pH Differential Method Research Articles

Spray-dried Ancellotta red wine: natural colorant with potential for food applications

Ancellotta red wine (Vitis vinifera L.) was encapsulated by spray-drying (inlet and outlet temperatures were 145 °C and 70 °C, respectively) to obtain a wine powder with a low water activity (aw) using maltodextrin DE10 as an encapsulating agent. The retention of total monomeric anthocyanins (TMA) in the wine powder was found to be greater than 80%. Anthocyanin profiles of Ancellotta liquid wine and wine powder were characterized by using HPLC–DAD and 33 compounds were identified. The wine powder was stored under two different water activity values (aw 0.25 and aw 0.33). Furthermore, the TMA (pH-differential method), total anthocyanins and malvidin-3-glucoside were determined by HPLC–DAD for up to 90 days’ storage at 38 °C. Total anthocyanins and malvidin-3-glucoside decreased very slowly during storage. The stability of anthocyanins and color differences (ΔE*ab) in 1% wine powder solution at different pHs and temperatures were evaluated. These results indicated that Ancellotta wine powder has the potential to be used as a food colorant in low pH and low water activity foods.

Cryoconcentration procedure for aqueous extracts of maqui fruits prepared by centrifugation and filtration from fruits harvested in different years from the same localities

BACKGROUND:At the present time, the food industry is increasingly interested in the development of formulations with maqui-berry extracts as a rich source of bioactive compounds. Maqui, native to Chile, is a relatively new food raw material that is often called a “superfruit”, The berries of this p lant are rich in anthocyanins, phenolic acids, and tannins; compounds that play an important role as sources of bioactive compounds in the health of consumers. Cryoconcentration, a technology that preserves thermolabile bioactive compounds by combining techniques of freezing-centrifugation, makes it possible to obtain concentrates with a greater content of bioactive compounds than traditional methods of concentration. In this study, maqui fruits were pulped to obtain juice (J) and chaff. The chaff was subjected to aqueous extraction with distilled water in a ratio of 1 : 1 p/v to obtain maqui extract (E). Combined J and E were homogenized, and vacuum filtered to obtain the final extract (A), which was cryoconcentrated at – 30°C and then subjected to 3 continuous cycles of freezing-centrifugation and filtration. MATERIAL AND METHODS:Three continuous centrifugation-filtration cycles were used. The polyphenol content was determined by the Folin-Ciocalteu method with gallic acid as a standard. Anthocyanins were identified by high-performance liquid chromatography (HPLC) and total anthocyanin content was determined by the pH differential method the anthocyaninds present were identified by high performance liquid chromatography (HPLC). RESULTS:After application of the cryoconcentration cycles assisted by centrifugation-filtration, the separation efficiency of solute was found to be maintained over 90%. The content of soluble solids significantly increased in the concentrated fractions and reached 54.2 °Brix at the end of the third cycle. Finally, the ratio of the concentration of total polyphenol and anthocyanin increased 2.8 and 6.7 times, with respect to the initial content in the maqui-berry extract. CONCLUSIONS:The maqui cryoconcentrate is a product with a large content of antioxidants and bioactive compounds commonly considered as functional characteristics. This concentration method also conserved the profile of anthocyanins present in maqui fruit extract. The efficient separation solutes and bioactive compounds achieved will permit scaling these process conditions to the industrial level. OBJECTIVE:To assess the process parameters and polyphenol-anthocyanin content of cryoconcentrates obtained from maqui-berry (Aristotelia chilensis (Mol.) Stuntz).

In vitro digestibility of gellan gels loaded with jabuticaba extract: Effect of matrix-bioactive interaction.

Jabuticaba is a native Brazilian fruit rich in phenolic compounds as anthocyanins, showing several benefits for human health but a high sensibility to physicochemical digestion conditions. Gellan is a biopolymer that could be used as a material to protect and carry bioactive compounds, since this polysaccharide is resistant to gastric pH conditions. In this context, gellan gels containing jabuticaba extract were produced using two different ionic strength values (adding calcium ions), which resulted in varied structures. These gels were subjected to two different in vitro digestion processes, modifying the type of mechanical forces applied to simulate stomach and intestine movement conditions. Anthocyanins release (by pH differential method), mechanical properties, confocal and light microscopy of gels were evaluated during in vitro digestibility. Results showed that jabuticaba extract exerted effect on gels mechanical-structural properties, since an increase of stress at rupture (hardness) and a decrease of strain at rupture (deformability) were observed only in gels without calcium addition. Although all gellan gels have improved anthocyanins retention during simulated gastrointestinal digestion process, gels without calcium were more efficient. Our results demonstrated that gellan gels could act as good carriers for anthocyanins, but their efficiency is dependent on the matrix composition, demonstrating that specific studies should be accomplished to determine which changes may occur in the matrix after bioactive addition. Furthermore, our results showed that the type of mechanical forces applied during in vitro digestion is an important variable, since the use of compression (a more similar-to-in vivo system) rather than shear forces increased the release of anthocyanins.

Effects of different cooking conditions on the anthocyanin content of a black rice (Oryza sativa L. ‘Violet Nori’)

The study is focused on the effect of different cooking conditions on the antioxidant content, particularly anthocyanins, of Oryza sativa L. ‘Violet Nori’, a new black rice cultivar. 10 different cooking tests were performed. The selected cooking conditions allowed to evaluate the effect of boiling, roasting, oven cooking, risotto cooking, and oriental cooking. The total anthocyanins amounts were evaluated by both a spectrophotometric pH differential method and High-Performance Liquid Chromatography (HPLC), together with the Total Phenolic Content (TPC) and the Radical Scavenging Activity (RSA). The obtained results showed that boiling with a low water amount (100 g rice/650 mL water) and oriental cooking, which allows a reduction of boiling times thanks to the lid of the pot, allow effectively saving at least part of their anthocyanins content. Similar results were obtained by boiling if rice was introduced in cold or boiling water, but on the contrary a ratio of 100 g rice/1000 mL water greatly enhanced the loss of antioxidant compounds. Risotto and oven cooking allowed obtaining results that were roughly intermediate between the ‘best’ and the ‘worst’ results. A high correlation existed between the amounts of total anthocyanins and both TPCs and RSAs. The ‘best’ results show that although cooking necessarily decreases the rice content of valuable antioxidants, a careful choice of the operative conditions allows effectively preserving amounts of total anthocyanins higher than 100 mg/100 g rice portion, which are close to or even higher than in other well-known sources of dietetic anthocyanins.

Effect of light intensity on the gas exchange characteristics and total pigment content of Psidium guajava

The gas exchange characteristics and photosynthetic pigments of a plant can be affected by the amount of light received by the plant. The objective of this research is to investigate the effect of light intensity on the gas exchange characteristics and total pigment content TPC of sun and shade leaves of Psidium guajava. Sun and shade leaves were studied, and their photosynthetic light response characteristics including light saturation point (LSP), light compensation point (LCP) and apparent quantum yield were estimated. Carotenoids (Car) and chlorophyll (Chl) contents were quantified spectrophotometrically, while total anthocyanin content (TAC) was determined using the pH differential method. The result of this study shows that high light intensity influence gas exchange, carotenoid content and total anthocyanin content while low light intensity influence chlorophyll content especially chlorophyll b of the studied plant. As the light intensity increases, Amax, light saturation point and light compensation point increases. There are significant differences between the photosynthetic light response characteristics and total pigment content of sun and shade leaves (P<0.05). The result leads to a conclusion that sun leaves of Psidium guajava contribute the greatest photosynthetic capacity to the plant than shade leaves. The high carotenoid and total anthocyanin contents of sun leaves provides photo protection to the plant.

Effects of In Vitro Gastrointestinal Digestion on the Antioxidant Capacity and Anthocyanin Content of Cornelian Cherry Fruit Extract.

Red fruits are considered a major source of antioxidant compounds in the human diet. They usually contain anthocyanins, phenolic pigments that confer them multiple health-promoting properties. The health benefits of these bioactive phytocompounds are strongly related to their bioavailability, which has been reported to be low. The aim of the present study is to investigate the changes in antioxidant capacity and anthocyanin content of Cornelian cherry fruit extract during gastrointestinal digestion. Thus, the work was designed using a simulated in vitro digestion model. The antioxidant capacity (AA) was tested by the 2,2-azinobis (3-ethylbenzothiazolyne-6-sulphonic acid) radical cation (ABTS) method, while quantification of anthocyanins (TAC) was accomplished by the means of the pH differential method and high performance liquid chromatography (HPLC). The results showed that gastric digestion had no significant effect on the TAC of the extract, while the AA slightly increased. After duodenal digestion, only 28.33% of TAC and 56.74% of AA were maintained. Cornelian cherries’ anthocyanins were stable in stomach, so they can be absorbed in order to manifest their antioxidant capacity at the cellular level. The duodenal digestion dramatically decreased the TAC and AA level in the fruit extract.

Evaluation of total monomeric anthocyanin, total phenolic content and individual anthocyanins of foam-mat freeze-dried and spray-dried blueberry powder

Anthocyanins in blueberries have generated considerable interest in the scientific community owing to their pleiotropic health benefits against cardiovascular diseases, diabetes and cancer. However, anthocyanins are labile in nature due to their sensitivity to temperature, light, pH, and oxidation and final concentrations in blueberry products is influenced by the processing technique employed. This study evaluated the effect of foam-mat freeze-drying (FMFD) and spray-drying (SD) using a feed rate of 180 and 360 mL/h on the total monomeric anthocyanin (TMA), total phenolic content and contents of individual anthocyanins cyanidin-3-glucoside (Cyn3Gl), delphinidin-3-glucoside (Del3Gl) and malvidin-3-glucoside (Mal3Gl) in blueberry powders. The protective effect of mixtures of encapsulating agents namely: maltodextrin (MD), trehalose, whey protein isolate (WPI), bovine serum albumin (BSA) and β-lactoglobulin on anthocyanins and phenolic content was also investigated. Anthocyanin content was measured using the pH differential and HPLC methods, while total phenolic content was evaluated using the Folin’s assay. The outcome of the study revealed that concentrations of TMA and individual anthocyanins were higher with FMFD (7.11–8.09 mg/g: TMA) compared to SD samples (4.34–5.69 mg/g: TMA). Furthermore, Del3Gl, Cyn3Gl and Mal3Gl retentions were greater, in the order: FMFD > SD 180 = SD 360. Retention of total phenolic ranged from 68 to 76% and 48–72% in FMFD and SD samples respectively and the choice of the matrix MD/WPI as encapsulating agent was the most effective in protecting blueberry anthocyanins. FMFD is therefore recommended for developing blueberry powders with good retention of anthocyanins.

Inhibition of Dipeptidyl Peptidase 4 (DPP IV) Activity by Some Indonesia Edible Plants

Background: Some edible plants are promising to control blood sugar level. These plants contained phenolic substances that suggested to be able to inhibit dipeptidyl peptidase 4 (DPP IV). Objective: The objective of this study was to investigate the inhibitory effect of several selected Indonesia plants on inhibiting of DPP IV activity and to determine the total phenolic content of the most active extract. Methods: Twelve Indonesia edible plants were macerated using 80% ethanol at room temperature. DPP IV activity was evaluated by using glycyl-prolyl-7-amino-4-methyl coumarin (Gly-Pro-AMC) substrate and the inhibitory effect of extracts were determined based on the level of free AMC group by measuring its fluorescence on excitation wavelength 350-360 nm and an emission wavelength 450-465 nm using a microplate reader. Total phenolic contents of the active extracts were determined with Folin-Ciocalteu 1:4 on 765 nm using microplate reader. Total anthocyanins from extract were determined using the pH differential method. Results: Among the tested samples, the extract of Ipomoea batatas roots at a concentration of 10 μg/mL showed the highest inhibition, followed by Cajanus cajan leaves and Gnetum gnemon rind, with percentage inhibition of 28.8, 24.9 and 24.1, respectively. I. batatas extract have an IC50 value of 65.53 μg/mL, while the IC50 value of the positive control Sitagliptin 9.37 μg/mL. Total phenolic content from the extracts of I. batatas, C. cajan and G. gnemon rind extract were 279.3; 152.8; and 141.3 mg GAE/gram, respectively. Total anthocyanin from I. batatas extract was 462.14 mg cyanidin- 3-glucoside/L. Conclusion: The extract of I. batatas showed the highest inhibition on DPP IV among other plants investigated and showed high content of phenolic compound and anthocyanin that correlated with activity as inhibitor DPP IV.

Natural pigment extraction optimization from coffee exocarp and its use as a natural dye in French meringue

This study aimed to optimize the pigment extraction process for coffee exocarp and to evaluate its coloring effect on French meringue. The anthocyanins were determined with the differential pH method and the process was optimized with the response surface methodology. The solvent concentration (SC) and solid solvent ratio (SSR) had a significant effect on the anthocyanin content and surface color of the coffee cherry extracts. The optimal extraction conditions 60% SC and 25% SSR resulted in the highest concentration of anthocyanins (0.145 mg cyanidin 3-glucoside/g of coffee fresh exocarp). For the French meringue, the 3% extract concentration had the smallest total color difference (ΔE), as compared to the control, evidencing the potential of coffee exocarp dyes in place of synthetic dyes in the manufacture of French meringue.

Total anthocyanins and cyanidin-3-O-glucoside contents and antioxidant activities of purified extracts from eight different pigmented plants

Background: Anthocyanin, a subcategory of flavonoid, is a natural water-soluble pigment. There are many plants rich in anthocyanins, and a high intake of anthocyanin food has been shown to have potential beneficial effects on various chronic diseases. Objective: The objective was to evaluate the contents of total anthocyanin and cyanidin-3-O-glucoside (C-3-G) and their contribution to the antioxidant activities in commonly consumed pigmented plants. Materials and Methods: The total anthocyanin in Lonicera caerulea L., Rubus fruticosus L., Ribes nigrum L., Morus alba L., Zea mays L. seed, Z. mays L. cob, Brassica oleracea L., and Dioscorea alata L. was extracted by tissue-smashing extraction method, and then the contents of total anthocyanin (TAC) and C-3-G contents (C-3-GC) in the purified extracts were determined by pH differential method and high-performance liquid chromatography, respectively. Antioxidant activities were assessed by 2,2-diphenyl-1-picrylhydrazyl, ferric-reducing antioxidant power, and total reducing power (TRP) assays. Results: TAC ranged from 97.11 to 320.27 milligrams cyanidin-3-glucoside equivalents per Gram of dry weight. TAC, C-3-GC, and antioxidant activities in most berry extracts were higher than that in vegetables. Z. mays cob showed the similar TAC, C-3-GC, and antioxidant activities to L. caerulea, and the two vegetables were the lowest. The major anthocyanin in the berries and grains was identified as C-3-G. There was a significant positive correlation between antioxidant activity and TAC. Conclusions: The closer the plant color is to black, the higher TAC is, and the stronger its antioxidant activity is. Z. mays cob will be a promising source of anthocyanin. This study provides a theoretical basis for the use of anthocyanin in functional food and further pharmacological research. Abbreviations used: C-3-G: cyanidin-3-O-glucoside; C3GC: cyanidin-3-O-glucoside contents; DPPH: 2, 2-diphenyl-1-picrylhydrazyl; FRAP: Ferric-reducing antioxidant power; HPLC: High-performance liquid chromatography; TAC: Total anthocyanin content; TAE: Total anthocyanin extract; TE: Trolox equivalent; TRP: Total reducing power; TPTZ: 1,3,5-tri (2-pyridyl)-2,4,6-triazine; TSE: Tissue-smashing extraction.

JENIS DAN KANDUNGAN ANTOSIANIN BUAH TOMI–TOMI

Batoko plum fruit (Flacourtia inermis, Roxb) is one of the plants that contains anthocyanins. The fruit has purplish red color and was thought to benefit health by reducing blood sugar levels, as anti-hyperten-sion agents or antioxidants. The aim of this research was to determine the total anthocyanin content and identify the type of anthocyanidin and anthocyanin of batoko plum fruit. The total anthocyanin content of batoko plum fruit which determined by differential pH method was 26.56±0.28 mg/100 g (w.b.) or 103.89±1.08 mg/100 g (d.b.). Based on the Rf value on TLC and the peak retention time in HPLC, it was confirmed that the anthocyanin was delfinidine. However, the wavelength maximum absorbance data of the TLC spot showed the presence of cyanidine. These results were possibly caused by the use of too diluted extracts or the degradation of the anthocyanin during acid hydrolysis. Based on the Rf value on TLC and glucosidation pattern in UV-VIS spectrophotometer, it is suspected that cyanidine 3-glucoside and delfinidine 3-glucoside were present.

Effect of Processing Variables on Anthocyanin and Total Polyphenol Extraction from Water Caltrop (Trapa bispinosa) Hull

Anthocyanins are water soluble pigments responsible for the brilliant orange red through deep purple colors in flower and fruits. The effects of different extraction variables (pH, particle size, temperature and time, extraction method) on anthocynin, total polyphenol content and antioxidant of the extracts were studied. The anthocyanin content of fresh and dried (55 °C for 2 h) water caltrop hull were 68.68 and 44.38 μg/100 g d.b. respectively. Temperature, particle size and pH played a significant role (p&lt;0.05) in aqueous extraction of anthonycinin. The optimum aqueous extraction condition were pH of 4.49, particle size of 300 μm, temperature of 67.2 °C and time of 25.38 min which gave 70.3% anthocynin extraction. There was a significant effect of extraction method (acidified ethanol, acidified ethanol and pH differential methods) and particles size on anthocynin extraction (p&lt;0.05). The total polyphenol content in the aqueous extracts from water caltrop hull powder of 300, 690 and 1080 μm were in the range of 55.02-60.31 mg GAE/g dm. The extraction of total polyphenol from 300 μm was significantly different from 690 and 1080 μm particle sizes, while there was no significant difference between from 690 and 1080 μm respectively (p&gt;0.05). The particle size had a significant effect (p&lt;0.05) on the antioxidant activity of the extract and the values ranged from 173.36 μg/mL to 193.69 μg/mL.

Standardization of monomeric anthocyanins extraction from fig fruit peels (Ficus carica L.) using single factor methodology

The present study aimed to establish the optimum extraction conditions of monomeric anthocyanins from Azenjer fig (Ficus carica L.) peels using the single factor methodology. The investigated parameters were extraction solvent (water, methanol, ethanol, and acetone), number of extractions, solid-to-solvent ratio (1/25 to 1/200), extraction time (30–240 min), methanol concentration (20–100%), type of acidification solution (hydrochloric acid, acetic acid, citric acid, tartaric acid), acid concentration (0.1–10%) and acid-to-solvent ratio (1/99 to 20/80). The content of monomeric anthocyanins was measured using the pH-differential method. Optimum extraction conditions that maximize the extracted anthocyanins were a double extraction with 90% methanol acidified to a ratio of 10/90 with 5% citric acid, using a solid-to-solvent ratio of 1/100, and an extraction time of 180 min, which gave a yield of 346.63 mg of monomeric anthocyanins per 100 g of dried fig peels.

Evaluation of different drying models for jabuticaba peel, dried in spouted bed dryer through performance indicators and the impact on anthocyanins

Jabuticaba fruit stands out for its energetic and nutritional value being widely consumed in the fresh form and used for the production of jellies, vinegar, wines, and liquor. The jabuticaba peel has a high content of natural antioxidants, such as carotenoids, anthocyanins, tocopherols, and phenolic compounds, these compounds give protection to the fruit. In order to promote preservation of the jabuticaba peel for an extended period of time, the drying process is applied to remove water from the product and, consequently, reduce the risks of microbial growth and enzymatic reactions. The objectives of this study were to evaluate four drying models for spouted bed drying of jabuticaba peel using the following performance indicators: accuracy factor (Af), bias factor (Bf) and mean square error (RMSE), and analyze the impact of drying temperatures on the content of monomeric anthocyanins. The drying process was done in a pilot spouted bed dryer unit at temperatures: 50, 60 and 70°C for 2.5 h. The total monomeric anthocyanin content was determined using the pH differential method. It was observed that for the temperatures of 60°C and 70°C, the Two-term, and Page models, respectively, are appropriated to describe the drying kinetic of the jabuticaba peel in a spouted bed drying under the studied conditions. Moreover, for anthocyanins content, it was noted that there was a greater degradation at the highest temperature studied (70°C) as expected since anthocyanins are heat-sensitive substances.

Production of purple sweet potato (Ipomoea batatas L.) juice having high anthocyanin content and antioxidant activity

The purpose of the study was to retrieve procedure of production of purple sweet potato (Ipomoea batatas L.) juice with the best total anthocyanin and antioxidant activity. Purple sweet potato was processed into purple sweet potato juice through a process of heating with temperature variations of 700C, 800C, and 900C and various duration of heating, which are 5 mins, 10 mins, and 15 mins. The total anthocyanin was determined by using pH differential method. The antioxidant activity was determined by using DPPH (2,2-Diphenyl-l-picrylhydrazyl) method. Total anthocyanin of purple sweet potato juice declined in the range between 215.08 mg/L - 101.86 mg/L. The antioxidant activity of purple sweet potato juice declined in the range between 90.63% - 67.79%. Antioxidant activity and total anthocyanin purple sweet potato juice decreases with increasing temperature and duration of heating. The best characteristics found in purple sweet potato juice were made with warming temperatures of 800C. The product with the highest antioxidant activity, total anthocyanins, and good durability was prepared at 800C heating temperature for 5 mins.

P-37 - Tropaeolum majus L. extract rich in anthocyanins reduces oxidative damage in psoriasis-like wounds in mice accelerating healing

Psoriasis pathogenesis includes immune activation and oxidative damage. Tropaeolum majus is a plant rich in antioxidant anthocyanins. This study aimed to evaluate the effect of Tropaeolum majus extracts on psoriasis-like wounds. The ethyl acetate, ethanolic and hydroethanolic extracts were obtained by maceration. Their anthocyanins content was determined by differential pH method. Mice were allocated in normal and negative control groups (n=12) treated with 10% glycerol and groups receiving extract (50 mg/mL). Topical treatments were daily (5 days). Later, half of each group was euthanized to collect skin for analyzes of TNF-α, IL-1β, lipid peroxidation, protein carbonylation and reduced glutathione (GSH). The other half was kept to determine the time for wounds’ clearance. Anthocyanins concentration was 0.6 ± 0.1; 6.9 ± 0.9 and 10.9 ± 0.6 mg/g in ethyl acetate, ethanolic and hydroethanolic extracts. Wounds severity was reduced by 35% and up to 45% by the ethanolic and hydroethanolic extracts, as well as the time for clearance. Concentration of TNF-α and IL-1β was normalized by these extracts, along with lipid peroxidation and protein carbonylation. Extracts caused recovery of GSH, mainly the hydroethanolic one. The antipsoriatic activity was associated with antioxidant action.

Black chokeberry (Aronia melanocarpa) pomace extract immobilized in chitosan for colorimetric pH indicator film application

During this study, different amounts of black chokeberry (Aronia Melanocarpa) pomace extract were mixed with chitosan to prepare colorimetric pH indicator films. The monomeric anthocyanin and total phenol content of ultrasonically extracted chokeberry pomace solution were determined by pH differential method and Folin-Ciocaltau assay. ATR-FTIR spectroscopy, CIELab method, solubility, swelling ability, dye migration and tensile strength measurements were used to characterize the films. The pomace extract contained enough active components to highly reduce the solubility and swelling of chitosan. The indicator films maintained their integrity even at acidic pH which was attributed to the interactions between the polymer chains and the phenolic components of the extract. With higher extract content, a higher resistance to water was observed, which also resulted in reduced dye migration. The immobilized dye in chitosan films responded well to the pH change and showed a high color difference from pH 1 to pH 10.

NEPHROPROTECTIVE OF ANTHOCYANIN PIGMENTS EXTRACT FROM RED CABBAGE (BRASSICA OLERACEA L. VAR. CAPITATA F. RUBRA) AGAINST GENTAMICIN-CAPTOPRIL-INDUCED NEPHROTOXICITY IN RATS

Objective: Red cabbage (Brassica oleracea L. var. Capitata f. rubra) has a fairly high anthocyanin content and is a source of powerful antioxidants. This study is basic for the development of a nutraceutical, which has nephroprotective activity.Methods: Red cabbage was extracted using ethanol and water with a mixture of citric acid with a variation of 1, 2, and 3%. The total anthocyanin was determined with pH-differential method. The Wistar strain male rats were divided into five groups. Group 1 as a negative control, Group 2 as a positive control treated with Vitamin E dose of 400 mg/kg BW day. Groups 3–5 were treated with three different extract dose of 100, 200, and 400 mg/kg BW. Gentamicin was given intraperitoneally and captopril orally for 3 days. Extracts and Vitamin E were administrated orally for 15 days after induction of gentamicin-captopril. Nephroprotective activity was determined by measuring the levels of serum creatinine, blood ureum, and macroscopic kidney.Results: The combination of 96% ethanol and citric acid 3% showed the percent of free radical 2,2-diphenyl-1-picrylhydrazyl arrest of 75.23% and contained 53.49 ± 5.01 mg/L of total anthocyanin. The anthocyanin pigment from red cabbage extract can decrease the levels of creatinine and ureum, which dose of 100 mg/kg BW showed the highest value of 48.72%. There were differences in the macroscopic morphology in the rat kidney.Conclusion: Based on the results, we concluded that ethanol with 3% citric acid produced higher anthocyanin and showed nephroprotective activity.

Browning Index of Anthocyanin-Rich Fruit Juice Depends on pH and Anthocyanin Loss More Than the Gain of Soluble Polymeric Pigments.

Fruit juice pigmentation depends on anthocyanins, pH, and other matrix components. Spectrophotometric methods to determine pigmentation include the browning index (ABS520 nm /ABS420 nm ), pH differential method for monomeric anthocyanin (MA) content, and bisulfite bleaching to determine percent polymeric color (%PC). In this study, anthocyanin-rich fruit juice browning index was strongly dependent on pH and MA content. MA loss, and to a lesser extent, a gain in newly-formed pigments at 420nm contributed to the browning index change during aging. Therefore, browning index is strongly associated with MA content and is useful for assessing fruit juice quality.

Estimating foliar anthocyanin content of purple corn via hyperspectral model.

To date, the foliar anthocyanin content was either determined via the pH differential or HPLC methods, both of which are slow and destructive. Here, a hyperspectral model was established to estimate the foliar anthocyanin content of purple corn (Zea mays L. var. Jingzi No. 1). The reflectivity (P) of the foliar hyperspectral was inverted to 1/P, lg P, 1/lg P, P′, 1/P′, lgP′, and 1/lgP′. The correlation coefficient between these inversions and the foliar anthocyanin content was plotted against the hyperspectral wavelength. The wavelength of inversions around 650 nm was sensitive to the foliar anthocyanin content. The hyperspectral model was fitted via linear, polynomial, power, exponential, and logarithmic functions with the sensitive band as independent variable and the anthocyanin content as function. The hyperspectral model (y = 3,000,000,000 × W 685 4.5896) fitted via inversion of lgP′ showed the highest determination coefficients (0.768) among all models. The hyperspectral model was well validated with a determination coefficient of 0.932 and an RMSE of 0.0065. Moreover, the accuracy and stability of the hyperspectral model were further enhanced with a determination coefficient of 0.954 and RMSE of 0.0047 when the anthocyanin content of the sample was below 20 mg/g. Hence, the hyperspectral model estimated the foliar anthocyanin content of purple corn quickly and nondestructively.