Ascorbic acid-induced degradation of liposome-encapsulated acylated and non-acylated anthocyanins of black carrot extract.

BACKGROUND: In the presence of ascorbic acid, the degradation of acylated (sinapic, ferulic and p-coumaric acid derivatives of cyanidin-3-xylosylglucosylgalactoside) and non-acylated anthocyanins of black carrot extract (BCE) encapsulated in liposomes was studied. BCEs (0.2% and 0.4% w/w) were encapsulated in liposomes using different lecithin concentrations (1%, 2% and 4% w/w). RESULTS: The liposomes were prepared with particle diameters of less than 50 nm and zeta potentials of about -21.3 mV for extract-containing liposomes and -27.7 mV for control liposomes. The encapsulation efficiency determined using high-performance liquid chromatography (HPLC) showed that increasing lecithin levels increased the efficiency to 59% at the same extract concentration. The concentrations of total anthocyanins and individual anthocyanins were determined for ascorbic acid (0.1% w/w)-degraded extract and liposomes (containing 0.2% w/w extract). Anthocyanin quantification of both liposomal and extract samples was performed by HPLC using cyanidin-3-O-glucoside chloride as standard. Five anthocyanins in the extract and encapsulated liposomes were quantified during 24 h (0-24 h): cyanidin-3-xylosylglucosylgalactoside 1.0-0.51 and 0.82-0.58 mg g-1 , cyanidin-3-xylosylgalactoside 2.5-1.1 and 2.2-1.7 mg g-1 , cyanidin-3-xylosyl(sinapoylglucosyl)galactoside 0.51-0.14 and 0.35-0.28 mg g-1 , cyanidin-3-xylosyl(feruloylglucosyl)galactoside 1.37-0.41 and 1.06-0.98 mg g-1 , and cyanidin-3-xylosyl(coumaroylglucosyl)galactoside 0.28-0.08 mg g-1 for extract and 0.27-0.26 mg g-1 for liposomes, respectively. CONCLUSIONS: This study demonstrates the potential beneficial effect of liposomal encapsulation on individual, particularly acylated, anthocyanins after addition of ascorbic acid during a storage time of 24 h.

Physical and chemical stability of anthocyanin-rich black carrot extract-loaded liposomes during storage.

In this study, the protection effect of black carrot extract on the stability of liposomes during storage was evaluated. The physical and chemical stability of the extract (0.4% w/w) including extract-loaded liposomes with various lecithin content (1%, 2%, and 4% w/w) were demonstrated. Z-average particle diameter and zeta potentials of liposomes were evaluated before and after 21 days of storage. The particle diameter of the samples was found to be lower than 50 nm after storage and no statistical change was determined (p < 0.05). The liposomes with and without extract were visualized by transmission electron microscopy (TEM) after negative staining. The TEM images revealed that unloaded and extract-loaded liposomes are similar in size. The degradation of extract (30%-90%), phenolic content (10%-29%), and antioxidant capacity (4%-33%) of liposomes depending on lecithin content were also determined during storage to evaluate the biochemical stability. A hexanal analysis was performed to investigate the lipid oxidation in liposomes within 60 days. According to the results, the oxidation of polyunsaturated fatty acids may be inhibited with the addition of the extract to liposomes; however, lipid content should be limited according to the extract concentration. The highest protection on oxidation was observed in extract-loaded liposomes containing 1% lecithin. The study provided valuable data on the contribution of an anthocyanin addition to liposomes to overcome oxidation of unsaturated phospholipids.

Impact of liposomal encapsulation on degradation of anthocyanins of black carrot extract by adding ascorbic acid.

Black carrot anthocyanins are known to be relatively stable because they contain acylated anthocyanins. The degradation of vitamin C (l-ascorbic acid) on anthocyanins is a known fact in beverage systems. In this study, the effects of various liposomal systems, including black carrot extract (0.1%, 0.2%, 0.4% w/w) and lecithin (1%, 2%, 4% w/w), on the color and degradation of anthocyanin in different ascorbic acid (0.01%, 0.025%, 0.05%, 0.1% w/w) concentrations were examined via UV/VIS spectroscopy and visual control of the color. The physical characteristics of the liposomal systems resulted in particle diameters of 41-46 nm and zeta-potentials of (-23)-(-20) mV. The encapsulation efficiencies of the liposomal systems increased up to 50% with increasing lecithin concentrations. The encapsulation of black carrot extract in liposomes enhanced the color and stability of the anthocyanins during storage. This study showed that the degradation of anthocyanins due to ascorbic acid can be reduced by liposomes in aqueous solutions.

Home-Processed Red Beetroot (Beta vulgaris L.) Products: Changes in Antioxidant Properties and Bioaccessibility.

In this study, the effects of home-processing on the antioxidant properties and in vitro bioaccessibility of red beetroot bioactives were investigated. For this purpose, fresh red beetroot and six different home-processed red beetroot products-including boiled, oven-dried, pickled, pureed, juice-processed, and jam-processed-were analyzed and compared for their total phenolic (TP) and total flavonoid (TF) contents, total antioxidant capacities (TAC), and individual anthocyanin contents. In addition, bioaccessibility of red beetroot antioxidants was determined using an in vitro simulated gastrointestinal digestion method. Dried, pureed, and fresh red beetroot samples had the highest TP, TF, and TAC values, which were 347 ± 23 mg gallic acid equivalent (GAE)/100 g, 289 ± 53 mg rutin equivalent (RE)/100 g, 3889 ± 982 mg trolox equivalent antioxidant capacity (TEAC)/100 g, respectively. The in vitro digestion method revealed the highest recovery for TP (16%) and TAC (1.3%) in jam. This study provides comparative data to evaluate the effects of various home-processing techniques on antioxidant potential of red beetroot products.

Potential Use of Turkish Medicinal Plants in the Treatment of Various Diseases.

Medicinal plants are sources of health-promoting substances, including phytochemicals and phytoalexins that comprise polyphenols, flavonoids, carotenoids, vitamins A, C, E and several other constituents. Many studies have indicated that medicinal plants have been used to treat human diseases for thousands of years owing to their antimicrobial and antioxidant activities. Medicinal plants reduce the oxidative stress in cells and prevent cancer, cardiovascular and inflammatory diseases, neurodegenerative and digestive system disorders. These potential beneficial effects have been attributed to the presence of bioactive compounds that show antioxidant properties by acting as free radical scavengers or metal chelators, reducing the reactions that produce reactive oxygen and nitrogen species (ROS/RNS). Considering the importance of medicinal plants in terms of their beneficial health effects, some of the medicinally important plants grown in Turkey are covered in this review with respect to their antioxidant potential and phytochemical profile.

Correlation of rutin accumulation with 3-O-glucosyl transferase and phenylalanine ammonia-lyase activities during the ripening of tomato fruit.

In tomato, the predominant flavonoid is quercetin-3-rutinoside (rutin). In this study, we aim to investigate the phenylalanine ammonia-lyase (PAL) and the quercetin-3-O-glucosyl transferase (3-GT) reactions in the formation of rutin during tomato fruit ripening. Tomatoes of the Moneymaker variety at different development stages (green, breaker, turning, pink, red, and deep red) were divided into flesh and peel fractions. In each sample, both the content of rutin and the enzymatic activities for PAL and 3-GT were recorded. The highest activities of PAL were recorded in the peel of turning fruit (3,000 µkat/mg fresh weight). In fruit flesh, maximal activity was observed in red fruit (917.3 µkat/mg). For both tissues, PAL activity strongly decreased at the final (deep red) fruit stage. The activity of 3-GT in peel peaked in the turning fruit stage (50.7 pkat/mg), while in flesh maximal activity (33.4 pkat/mg) was observed in green fruit, which rapidly declined at the turning stage. Higher levels of rutin were detected in the tomato peel compared to the flesh part with the highest level being found at the green stage. The relation of PAL and 3-GT activities to rutin content is also evaluated.

Bioactive healthy components of bulgur.

Bulgur has been one of the most important traditional Durum wheat products in Turkey and Middle Eastern countries for ages. The objective of this study was to reveal the composition of some healthy components of industrial bulgur samples produced in Turkey. Total starch, resistant starch, dietary fibre and total phenolic contents and their high-performance liquid chromatography (HPLC) profile and antioxidant capacity of bulgur samples using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activity methods were investigated. The results showed that total dietary fibre ranged between 5.8 ± 0.7 and 8.2 ± 0.7% and resistant starch between 2.1 ± 0.2 and 2.8 ± 0.2%. Moreover, phenolic content with an average of 59.5 ± 5.2 mg Gallic acid/100 g dry matter and a moderate level of antioxidant capacity with an average of 22.2 ± 2.4% DPPH scavenging activity and 563.3 ± 60.7 µmol Trolox Equivalent Antioxidant Capacity/100 g dry matter of ABTS scavenging activity add value to the health benefits of bulgur product.