pH敏感性材料在智能食品包装中的应用进展

随着消费者食品安全意识的增强,通过包装颜色变化对食品品质进行直观判断成为一个新的需求,智能包装近年来成为学界和产业界的共同关注点。pH敏感性材料与聚合物混合后获得的食品包装膜,在不同的pH条件下显示不同颜色,具有实时监测肉、虾、牛奶等食品新鲜程度的效果。本文介绍了化学显色剂和天然色素显色剂两大pH敏感性型指示器,分类介绍花青素、姜黄素、茜素、紫草素、甜菜碱等天然食品色素在不同pH下的变色机理,总结了pH敏感性材料与不同聚合物共混改性后在食品包装领域的研究进展、应用现状和研究趋势,为制备性能良好、绿色环保的智能食品包装提供参考。     

基于天然色素的食品新鲜度指示包装研究进展

随着食品安全意识的不断增强,消费者希望通过更加快捷直观的方式了解他们所购买食品的质量。由此出现了能在食品运输和储藏过程中,向人们提供食品质量信息的食品新鲜度指示包装。考虑到食品的安全性,越来越多的研究者开始利用植物中提取的天然色素作为指示剂。本文综述了近年来以花青素、姜黄素、茜素和紫草素为染料的食品新鲜度指示膜的研究现状。分析了基于天然色素的食品新鲜度指示膜在生鲜肉、水产品、牛奶和水果中的应用原理及其研究进展,并对食品新鲜度指示包装的研究和应用前景进行了展望。     

花青素pH响应型智能包装及其在食品新鲜度监测中的应用

随着消费者对食品安全和质量的要求不断提高，以及食品包装技术的发展进步，近年来食品智能包装发展迅速。pH响应型智能包装能通过感知食物或其周围pH值的变化产生颜色反应实现对食物新鲜程度和腐败程度的反馈，是研究的热点。花青素因其获得简便、安全性高和优异的pH响应性等特点被广泛研究。该文介绍了花青素的来源及结构，阐述了花青素在不同pH值下的变色机理，总结了基于花青素或富含花青素提取物的pH响应型智能膜的制备方法和其在食品新鲜度监测中的应用，指出了其在应用中的局限性及研究趋势。     

胭脂萝卜花色苷活性智能指示膜的制备及其特性分析

基于花青素和生物可降解材料的智能指示膜因其能够可视化反应食品质量或新鲜度而受到广泛关注。此试验以羧甲基纤维素钠(carboxymethyl-cellulose sodium, CMC-Na)和魔芋葡甘露聚糖(konjac glucomannan, KGM)为成膜基材,以胭脂萝卜花色苷(ANS)作为指示剂,以茶多酚(tea polyphenols, TP)作为抗氧化剂,制备活性智能指示膜,比较5种膜(CMC+KGM, CMC+KGM+ANS, CMC+KGM+ANS+0.02%TP, CMC+KGM+ANS+0.1%TP和CMC+KGM+ANS+0.2%TP)的力学性能、透气性、透光率、稳定性和抗氧化活性。结果表明,胭脂萝卜花色苷对pH响应好,可作为膜的指示剂,茶多酚添加增加膜的抗拉伸强度,改善膜的稳定性,同时显著增加膜的抗氧化活性。     

花青素稳定性研究进展

花青素作为天然色素,由于其无毒、广泛的颜色具有保健功效,已经引起越来越多学者的兴趣。尽管花青素在食品、制药和化妆品行业有着巨大潜力,但由于其相对不稳定性,使其使用受到了很大限制。该文主要综述了近年来对花青素的化学研究概况,重点论述了pH、辅色作用、金属离子络合和抗氧化活性对其稳定性的影响,同时也简要介绍了一种更加稳定的新型花青素——吡喃花青素。     

用于食品质量监测的pH智能指示剂的研究进展

近年来,消费者对于食品安全要求的改变促进了包装新技术的发展。目前用于食品质量监测的智能包装技术主要有指示剂、数据载体装置以及传感器等。其中,pH智能指示剂由于其成本低、体积小、制备方便和指示效果好等优点而成为研究热点。通常来说,指示剂是由负载基和pH染料组成。同时天然pH染料如茜素、姜黄素、类胡罗卜素、花青素等对于环境酸碱性的改变能表现出明显的颜色变化。以天然pH染料制备的pH智能指示剂能够传递食品的实时信号（颜色、化学或电子）,以表现实时的质量信息。本文主要对以天然染料和生物聚合物为基础的pH智能指示剂的研究现状进行了概述,讨论了基于天然pH染料和合成pH染料相比的pH智能指示剂的重要性,以及未来的研究趋势。     

花青素加工贮藏稳定性的改善及应用研究进展

花青素是一类广泛存在于果品蔬菜等植物性食品中的水溶性类黄酮色素,不仅为食品提供了丰富的颜色, 而且其呈现的抗氧化、抗炎、抗肿瘤等生理活性使其成为功能性食品研究开发的热点。由于花青素不稳定,其在食 品饮料和膳食补充剂中的应用受到限制。本文在广泛查阅文献的基础上,综述了近年来改善花青素加工贮藏稳定性 的方法和技术,重点论述了共色作用、复合作用及载体包埋等技术方法在提升花青素加工贮藏稳定性方面的进展, 以期为花青素的深入研究和工业化利用提供参考。     

甲基橙——靛红指示剂测定壳聚糖脱乙酰度

研究利用甲基橙--靛红指示剂测定低脱乙酰度壳聚糖方法,通过与电导测定法测定结果进行比较,优选出最佳配比.并对不同脱乙酰度壳聚糖样品进行测定.结果表明,甲基橙--红(2:1)混合指示剂指示终点准确,变色明显,稳定性好,可以作为测定不同脱乙酰度壳聚糖样品的通用指示荆.     

姜黄素-明胶-酪蛋白钙复合膜理化特性研究

本研究将不同浓度的姜黄素添加到明胶-酪蛋白钙中,开发出一系列姜黄素-明胶-酪蛋白钙抗氧化复合膜,并对其力学特性、光学特性、表面形貌、抗氧化活性和保鲜效果进行分析。结果表明:加入姜黄素后,姜黄素中的成分物质与明胶相互作用,导致复合膜的厚度和断裂伸长率逐渐增大,外观颜色变深,抗拉强度、水溶性和水蒸气透过系数逐渐降低,对食物中脂类的氧化有明显抑制作用且逐渐增强,原子力显微镜观测其表面粗糙程度逐渐增大,对冷藏肉的抗氧化效果越来越好。因此,姜黄素-明胶-酪蛋白钙复合膜的开发在食品包装和保鲜等方面表现出潜在的应用价值。     

含花青素双层指示薄膜的贮藏稳定性

目的:探索花青素指示薄膜的最佳贮藏条件。方法:以含花青素的双层指示薄膜为研究对象,测定其在不同贮藏时间(0,7,14,21,28,35 d)和温度(25,4,18 ℃)下的机械性能(抗拉强度和断裂伸长率)、厚度、颜色和抗氧化性能(总酚含量、DPPH自由基清除能力和ABTS自由基清除能力)。结果:指示薄膜的厚度总体稳定保持在0.15 mm左右,18 ℃条件下贮藏的薄膜颜色变化最小。抗氧化活性试验表明,25 ℃贮藏的指示薄膜比4 ℃和18 ℃ 贮藏的抗氧化活性更高,尤其是清除DPPH自由基能力。结论:含花青素双层指示薄膜的最佳贮藏温度为25 ℃,最佳贮藏时间为28 d。     

Anthocyanin Pigments—Bioactivity and Coloring Properties

ABSTRACT: Anthocyanin pigments are responsible for the attractive red to purple to blue colors of many fruits, vegetables, flowers, and cereal grains. In plants they serve as attractants for pollination and seed dispersal, give protection against the harmful effects of UV irradiation, and provide antiviral and antimicrobial activities. Anthocyanin-based colorants are commercially manufactured for food use from horticultural crops and from processing wastes. There is a large body of knowledge on anthocyanin chemistry in the literature that includes established, systematic methods for identifying anthocyanins and measuring their concentration and color properties. Structural variation (B-ring substitution, glycosidic substitution, and acylation) produces a multiplicity (over 400) of anthocyanins. Color intensity and hue, as well as stability, are markedly affected by pH, which can be a major limitation for many food applications. Increased glycosidic substitution and acylation with cinnamic acids will improve pigment stability. However, the matrix in which the pigments exist can have a much greater impact on pigment degradation. Anthocyanin pigments are very effective scavengers of free radicals. Currently, there is much research activity on their possible health benefits. While anthocyanin-based colorants are universally approved for food use, there are considerable regulatory differences among countries.     

花色苷分子结构修饰及其生理活性研究进展

花青素是植物界分布最广、种类众多的一类天然色素,是植物的主要呈色物质,在自然界中多以糖苷（花色苷）的形式存在,具有多种重要的生理功能和生物活性。花色苷具有酚羟基,结构稳定性较差,易受外界条件如pH值、温度、光、O2、金属离子和酶等因素的影响,在食品加工中易分解失去原有的鲜艳颜色,限制了花色苷的贮藏和在食品加工领域中的应用。花色苷分子结构修饰可增加其对外界环境和食品添加剂及食品加工中的稳定性,使其在较大pH值范围内呈现良好色泽。本文系统介绍了不同类型（花色苷酰基化、花色苷酯基化及形成吡喃类衍生物）花色苷结构修饰的原料来源、结构特征及其生理活性,为进一步开展花色苷的结构稳定性与生理活性研究及其在食品加工领域中的护色与应用提供参考。     

Stabilization of anthocyanin extract from jabuticaba skins by encapsulation using supercritical CO2 as solvent

Anthocyanins are one of most important group of water-soluble and vacuolar pigments in nature. This phytochemical has attracted great interest to the food industry due to the wide range of biological activities including antioxidant and anti-inflammatory activities. However, the introduction of anthocyanins into food and/or medical fields has proved to be a major technological challenge since these compounds have low stability to environmental conditions during processing and storage. In this context, the present study evaluates the encapsulation of anthocyanin extract obtained from jabuticaba (Myrciaria cauliflora) skins in Polyethyleneglycol using supercritical CO₂ as solvent and ethanol as co-solvent. For comparison, a conventional method, ionic gelification, was employed to produce encapsulated particles by entrapment in Ca-alginate beads. The encapsulation efficiency of the extract in Ca-alginate beads was higher (98.67%) than those obtained by Rapid Expansion of Supercritical Solution (RESS) process (79.78%). Encapsulated particles made by RESS at different pressures, and temperatures, retained the extracts' biological activity. The best operating RESS process condition for anthocyanin extract encapsulation was determined as 313.15 K and 20 MPa. The degradation studies indicated that both encapsulated systems were more stable to light and temperature than the free extract. Ca-alginate encapsulated Anthocyanin extract release in acid buffer solution was incomplete and slower than when the extract was encapsulated by PEG. Both systems increased the stability of anthocyanin, although presenting different characteristics.     

天然花色苷色素稳定化研究进展

文章综述了近些年花色苷的保护技术,包括添加大分子物质、小分子辅色、金属离子螯合和包埋技术等,指出未来需要进一步加强新技术、新材料在花色苷保护方面的应用,以及针对不同种类食品体系专属定制稳定化方法的研究开发。     

影响低温肉制品褪色因素研究进展

低温肉制品在贮藏过程中易褪色,是由主导色素亚硝酰血色原氧化引起的。原料肉来源、蒸煮温度、滚揉和烟熏等工艺均对低温肉制品颜色有影响。光照和氧气直接导致了色素氧化,进而引起褪色,适宜的冷藏温度和气调包装能减缓色素氧化并保护产品颜色。添加剂如亚硝酸盐、抗氧化剂和色素对低温肉制品颜色有不同程度的影响。     

Thermal Degradation of Acylated and Nonacylated Anthocyanins

ABSTRACT:  The thermal degradation pathways of acylated and nonacylated anthocyanins from 3 commercial sources have been investigated. Strawberry, elderberry, and black carrot concentrates were purified on XAD-16-HP and Sephadex-LH-20 columns to remove sugars, amino acids, salts, and phenolic compounds, respectively. The so obtained anthocyanin isolates were heated at 95 °C at pH 1, the optimum stability condition for the flavylium cation. During 7 h of thermal exposure, the samples were monitored by HPLC-DAD-MS³ at 280, 320, and 520 nm, respectively, together with spectrophotometric color and anthocyanin assessment. Total anthocyanin content lightness, and chroma, but not hue angle, were appropriate parameters to monitor anthocyanin loss on a statistically significant level. Anthocyanin glycosides were generally cleaved by successive loss of sugar moieties and pentoses were more readily split off than hexoses. Anthocyanin aglycones were further degraded by scission into phloroglucinaldehyde (cyanidin, pelargonidin), 4-hydroxybenzoic acid (pelargonidin), and protocatechuic acid (cyanidin), the residues of the A- and B-rings, respectively. Most interestingly, acylated cyanidin-triglycosides from black carrot were degraded into their corresponding diglycoside derivatives, which are not genuine carrot pigments. Moreover, hydroxycinnamic acid glycosides were generated. It is therefore assumed that the thermal burden during processing of anthocyanic food can be deduced by monitoring the colored and colorless compound profiles.     

Color Stability of Strawberry Jam as Affected by Cultivar and Storage Temperature

The stability of three strawberry cultivars was evaluated for changes in jam color quality during processing and storage at 20°, 30° and 37°C for 200 days. Anthocyanin content was determined by HPLC. The effect of cultivar, processing and storage on jam pigments, instrumental color (L*, a*, b*) and consumer preference were also determined. ‘Oso grande’ jam had the lowest anthocyanin concentration (110 mg/g f.w), higher monomeric pigment degradation during processing and storage, highest pH, least desirable color score from the sensory panel and shortest shelf-life. Similarities were found between jams prepared with ‘Chandler'and Tudla’ cultivars, as well as initial differences in total anthocyanin concentrations (195 and 130 mg/g f.w.).