-8.0 and juice osmotic pressure of 900-1100 mOsm/kg. Microbiological denitrification procedure affected colour, taste and aroma of the juice. However, the use of juice as food colouring and component was made feasible by acidification and partial evaporation of water together with volatile substances.     

天然红色素在肉制品中的应用

<正> 目前国内在肉制品中应用较多的天然红色素是红曲米粉、红曲红色素和高粱红。但是这些天然色素远远不能满足现代肉制品加工的需要,开发新的天然红色素,对原有工艺进行改进,已成为迫切的问题。而花生衣色素、枣皮红色素和荞麦皮红色素因其营养价值高、性质稳定、来源广泛,将在肉制品中有着良好的应用前景。 1、红曲米 红曲米义称赤曲、红米、福米。是将稻米清洗后用0.2％柠檬水溶液浸泡,蒸     

Use of Red Beet (<Emphasis Type="Italic">Beta vulgaris</Emphasis> L.) for Antimicrobial Applications—a Critical Review

Red beets (Beta vulgaris L.) have high levels of betalains and other phytochemical compounds that are associated with antioxidant activity. They are ranked higher than other fruits and vegetables that are known for excellent health-promoting properties, such as Swiss chard. Red beet pigments have been extensively used in the food industry as a natural colorant. Although the antimicrobial activity of red beet has many potential applications in the food and consumer product industries, it has not been thoroughly investigated. In this article, we summarize the findings from recent studies quantifying phytochemical antioxidants in red beet in comparison with other natural sources and critically examine the current research where the antimicrobial potential of red beet extract has investigated, highlighting the associated challenges and limitations of these approaches. Finally, we discuss how red beets can be commercially exploited for their antimicrobial properties and future prospects for new value-added red beet products.     

Natural Colorant from Marigold-Chemistry and Technology

Natural pigments offer an alternative to synthetic dyes, but for successful application, an understanding of the chemical and physical properties of the pigment is essential. With the growing legislative restrictions on the use of synthetic colors, a reappraisal of natural plant pigments is taking place with a view to use them as possible colorants in foods. For natural pigments to be accepted as food colorants, legal sanction is a must. With the application of new innovations, natural pigments can become more cost effective and increase their competitiveness against certified dye and dye products. Marigold flowers, which are yellow to orange red in color, are a rich source of lutein, a carotenoid pigment. This pigment has acquired greater significance because of its antioxidant property and for its eye health protection. Although marigold flower extract has been used in veterinary feeds, the potential use of marigold as a natural food colorant has not been exploited to the full extent due to the lack of information on its safety, stability, and compatibility in foods. This article deals with the chemistry, processing, and stability of the pigment and its applications.     

橙子果皮诱导抗病组分对意大利青霉的抑菌活性及作用机制

对前期研究发现的毛霉诱导脐橙果皮产生的抗病性红色物质组分进行分离纯化,并分析其对柑橘意大利青霉的抑菌活性及作用机制。结果表明,在50～200 μg/mL质量浓度下,红色物质组分对意大利青霉孢子萌发、芽管伸长、菌落生长和菌丝生物量增加表现出很强的剂量依赖型抑制作用。进一步研究表明：红色物质处理改变了菌丝细胞壁几丁质结构与分布,降低了几丁质含量;破坏了细胞膜通透性,降低了细胞膜总脂质含量和麦角固醇含量,影响了细胞膜的正常功能。说明红色物质作为替代化学杀菌剂的新型柑橘采后安全保鲜剂具有良好的研究和开发前景。     

食品着色剂亚硝基血红色素的研究

以健康的猪、牛、羊的新鲜牲血为原料，经化学提取、合成及酶解等简单步骤，制成了食品着色剂亚硝基血红色素。该产品可替代具有毒性作用的亚硝酸盐而直接加入食品着色，是一种无毒副作用的理想的调味食品着色剂，同时也增强了食品的营养成分。     

花色苷及微胶囊化天然色素的应用效益

<正> 在食品中添加色素,不但能使产品重获加工时失去的色泽,保证所有批次产品的均匀性,而且还能改进制成品的外观。随着消费者对合成色素安全性的日益关注,天然色素应运而生,在过去数年间,其在全球食品工业中的应用愈来愈广泛。然而,当天然色素从其来源如水果、植物中抽提后,便会因失去原有的保护环境而丧失抗降解能力,采用微胶囊技术将天然色素包埋在     

天然色素的资源和应用

天然色素作为食品添加剂应用于食品已有几个世纪的历史，开发利用天然色素在工业生产中具有重要的研究意义。介绍了天然色素的概念、特点、资源并与合成色素比较，阐述了天然色素的研究方法和应用现状，指出综合利用天然资源开发色素具有巨大的工业发展潜力。     

中国红米色素的研究

<正> 育种科学家和植物化学家早已证实,红米色素是花色苷受多基因控制的显性遗传。不同品种、不同栽培条件下种皮的颜色不尽一致,Nagal认为红米种皮色素是花青3-葡糖苷(chrysanthemin),花青素鼠李葡糖苷(keracyanin)和湿生金丝桃素(Uliginosin)。Gutek等认为野生稻的色素主要是花青3-葡糖苷和花青素鼠李葡糖苷。关于我国栽培的红米的色素尚未见报道。我们首次将红米色素加工成食品着色剂,并对其性质、稳定性、安全性和加工工艺等作了研究,现将有关部分内容叙述如下:     

常用天然色素抗氧活性的研究

对花青素类、黄酮类、类胡萝卜素类和醌类等十四种常用天然色素的抗氧活性研究表明:姜黄色素、两种高粱色素、可可壳色素、葡萄皮色素和洋葱色素具有较强的抗氧活性;紫草红色素、紫胶红色素、叶绿素铜钠盐、栀子黄色素和辣椒红色素具有一定的抗氧活性;甜菜红色素仅有一点抗氧活性;而红曲米色素和栀子蓝色素不具有抗氧活性。     

Bioactive compounds and health benefits of exotic tropical red–black berries

Tropical countries produce a large amount of native and exotic fruit species which are potentially interested in the food industry. The nutritional and therapeutic values in this fruits are mainly due to the presence of bioactive compounds, especially polyphenols. The anthocyanins belong to the flavonoid family and represent a group of pigments responsible for most of the colors in fruits, leaves, flowers, stems and roots of plants. Several investigations have focused on the health benefits of consumption of red–black fruit, claiming these as natural sources of bioactive compounds with highly promising antioxidant and anti-inflammatory characteristics. Furthermore, the consumption of red–black berries brings a positive impact on several chronic conditions, such as obesity, diabetes, cancer, cardiovascular and neurodegenerative diseases. This article summarizes the foremost bioactive compounds and the health properties of exotic tropical red–black berries, specifically Euterpe oleracea, Eugenia uniflora, Myrciaria cauliflora, Myrciaria dubia, Syzygium cumini.     

Effect of nonthermal treatments on selected natural food pigments and color changes in plant material

In recent years, traditional high-temperature food processing is continuously being replaced by nonthermal processes. Nonthermal processes have a positive effect on food quality, including color and maintaining natural food pigments. Thus, this article describes the influence of nonthermal, new, and traditional treatments on natural food pigments and color changes in plant materials. Characteristics of natural pigments, such as anthocyanins, betalains, carotenoids, chlorophylls, and so forth available in the plant tissue, are shortly presented. Also, the characteristics and mechanism of nonthermal processes such as pulsed electric field, ultrasound, high hydrostatic pressure, pulsed light, cold plasma, supercritical fluid extraction, and lactic acid fermentation are described. Furthermore, the disadvantages of these processes are mentioned. Each treatment is evaluated in terms of its effects on all types of natural food pigments, and the possible applications are discussed. Analysis of the latest literature showed that the use of nonthermal technologies resulted in better preservation of pigments contained in the plant tissue and improved yield of extraction. However, it is important to select the appropriate processing parameters and to optimize this process in relation to a specific type of raw material.     

Valorisation of food wastes to produce natural pigments using non-thermal novel extraction methods: a review

Waste or by-products produced during food processing can be used as a potential source of bioactive compounds including natural pigments. Natural pigments/colourants have numerous health benefits whereas the synthetic colourants have many negative effects on human health. Thus, there is a considerable interest worldwide in pigments extraction from natural sources. Conventional extractions such as soxhlet extraction, water distillation, and solvent extraction have many limitations such as large solvent consumption, long extraction time, and low extraction yields. Therefore, novel techniques such as high pressure, ultrasound, negative pressure and electric field have been employed to assist the pigment extraction process. The novel extraction methods are being developed with the primary aim of higher pigment yield, lower solvent consumption, minimised environmental effects and the convenience of extraction. With this perspective, the present review provides recent insights into the recovery of natural pigments from food wastes/by-products and the application of novel non-thermal technologies for their recovery.     

3‐Deoxyanthocyanidin Colorant: Nature,Health, Synthesis,and Food Applications

3‐Deoxyanthocyanidins are a rare type of anthocyanins that are present in mosses, ferns, and some flowering plants. They are water‐soluble pigments and impart orange‐red and blue‐violet color to plants and play a role as phytoalexins against microbial infection and environmental stress. In contrast to anthocyanins, the lack of a hydroxyl group at the C‐3 position confers unique chemical and biochemical properties. They are potent natural antioxidants with a number of potential health benefits including cancer prevention. 3‐Deoxyanthocyanidin pigments have attracted much attention in the food industry as natural food colorants, mainly due to their higher stability during processing and handling conditions compared with anthocyanins. They are also photochromic compounds capable of causing a change in “perceived” color, when exposed to UV light, which can be used to design novel foods and beverages. Due to their interesting properties and potential industrial applications, great efforts have been made to synthesize these compounds. For biosynthesis, researchers have discovered the 3‐deoxyanthocyanidin biosynthetic pathway and their biosynthetic genes. For chemical synthesis, advances have been made to synthesize the compounds in a simpler and more efficient way as well as looking for its novel derivative with enhanced coloration properties. This review summarizes the developments in the research on 3‐deoxyanthocyanidin as a colorant, from natural sources to chemical syntheses and from health benefits to applications and future prospects, providing comprehensive insights into this group of interesting compounds.