Antioxidant properties, quantification and stability of betalains from pitaya (Hylocereus undatus) peel / Propriedades antioxidantes, quantificação e estabilidade das betalaínas da casca da pitaya (Hylocereus undatus)

Pitaya peel can be used as a raw material for betalains extraction. The aim of this research was to quantify phenolic compounds, antioxidant activity and betalains on pitaya peel. Furthermore, evaluate the betalains stability against various pH conditions and exposure time of heating. The results showed that pitaya peel contains phenolic compounds and presented antioxidant activity. Moreover it showed high concentration of betalains (101.04mg equivalent to betanin. 100g-1) which were stable over a wide pH range (3.2 - 7.0) and were resistant to heating (100oC) up to 10 minutes at pH range from 3.7 to 5.5. Therefore, pitaya peel is a promising source of betalains which can be applied as a natural colorant for food.

A casca da pitaya pode ser utilizada como matéria prima para a extração de betalaínas. O objetivo deste trabalho foi quantificar os compostos fenólicos, atividade antioxidante e as betalaínas presentes na casca da pitaya. Além disso, foi avaliada a estabilidade das betalaínas em diferentes condições de pH e tempo de exposição ao aquecimento. Os resultados mostraram que a casca da pitaya contém compostos fenólicos e apresenta atividade antioxidante. Além disso, a casca da pitaya apresenta alta concentração de betalaínas (101,04mg equivalente a betanina. 100g-1) as quais apresentaram-se estáveis em uma ampla faixa de pH (3,2 - 7,0) e resistentes ao aquecimento (100oC) por até 10 minutos em uma faixa de pH de 3,7 a 5,5. Portanto, a casca da pitaya é uma fonte promissora de betalaínas as quais podem ser aplicadas como corante natural para alimentos.

An in vitro cytotoxicity study of colorized zirconia by immersion method / 实用口腔医学杂志

Objective:To evaluate the cytotoxicity of colorized zirconia ceramics.Methods:Zirconia ceramic 3Y-TZP blocks were colorized by NH4 VO3 ,FeCl3 ,Co(NO3 )3 ,Ni(NO3 )3 and MoCl3 respectively.The cytotoxicity of colorized zirconia to L-929 cells was examined by immersion method and MTT assay.Results:During 3 days culture,L929 cells in all groups showed similar prolifera-tion and normal morphology.The toxicity gradation of all groups was 0 -I.Conclusion:Zirconia ceramics colorized with the 5 kinds of colorants has no cytotoxicity.

Study of placebo used in the Chinese medicinal clinical trail / 国际中医中药杂志

Objective To study the influencing factors of the colorants used in the placebo of herbal medicine.Methods The effect of pH value,temperature,and illumination and sterilization method on the coloring of the pigments like carmine,sunset yellow 60,brilliant blue 60 and caramel were investigated by determining the Lab value with the instrument.Results PH value of solution had effects on the coloring of carmine and sunset yellow 60,but no effects on the brilliant blue 60 and caramel.When pH values of the solutions were adjusted to 10,chromatic aberration values of carmine and sunset yellow 60 were 17.29 and 27.29,respectively; In the conditions of acidification,the color of carmine and sunset yellow 60 solutions were not changed much; short heating and illumination had no effects on all the four pigments,and all the chromatic aberration values were less than 1.5; 60Co-ray irradiation had great effects on the coloring,and the chromatic aberration values of carmine,sunset yellow 60,brilliant blue 60 and caramel solutions after 60Co-ray irradiation were 12.43,22.45,37.53 and 19.22,respectively; While autoclaving (121 ℃,20 min) would not change the color of solution,and all those chromatic aberration values were less than 1.5.Conclusion These colorants are suitable for the placebo preparation of Chinese medicine decoction,which is recommended to be added in the preparation of the final link.60Co-ray irradiation sterilization is forbidden.

Carotenoides bixina e norbixina extraídos do urucum (Bixa orellana L.) como antioxidantes em produtos cárneos / Carotenoids bixin and norbixin from annatto (Bixa orellana L.) as antioxidants in meat products

A oxidação lipídica é uma das principais alterações que acometem os derivados cárneos em razão da composição química rica em lipídios e íons ferro, utilização de processos térmicos e de moagem, além do frequente uso do cloreto de sódio, um reconhecido catalisador desta reação. Os antioxidantes são substâncias utilizadas para inibir ou retardar a rancidez oxidativa, porém, seu uso desperta a atenção de consumidores e agências reguladoras, quanto à segurança que acompanha o consumo de aditivos sintéticos. Este trabalho teve por objetivo avaliar o uso dos carotenoides bixina e norbixina como antioxidantes em produtos cárneos por meio da revisão de suas características químicas, métodos de obtenção, toxicidade e aplicações tecnológicas. Esses pigmentos são extraídos das sementes do urucum (Bixa orellana L.) por métodos que envolvem o uso de solventes orgânicos, extração supercrítica ou ainda a utilização da tecnologia de micro-ondas. No Brasil, o uso dessas substâncias é previsto na legislação como corante alimentício, porém, estes carotenoides apresentam extensas cadeias carbônicas insaturadas que permitem a adição de radicais livres e lhes conferem a capacidade de atuar como antioxidantes. As diferenças estruturais entre bixina e norbixina resultam em particularidades quanto à polaridade, solubilidade, coloração e, por consequência, determinam singulares aplicações tecnológicas. Nas concentrações previstas pelas agências reguladoras, o consumo desses carotenoides é seguro e além das aplicações como corante, podem ser utilizados pela indústria como antioxidantes naturais, oportunizando uma alternativa capaz de substituir ou minimizar o uso de aditivos sintéticos em produtos cárneos.

Lipid oxidation is one of the major modifications that affect meat products due to chemical composition, heat and grinding processes beyond the routine use of sodium chloride, a recognized catalyst of this reaction. Antioxidants are substances used to inhibit or retard oxidative rancidity. However the use of these compounds has been drawing the attention of consumers and regulatory agencies about the safety of synthetic additives consumption. This study aimed to evaluate the use of carotenoids bixin and norbixin as antioxidants in meat products by review of the chemical characteristics, methods of production, toxicity and technological applications. These pigments are extracted from annatto (Bixa orellana L.) using organic solvents, supercritical extraction or microwaves. In Brazil, the use of these substances is forecast by law as food colorant, however, this carotenoids show a large unsaturated carbon chains that allow the addition of free radicals and enable their use as antioxidant. The structural differences between bixin and norbixin result in distinct polarity, solubility and coloration, and consequently in different technological applications. At concentrations established by regulatory agencies, the use of these compounds is safe and, in addition to applications such as dyes, can be used by industries as natural antioxidants, which is an alternative capable of replace or minimize the use of synthetic additives in meat products.

Identification and quantification of anthocyanin pigments in colored rice

Anthocyanin pigments from varieties of black, red and wild rice were identified and quantified to evaluate their potential as nutritional function, natural colorants or functional food ingredients. Anthocyanin extraction was conducted with acidified methanol with 0.1M HCl (85:15, v/v) and identification of anthocyanin, aglycone and sugar moieties was conducted by comparison with purified standards by HPLC, Ultraviolet-Visible absorption spectrophotometer and paper chromatography. Black and wild rice showed three different types of pigments by HPLC whereas red rice variety did not show any anthocyanins. Out of three pigments detected, one (peak 2) was characterized as cyanidin-3-glucoside (C3G) by comparison of spectroscopic and chromatographic properties with an authentic standard, and another (peak 3) was tentatively identified as cyanidin-fructoside on the basis of spectroscopic properties with lambdamax of aglycone in 1% HCl methanol at 537 nm, electrospray ionization mass spectra with major ions at 449 and 287 m/z and chromatographic properties. But another pigment (peak 1) has not been characterized. The most abundant anthocyanin in black and wild rice was C3G.