Color and Stability of Anthocyanins of Chagalapoli (Ardisia compressa K.) Fruit Added to an Isotonic Beverage as Microcapsules and as Free Extract.

The demand for natural pigments in the food industry is increasing. Color and stability of anthocyanins of chagalapoli (Ardisia compressa K.) fruit added to an isotonic beverage as microcapsules and free extract were evaluated at two temperatures (4 and 25 °C) in the absence of light. Anthocyanins degradation followed first-order kinetics in the evaluated conditions. The stability of anthocyanins, measured by the variables reaction rate (K), half-life time (t1/2), and anthocyanin retention (AR), was affected significantly (p < 0.01) by temperature. At the end of storage at 4 °C, AR was 91.2 ± 0.28% and 89.63 ± 0.22% in the beverages with microcapsules (BM) and with anthocyanins from extract (BE), respectively, without a significant difference (p ≥ 0.05) between them. However, at 25 °C, AR in the BM was 53.72 ± 0.27%, a significantly lower value (p ≤ 0.05) than that in BE (58.83 ± 1.37%). The color difference values (ΔE) in beverages stored at 4 °C were 3.81 and 2.17 for BM and BE, respectively, while at 25 °C, it was 8.57 and 8.21, respectively. The most stable anthocyanin was cyanidin 3-galactoside. Chagalapoli anthocyanins, both as microcapsules or as an extract, are adequate for adding natural color to isotonic beverages.

Physicochemical, calorimetric and texture profile characteristics of various gluten-free flours.

It is important to understand how the composition and structure of proteins from other flours differ from proteins in wheat, in order to have a better option to substitute gluten products with gluten-free food products. The aim of this study was the characterization of gluten-free flours and comparison of their rheological and calorimetric properties against wheat flour, for its use as gluten-free alternative. Chemical composition analysis, water solubility index (WSI), water absorption index (WAI), texture and calorimetric profile were determined. The closest WAI to wheat flour (1.45 g gel/g sample) was corn flour (2.41 g gel/g sample), while the WSI of chickpea flour was 5.51% approaching that of wheat flour of 5.88%. The hardness and adhesiveness values closest to wheat (1.65 kgf and 0.03 mJ) were amaranth flour with 0.85 kgf and 0.01 mJ, respectively. The phenolic content and antioxidant capacity were higher in the corn and bean flours with 244.4 mg GAE/100 g, 148 mg GAE/100 g and 190 mg AAE/100 g and 170 mg AAE/100 g, respectively. The combination of these non-conventional flours can be an innovative source of gluten-free formulas.

Anthocyanin-rich extract from black beans exerts anti-diabetic effects in rats through a multi-genomic mode of action in adipose tissue.

Black beans (BB) are an important source of a range of plant bioactive compounds including polyphenols, particularly anthocyanins. Several studies support that consumption of BB is associated with health benefits, including prevention of type 2 diabetes mellitus (T2DM). However, molecular mechanisms underlying the potential health properties of BB on adipose tissue (AT) are still largely unknown. The purpose of this study was to investigate multi-genomic effects of BB intake and identify regulatory networks potentially mediating T2DM on AT. Male Wistar diabetic rats consumed an anthocyanin-rich black bean extract for 5 weeks. Global gene expression from AT, protein coding and non-coding RNA profiles were determined using RNAseq. Biological function analyses were performed using a variety of bioinformatic tools. The evaluation of global gene expression profiles exhibited significant change following BB consumption with 406 significantly differentially expressed genes, 33 miRNA and 39 lncRNA and 3 snRNA. Functional analyses indicated that these genes play an important role in regulation of PI3K signaling, NIN/NF-kB signaling, insulin secretion, and endoplasmic reticulum (ER) organization. Interestingly, transcription factors such as GATA2, or POU2AF1 demonstrated to modulate their activity by BB extract by direct interaction with polyphenol metabolites, or by interactions with cell signaling proteins, like PKB, AKT or PI3K, that could control transcription factor activity and as a result impact on adipogenesis regulation. Therefore, the constant consumption of an anthocyanin-rich black bean extract may have anti-diabetic protective effects by modulating gene expression, resulting in a promising alternative for T2DM patients.

Nutraceutical, Physicochemical, and Sensory Properties of Blue Corn polvorones, a Traditional Flour-Based Confectionery.

Blue corn is an anthocyanin-rich material that can be used in the preparation of baking products. The aim of this work was to evaluate the physicochemical, nutraceutical, and sensory properties of polvorones (a traditional flour-based confectionery) made with whole blue-corn flour. All samples showed similar bromatological composition, but polvorones from whole blue-corn flour had a higher phenolics (837.1 mg gallic acid/kg) and anthocyanins (373.0 mg cyanidin-3-glucoside/kg) content, which exerted an influence on their higher antioxidant activity compared with wheat flour-based laboratory and commercial samples. The transformation of raw blue-corn flour into polvorones produced the degradation of some acylated anthocyanins into non-acylated forms. The substitution of wheat flour with whole blue-corn flour enhanced overall acceptability, as well as the color and flavor of polvorones. Our findings demonstrated that it is possible to use whole blue corn in the formulation of polvorones with more health beneficial properties and better consumer acceptability than refined wheat products.

Encapsulation and pigmenting potential of betalains of pitaya (Stenocereus pruinosus) fruit.

Betalains of pitaya (Stenocereus pruinosus) fruit can be used as natural pigment, but they are susceptible to deterioration by temperature, pH, and presence of sugars. In this work, a refined extract (Er) of betalains was obtained through aqueous two-phase extraction, which reduced significantly sugar and mucilage contents. In order to favor stability, the encapsulation of the refined extract was evaluated, with native potato starch that was modified through phosphorylation or succinylation and reactive extrusion. Starches were evaluated in terms of degree of substitution, Fourier transform infrared spectroscopy, scanning electron microscopy, and viscous behavior. Microcapsules were formed by spray drying and their stability was evaluated at 40 °C for 39 days and by using them as pigmenting agent of yogurt at 4 °C during 32 days. The behavior of modified starches during encapsulation was superior to that of commercial N-Lok® starch. Microcapsules based on modified starches showed better pigmenting potential and higher stability than Er and microcapsules based on N-Lok® starch. The separation of betalains from pitaya fruit may be a good alternative for adding value to this plant genetic resource.

Preparation and characterization of octenyl succinylated normal and waxy starches of maize as encapsulating agents for anthocyanins by spray-drying.

The encapsulation by spray drying of maize anthocyanins was evaluated using two types of wall materials, consisting of normal and waxy maize starch, which were esterified with octenyl succinic anhydride. The X-ray diffraction analysis revealed that SWMS possessed a completely amorphous, while SNMS had a crystalline structure. SNMS showed peaks at 2θ = 13.1°, 19.8° and 22.4°. The results revealed that SNMS and SWMS had almost the same encapsulation productivity (EP); SNMS showed the best performance because its EP was higher (95%) than in SWMS (90%). The stability of microcapsules produced with SNMS showed the highest anthocyanin retention after storage in the water activity (aw) range of 0.11-0.94 at 40 °C.

Factors influencing anthocyanin loss during nixtamalization of blue purple maize grain.

Blue purple maize grain loses a great amount of anthocyanins during the nixtamalization processing. The impact of the process factors on anthocyanins losses has not been studied in detail. The objectives of this work were to: (1) determine the step of the nixtamalization procedure where the greatest anthocyanin loss occurs and (2) study the effect of cooking time, alkali concentration, and sample size on anthocyanin losses (AL), and on the color of masa and tortilla from blue purple maize grain. Two cooking times were assayed (25 and 35 min), three alkali concentrations (0.5, 0.7, and 1.0% w/w), and two maize grain sample sizes (100 and 1000 g). Alkali concentration determines the time required to solubilize the maize grain pericarp, higher concentrations resulted in shorter maize grain pericarp solubilization times and this variable was related with AL. The greatest AL occurred during the grain cooking step, but an additional loss took place during the steeping of cooked grain. For the cooking time of 25 min, AL were of 38.3% during the cooking step, and 21.3% during the steeping of cooked grain. The cooking time had no effect (p > 0.05) on AL in masa and tortilla whereas alkali concentration and sample size significantly affected it. The greater the concentration and size, the higher the AL. The color of masa and tortilla were affected by cooking time and alkali concentration. Increasing alkali concentration during the nixtamalization procedure, reduced the brightness and chroma of masa and tortilla and made these products seem darker and dull.

Betalains and phenolic compounds profiling and antioxidant capacity of pitaya (Stenocereus spp.) fruit from two species (S. Pruinosus and S. stellatus).

Pitaya fruits (Stenocereus spp.) contain betalains and phenolic compounds that have not been completely characterized. Fruits of two ecotypes of S. pruinosus, red-fleshed (SpR) and orange-fleshed (SpO), and two of S. stellatus, red-fleshed (SsR) and white-fleshed (SsW), were characterized in their betalains and phenolic compounds. The chromatographic profile of betalains was similar in SpR, SpO, and SsR, where indicaxanthin, gomphrenin I, phyllocacthin, and their isomers predominated. Betaxanthins content was higher than betacyanins and ranged from 17,706.7±1128.1 to 22,053.6±328.1µg/g dry sample. The identified phenolics mostly corresponded to hydroxycinnamoyl derivatives, flavonols and flavanones. The phenolics content was higher in S. stellatus than in S. pruinosus. The ecotype SsW, that had flesh without color, showed the highest concentration. The antioxidant capacity varied within 9.21±0.84 and 2.41±0.36µmolTrolox/g fresh sample, as determined by the ABTS assay. By its phytochemical composition, the fruits of pitaya can be a good source of antioxidant compounds.

Physical, chemical, and antioxidant activity characterization of pitaya (Stenocereus pruinosus) fruits.

Fruits with red and orange flesh of the columnar cactus pitaya (Stenocereus pruinosus) were studied to evaluate physical characteristics, total soluble solids, betalains and soluble phenols content, and antioxidant activity. Fruits had, in average, weight of 179.0 g, 9.8 °Brix, 9.4 % carbohydrates, 1.25 % protein, 0.11 % ethereal extract, 0.60 % crude fiber, and 0.62 % ash. Also, fruits resulted rich in Fe (22.8-27.8 mg/kg). Hue angle and contents of betacyanins, betaxanthins (µg/g dry sample), and total soluble phenols (mg GAE/g fresh sample) were 19.8°, 2860.0, 3210.0, and 1.6 in the red material, and 28.9°, 470.0, 2670.0, and 1.2, respectively, in the orange fruit. The antioxidant capacity was higher in the red material, since the ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) technique reported 1090.6 and 735.4 µmol of Trolox equivalents/g fresh flesh in red and orange fruits, respectively, while the oxygen radical absorbance capacity (ORAC) assay reported 7.84 and 5.16 µmol of Trolox equivalents/g fresh flesh, respectively. The chromatographic profile showed five betalains in red fruits, but only four of them were observed in those orange fleshed.

Grain and tortilla quality in landraces and improved maize grown in the highlands of Mexico.

The maize produced in the highlands of Mexico (>2,400 masl) is generally not accepted by the flour and masa and tortilla industry. The objective of this work was to evaluate the grain quality and tortilla properties of maize landraces commonly grown in the highlands of Mexico and compare them with improved germplasm (hybrids). Germplasm analysis included 11 landraces, 32 white hybrids, and six yellow hybrids. Grain quality was analyzed for a range of physical and chemical factors, as well as for alkaline cooking quality. Landrace grains tended to be heterogeneous in terms of size, hardness and color. All landraces had soft-intermediate grains with an average flotation index (FI) of 61%. In contrast, hybrid grains were homogenous in size and color, and harder than landrace grains, with a FI of 38%. Protein, free sugars, oil and phenolic content in landraces were higher than in the hybrids. Significant correlations were found between phenolic content and tortilla color (r= -0.60; p<0.001). Three landraces were identified as appropriate for the masa and tortilla industry, while all the hybrids evaluated fulfilled the requirements of this industry.

Factors influencing the geographical distribution of Dendroctonus rhizophagus (Coleoptera: Curculionidae: Scolytinae) in the Sierra Madre Occidental, México.

The bark beetle, Dendroctonus rhizophagus Thomas & Bright, is endemic to the Sierra Madre Occidental (SMOC) in México. This bark beetle is a major pest of the seedlings and young saplings of several pine species that are of prime importance to the nation's forest industry. Despite the significance of this bark beetle as a pest, its biology, ecology, and distribution are poorly known. Three predictive modeling approaches were used as a first approximation to identify bioclimatic variables related to the presence of D. rhizophagus in the SMOC and to obtain maps of its potential distribution within the SMOC, which is a morphotectonic province. Our results suggest that the bark beetle could have an almost continuous distribution throughout the major mountain ranges of the SMOC. This beetle has a relatively narrow ecological niche with respect to some temperature and precipitation variables and inhabits areas with climatic conditions that are unique from those usually prevalent in the SMOC. However, the bark beetle has a broad ecological niche with respect to the number of hosts that it attacks. At the macro-scale level, the D. rhizophagus distribution occurs within the wider distribution of its main hosts. The limit of the geographical distribution of this bark beetle coincides with the maximum temperature isotherms. Our results imply a preference for temperate habitats, which leads to the hypothesis that even minor changes in climate may have significant effects on its distribution and abundance.

Extracción y uso de pigmentos del grano de maíz (zea mays L) como colorantes en yogur / Extraction and use of pigments from maize grains (zea mays L) as colorants in yogur

El objetivo del presente trabajo fue determinar el uso potencial de las antocianinas extraídas de granos de maíz, como colorantes en yogur. Se emplearon cuatro variedades nativas de maíz (Arrocillo, Peruano, Purepecha y Cónico), que posee alta concentración de antocianinas en el pericarpio y en la capa de aleurona. Estas estructuras del grano se separaron mecánicamente con ayuda de una perladora de cebada Strong-Scott, obteniendo la fracción pericarpio-capa de aleurona (FPCA), que se caracterizó en términos del contenido total de antocianinas, y se obtuvo su perfil de antocianinas mediante HPLC. Las antocianinas extraídas de la FPCA fueron añadidas a un yogur natural comercial, en concentración de 1 mg/100 g de yogur. Las muestras de yogur coloreadas se almacenaron bajo condiciones de refrigeración (4°C ±1) durante 25 días y se les midió color y pH cada 5 días. El más alto contenido de antocianinas se obtuvo en la FPCA del maíz Peruano y fue de 259.4 mg/100 g de muestra. El color del yogur obtenido con los cuatro extractos fue diferente. Los coloreados con los extractos de los maíces Peruano y Arrocillo mostraron un tono rojizo más intenso que los obtenidos con los de Cónico y Purepecha. El color de los yogures se mantuvo sin cambios durante los primeros cuatro días, pero entre los días 5 y 10 de almacenamiento, cambió a una tonalidad más amarillenta, al incrementarse los valores de Hue. Sin embargo, estos cambios no fueron visualmente evidentes, por lo que es posible el uso de los pigmentos del grano de maíz para teñir alimentos de acidez intermedia como el yogur

[Extraction and use of pigments from maize grains (Zea mays L) as colorants in yogur]. / Extracción y uso de pigmentos del grano de maíz (Zea mays L.) como colorantes en yogur.

The aim of the present work was to determine the potential use of anthocyanins from maize grains as colorants in yogurt. Pigments were extracted from four native maize varieties (Arrocillo, Peruano, Purepecha and Cónico), which possess a high anthocyanin concentration in the pericarp. Pericarp and aleurone layer were mechanicallly removed from grain using a Strong-Scott barley pearled. Yields of pericarp and aleurone layer fraction (PALF) were evaluated. Total anthocyanin content in this fraction was determined by a conventional spectrophotometric method and the anthocyanin profile was obtained by HPLC. One mg of anthocyanin extracts from the PALF was added to 100 g of a commercial plain yogurt. Yogurt samples were kept under refrigerated conditions and color and pH were monitored every 5 days interval, during three weeks. The yields of PALF were 48.4%, 55.1%, 40.2%, and 40.0% for Arrocillo, Peruano, Cónico and Purepecha varieties, respectivelly. The highest total anthocyanin content (259.4 mg of anthocyanins/100 g sample) was observed in Peruano PALF. The color of yogurts dyed with each of the four extracts was different. Yogurts dyed with Peruano and Arrocillo extracts showed a more intense reddish tone than those dyed with Cónico and Purepecha. After 5 to 10 days under refrigerated storage, the color of all yogurt samples changed to a slight yellowish tone according to the Hue values, Nevertheless, these changes were not visually evident.

Physicochemical and rheological characteristics of commercial nixtamalised Mexican maize flours for tortillas.

Three commercial nixtamalised Mexican maize flours (CNMFs) designated HI-A, HI-B and HI-C were evaluated in this work. For each brand, four samples corresponding to four consecutive months of production were evaluated. Tortillas prepared by the traditional process of nixtamalisation were used as the control. The maize flours and their respective tortillas showed variations between samples in their physical, chemical and rheological parameters. The three commercial maize flours incorporated additives and preservatives. The moisture content, colour, pH, subjective water absorption capacity, water solubility index, water absorption index and swelling capacity of flours showed strong differences between the three CNMFs with respect to the chemical analysis. Important differences in the protein, calcium and amylose contents were observed. Tortillas from CNMFs had a blander maize flavour, less desirable texture and staled more rapidly than traditional tortillas. Some modifications are required in the current Official Mexican Quality Standard, principally in the appropriate selection of additives and levels used in the preparation of CNMFs. © 2000 Society of Chemical Industry.