Addition Of Anthocyanins Research Articles

Development of carboxymethyl cellulose/starch films enriched with ZnO-NPs and anthocyanins for antimicrobial and pH-indicating food packaging

Active packaging, which can monitor food freshness and extend the shelf life, has gained significant attention in recent years. This study aims to develop a novel carboxymethyl cellulose (CMC)/starch/anthocyanins/ZnO active films with enhanced properties and specific functionalities. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) revealed that the addition of anthocyanins and nano-ZnO particles (ZnO-NPs) led to heterogeneous microstructures and a slight decrease in the crystallinity. Fourier transform infrared spectroscopy (FTIR) indicated that there were no chemical interactions among film components. Active films containing ZnO-NPs exhibited improved ductility, as well as enhanced light barrier and water resistance properties. Notably, a shift from hydrophilic to hydrophobic behavior of the films was observed with high ZnO-NP content, as evidenced by a significant increase in the water contact angle (from 63.44° to 114.22°). Furthermore, the presence of only 1 % ZnO-NPs resulted in efficient inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) growth. Moreover, active films containing both anthocyanins and ZnO-NPs were highly sensitive to pH changes in buffer solutions (pH 2–11). Based on the results, a recommended film formulation for future active packaging applications is a 80:20 CMC/starch blend with 3 % ZnO-NPs and 0.1 g anthocyanins.

Colorimetric Films Based on Polyvinyl Alcohol and Anthocyanins Extracted from Purple Tomato to Monitor the Freshness of Shrimp.

Anthocyanin extracts from purple tomato (PTA) were incorporated with polyvinyl alcohol (PVA), resulting in a series of colorimetric PVA/PTA films with PTA concentrations of 0%, 1%, 3%, and 5% (based on PVA). The role of anthocyanin on color response, Fourier-transform infrared (FTIR), thickness, water content, mechanical properties, antioxidant activity, and water vapor permeability (WVP) through the films was examined. In addition, its application in smart packaging to assess the freshness of shrimp was studied. It was found that the tensile strength, contact angle and WVP of PVA/PTA films increases with the addition of more PTA, while the elongation at break and water content decreased. FTIR analysis showed that there are interactions between PTA and the PVA matrix. The addition of anthocyanins caused significant improvement in the antioxidant properties of PVA films. Furthermore, the total volatile alkaline nitrogen (TVB-N), total plate count (TPC), and pH value of shrimp were monitored after 4 days of refrigeration, and the color change of the indexes was recorded. The PVA/PTA films changed color from purple to yellow-green during the storage time of 0-4 days for shrimp. This suggests that the film could be used in smart packaging as a real-time freshness indicator for shrimp.

Gelatin/poly(vinyl alcohol)-based dual functional composite films integrated with metal-organic frameworks and anthocyanin for active and intelligent food packaging

Innovative active and pH-colorimetric composite films were fabricated from gelatin/poly(vinyl alcohol) (Gel/PVA) integrated with copper-based metal-organic frameworks (Cu-MOFs) and red cabbage anthocyanin (RCA). The incorporation of Cu-MOFs improved the tensile strength, water resistance, and UV shielding properties of the developed composite films. The addition of anthocyanins and 3 wt% Cu-MOFs endowed the polymer matrix with excellent antioxidant (100 % against ABTS and DPPH radicals) and antibacterial (against Gram-positive and Gram-negative foodborne pathogenic bacteria) functions. The fabricated composite films exhibited significant color change at alkaline conditions of pH 7–12 and a marked color change upon exposure to ammonia. The designed indicator films used for shrimp freshness tracking and a visual color change from pink (for fresh shrimp) to green (for spoiled shrimp) was observed during storage at 28 °C for 24 h. The potential applications of the engineered composite films were studied by shrimp packaging, and the quality parameters of packaged samples were monitored during storage. The synergistic effects of adding anthocyanins and MOF nanostructures works for better product freshness preservation and responds well to shrimp spoilage level, introducing novel active and intelligent packaging options for practical smart packaging applications.

Study of Anthocyanin Extraction from Red Banana (Musa sapientum L. var Rubra) Waste and Characteristics of Light Effects

Anthocyanins are compounds responsible for plants’ blue, purple, violet, magenta, red, and orange colours. Anthocyanins are found in tropical fruits. Generally, anthocyanins are found in the peel tissues of plants. The increasing interest in anthocyanins, especially in the field of food and health, supports the development of anthocyanin exploration research. One of the uses of anthocyanins that are widely developed today is the addition of anthocyanins as indicators in smart packaging. For application on the packaging, in addition to extraction techniques, it is also necessary to assess the characteristics of anthocyanins in the environment. This study aims to examine the anthocyanin potential of red banana waste and the effect of light on anthocyanin stability. The anthocyanins observed are the result of anthocyanin extraction from the red banana peel and bracts using the maceration method. The solvent used is water acidified with citric acid. The study results showed that the total anthocyanin content in red banana bracts extract was higher than in extract from red banana peel. A concentrated extract from the bracts of a red banana contains 114.26 μg/g FW of total anthocyanins. In comparison, the concentrated extract of red banana peel contains 110.27 μg/g FW of total anthocyanins. Identification of concentrated extracts of red banana peel and flower through FTIR test, maximum wavelength test with UV-Vis and discolouration test showed that the extract contains anthocyanin compounds. Irradiation with a 25-watt bulb lamp, UV lamp and sunlight on concentrated extracts of the red banana peel and bracts showed degraded anthocyanin content. The results of this study show that the peel and flower of red bananas have the potential to be developed as a source of anthocyanins.

Effect of Purple Corn Anthocyanin on Antioxidant Activity, Volatile Compound and Sensory Property in Milk During Storage and Light Prevention.

The aim of this study was to observe the effect of purple corn anthocyanin on the light-induced antioxidant activity, free radicals, volatile compounds, color parameters, and sensory properties of milk during storage. There were four groups: (1) negative control, no addition of anthocyanins + exposure to fluorescent light (NC); (2) positive control 1, no addition of anthocyanins + protected from fluorescent light (PC1); (3) positive control 2, the addition of 0.3% (w/v) anthocyanins + exposure to fluorescent light (PC2); and (4) the addition of 0.3% anthocyanins + protected from fluorescent light (AC). The results indicated that the concentration of antioxidant activity parameters in the NC group decreased during the entire storage period, whereas antioxidant activity parameters were unchanged except for the glutathione peroxidase (GSH-Px) in the AC group. Moreover, the NC group showed lower levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and higher levels of superoxide anion and hydrogen peroxide than the other groups after 1 d of storage period. The extent of malondialdehyde accumulation and lipid peroxidation in the control groups were greater than that of the AC group. Twenty-two volatile compounds were determined in milk, which consisted of eight alcohols, three ketones, five aldehydes, two esters, and four hydrocarbons by headspace gas chromatography mass spectrometer analysis. Specifically, individual aldehydes, esters and hydrocarbons in the AC group remained at relatively stable values during storage relative to the other three groups. Stronger positive correlations were detected between several antioxidant activities (superoxide dismutase, GSH-Px) and DPPH scavenging activity as well as total ketones in milk. Adding of anthocyanin did not impact on the color values of L*, a* and b* in light-protected milk during the entire storage period. Some sensory evaluation parameters (flat, garlic/onion/weedy, oxidized-light, oxidized-metal, rancid) in AC group were significantly higher than that of the control group at the end of the period. In conclusion, the current study revealed that the addition of purple corn anthocyanin pigment to light-protected milk had the potential to prevent lipid oxidation, enhance antioxidant activity, maintain volatile compounds and increase the sensory scores.

Multiple spectra analysis and calculation of the interaction between Anthocyanins and whey protein isolate

The objective of this work was to investigate the interaction between whey protein isolate (WPI) and anthocyanins (AN) by various spectral techniques (Fluorescence, ultraviolet (UV) and Fourier transform infrared spectra). The results indicated that the apparent binding constants of the interaction between AN and WPI at different temperatures were 0.49 × 104 (298 K), 1.13 × 104 (306 K) and 1.88 × 104 (314 K) L/mol, respectively. The corresponding binding sites were 0.91, 0.99 and 1.05 respectively; The reaction between AN and WPI was a spontaneous endothermic process according to the thermodynamic data results, and the main acting force was hydrophobic interaction. The results of ultraviolet (UV) spectra and Fourier transform infrared spectra showed that the addition of AN changed the conformation of WPI. At the same time, the emulsifying properties of the WPI-AN composite solution were significantly improved.

Short communication: Effect of purple corn pigment on change of anthocyanin composition and unsaturated fatty acids during milk storage

Unsaturated fatty acids (UFA) in milk give rise to radicals and lead to lipid oxidation during storage, reducing the commercial value of milk. The objective of this study was to observe the effect of anthocyanins from purple corn pigment on the oxidation of UFA in milk. Milk samples were randomly divided into 2 groups: (1) the control (without purple corn pigment) and (2) treatment (0.3% purple corn pigment), using a completely randomized design. The milk samples were placed into plastic tubes and stored at 4°C for a period of 0, 1, 3, and 7 d. Individual anthocyanin composition and UFA were detected by HPLC-mass spectrometry and gas chromatography-mass spectrometry, respectively. The results indicated that pelargonidin (0.258 vs. 0.054 µg/mL), cyanidin (5.550 vs. 1.808 µg/mL), petunidin (0.464 vs. 0.107 µg/mL), delphinidin (2.061 vs. 0.123 µg/mL), and total anthocyanin (8.332 vs. 2.091 µg/mL) significantly decreased in response to increasing storage day. Of interest, purple corn pigment had a significant effect on most of the UFA (C14:1n-5, C16:1n-7, C18:1n-9, C18:2n-6, C18:3n-3, C18:3n-6, C20:2n-6, C20:3n-3, and C20:4n-6), except for C17:1n-7 and C20:3n-6. Specifically, various stronger positive correlations were noted for anthocyanin composition and UFA (pelargonidin and petunidin with C14:1n-5, C17:1n-7, C18:2n-6, C20:2n-6, C20:3n-3, and C20:4n-6; and cyanidin and total anthocyanins with C14:1n-5, C16:1n-7, C17:1n-7). Collectively, the current study suggested that the addition of anthocyanins from purple corn pigment had the potential to maintain UFA concentrations in milk during the storage period.

Comparison of the physical and functional properties of starch/polyvinyl alcohol films containing anthocyanins and/or betacyanins

Anthocyanins and betacyanins are two different types of natural pigments. In this study, active and intelligent packaging were prepared by adding anthocyanins or betacyanins or anthocyanins/betacyanins mixture (in the weight ratios of 3:1, 1:1 and 1:3) into starch/polyvinyl alcohol (PVA) films. The physical and functional properties of developed films were compared. Results showed anthocyanins were more pH-sensitive than betacyanins. However, betacyanins were more beneficial to improve the compactness of the films and had stronger hydrogen bonding interactions with film matrix as compared with anthocyanins. The addition of anthocyanins and/or betacyanins slightly decreased the crystallinity of the films but significantly increased the ultraviolet-visible light barrier, water vapor barrier, antioxidant, antimicrobial, and ammonia-sensitive properties of the films. Moreover, the barrier, antioxidant and antimicrobial properties of the films increased with the increase of betacyanins proportion. Amongst different films, the film containing anthocyanins/betacyanins mixture in the weight ratio of 1:3 presented obvious color changes when the film was utilized to monitor the freshness of pork. Our results suggested betacyanins was more beneficial to enhance the barrier, antioxidant and antimicrobial properties of starch/PVA films. Starch/PVA films simultaneously added with anthocyanins and betacyanins were more suitable to monitor the freshness of pork.

Development of pH indicator and antimicrobial cellulose nanofibre packaging film based on purple sweet potato anthocyanin and oregano essential oil

A pH indicator and antimicrobial cellulose nanofibre packaging film was developed based on cellulose nanofibres as film matrix, anthocyanins from purple sweet potato as a natural dye and oregano essential oil as an antimicrobial agent. The colour of the anthocyanin solution was noticeably different from pH 2 to pH 12. The developed film sensitively responded to a change of pH and showed an obvious colour change from red to yellow, with pH ranging from 2 to 12, which indicated that the film had a superior colorimetric performance to pH change. Moreover, the film showed excellent antimicrobial activity and the inhibition rate against Escherichia coli and Listeria monocytogenes reached 99.99%. Bio-compatibility between anthocyanins and cellulose nanofibre matrix was confirmed by the analysis of cross-section morphology of the film. The XRD pattern revealed that the crystallinity index of the film decreased with the addition of anthocyanins and oregano essential oil. The film had a good barrier performance to ultraviolet and visible light; its tensile strength, elongation at break, and elastic modulus was 9.28 MPa, 9.87%, and 0.15 GPa, respectively. The developed pH indicator and antimicrobial film could intuitively indicate the change of food quality during storage and effectively prolong food shelf life.

Preparation of an intelligent pH film based on biodegradable polymers and roselle anthocyanins for monitoring pork freshness

This study aims to develop an intelligent indicating film based on biodegradable polymers incorporated with roselle anthocyanins to monitor pork freshness. Three different films were prepared by using two substances of starch, polyvinyl alcohol and chitosan. The UV–vis spectra and color of anthocyanins changed at pH 2–12. SEM photographs showed that the compatibility of films was improved with the addition of anthocyanins. Furthermore, the polyvinyl alcohol/chitosan/roselle anthocyanins film had the highest tensile strength (98.28 MPa). The starch/polyvinyl alcohol/roselle anthocyanins film had the highest antioxidant activity (524.07%) and the best color stability. The starch/polyvinyl alcohol/roselle anthocyanins film showed visible changes from red to green when employed to monitor the freshness of pork stored at 25 °C, before the TVB-N value of the pork gradually increased to the rejection limit (15 mg/100 g) at 36 h. Therefore, the indicator film can be used to monitor pork freshness for intelligent packaging.

Development of a colorimetric pH indicator based on bacterial cellulose nanofibers and red cabbage (Brassica oleraceae) extract

This work aimed to develop and characterize a smart label for pH monitoring based on bacterial cellulose (BC) nanofibers doped with anthocyanins extracted from red cabbage (Brassica oleracea). The relationship between the concentration of anthocyanins (32 and 193mgL−1) and the morphological properties and color response efficiency of pH indicator labels was investigated. The FT-IR results reflected that some new interactions have occurred between BC membrane and anthocyanins. The XRD analyses showed a decrease in diffraction intensities of BC by addition of concentrated form of anthocyanins. SEM results indicated that concentrated anthocyanins caused to partial disintegration and deformation of the cellulose microfibrils with more cracks on the labels. But the intrinsic morphology and structure of the BC nanofibers were preserved by addition of diluted anthocyanins. A concentration dependent decrease was observed in the tensile strength of anthocyanin loaded labels but elongation percentage and moisture absorption of BC was increased by addition of anthocyanins. The color variation in different pH range (2–10) was measured with the CIELab methodology. The label containing diluted anthocyanins showed a more clear response to pH variation. Therefore, it has potential to be used as a visual indicator of the pH variations during storage of packaged food.

Antioxidant components and physico-chemical characteristics of jamun powder supplemented pear juice

Studies were conducted to develop jamun powder supplemented pear juice. Two drying methods (Hot air cabinet drying and freeze drying) were used to prepare jamun pulp powder. Jamun powder was then blended with pear juice at 1, 2, 3, 4 and 5% levels for preparation of jamun powder supplemented pear juice. Among the drying methods used, freeze dried powder retained better bioactive compounds and possessed higher antioxidant activity as compared to hot air dried jamun powder. Analysis of color properties (L*, a*, b*) revealed lower L*, b* values and higher a* values with progression of supplementation levels indicating decreased brightness of product. Pear juice supplemented with 4% jamun powder received highest overall acceptability scores and was chosen for development of final product. Physico-chemical characteristics of control pear juice did not vary much fromwhen compared to jamun powder supplemented pear juice. Bioactive components mainly total phenols enhanced (9.24% higher) with addition of jamun powder in pear juice. Addition of anthocyanins from jamun powder to pear juice upon blending improved antioxidant activity of the final product. Supplemented pear juice had 18.13% higher antioxidant activity than pear juice without supplementation. Storage period of 6months resulted in significant (p<0.05) decrease of bioactive compounds and antioxidant activity in jamun powder supplemented pear juice.

Degradation kinetics of anthocyanins in freeze-dried microencapsulates from lowbush blueberries (Vaccinium angustifolium Aiton) and prediction of shelf-life

ABSTRACTThe addition of anthocyanins in food products is limited by their instability. In this study, an extract containing anthocyanins from lowbush blueberries was encapsulated by freeze-drying in three maltodextrin matrices with different dextrose equivalents, for potential use as a colorant and functional ingredient. The resultant encapsulates differed in physicochemical properties. Kinetic and thermodynamic parameters for anthocyanin degradation in accelerated shelf life studies at 70, 80, and 90°C were determined using the Arrhenius model. The half-life (t1/2) varied from 0.96 h (freeze-dried extract) to 108 days (encapsulated extract). Our results demonstrate that freeze-dried berry encapsulates effectively retard anthocyanin degradation during storage.

Concentration and time dependent cytoprotective effects of anthocyanins against oxidative hemolysis induced by water and lipid soluble free radical initiators: an &amp;lt;i&amp;gt;in vitro&amp;lt;/i&amp;gt; study

The non-enzymatic, free radical-mediated peroxidation of erythrocyte membranes is now correlated with a variety of pathological conditions, and considered as a primary event associated with hematotoxicity of variety of drugs and chemicals that induce erythrocyte hemolysis. The plant derived polyphenols including anthocyanins have been suggested to enhance red blood cell resistance to oxidative stress both in vitro and in vivo. The present study was designed to investigate the concentration and time dependent anti-hemolytic activity of anthocyanins using in vitro models of azo compounds-induced erythrocyte membrane peroxidative damage. Three different concentrations (1, 0.1 and 0.01 mg/ml) of anthocyanins solution were incubated with erythrocytes suspension 30 min before addition of either water soluble (AAPH) or lipid soluble (AMVN) free radical initiators. The level of hemoglobin released into the solution was determined spectrophotometrically, both in presence and absence of anthocyanins. Moreover, the most effective concentration was selected to be added at different time intervals (zero time, 2 and 3 hours) post challenge with either AAPH or AMVN and the extent of hemolysis was determined as mentioned before. The results showed that anthocyanins, concentration dependently attenuated hemolysis induced by azo compounds, and substantial cytoprotective effects of anthocyanins were observed when they added simultaneously with azo compounds, while delayed addition of anthocyanins for 2 and 3 h diminished but not abolished the protective effect of anthocyanins. In conclusion, anthocyanins can effectively display concentration and time dependent cytoprotective properties against azo compounds-induced peroxidative hemolytic damage.

Effects of Purple Sweet Potato Anthocyanins on Development and Intracellular Redox Status of Bovine Preimplantation Embryos Exposed to Heat Shock

The development of cleavage stage preimplantation embryos is disrupted by exposure to heat shock, such as high temperatures in the summer season. In this study, we investigated whether addition of anthocyanins, which are strong scavengers of reactive oxygen species (ROS), improves development and intracellular redox status of heat-exposed bovine preimplantation embryos by reduction of heat shock-derived oxidative stress. After in vitro fertilization (IVF), embryos were cultured at 38.5 C through Day 8 (Day 0=day of IVF) with 0, 0.1, 1 and 10 microg/ml anthocyanins (non-heat-shocked group). On Day 2, embryos were cultured at 41.5 C for 6 h with 0, 0.1, 1 and 10 microg/ml anthocyanins followed by culture at 38.5 C until Day 8 (HS group). After exposure to heat shock, the intracellular ROS and glutathione (GSH) contents of individual embryos were measured in the non-heat-shocked and HS groups using fluorescent probes. On Day 8, the blastocysts formation rates of the embryos and total cell numbers of blastocysts were evaluated. Embryos exposed to heat shock without anthocyanins showed a significant decrease in blastocyst formation rate and GSH content (P<0.05) and an increase in intracellular ROS (P<0.05) compared with non-heat-shocked embryos. In contrast, addition of 0.1 microg/ml anthocyanins significantly (P<0.05) improved the blastocyst formation rate of the heat-shocked embryos. Addition of any dose of anthocyanins produced a significant decrease in the ROS levels (P<0.05) and tended to increase the GSH levels under heat-shock conditions. However, addition of higher concentrations (1 and 10 microg/ml) of anthocyanins to the culture media under heat shock did not improve the development of embryos. These results indicate that anthocyanins maintain the intracellular redox balance of heat-shocked bovine embryos by reducing intracellular oxidative stress and increasing the GSH levels. Thus, alterations of the redox state using natural antioxidative polyphenols is a useful approach for reducing heat shock-derived oxidative stress.

Isolation of the first C-2 addition products of anthocyanins

Addition of anthocyanins with nucleophilic agents normally occurs at the C-4 centre and the isolation of C-2 adducts between acetone and cyanidin-3- and delphinidin-3-rutinosides is the first definitive demonstration of the reactivity of this carbon site. These C-2 addition products were isolated as diastereoisomers and their chemical structures elucidated by 1D and 2D NMR spectroscopy.

Anthocyanin degradation in oxidising grape musts

AbstractWhite musts with added grape anthocyanis were prepared and oxidised using known amounts or oxygen. Although malvidin and peonidin glucosides were degraded at a slower rate than o‐diphenolic anthocyanins, important losses of all pigments occurred in oxidising grape musts. Degradation was inhibited by glutathione in excess, meaning that enzymically generated quinones of caffeoyltartaric acid were involved in the degradation mechanisms. Addition of anthocyanins hardly modified the kinetics of caffeoyltartaric acid oxidation and conversion to 2‐S‐glutathionyl caffeoyltartaric acid (grape reaction product). All musts browned considerably during oxidation. Browning of white musts was measured as an increase of redness (a*) and a decrease of lightness (L*) and yellowness (b* and hue angle) whereas browning in anthocyanin added musts appeared essentially as a loss of red colour (a*).