Phenolic Color Research Articles

A food color-based colorimetric assay for Cryptococcus neoformans laccase activity.

Cryptococcus neoformans is a fungal pathogen that causes cryptococcosis primarily in immunocompromised patients, such as those with HIV/AIDS. One survival mechanism of C. neoformans during infection is melanin production, which catalyzed by laccase and protects fungal cells against immune attack. Hence, the comparative assessment of laccase activity is useful for characterizing cryptococcal strains. We serendipitously observed that culturing C. neoformans with food coloring resulted in degradation of some dyes with phenolic structures. Consequently, we investigated the color changes for the food dyes metabolized by C. neoformans laccase and by using this effect explored the development of a colorimetric assay to measure laccase activity. We developed several versions of a food dye-based colorimetric laccase assay that can be used to compare the relative laccase activities between different C. neoformans strains. We found that phenolic color degradation was glucose-dependent, which may reflect changes in the reduction properties of the media. Our food color-based colorimetric assay has several advantages, including lower cost, irreversibility, and not requiring constant monitoring , over the commonly used 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay for determining laccase activity. This method has potential applications to bioremediation of water pollutants in addition to its use in determining laccase virulence factor expression.IMPORTANCECryptococcus neoformans is present in the environment, and while infection is common, disease occurs mostly in immunocompromised individuals. C. neoformans infection in the lungs results in symptoms like pneumonia, and consequently, cryptococcal meningitis occurs if the fungal infection spreads to the brain. The laccase enzyme catalyzes the melanization reaction that serves as a virulence factor for C. neoformans. Developing a simple and less costly assay to determine the laccase activity in C. neoformans strains can be useful for a variety of procedures ranging from studying the relative virulence of cryptococci to environmental pollution studies.

Elucidating the effects on polyphenol oxidase activity and allelic variation of polyphenol oxidase genes on dough and whole wheat-derived product color parameters

ABSTRACT Polyphenol oxidase (PPO) activity is a primary cause of the development of unattractive dark brown discoloration of wheat-based end products. The present study aims to evaluate a set of 41 diverse wheat genotypes grown at three different locations in India for grain phenol color reaction, PPO activity and molecular marker-based characterization of alleles of PPO genes. Relationships among these parameters were analyzed along with the effects of grain PPO activity on dough and chapati color at different time intervals. The mean PPO activity ranged from 7.42 to 27.57 min−1 g−1 10−3 among the genotypes and it showed a significant negative correlation with color brightness (L*) of dough rested for 0 min (r = -0.406), 15 min (r = -0.406), 2 h (r = -0.502) and 4 h (r = -0.551) and whole wheat flour-derived chapati rested for 2 h (r = -0.267) and 4 h (r = -0.424). The overall quality color score was negatively correlated with PPO activity (r = -0.863) and showed a positive correlation with both dough and chapati visual color measured at different time intervals. PPO activity in the genotypes carrying different alleles was found to be Ppo-A1a>Ppo-A1b; Ppo-B2d>Ppo-B2a; and Ppo-D1b>Ppo-D1a. The allelic constitution Ppo-A1bPpo-B2aPpo-D1a and Ppo-A1bPpo-B2dPpo-D1 was found to produce the lowest PPO activity, and thus these alleles are recommended to be used in marker assisted breeding for low PPO activity genotypes to minimize the discoloration of wheat-based end-products.

Standardization of phenol colour reaction test in rice (Oryza sativa) varieties

Standardization of phenol colour reaction test in rice (Oryza sativa) varieties

L-DOPA Assay of Polyphenol Oxidase (PPO) for Varietal Identification in Rice (Oryza sativa L.)

A phenol colour response test on the grain is used to identify varieties of wheat and rice. It is a harmful, damaging procedure due to the carcinogenic properties of phenol. The activity of polyphenol oxidase (PPO) provides the basis for the phenol colour reaction. The goal of this research was to assess a method similar to the phenol colour reaction, by determining where the polyphenol oxidase activity threshold lies for classifying rice types into different groups. The new PPO assay was applied to commercially available rice varieties with the intention of classifying those that ranged from extremely high to extremely low PPO levels into manageable categories. Substrates such as phenol, L-tyrosine, catechol and 3,4-dihydroxyphenylalanine (L-DOPA) were tested. Twenty cultivars cultivated under identical conditions were put through a screening using a standard assay [1.5 mL of 10 mM L-DOPA in 50 mM 3-(N-morpholino) propane sulphonic acid (MOPS) buffer, pH 6.5, with 3 to 5 seeds constantly rotated in a 2-mL microcentrifuge tube for 0.5 or 1 hour at room temperature]. At 30 minutes, PPO levels were assessed. Based on the PPO values, the varieties belonging to phenol colour groups such as black, dark brown, brown, light brown or no colour matched perfectly. Considering easiness in estimation and other advantages of PPO activity, L-DOPA is proposed as a means of identifying rice varieties instead of the phenol colour reaction test.

Phenol colour reaction and its biochemical basis in cultivated wheat genotypes

For seed to play a catalytic role, it should reach farmers in a good quality state, i.e. high genetic purity and identity. So, varietal purity testing plays a critical role in preventing varietal admixtures. Phenol colour reaction is being used as a rapid varietal identification technique for a long time. PPO has been implicated to cause this enzymatic browning. Polyphenol oxidase activity (PPO) must be reduced or eliminated if wheat quality is to be improved. This research was undertaken for development of quick genetic purity testing method in wheat varieties and to study the effect of PPO activity during storage in cultivated wheat. The biochemical studies of the pathway which gives phenol colouration has also been studied.

Green banana biomass (Musa sp.) as an ingredient in the development of pasta

Green banana biomass (GBB) can be used as a functional and technological ingredient in various food preparations, making them healthier and more nutritious. The aim of the present study was to determine the physicochemical compositions as well as color parameters of different GBB samples, and applying them to gnocchi pasta to determine the resulting technological and cooking properties. The bananas (‘BRS Platina, ‘Fhia 01,’ and ‘Fhia 18’) were grown in an area of the Agroecological Production Integrated System, in Seropédica-RJ, Brazil; the bananas were harvested unripe and pressured cooked to obtain their biomass. The pH values, total titratable acidity, total soluble solids, reducing sugars, moisture, ash, proteins, lipids, total starch, total energetic value (TEV), vitamin C, total phenolic compounds (TPC), minerals, and color were significantly different among the different GBB samples used. Each GBB showed different values of certain analyzed parameters; for instance, ‘BRS Platina’ presented low contents of total starch, lipids, TEV and high levels of vitamin C and TPC. The GBB ‘Fhia 01’presented the highest levels of moisture, proteins, and potassium. All GBBs provided good technological attributes (cooking time, weight increase, cooking loss, and volume increase) for the prepared gnocchi dough. Overall, the application of GBB as an ingredient in gnocchi formulation provided good technological quality and increased nutritional value, thus meeting the growing demand of the consumer market for products with greater health benefits.

Turmeric oleoresin encapsulated by spray drying in maltodextrin/gelatin and starch/gelatin blends: storage stability and water sorption

Turmeric oleoresin is a widely used a flavoring agent and a food color with relevant nutraceutical properties. It is obtained by organic solvent extraction of turmeric (Curcuma longa L.). Microencapsulation is a good alternative to transform liquid food flavorings free-flowing powders and to improve stability of protection of compounds of interest. Thus, the aim of this study was to assess microencapsulation by spray drying of turmeric oleoresin using blends of maltodextrin-gelatin and starch-gelatin, evaluating its sorption isotherms and the storage stability at different temperatures. Turmeric oleoresin encapsulated was stored at - 20, 25 and 60°C, in the absence of light, and at 25ºC in the presence of light, and analyzed over a period of 35 days for curcumin and total phenolic contents and color. The encapsulation efficiency was 72.3% for capsules with starch-gelatin blends and 52.1% with maltodextrin-gelatin blends. Besides the greater encapsulation efficiency, starch-gelatin blends also showed greater stability during storage and retention of curcumin and phenolic compounds. Encapsulated materials were more stable during storage at - 20ºC and less stable at 25°C in the presence of light. Water adsorption of turmeric oleoresin microcapsules were well described by GAB model and the microcapsules produced with starch-gelatin blends showed high hygroscopic behavior.

Effect of varying levels of acorn flour on antioxidant, staling and sensory properties of Iranian toast

Due to the high level of antioxidant activity of acorn fruits, they can be used as an ingredient the production of functional foods. The goal of the this research was to partially substitute wheat flour with varying levels (10% - 50% w/w) of debittered acorn flour and to investigate its effects on the rheological characteristics of the dough, total phenolic content (TPC), staling, colour indices and sensory properties of toast bread. The farinograph degree of softening and water absorption of the dough decreased with increasing the acorn flour content, while the stability and time of development of the dough increased. Resistance and extensibility to deformation of the samples respectively increased and decreased compared to those of the control. Toast bread with 30% acorn flour replacement was observed to have lower staling than the control. The highest TPC (9.44 mg GAE/g) and the lowest peroxide value (0.36 m eq O2/kg) were obtained for the bread having 30% acorn flour substitution. Moreover, the breads showed darker crumbs with significantly lower specific loaf volumes. Overall, the bread with 30% of acorn flour substitution showed good rheological, staling properties and reasonable anti-oxidant content compared to the control bread as well as the highest sensorial acceptability.

Inter- and intra-plant variation in phenol content in grains of rice (Oriza sativa varieties using phenol colour reaction

Different stages of phenol colour reaction showed induction of phenol colour reaction occur post anthesis, i.e. stage 2. In the later stages, i.e. stage 3 (dough) and 4 (harvest maturity) seeds showed similar phenol reaction with less intensity. Phenol content estimated at different stages of growth and maturity showed the highest at post fertilization stage, i.e. stage 2 and it decreased in stage third and fourth. Inter-panicle phenol content was not significantly different whereas intra-panicle difference in phenol content was observed.

Impacts of added oenological tannins on red wine quality to counteract <i>Botrytis</i> infection in Merlot grapes

The contamination of grape berries by Botrytis cinerea can drastically damage wine quality, in particular causing colour degradation. In musts obtained from botrytised grapes, SO2 addition is the main means of avoiding oxidation damage due to laccases excreted by the pathogen. However, consumers are becoming increasingly reluctant to accept SO2 addition to wine. Oenological tannins are used for fining wines because of their colloidal properties, and for wine colour stabilisation due to their ability to condense with anthocyanins. They are also known for their antioxidant and antioxidasic properties. They were thus investigated in the present study for their potential as an alternative to SO2 against laccase oxidation.The impact of various types of oenological tannins on musts and wines was studied once added to musts obtained from the Merlot cultivar, comprising 20 % and 50 % botrytised grapes. Laccase activity, antioxidant capacity, composition of phenolic compounds, spectrophotometric and CIELAB colour parameters were assessed in the musts and wines. Sensory analyses were also performed on 3-month-old wines to evaluate the visual, olfactory and gustative consequences of tannin addition. At a 50 % botrytisation rate, the addition of any type of oenological tannins (at a concentration of 100 g/hL) had no effect on laccase activity and did not protect phenolic compounds. However, at the same concentration and at a 20 % botrytisation rate, proanthocyanidin tannins from grape skin were found to be the most promising tannins with simultaneous protective effects, such as an inhibitory effect on laccase enzymes, protection of colour from complete degradation and preservation of some procyanidin compounds.Oenological tannins are promising candidates for protecting wines from Botrytis damage and they induce a differential effect according to their origin and structure. They could be used to reduce the amount of SO2 that is added during vatting. More research is needed to confirm and better understand the mode of action of various tannins at levels lower than the 20 % botrytised rate tested in the present study.

Determination of production factors of dehydrated strawberries by using Taguchi method approach

Dehydrated fruit is important as an alternative to increase shelf-life and the value of the fresh fruit. Hence, it is important to know approach for this processing. Objective of the study was to know the optimal combination for treatments of material and process for production of dehydrated strawberries by using Taguchi method. The treatments were the combinations from orthogonal array and signal to noise ratio from Taguchi method with several control variables of processing of timing and concentration during immerse in osmotic solution (30,45,60 minutes) and (30, 40,50 0Brix) and also drying temperature (50, 60, 70 °C) were applied in this processing. Several quality parameters of dehydrated fruits were determined such as color of skin fruit, texture, water content, vitamin C, total phenol, acidity, and total soluble solid were measured using standard method. Results showed that, optimum condition for drying temperature was 70°C, and concentration and timing during osmotic dehydration were 60 minutes and 50 0Brix, respectively. Drying temperature was highest factor that affected quality of the dehydrated fruit processing. Physical characterization of dehydrated strawberries were skin drying with softened flesh of fruit, darker red color, and chemical characterization sweet taste, low acidity, high vitamin C and total phenol.

EFFECT OF HOT AIR OVEN, MICROWAVE, MICROWAVE CONVECTIVE, FREEZE DRIED PINEAPPLE PULP ON STORAGE STABILITY OF CASEIN BALL (RASGULLA)

Casein ball (rasgulla) is a round-shaped white coloured cheese ball of a very soft springy and porous texture dipped in sugar syrup and is one of the traditional milk-based sweets of India. Both fresh pineapple pulp (PP) and hot air (PH), microwave (PMW), microwave convective (PMWC) and freeze-dried (PF) pineapple powder mixed with chhana in 1:4 ratio were used to prepare the pineapple fortified rasgulla and coded as PP, PH, PMW, PMWC and PF, respectively. Pineapple (Ananas comosus) was chosen mainly due to its high amount of bioactive components, which reduce the rate of deterioration along with value addition purpose. The study aims to observe the effect of period of storage over 0-50 hours at room temperature (25±2°C) on casein ball (rasgulla) samples (fortified using differently dried pineapple), based on different physicochemical parameters such as phenolic content, antioxidant activity, colour change, hardness and sensory analysis. With the progress in storage time, the colour difference and hardness of all the rasgulla samples also increased and on the other hand, the total polyphenol content (TPC) and DPPH activity values decreased. The addition of differently dried pineapple powder to rasgulla helped to increase the TPC and DPPH scavenging activity, TPC and DPPH both increased by 3.5 fold and 5 fold respectively for PMWC (Microwave convective dried pineapple rasgulla). Also, hardness was decreased by 8.07 % in PMWC than NR (Normal rasgulla).Least colour difference was observed for PP (Pineapple pulp rasgulla) after 50 hours of storage. Significant changes on different

The Effect of Inulin on the Physical and Textural Properties of Biscuits Containing Jet Milled Barley Flour

The quality properties of biscuits with partial replacement of sugar by inulin (at 0, 10, 20 and 30%) and wheat flour by barley flour (at 0, 10, 20, 30 and 40%) were studied. A commercial and a jet milled finer barley flour were used. For all flour substitutions, elevated amounts of inulin led to increased weight and decreased spread ratio of the biscuits. Inulin biscuits, within the same flour composition, were softer than those with no inulin but inulin’s concentration was not statistically important. The incorporation of barley flour resulted in reduced lightness, more evident in the case of the finer barley flour. Inulin also affected the lightness of the biscuits. Phenolic content was affected by the presence of barley flour but no clear trend of inulin’s effect was detected. The interactions between barley substitution, inulin substitution and particle size of the barley flour were important for all studied properties, i.e., weight, spread ratio, hardness, total phenolic content and color.

Elaboration of mangaba vinegar by semi-solid fermentation combined with enzymatic activity: chemical characterization and sensory evaluation

ABSTRACT: The objective of this study was to produce vinegar from mangaba pulp using semi-solid alcoholic fermentation combined with the enzymatic activity of pectinase and to investigate the chemical composition and sensory characteristics of the final product. was evaluated for volatile acidity and the reduced dry extract was evaluated for ashes, alcohol content, sulfates, pH, total phenolic compounds, total carotenoids, color parameters, yield, productivity, and sensory analysis. Average and standard deviation was used for descriptive statistics. Principal component analysis (PCA) was applied to all variables except total carotenoid content. Physicochemical characterization of the raw and alcoholically fermented pulp was also carried out. The main results showed that, in the vinegar, the reduced dry extract, volatile acidity, pH, and ashes were 44.3±1.5 (g/L), 4.4±0.1 (% w/v), 3.1±0.0, and 3.0±0.41 (g/L), respectively. The total phenolic compound content and total carotenoid content for the mangaba vinegar were 19.2±8.20. mg/100 g and 2.6±0.6. mg/100 g, respectively. The conversion yield from ethanol to acetic acid was 90%. PCA showed that pH and volatile acidity had a strong influence on the product, and there was a strong positive correlation between color and aroma. The final product met all legal requirements, showing that it is possible to produce mangaba vinegar with antioxidant potential for consumers. In the sensory evaluation, it was favored by the tasters, demonstrating potential economic value in the Cerrado fruit.

Identification of chilli (Capsicum Annuum L.) cultivars based on chemical tests and Sds-page of total soluble proteins

Identification of chilli cultivar is prime importance to ensuring seed quality during seed production, certification and quality control. Fifteen cultivars were subjected to different biochemical tests Viz., phenol test, modified phenol test with FeSO4 and CuSO4, analysis of soluble seed proteins by SDS-PAGE. No single varieties were so distinct in case of phenol colour reaction, while it helped to group the cultivars. Based on modified phenol text with ferrous sulphates 1per cent (FeSO4) and 0.5 per cent copper sulphate (CuSO4) helped in further classification of cultivars. The cultivars Gouribidanur Local and Phule Jyothi showed unique bands at 14 (Rm: 0.624) and 2 (0.191) level of band. All the cultivars were distinct among each other showing SDS-PAGE as efficient method in chilli cultivar identification.

Estimation of genetic variability parameters for various qualitative and quantitative traits in bread wheat (Triticum aestivum L. EM. Thell)

The present investigation was carried out during Rabi 2017-2018 at Norman E. Borlaug Crop Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. The experimental material comprised of 17 parental genotypes (14 lines, 3 testers) and 42 F1 hybrids, obtained after crossing them in a line × tester fashion with the objective to study genetic variability parameters for various qualitative and quantitative traits. The experiment was carried out in Randomized Block Design (RBD) with three replications and observations were recorded on various qualitative and quantitative characters. In general, PCV was higher than GCV for all the characters studied. GCV was higher than ECV for most of the characters. The magnitude of PCV and GCV was highest for phenol color reaction followed by number of effective tillers per plant and number of grains per spike. High heritability was observed for grain yield per plant, grain weight per spike and biological yield per plant. High genetic advance as percent of mean was found for phenol color reaction, number of effective tillers per plant and number of grains per spike. High heritability with high genetic advance is helpful for improvement through mass selection by fixing additive gene action, while high heritability with low genetic advance showed the preponderance of non-additive gene action due to high influence of environment.

Phylogenetic analysis of the Si7PPO gene in foxtail millet, Setaria italica, provides further evidence for multiple origins of the negative phenol color reaction phenotype.

To elucidate the diversity and evolution of the Si7PPO gene that controls phenol color reaction (Phr) in foxtail millet, Setaria italica, we analyzed sequence polymorphisms of the Si7PPO gene in 39 accessions consisting of foxtail millet landraces (32 accessions) and their wild ancestor ssp. viridis (seven accessions) collected from various regions in Europe and Asia. The accessions included wild type (positive Phr) and three different types of loss-of-function phenotype (negative Phr), "stop codon type", "TE1-insertion type" and "6-bp duplication type", found in our previous study. We constructed a phylogenetic tree of the gene and found that accessions with positive Phr showed higher genetic diversity at the nucleotide sequence level. We also found that the three different loss-of-function types formed different clusters, suggesting that landraces with negative Phr have multiple origins from three different lineages including both landrace and ssp. viridis accessions with positive Phr.

Moving bed biofilm reactor for treatment of Kraft pulp effluent with high organic load rate

The pulp industry uses more than 40 m3 of water per ton of pulp produced, generating high effluent flows. In general, it presents high concentrations of organic matter, color and ecotoxicity. The most widely used effluent treatment systems in the pulp industry are biological, including moving bed biofilm systems that are efficient in removing biodegradable organic matter. This work evaluated the removal of organic matter, total phenolic compounds, color and lignin derivatives in the treatment of Kraft cellulose effluent using the moving bed biofilm reactor (MBBR), and also evaluated the support media biofilm development by solid analysis and scanning electron microscopy. The parameters evaluated during treatment were: BOD5, COD, color, total phenolic compounds, lignin derivatives, and solids, with tests performed on organic loads from 0.7 and 8.9 kgCOD m-3 d-1. Organic matter removal remained stable, being over 80% to BOD5 and over 42% to COD. The color and the total phenolic compounds were removed up to approximately 7 and 28%, respectively. Over 19% removal of derivatives of lignin compounds was observed in both organic load rates. In the MBBR, biofilm was confirmed and enabled this biological system to treat the cellulose effluent in a stable way.

A Comparative Study on Trichoderma harzianum and a Combination of Candida/Bacillus as Tools for the Bioremediation of Table Olive Processing Water.

A comparative study was performed on Trichoderma harzianum and a combination of Candida boidinii/Bacillus pumilus to reduce the polluting effect of TOPW (Table Olive Processing Water) from the Spanish style. A 2k fractional design was used to study the effect of pH (6–11 for the fungus and 6–9 for Candida/Bacillus), temperature (10–35 °C) and duration (7–14 days for Candida/Bacillus and 14–21 days for T. harzianum), and the effect on phenol reduction, COD and color was evaluated. The experiments were also performed on diluted TOPW (dilution ratio 1:1). Generally, Trichoderma removed higher amounts of phenols and reduced COD more than the combination Candida/Bacillus, thus confirming the higher efficiency of filamentous fungi reported in the literature. The dilution of TOPW had an effect only on COD reduction; however, the effect was mild, at least for T. harzianum (4%), while yield increase was 9% for Bacillus/Candida. pH acted in a different way on phenol removal and COD reduction; an increase of pH caused a reduction of efficiency for COD, while the effect was positive for phenols.

Evolution of the content of phenolic compounds, antioxidant activity and color in organic sugarcane spirit aged in barrels of different woods

During the aging of sugarcane spirit several chemical reactions occur. Therefore the aim of this work was to study the evolution of phenolic content, antioxidant activity and changes in color in organic sugarcane spirit aged in different woods for twelve months. The sugarcane spirit aged in barrels of jatobá showed higher levels of phenolic compounds and antioxidant activity (277.3 mg EAG.100 g-1 and -7.749 mg.L-1), followed by sassafras (83.8 mg EAG.100 g-1 and -0.299 mg.L-1) and ipê (67.6 mg EAG.100 g-1 and 4.180 mg.L-1). The colorimetric variables (brightness, chroma and metric hue angle) were significantly influenced by the species of the woods.