Model Beverage System Research Articles

Application of complexes from phycocyanin and pectin in a model beverage system

The blue-appearing phycocyanin from the cyanobacteria Arthrospira platensis undergoes severe color losses during food production or storage. Thus, many studies have looked at stabilizing phycocyanin against processing conditions such as heat with biopolymer complexes. The promising results have not yet been applied to beverage systems. In this study, complexes of pectin and phycocyanin were evaluated for color stability in double distilled water and a model beverage system. The color stability was tested under severe storage conditions. With a z-average diameter of 326 ± 26 nm, the complexes of phycocyanin and pectin remained smaller than pure phycocyanin (415 ± 71 nm) after heating and storage for 13 days. This could assure a better colloidal stability of the color. Kinetic modelling showed that the color degradation was slowed down by the application of complexes between phycocyanin and pectin from a half-life (t1/2) of 74 days to 117 days. A decreased color degradation could be confirmed in the model beverage although an initial color shift which needs to be considered. The color difference between the original hue at day 0 and the samples stained with phycocyanin alone exceeded that of the beverages stained with the complexes from day 10 to 13.

Lipote fruit anthocyanin-rich extracts as food colourants: extraction optimization and stability of natural and copigmented anthocyanins

Natural pigments such as anthocyanins are currently being explored for food colouring applications due to safety issues associated with synthetic colourants. Lipote (Syzygium polycephaloides), an underutilized fruit in the Philippines, is found to contain high amounts of this natural pigment. Thus, this study aimed to optimize parameters for maximum anthocyanin extraction from these fruits by mixture design and response surface methodology followed by the evaluation of the extracts’ stability using model beverage systems. Results revealed that the optimum solvent for maximum anthocyanin recovery was 55% acidified ethanol while optimum extraction temperature and time were 45.8°C and 92 mins, respectively. Stability tests showed that the lipote fruit extract, in its natural form, was most stable in the dark, at low pH (pH 3.0) and low storage conditions (4°C) with an extrapolated half-life (t1/2) of 169.06 days. Anthocyanin stability was further enhanced by copigmentation with caffeic acid resulting in an even higher t½ of 223.60 days.

Interaction of preheated whey protein isolate with rose anthocyanin extracts in beverage model system: Influence on color stability, astringency and mechanism

Preheating proteins have the potential to improve anthocyanin stability. Our aim was to investigate the effect of preheated whey protein isolate (WPI) on the color stability and astringency of the beverage model system in the presence of rose anthocyanin extracts (RAEs), and to explore the mechanism of interaction between preheated WPI and RAEs. The secondary structure, particle size and transparency of WPI were obviously changed by preheating. WPI preheated at 100°C (WPI100) could effectively improve the color stability of RAEs in the beverage model system. Importantly, the WPI100-RAEs in the beverage model system exhibited the smallest particle size and the weakest astringency effect. In addition, different preheated WPIs could interact with RAEs non-covalently, and the interaction forces are hydrogen bonding and van der Waals forces, among which WPI100 had the strongest binding ability to RAEs. These results will provide a new insight into the development of protein-anthocyanin beverages.

Protective effect of amino acids on the stability of bayberry anthocyanins and the interaction mechanism between l-methionine and cyanidin-3-O-glycoside

The protective effects of three amino acids (l-phenylalanine, l-tryptophan and l-methionine) on the stability of bayberry anthocyanins were investigated. The anthocyanin stability under constant illumination (5000 Lux, 50 Hz) or in the presence of ascorbic acid were evaluated by degradation kinetic parameters, and the interaction between l-methionine and cyanidin-3-O-glucoside (C3G) in a model beverage system was analyzed using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, X-ray diffraction, molecular docking, and molecular dynamics simulation. Results indicated that the three amino acids significantly reduced the degradation rate of bayberry anthocyanins (p < 0.05), with the most effect by l-methionine. l-methionine could bind to C3G via hydrogen bonds and Van der Waals forces. This study suggested that l-methionine could well protect anthocyanin against degradation in the aqueous solution and have the potential to be used as a co-pigment to improve the sensory property and extend the shelf life of anthocyanin rich berry products.

Study on the color effects of (-)-epigallocatechin-3-gallate under different pH and temperatures in a model beverage system

The effects of pH (2.2–8.0) and temperature (25–100 °C) on the instrumental color of a model beverage containing (−)-epigallocatechin-3-gallate (EGCG) were investigated. As the pH and temperature increased, the lightness (L*) decreased while the redness and yellowness (a* and b*, respectively) increased. Using spectral scanning, it was possible to verify that color changes might be related to the structural rearrangement of the EGCG aqueous solution in the system under alkaline and heating conditions. There were 6 key substances identified in the EGCG solutions, among which (2R)-2-Hydroxy-3-(2,4,6-trihydroxyphenyl)-1-(3,4,5-trihydroxyphenyl)-1-propanone 2-O-gallate (m/z 473.0720) and theacitrin C/dehydrotheasinensin AQ (m/z 911.1340) were identified as key coloring substances. Color changes did not decrease antioxidant activity of the beverage model. These results provide new insights on the mechanism of color change during storage of green tea beverages, and enable the understanding of key contributors to the browning of infusions color in tea beverages for the first time.

Copigmentation with Chlorogenic and Ferulic Acid Affected Color and Anthocyanin Stability in Model Beverages Colored with Sambucus peruviana, Sambucus nigra, and Daucus carota during Storage.

The food industry is looking for alternatives to synthetic colorants. Anthocyanins (ACNs) are suitable replacements due to their color characteristics and potential health benefits. The application of sauco (Sambucus peruviana, SP) as a potential source of ACN-based colorants was evaluated and compared to elderberry (Sambucus nigra, SN) and an extract from purple carrots (PC). Color and pigment stability were evaluated using a model beverage system during eight weeks of storage. Copigmentation with chlorogenic acid (CGA) and ferulic acid (FA) were also evaluated. SP ACNs provided darker and more intense colors than those obtained with SN but less intense than those obtained with PC. Addition of CGA and FA resulted in significantly darker colors with higher chroma in beverages colored with SP and SN but not in beverages colored with PC. Copigmentation with FA reduced monomeric pigment half-lives for all ACN sources but increased the chroma half-lives of beverages colored with SP and SN, from 23 to 49 weeks, and from 23 to 55 weeks, respectively. Analyses using liquid chromatography coupled to photodiode array detection and mass spectrometry showed that interaction between non-acylated ACNs and FA resulted in the formation of pyranoanthocyanins. Overall, ACNs from non-acylated sources such as SP, in combination with FA, showed potential for commercial food applications.

Protective effect and mechanism of action of xanthan gum on the color stability of black rice anthocyanins in model beverage systems

We investigated the effect and mechanism of action of xanthan gum (XG) on the color stability of black rice anthocyanins (BRA) in model beverage systems (pH 3.0) containing l-ascorbic acid under different conditions. The color stability of BRA was significantly enhanced in the presence of XG under accelerated storage conditions (40 °C), particularly at 0.25% (w/v). The degradation of BRA followed a first-order reaction rate (R2 > 0.89) during storage and thermal processing conditions. The addition of XG effectively improved the storage stability of BRA in the presence of l-ascorbic acid, particularly at 4 °C in the dark. Moreover, the thermal stability of BRA was enhanced by XG under thermal treatment (80 °C, 90 °C and 100 °C). The FTIR spectrum, X-ray diffraction and molecular simulation results showed that the interaction between XG and BRA was driven mainly by hydrogen bonds and hydrophobic interactions, leading to the increased stability of BRA. Our study demonstrated the benefits of using XG to improve the color stability of BRA in model beverage systems, further expanding the practical application of XG in anthocyanin-rich beverages.

Evaluating the effect of additives on stability of betacyanin pigments from Basella rubra in a model beverage system during storage.

The effect of selected additives (catechin, ascorbic acid, β-cyclodextrin and EDTA) on the stability of betacyanin pigments from Basella rubra in a model beverage system was investigated and they exhibited remarkable outcomes. The major betacyanin pigment in B. rubra extract was identified to be gomphrenin-I using HPLC-ESI-MS analysis method. The degradation kinetics of betacyanin pigment in the model beverage variants was established, and temperature was found to be the most detrimental factor. If effect of additives on stability of B. rubra betacyanin pigments in model beverage stored at 4°C in the absence of light and oxygen is considered, maximum stabilizing effect was demonstrated by catechin (t1/2 203.9days) followed by EDTA (t1/2 187.3days) and then β-cyclodextrin (t1/2 144.4days) when compared with control (t1/2 119.5days) whereas, ascorbic acid acted as a prooxidant and reduced storage stability of the pigment (t1/2 78.8days).

Phenolic composition by UHPLC-Q-TOF-MS/MS and stability of anthocyanins from Clitoria ternatea L. (butterfly pea) blue petals.

The aim of the present study was to evaluate the phenolic composition of crude lyophilized extracts (CLE) and partially purified (PPE) extracts of C. ternatea blue petals as well as the anthocyanin stability against pH, temperature and light in the presence and absence of fructooligosaccharides. Twelve compounds were tentatively identified by UHPLC-Q-TOF-MS/MS in CLE and PPE extracts. In direct/reverse spectrophotometric titration, anthocyanins showed colour changes between pH 2.25 to 10.20, and colour reversibility, maintaining antioxidant activity against the DPPH radical. The aqueous extracts at pH 3.6 and 5.4 exhibited thermal stability with the presence and absence of fructooligosaccharides with activation energy higher than 99kJ/mol. The addition of fructooligosaccharides in the extracts at pH 5.4 exposed to light provided a protective effect against anthocyanin photodegradation. The data show the technological potential of aqueous extract of C. ternatea blue petals as a natural colourant in a functional beverage model system.

Heat and light stability of natural yellow colourants in model beverage systems

ABSTRACT The performance of 10 natural yellow colourants at different concentrations (0.001–0.3% w/v) was investigated in a model beverage system at various pH levels (3.5, 5.5 and 7.5) containing 10% w/v of sucrose, with or without ethanol (15% v/v) to simulate both alcoholic and non-alcoholic lemon-like beverages. Thus, the incidence of pH, ethanol and colourant concentration on spectral properties as well as turbidity were evaluated. The λmax was found to be independent from concentration in the tested range (0.001– 0.3% w/v), whereas the specific absorbance at λmax increased linearly. Moreover, the absorption spectrum and λmax of yellow pigments were found to be independent of pH and ethanol. Gardenia, safflower, and curcumin had the highest colour intensity and the lowest turbidity level. Heat and light stability were studied for these as well. Safflower was found to be the most stable colourant against heat (25, 40, 60, 80°C) and light (550 W/m2, 30°C).

Effects of β-cyclodextrin, whey protein, and soy protein on the thermal and storage stability of anthocyanins obtained from purple-fleshed sweet potatoes

The effects of β-cyclodextrin (β-CD), whey protein (WP), and soy protein (SP) on the color loss and degradation of anthocyanins in purple-fleshed sweet potato anthocyanin extracts (PFSPAEs) during thermal treatment and shelf-life storage in model beverage systems by performing chromaticity, degradation kinetics, and principal component analysis. Results showed that WP and SP improved the thermal stability of the PFSPAE, but WP accelerated the color loss of the extract. However, the addition of 25 mg/L SP improved the color and thermal stability of the anthocyanins when heated at 100 °C for 30 min. With regard to the shelf-life storage, the addition of SP and WP showed non-significant effect on the storage stability of the PFSPAE. However, the addition of 2500 mg/L β-CD significantly improved the storage stability of the PFSPAE. In summary, our findings provide useful information on improving the thermal and storage stability of PFSPAEs in beverage systems using food biopolymers.

Characterization of the binding of cyanidin-3-glucoside to bovine serum albumin and its stability in a beverage model system: A multispectroscopic and chemometrics study

Anthocyanins as one of the main natural groups of food colorants undergo quick color fading, which can be diminished through protein association. The stabilization of cyanidin-3-glucoside (CYG) through binding to bovine serum albumin (BSA) was investigated at pH 3.0 using atomic force microscopy and differential scanning calorimetry along with UV–Vis absorption, steady-state fluorescence, circular dichroism, and three-dimensional emission spectral analyses merged with the multivariate curve resolution-alternative least square method. The stabilized CYG molecules were found at the site II of BSA with combined static and dynamic quenching mechanisms. Approximately 93% of the BSA binding sites were occupied in the BSA-CYG complex through hydrogen bonds and van der Waals forces with the binding constant and stoichiometry ratio of 1.88 × 105 M−1 and 1:13, respectively. The results also revealed that CYG molecules caused partial unfolding of the BSA structure, while it was not enough for significant alteration of denaturation temperature. The binding results also indicated that the reduction of H2O2-induced-CYG oxidation rate (34.78%) at pH 3.0 was mainly driven via the BSA-hemiketal association, although the colored species of CYG had a greater affinity towards BSA in the equilibrated system at pHs 1.0 and 5.0.

Furan formation from ingredient interactions and furan mitigation by sugar alcohols and antioxidants of bamboo leaves in milk beverage model systems.

Furan is a potential carcinogen that can be formed in various heat-treated foods, including milk beverages. Studies on the formation and mitigation of furan in milk beverages are rare. In the present study, the effects of ingredients on furan formation and the reduction of furan by sugar alcohols and antioxidants of bamboo leaves (AOB) were investigated in a milk beverage model system. The results obtained demonstrated that the Maillard reaction is the major pathway for furan formation in a milk beverage model system, and the type of sugar has a great influence on furan formation. High fructose corn syrup (HFCS 55) was more favorable for furan formation than sucrose. Thermal oxidation of ascorbic acid and lipids significantly enhanced furan generation. Xylitol, sorbitol and mannitol inhibited furan formation in model systems by replacing sucrose or HFCS. The maximum inhibition percentage of furan formation was observed when sucrose/HFCS was substituted completely by xylitol and the inhibition rate was 78.28% and 88.64% separately for the sucrose/HFCS-containing system. AOB significantly inhibited furan formation and the inhibition rate reached 32.13% and 28.52% separately for the sucrose/HFCS-containing system. The present study demonstrates that the use of sugar alcohols and AOB could be a feasible way of reducing furan formation in thermally processed milk beverages. © 2019 Society of Chemical Industry.

Texture and mouthfeel perceptions of a model beverage system containing soluble and insoluble oat bran fibres

Dietary fibre fortified products have increased in popularity as health-conscious consumers seek convenient ways to increase fibre intake. Fibres from wholegrains are particularly desirable inclusions in food products because of their proven physiological health-benefits. When fortifying beverages with fibre, however, the insoluble dietary fibre components present in wholegrains often contribute to unpleasant gritty sensations making the products unpalatable. Consequently, designing wholegrain-fortified beverages with sufficient fibre-content to make health related fibre claims is a major challenge in the food manufacturing industry. This work aims to take a systematic approach in identifying the texture/mouthfeel related sensory impact and interaction between two commercial oat fibre ingredients (Oatwell28XF® and Milled Oats) when added to a model beverage system. Eighteen samples were prepared containing either or both the ingredients, at varying levels, and were assessed by a trained panel using conventional sensory descriptive techniques. The results indicate that the two different oat bran fibres produced distinct mouthfeel perceptions which could be attributed to the varying soluble and insoluble fibre content of the samples. Insoluble dietary fibre concentrations above 2% (w/w) resulted in particle-related sensory properties chalkiness, dryness and particle perception, which dominated the overall mouthfeel and textural sensory perception of the samples. Samples with predominantly soluble β-glucan, resulted in perceptions of smoothness, sliminess and stickiness residue, while thickness, mouthcoating and cloying sensations were driven by total fibre concentration, irrespective of fibre solubility. This work provides a solid foundation for food manufacturers aiming to rationally design and develop nutritionally superior fibre-fortified beverages and is relevant to fibre content concentrations required for labelling/nutrition claims for consumer products in many developed nations.

Effects of low acyl and high acyl gellan gum on the thermal stability of purple sweet potato anthocyanins in the presence of ascorbic acid

This study investigated the different effects of low acyl (LA) and high acyl (HA) gellan gum on the thermal stability of anthocyanin-containing model beverage systems in the presence of ascorbic acid. The addition of gellan gum, especially HA, resulted in higher absorbance values, which suggested higher anthocyanin stability during heat treatment. The thermal stability of each anthocyanin was significantly improved by the addition of gellan gum (P < 0.05). Moreover, diacylated anthocyanins exhibited higher heat resistance than monoacylated anthocyanins. The molecular dynamics simulations revealed that the improvement in the anthocyanin stability following the addition of gellan gum was due to the binding between the gellan gum and the anthocyanins. HA was found to have stronger interactions with the anthocyanins than LA, which was attributed to the increased steric hinderance and flexibility caused by the acyl groups. In summary, we revealed that gellan gum can potentially be used to enhance the thermal stability of anthocyanins in beverages and identified the important role of the acyl groups of gellan gum in stabilizing the anthocyanins. These findings will broaden the applications of gellan gum and improve the popularity of anthocyanin-containing beverages.

Effect of ozone processing conditions on stability of fungal pigments

Abstract The aim of the present study was to analyze the impact of ozone processing technology on the stability of fungal pigments produced by Talaromyces spp. suspended in a buffer of pH 6 and a beverage model system (BMS). Both samples were ozonated by different ozone levels (0.031 to 0.064 mg/min/mL) and processing times (0 to 10 min). The impact of these processing variables on color degradation parameters was studied. Significant changes in pigmented extract and pigmented beverage model system (BMS) were observed. Ozone concentration and treatment time demonstrated to be critical factors in the color degradation of fungal pigments. First-order kinetic models adequately described the degradation pattern of pigments during ozonation. Degradation rate constants ranged from 0.127 to 0.206 in the buffer and from 0.068 to 0.119 in the BMS. The CIE L*a*b* parameters also confirmed the degradation behavior during ozonation process. Results from this study indicated that color stability of microbial pigments is affected by ozone processing conditions, thus, this quality aspect should be considered before applying this type of colorants in food products processed with ozone. Industrial relevance Natural colorants sources are required to meet the recent growing demands by the food industry due to consumers concerns of using synthetic pigments. Microbial pigments are of increasing interest as a result of the high yields that can be produced by microorganisms. Recently, Talaromyces spp. has gained attention as a good pigment producer strain. However, the application of these pigments in food manufacturing will depend on their stability to food processing (thermal and non-thermal). Accordingly, this work aimed to determinate if the colorants produced by Talaromyces spp. are applicable given their stability under ozone pasteurization. Results indicated that fungal pigments exposed to ozone could be considered as a potential natural ingredient to replace the color loss of some fruit juice processed under ozone technology. These results are promising for future applications in the food sector.

Effect of ohmic heating processing conditions on color stability of fungal pigments

The aim of this work was to analyze the effect of ohmic heating processing conditions on the color stability of a red pigment extract produced by Penicillium purpurogenum GH2 suspended in a buffer solution (pH 6) and in a beverage model system (pH 4). Color stability of pigmented extract was evaluated in the range of 60-90 ℃. The degradation pattern of pigments was well described by the first-order (fractional conversion) and Bigelow model. Degradation rate constants ranged between 0.009 and 0.088 min-1 in systems evaluated. Significant differences in the rate constant values of the ohmic heating-treated samples in comparison with conventional thermal treatment suggested a possible effect of the oscillating electric field generated during ohmic heating. The thermodynamic analysis also indicated differences in the color degradation mechanism during ohmic heating specifically when the pigment was suspended in the beverage model system. In general, red pigments produced by P. purpurogenum GH2 presented good thermal stability under the range of the evaluated experimental conditions, showing potential future applications in pasteurized food matrices using ohmic heating treatment.

Loading of anthocyanins on chitosan nanoparticles influences anthocyanin degradation in gastrointestinal fluids and stability in a beverage.

The optimal preparation parameters to create anthocyanin-loaded chitosan nanoparticles was predicted using response surface methodology (RSM). A Box-Behnken design was used to determine the preparation parameters that would achieve the preferred particle size and high encapsulation efficiency. The result suggested that the optimized conditions were 2.86mg/mL carboxymethyl chitosan (CMC), 0.98mg/mL chitosan hydrochloride (CHC) and 5.97mg anthocyanins. Using the predicted amounts, the experimentally prepared particles averaged 219.53nm with 63.15% encapsulation efficiency. The result was less than 5% different than the predicted result of 214.83nm particle size and 61.80% encapsulation efficiency. Compared with the free anthocyanin solution, the anthocyanin-loaded chitosan nanoparticles showed a slowed degradation in simulated gastrointestinal fluid. Compared with the free anthocyanin solutions in a model beverage system, the stability of the anthocyanins was increased in the anthocyanin-loaded chitosan nanoparticles.

Enhancement of colour stability of anthocyanins in model beverages by gum arabic addition

This study investigated the potential of gum arabic to improve the stability of anthocyanins that are used in commercial beverages as natural colourants. The degradation of purple carrot anthocyanin in model beverage systems (pH 3.0) containing l-ascorbic acid proceeded with a first-order reaction rate during storage (40°C for 5days in light). The addition of gum arabic (0.05–5.0%) significantly enhanced the colour stability of anthocyanin, with the most stable systems observed at intermediate levels (1.5%). A further increase in concentration (>1.5%) reduced its efficacy due to a change in the conformation of the gum arabic molecules that hindered their exposure to the anthocyanins. Fluorescence quenching measurements showed that the anthocyanin could have interacted with the glycoprotein fractions of the gum arabic through hydrogen bonding, resulting in enhanced stability. Overall, this study provides valuable information about enhancing the stability of anthocyanins in beverage systems using natural ingredients.

Enhanced stability of anthocyanin-based color in model beverage systems through whey protein isolate complexation

Anthocyanins are often used in functional foods and beverages as colorants and nutraceuticals. However, these natural compounds may undergo chemical degradation during storage leading to color fading and loss of bioactivity. In particular, vitamin C (l-ascorbic acid) is known to accelerate anthocyanin degradation. In this study, the influence of various food-grade biopolymers on the physical and chemical stability of model beverages containing anthocyanin (0.025%), ascorbic acid (0 or 0.05%), and calcium salt (0 or 0.01%) was examined under accelerated conditions (40°C for 7days). Four biopolymers (1%) were examined for their potential to inhibit anthocyanin degradation: native whey protein; denatured whey protein; citrus pectin; and beet pectin. The physical stability was determined by measuring changes in absorbance, color, and visual appearance. Solutions containing anthocyanin and calcium salt (0 or 0.01%) were stable throughout storage, while those with added ascorbic acid were the least stable. The addition of biopolymers, particularly heat denatured whey protein, significantly enhanced the stability of the anthocyanin during storage. Fluorescence quenching studies showed that the anthocyanin may have formed complexes with the whey protein through hydrogen bonding that resulted in their enhanced stability in the presence of ascorbic acid. This study provides information that may improve the stability of anthocyanins in food and beverage systems.