Planted forests are increasing in many upland regions worldwide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here, the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4-64% of catchment area). (210) Pb-dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (δ(13) C) and nitrogen (δ(15) N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to sixfold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39-116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (β-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilization and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance.
The antioxidant activity of fresh and dried plant extracts of Paederia foetida and Syzygium aqueum were studied using beta-carotene bleaching and the 2,2'-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The percentage of antioxidant activity for all extract samples using both assays was between 58 and 80%. The fresh samples of both plants had higher antioxidant activity than the dried samples. The results of the beta-carotene bleaching assay were correlated (R(2) = 0.9849) with those of the ABTS assay.
The antioxidant components of cocoa powder, which is rich in polyphenols, were isolated using column chromatography and high performance liquid chromatography. Polyphenolic compounds were then characterized by high-performance liquid chromatography/Ultraviolet and electronspray ionization-tandem mass spectrometry (HPLC-UV-/ESI-MS-MS). As a result, five phenolic compounds were detected. In this study we also investigated scavenging or the total antioxidant capacity (%) of cocoa polyphenol (CP) fractionated from cocoa powder extract. 114.0 mg/g of gallic acid -equivalent phenolics and 94.3 mg/g catechin- equivalent flavonoids were quantified in this extract. Their free radical-scavenging activity was assessed by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay, β-carotene bleaching test, and xanthine oxidase inhibitory activity (OX). Total antioxidant capacity (TAC) was further assessed against the myoglobin-induced oxidation of 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (ABTS) and expressed as Trolox equivalent. A high correlation between TAC and phenolic contents indicated that phenolic compounds from cocoa were a major contributor of antioxidant activity (0.967 ≤ r ≤ 1.00). CP extract had significantly (P
The evolution of cosmetic products results in the growing demands for cosmetics that are preservatives free. Plant essential oils were found to be a promising antimicrobial and also antioxidant agent. In this study, Cymbopogon citratus (lemongrass), Laurus nobilis (bay leaf) and Backhousia citriodora (lemon myrtle) essential oils were selected and evaluated for their antimicrobial properties. It was found that Laurus nobilis exhibited strong antimicrobial activity against the selected bacteria Streptococcus saprophyticus (ATCC 49619), Streptococcus aureus (ATCC 22923), Streptococcus pyogenes (ATCC 29436), Pseudomonas aeruginosa (ATCC 13048), Klebsiella pneumoniae (ATCC 700603), Escherichia coli (ATCC 22922) with MIC ranging between 7.8 ug/mL to 250 μg/mL. The antioxidant activity of selected essential oils was determined by antioxidant assays which were 1,1-Diphenyl-2-picrylhydrazyl assay (DPPH), determination of ferric reducing antioxidant power assay (FRAP) and β-Carotene/linoleic acid bleaching assay. Backhousia citriodora and Laurus nobilis showed the highest antioxidant activity.
n-Octanal and β-Selinene were identified to be the major components with peak area of 26.37 % and 13.92 % respectively in secondary metabolites analysis by Gas Chromatography-Mass Spectrometry (GCMS).
Three species of Malaysian edible seaweed (Eucheuma denticulatum, Sargassum polycystum and Caulerpa lentillifera) were analyzed for their carotenoid composition using a combination of high-performance thin layer chromatography (HPTLC) and ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS), while the antioxidant capacities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. The HPTLC analysis exhibited a distinct carotenoid pattern among the three seaweed groups. The UHPLC-ESI-MS/MS analysis showed fucoxanthin as the major carotenoid present in S. polycystum while lutein and zeaxanthin in E. denticulatum. For C. lentillifera, β-carotene and canthaxanthin were the major carotenoids. Some of the carotenoids, such as rubixanthin, dinoxanthin, diatoxanthin and antheraxanthin, were also tentatively detected in E. denticulatum and S. polycystum. For antioxidant activity, S. polycystum (20 %) and E. denticulatum (1128 μmol TE/g) showed the highest activity in the DPPH and ORAC assays, respectively. The findings suggest the three edible varieties of seaweeds may provide a good dietary source with a potential to reduce antioxidative stress.
Microalgae can use either ammonium or nitrate for its growth and vitality. However, at a certain level of concentration, ammonium nitrogen exhibits toxicity which consequently can inhibit microalgae productivity. Therefore, this study is aimed to investigate the tolerance of Tetraselmis tetrathele to high ammonium nitrogen concentrations and its effects on growth rate, photosynthetic efficiency (F v /F m ), pigment contents (chlorophyll a, lutein, neoxanthin, and β-carotene), and fatty acids production. Experiments were performed at different ammonium nitrogen concentrations (0.31-0.87 gL-1) for 6 days under a light source with an intensity of 300 μmol photons m-2 s-1 and nitrate-nitrogen source as the experimental control. The findings indicated no apparent enhancement of photosynthetic efficiency (Fv/Fm) at high levels of ammonium nitrogen (
NH
4
+
-N) for T. tetrathele within 24 h. However, after 24 h, the photosynthetic efficiency of T. tetrathele increased significantly (p < 0.05) in high concentration of
NH
4
+
-N. Chlorophyll a content in T. tetrathele grown in all of the different
NH
4
+
-N levels increased significantly compared to nitrate-nitrogen (NO3-N) treatment (p < 0.05); which supported that this microalgal could grow even in high level of
NH
4
+
-N concentrations. The findings also indicated that T. tetrathele is highly resistant to high ammonium nitrogen which suggests T. tetrathele to be used in the aquaculture industry for bioremediation purpose to remove ammonium nitrogen, thus reducing the production cost while improving the water quality.
Pumpkin (Cucurbita maxima) is a vegetable crop which is commonly consumed as vegetables or incorporated into food products. Pumpkin flesh was reported abundant with carotenoid compounds includes α-carotene, β-carotene, β-cryptoxanthin, lutein and zeaxanthin. As this antioxidant related to the colour pigment, these nutrients highly potential to be in other parts of pumpkin such as peel and seed. Therefore, the aim of this was to determine the total lutein content in different parts of pumpkin and their antioxidant properties. The pumpkin would be collected and evaluated at the commercial maturity stage (60% to fully orange-yellow of fruit peel). The presence of the lutein properties using DPPH, FRAP and ABTS assays in different parts of pumpkin was tested by using microplate spectrophotometer and analysed statistically with SPSS version 20. Among of all pumpkin fruit parts, flesh presented the highest concentration of potential lutein extracts, followed by peel and seed, respectively. On the contrary, potential lutein extracts from the pumpkin peel had the highest antioxidant activity in terms of DPPH, FRAP and ABTS assays when compared to the lutein extracts in flesh and seeds. This study indicates that the potential lutein from Cucurbita maxima especially peel may be the alternative to be used as both natural antioxidants in food products due to increasing demand for natural food preservatives. Therefore, this study may act as a source for others to further study to optimize the usage of pumpkin by-products
Introduction: Manilkara zapota (L.) P. Royen or sapodilla is a fruit-bearing tree that has been cultivated mainly in tropical areas including Mexico and South East Asia. The fruits and the other parts of M. zapota plant have been used since ages ago for various medicinal purposes. However, the data on the antioxidant properties of various parts of M. zapota is limited. Therefore, we aimed to measure the content and capacity of antioxidants in various M. zapota plant parts and also to screen the phytoconstituents present in the part with the highest antioxidant content and capacity. Methods: The in vitro antioxidant evaluation including the content of total phenolic (TPC) and total flavonoids (TFC) as well as β-carotene bleaching and 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability of the leaves, seeds, flesh, and peels of M. zapota extracted by aqueous and ethanol were determined. The plant part that exhibited the highest TPC, TFC, and antioxidant capacity was selected for phytoconstituents identification using liq- uid chromatography mass spectrometry. Results: M. zapota leaves aqueous extract exhibited the highest TPC, TFC, and antioxidant capacities and therefore selected for phytoconstituents identification. Our study provide additional data in which a total of 39 phytoconstituents have been identified in the M. zapota leaves including m-coumaric acid, quinic acid, robinetinidol-4alpha-ol, isoorientin 6’’-O-caffeate, apocynin A, and C16 Sphinganine. Conclusion: Thus, our study revealed that M. zapota leaves aqueous extract has potential as a promising naturally-occurring an- tioxidant candidate which could be useful for medicinal and nutritional functions.
Microalgae can produce various natural products such as pigments, enzymes, unique fatty acids and vitamin that benefit humans. The objective of the study is to study the bioaccessibility of carotenoids (β-carotene and lycopene) and vitamin E (α- and β-tocopherol) of Nannochloropsis oculata and Chaetoceros calcitrans. Analyses were carried out for both the powdered forms of N. oculata and C. calcitrans, and the dried extract forms of N. oculata and C. calcitrans. In vitro digestion method together with RP-HPLC was used to determine the bioaccessibility of carotenoids and vitamin E for both forms of microalgae. Powdered form of N. oculata had the highest bioaccessibility of β-carotene (28.0 ± 0.6 g kg-1), followed by dried extract N. oculata (21.5 ± 1.1 g kg-1), dried extract C. calcitrans (16.9 ± 0.1 g kg-1), and powdered C. calcitrans (15.6 ± 0.1 g kg-1). For lycopene, dried extract of N. oculata had the highest bioaccessibility of lycopene (42.6 ± 1.1 g kg-1), followed by dried extract C. calcitrans (41.9 ± 0.6 g kg-1), powdered C. calcitrans (39.7 ± 0.1 g kg-1) and powdered N. oculata (32.6 ± 0.7 g kg-1). Dried extract C. calcitrans had the highest bioaccessibility of α-tocopherol (72.1 ± 1.2 g kg-1). However, β-tocopherol was not detected in both dried extract and powdered form of C. calcitrans. In conclusion, all samples in their dried extract forms were found to have significantly higher bioaccessibilities than their powdered forms. This may be due to the disruption of the food matrix contributing to a higher bioaccessibility of nutrients shown by the dried extract forms.
This study evaluated and compared the antioxidant capacity between freshly prepared and lactic fermented Malaysian herbal teas. Herbal teas are rich in antioxidants. Fermentation has been known to be the oldest and cost effective method with the ability to preserve or improve food nutritional qualities. Information on the antioxidant capacity of lactic fermented food or beverage is still lacking. Hence, the objective of this study is to determine the changes in the antioxidant properties of Malaysian herbal teas after being subjected to lactic fermentation. Commercially available local herbal teas were used for this study. Herbal teas such as “Allspice”, “Scaphium”, “Gora” and “Cinnamon” were purchased from the local store in Malaysia and were subjected to 24-hour lactic fermentation. Lactic fermented herbal teas were analyzed for their total phenolic, total flavonoid and antioxidant properties via DPPH, FRAP, and β-carotene linoleate bleaching assay. All lactic fermented herbal teas exhibited higher phenolic contents, flavonoid contents and antioxidant properties compared to the freshly-prepared herbal teas with majority showing significant changes (p < 0.05) in FRAP and β-carotene bleaching assay. Lactic fermented herbal teas also showed an increase in antioxidant capacity in DPPH assay, however non-significant changes were observed.
Green leafy vegetables are good sources of carotenoids. Generally, food composition databases related to raw foods are available, but data on cooked foods in Malaysia are still lacking. Since carotenoids are prone to degradation during cooking processes, the present study was undertaken to evaluate the extent of nutrient loss in vegetables subjected to two conventional cooking methods, which were boiling and stir-frying with cooking durations of 4 and 8 minutes. The vegetables selected were Chinese cabbage (Brassica Pekinensis var. cephalata), swamp cabbage (Ipomoea aquatica), spinach (Spinacia oleracea), Ceylon spinach (Basella rubra), red spinach (Amaranthus gangeticus), white spinach (Amaranthus viridis) and tapioca shoots (Manihot utilissima). Percentage losses of nutrients after cooking treatment were calculated based on retention factors. Results obtained showed that stir-frying had reduced lutein content for all vegetables ranging from 8-89% while the effect of boiling for lutein varied (0-428%) with different vegetables at both cooking durations of 4 and 8 min. Boiling for 8 min increased retention of β carotene in all vegetables ranging from 18-380% except for Chinese cabbage and spinach compared with 4 min, while stir-frying generally increased the retention of β-carotene for all vegetables 2-3 times except for spinach. Cooked vegetables have variations in carotenoids composition brought by varying cooking conditions (time and temperature), type of vegetables and the interaction between cooking methods and type of vegetables.
Studies were conducted to assess the percutaneous absorption of the triacyglycerols (TAGs), tocols and carotenoids present in crude and refined palm oil. In vitro experiments using upright Franz diffusion cells were employed to investigate the permeability of these compounds across full thickness human skin and into the receptor solution. Cetrimide, a cationic surfactant was chosen to be used as a solubilising agent in the receptor phase with an optimum concentration of 3.0 mg/mL and was able to provide sink conditions throughout the permeation. TAGs, tocols and carotenoids all permeated human skin from crude palm oil (CPO), whereas only TAGs permeated when refined palm oil (RPO) was used. Of the TAGs, oleic acid-containing TAGs was preferentially absorbed despite palmitic acid being the most prevalent fatty acid (FA) in TAGs. Tocols in the form of α-T3 showed the highest permeation followed by γ-T3, α-T and the lowest permeation was observed for δ-T3. Carotenoids (α-carotene and β-carotene) also showed an appreciable amount of permeation from CPO.
The bioactive compounds and "in vitro" antioxidant activity measured by three antioxidant assays of some traditional and non-traditional cold-pressed edible oils from Macedonia were object of this study. The fatty acid composition showed dominance of monounsaturated oleic acid in "sweet" and "bitter" apricot kernel oils with percentages of 66.7 ± 0.5 and 57.8 ± 0.3%, respectively. The most dominant fatty acid in paprika seed oil was polyunsaturated linoleic acid with abundance of 69.6 ± 2.3%. The most abundant tocopherol was γ-tocopherol with the highest quantity in sesame seed oil (57.6 ± 0.1 mg/100 g oil). Paprika seed oil, sesame seed oil and sweet apricot oil were the richest source of phytosterols. DPPH assay was the most appropriate for the determination of the antioxidant activity of cold-pressed sunflower oil due to high abundance of α-tocopherol with a level of 22.8 ± 1.1 mg/100 g of oil. TEAC assay is the best for the determination of the antioxidant activity of sesame seed oil and paprika seed oils as the richest sources of phenolic compounds. β-carotene assay was the most suitable assay for oils obtained from high pigmented plant material. Triacylglycerols and phytosterol profiles can be used as useful markers for the origin, variety and purity of the oils.
Oil palm (Elaeis guineensis Jacq.) fronds (OPF) are the most abundant oil palm solid wastes that are generated during oil palm agriculture and harvest. Palm oil and some other palm wastes have been reported to contain high concentrations of carotenoids with vital bioactive properties. However, the extraction and quantification of carotenoids from OPF have not been reported. In this study, ultrasonic-assisted extraction, HPLC-FLD for quantification, and response surface methodology (RSM) for optimization of β-carotene, lutein, and zeaxanthin from OPF extracts were investigated. The effects of extraction temperature (X1: 30-70°C), extraction time (X2: 10-50 min), and solvent-sample ratio (X3: 10-50 mL/g) on the recovery of β-carotene (Y1), lutein (Y2), and zeaxanthin (Y3) were investigated using three-level Box-Behnken design (BBD) experiment. At a desirability of 1, the optimum extraction conditions for β-carotene (30.14°C, 37.11 min, and 23.18 mL/g), lutein (30.00°C, 39.09 min, and 19.24 mL/g), and zeaxanthin (30.09°C, 36.76 min, and 22.38 mL/g) yielded carotenoid concentrations of 17.95 μg/g dry weight (DW), 261.99 μg/g DW, and 29.99 μg/g DW, respectively.
Effect of various cooking methods on antioxidant content and radical scavenging activity of pumpkin was evaluated. Pumpkin (Cucurbita moschata) was boiled and stir-fried for 2, 4 and 6 minutes respectively. Beta-carotene and lycopene were determined using HPLC and total phenolics measured using Folin-Ciocalteu method. The free radical scavenging activity of the samples was determined using 1, 1-diphenyl-2 picrylhydrazyl assay. Interestingly, result of the study showed an increase in both beta-carotene (2 to 4 times) and lycopene (17 to 40 times) content of pumpkin after cooking for 2, 4 and 6 minutes. However, the treatment resulted in 18 to 54% losses of total phenolics content of the pumpkin. Nevertheless, the free radical scavenging activity exhibited by cooked pumpkins was found to be high, in the range of 81.1% to 94.6% with IC50 of 1.41 to 1.62 mg ml-1
.
Pepper of the Capsicum species is a common ingredient in various food preparations by different cultures worldwide. The Capsicum is recognised by its five main domesticated species, namely Capsicum annuum, C. baccatum, C. chinense, C. frutescens and C. pubescens. The genetic diversity in Capsicum offers fruits in wide ranges of morphology and carotenoid profile. Carotenoids enhance the value of pepper from a nutritional standpoint, despite being commonly prized for the pharmacologically active pungent capsaicinoids. Carotenoids of pepper comprise mainly of the unique, powerful and highly stable capsanthin and capsoroubin, together with β-carotene, β-cryptoxanthin, lutein, zeaxanthin, antheraxanthin and violaxanthin. These carotenoids are present at diverse profile and varying levels, biosynthetically connected to the fruit maturity stages. This review describes the health-promoting functional attributes of the carotenoids that are mainly associated with their excellent role as lipophilic antioxidants. Capsicum as a great source of carotenoids is discussed in the aspects of main domesticated species, biosynthesis, pigment profile, antioxidant activity and safety. Findings from a number of in vitro, in vivo and clinical studies provided appreciable evidence on the protective effects of pepper's carotenoids against degenerative diseases. Hence, pepper with its functional carotenoids might be recommended in health-promoting and disease preventing strategies.
Encapsulation has been used to overcome the problem of instability of functional pigments such as carotenoids from natural sources. In this study, β-carotene in carrot juice was spray dried with four different wall materials namely maltodextrin, resistant maltodextrin, octenyl succinate anhydride (OSA) starches Capsul (CAP) and HICAP-100 (HCAP). The objective of this research was to study the effects of various wall materials on physicochemical properties and stability of β-carotene powders along with its stability after incorporation into sugar confection. All four wall materials produced powders of acceptable quality in terms of moisture content, water activity, hygroscopicity, solubility as well as onset glass transition temperature. OSA starches exhibited better pigment retention post spray drying where juices encapsulated with HCAP showed the highest retention (94.34%). This was also represented in more orange Hue values (H°) in powders produced with CAP (53.93) and HCAP (53.33). Powders produced with HCAP also showed the longest half-life after storage at 4 °C, 25 °C, and 40 °C, as well as under exposure to light. Similarly, carrot powders produced with OSA starches also exhibited better β-carotene retention after production of hard candy confection. Though candies with HCAP encapsulated juices showed the highest β-carotene retention post candy processing, candies with CAP encapsulated carrot juices exhibited better long term stability after storage at 25 °C and 40 °C as well as under exposure to light.
In the last decade, non-thermal processing for inactivating microorganisms has been developed in response to the worldwide interest for more fresh and improved quality of food products. Winter melon is a very perishable fruit, hence, processing into puree is a necessity. However application of heat in the production of puree could affect the nutritional values, thus, application of non thermal treatment in combination with preservation method is significant for this fruit. This study was conducted to evaluate the effect of non-thermal processing in combining with preservation method on antioxidant activity, level of key antioxidant groups (total phenolic and ascorbic acid content) and the color of winter melon puree. Total phenolic content (TPC) was measured using Folin-Ciocalteu reagent. Ascorbic acid (AA) was determined using 2,6-dichlorophenol-indophenol titration method. Antioxidant activity were determined using four antioxidant assays namely Ferric Reducing Antioxidant Potential (FRAP), Oxygen Radical Absorbance Capacity (ORAC), 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and β-Carotene Bleaching Assays. For the TPC, puree with pH 3 (28.5±1.3 GAE/g fresh weight) exhibited high in TPC as compared to puree with pH 3.5 and unprocessed puree. In contrast, unprocessed puree contains significantly high ascorbic acid (AA) content (35.9 ± 1.8 mg/100 g fresh mass) as compared to pH 3.0 and pH 3.5 purees. In general, antioxidant activity for all assays of pH 3.0 and pH 3.5 purees were significantly higher (p