Quick screening of maize kernels for provitamin A content

Does Plant Breeding for Antioxidant-Rich Foods Have an Impact on Human Health?

Given the general beneficial effects of antioxidants-rich foods on human health and disease prevention, there is a continuous interest in plant secondary metabolites conferring attractive colors to fruits and grains and responsible, together with others, for nutraceutical properties. Cereals and Solanaceae are important components of the human diet, thus, they are the main targets for functional food development by exploitation of genetic resources and metabolic engineering. In this review, we focus on the impact of antioxidants-rich cereal and Solanaceae derived foods on human health by analyzing natural biodiversity and biotechnological strategies aiming at increasing the antioxidant level of grains and fruits, the impact of agronomic practices and food processing on antioxidant properties combined with a focus on the current state of pre-clinical and clinical studies. Despite the strong evidence in in vitro and animal studies supporting the beneficial effects of antioxidants-rich diets in preventing diseases, clinical studies are still not sufficient to prove the impact of antioxidant rich cereal and Solanaceae derived foods on human

European Database of Carotenoid Levels in Foods. Factors Affecting Carotenoid Content

Many studies indicate that diets including carotenoid-rich foods have positive effects on human health. Some of these compounds are precursors of the essential nutrient vitamin A. The present work is aimed at implementing a database of carotenoid contents of foods available in the European market. Factors affecting carotenoid content were also discussed. Analytical data available in peer-reviewed scientific literature from 1990 to 2018 and obtained by HPLC/UHPLC were considered. The database includes foods classified according to the FoodEx2 system and will benefit compilers, nutritionists and other professionals in areas related to food and human health. The results show the importance of food characterization to ensure its intercomparability, as large variations in carotenoid levels are observed between species and among varieties/cultivars/landraces. This highlights the significance of integrating nutritional criteria into agricultural choices and of promoting biodiversity. The uncertainty quantification associated with the measurements of the carotenoid content was very rarely evaluated in the literature consulted. According to the EuroFIR data quality evaluation system for food composition tables, the total data quality index mean was 24 in 35, reflecting efforts by researchers in the analytical methods, and less resources in the sampling plan documentation.

Effects of Ultraviolet Radiation (UV-A+UV-B) on the Antioxidant Metabolism of the Red Macroalga Species Acanthophora spicifera (Rhodophyta, Ceramiales) From Different Salinity and Nutrient Conditions

Acanthophora spicifera (M.Vahl) Børgesen is a macroalga of great economic importance. This study evaluated the antioxidant responses of two algal populations of A. spicifera adapted to different abiotic conditions when exposed to ultraviolet-A+ultraviolet-B radiation (UV-A+UV-B). Experiments were performed using the water at two collection points for 7 days of acclimatization and 7 days of exposure to UVR (3 h per day), followed by metabolic analyses. At point 1, water of 30 ± 1 practical salinity unit (psu) had concentrations of 1.06 ± 0.27 mm NH 4 + , 8.47 ± 0.01 mm NO 3 - , 0.17 ± 0.01 mm PO 4 - 3 and pH 7.88. At point 2, water of 35 ± 1 psu had concentrations of 1.13 ± 0.05 mm NH 4 + , 3.73 ± 0.01 mm NO 3 - , 0.52 ± 0.01 mm PO 4 - 3 and pH 8.55. Chlorophyll a, phycobiliproteins, carotenoids, mycosporins, polyphenolics and antioxidant enzymes (catalase, superoxide dismutase and guaiacol peroxidase) were evaluated. The present study demonstrates that ultraviolet radiation triggers antioxidant activity in the A. spicifera. However, such activation resulted in greater responses in samples of the point 1, with lower salinity and highest concentration of nutrients.

Effect of green juice and their bioactive compounds on genotoxicity induced by alkylating agents in mice

Kale juice (Brassica oleracea L. var. acephala D.C.) is a reliable source of dietary carotenoids and typically contains the highest concentrations of lutein (LT) and beta-carotene (BC) among green leafy vegetables. As a result of their antioxidant properties, dietary carotenoids are postulated to decrease the risk of disease occurrence, particularly certain cancers. The present study aimed to (1) examine the genotoxic and antigenotoxic activity of natural and commercially available juices derived from Brassica oleracea and (2) assess influence of LT or BC against DNA damage induced by alkylating agents such as methyl methanesulfonate (MS) or cyclophosphamide (CP) in vivo in mice. Male Swiss mice were divided into groups of 6 animals, which were treated with water, natural, or commercial Brassica oleraceae juices (kale), LT, BC, MMS, or CP. After treatment, DNA damage was determined in peripheral blood lymphocytes using the comet assay. Results demonstrated that none of the Brassica oleraceae juices or carotenoids produced genotoxic effects. In all examined cell types, kale juices or carotenoids inhibited DNA damage induced by MMS or CP administered either pre- or posttreatment by 50 and 20%, respectively. Under our experimental conditions, kale leaf juices alone exerted no marked genotoxic or clastogenic effects. However, a significant decrease in DNA damage induced by MMS or CP was noted. This effect was most pronounced in groups that received juices, rather than carotenoids, suggesting that the synergy among constituents present in the food matrix may be more beneficial than the action of single compounds. Data suggest that the antigenotoxic properties of kale juices may be of therapeutic importance.

In vitro exposure of Ulva lactuca Linnaeus (Chlorophyta) to gasoline - Biochemical and morphological alterations

Refined fuels have considerable share of pollution of marine ecosystems. Gasoline is one of the most consumed fuel worldwide, but its effects on marine benthic primary producers are poorly investigated. In this study, Ulva lactuca was chosen as a biological model due to its cosmopolitan nature and tolerance to high levels and wide range of xenobiotics and our goal was to evaluate the effects of gasoline on ultrastructure and metabolism of that seaweed. The experimental design consisted of in vitro exposure of U. lactuca to four concentrations of gasoline (0.001%, 0.01%, 0.1%, and 1.0%, v/v) over 30 min, 1 h, 12 h, and 24 h, followed by cytochemical, SEM, and biochemical analysis. Increase in the number of cytoplasmic granules, loss of cell turgor, cytoplasmic shrinkage, and alterations in the mucilage were some of the ultrastructural alterations observed in thalli exposed to gasoline. Decrease in carotenoid and polyphenol contents, as well as increase of soluble sugars and starch contents were associated with the time of exposure to the xenobiotic. In combination, the results revealed important morphological and biochemical alterations in the phenotype of U. lactuca upon acute exposure to gasoline. This seaweed contain certain metabolites assigned as candidates to biomarkers of the environmental stress investigated and it is thought to be a promise species for usage in coastal ecosystems perturbation monitoring system. In addition, the findings suggest that U. lactuca is able to metabolize gasoline hydrocarbons and use them as energy source, acting as bioremediator of marine waters contaminated by petroleum derivatives.

Provitamin A potential of landrace orange maize variety (Zea mays L.) grown in different geographical locations of central Malawi

The provitamin A potential of landrace orange maize from different locations (A, B, C and D) of central Malawi has been evaluated. Physicochemical compositions, color, total carotenoid content (TCC), carotenoid profiles, and oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity as antioxidant capacities of maize were determined. Color values of orange maize had correlations with β-cryptoxanthin (r>0.36). TCC of white and orange maize averaged 2.12 and 59.5 mg/kg, respectively. Lutein was the most abundant carotenoid (47.8%) in orange maize, followed by zeaxanthin (24.2%), β-carotene (16.4%) and β-cryptoxanthin (11.6%). Location D showed the highest levels of lutein, zeaxanthin and antioxidant capacity. Provitamin A content of orange maize met the target level (15 μg/g) of biofortification. Retinol activity equivalent (RAE) from β-cryptoxanthin and β-carotene in orange maize averaged 81.73 μg/100g. In conclusion, orange maize has the potential to be a natural source of provitamin A.

Phytochemical and antiproliferative activity of proso millet

The phytochemical content, antioxidant activity and antiproliferative properties of three diverse varieties of proso millet are reported. The free phenolic content ranged from 27.48 (Gumi 20) to 151.14 (Mi2504-6) mg gallic acid equiv/100 g DW. The bound phenolic content ranged from 55.95 (Gumi20) to 305.81 (Mi2504-6) mg gallic acid equiv/100 g DW. The percentage contribution of bound phenolic to the total phenolic content of genotype samples analyzed ranged between 62.08% and 67.05%. Ferulic acid and chlorogenic acid are the predominant phenolic acid found in bound fraction. Caffeic acid and p-coumaric acid were also detected. Syringic acid was detected only in the free fraction. The antioxidant activity was assessed using the hydrophilic peroxyl radical scavenging capacity (PSC) assay. The PSC antioxidant activity of the free fraction ranged from 57.68 (Mi2504-6) to 147.32 (Gumi20) µmol of vitamin C equiv/100 g DW. The PSC antioxidant activity of the bound fraction ranged from 95.38 (Mizao 52) to 136.48 (Gumi 20) µmol of vitamin C equiv/100 g DW. The cellular antioxidant activity (CAA) of the extract was assessed using the HepG2 model. CAA value ranged from 2.51 to 6.10 µmol equiv quercetin/100 g DW. Antiproliferative activities were also studied in vitro against MDA human breast cancer and HepG2 human liver cancer cells. Results exhibited a differential and possible selective antiproliferative property of the proso millet. These results may be used to direct the consumption of proso millet with improved health properties.

Carotenoid content and antioxidant activity of hexane extracts from selected Croatian corn hybrids

Carotenoids, which occur naturally in corn grains, have been associated with reduced risk of degenerative diseases. The aim of this research was to measure the carotenoid content of hexane extracts of six commercial high-yield corn hybrids and determine the relationship between carotenoid content and antioxidant activity. Levels of lutein, zeaxanthin, β-cryptoxanthin and β-carotene in hexane extracts were determined using HPLC, and antioxidant activity was assayed using the TEAC system based on the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS(+)), and the TBARS system based on a linoleic acid emulsion. Corn hybrids varied in carotenoid content and antioxidant activity in both assays. Lutein and zeaxanthin were the predominant carotenoids; their levels were 15-fold higher than those of β-cryptoxanthin and β-carotene. Antioxidant activity in both assays increased linearly with total carotenoid content. Lutein and β-carotene were the primary contributors to TEAC activity, while lutein, β-cryptoxanthin and β-carotene were primary contributors to TBARS activity.

The effects of lead and copper on the cellular architecture and metabolism of the red alga Gracilaria domingensis

The effect of lead and copper on apical segments of Gracilaria domingensis was examined. Over a period of 7 days, the segments were cultivated with concentrations of 5 and 10 ppm under laboratory conditions. The samples were processed for light, confocal, and electron microscopy, as well as histochemistry, to evaluate growth rates, mitochondrial activity, protein levels, chlorophyll a, phycobiliproteins, and carotenoids. After 7 days of exposure to lead and copper, growth rates were slower than control, and biomass loss was observed on copper-treated plants. Ultrastructural damage was primarily observed in the internal organization of chloroplasts and cell wall thickness. X-ray microanalysis detected lead in the cell wall, while copper was detected in both the cytoplasm and cell wall. Moreover, lead and copper exposure led to photodamage of photosynthetic pigments and, consequently, changes in photosynthesis. However, protein content and glutathione reductase activity decreased only in the copper treatments. In both treatments, decreased mitochondrial NADH dehydrogenase activity was observed. Taken together, the present study demonstrates that (1) heavy metals such as lead and copper negatively affect various morphological, physiological, and biochemical processes in G. domingensis and (2) copper is more toxic than lead in G. domingensis.

Distribution of carotenoids in endosperm, germ, and aleurone fractions of cereal grain kernels

To compare the distribution of carotenoids across the grain, non-corn and corn cereals were hand dissected into endosperm, germ and aleurone fractions. Total carotenoid content (TCC) and carotenoid composition were analysed using spectrophotometry and HPLC. Cereal carotenoid composition was similar; however, concentrations varied significantly (p<0.05). Endosperm fractions had TCC ranging from 0.88 to 2.27 and 14.17 to 31.35 mg/kg in non-corn cereals and corn, respectively. TCC, lutein and zeaxanthin in germ fractions were higher in non-corn cereals than in corn. Lutein and zeaxanthin contents were lower in non-corn cereal endosperms. The aleurone layer had zeaxanthin levels 2- to 5-fold higher than lutein among the cereals. Positive significant correlations (p<0.05) were found between TCC, carotenoids analysed by HPLC and DPPH results. This study is the first to report on carotenoid composition of the aleurone layer. Our findings suggest that the aleurone of wheat, oat, corn and germ of barley have significantly enhanced carotenoid levels.

Effects of natural radiation, photosynthetically active radiation and artificial ultraviolet radiation-B on the chloroplast organization and metabolism of Porphyra acanthophora var. brasiliensis (Rhodophyta, Bangiales)

We undertook a study of Porphyra acanthophora var. brasiliensis to determine its responses under ambient conditions, photosynthetically active radiation (PAR), and PAR+UVBR (ultraviolet radiation-B) treatment, focusing on changes in ultrastructure, and cytochemistry. Accordingly, control ambient samples were collected in the field, and two different treatments were performed in the laboratory. Plants were exposed to PAR at 60 μmol photons m-2 s-1 and PAR + UVBR at 0.35 W m-2 for 3 h per day during 21 days of in vitro cultivation. Confocal laser scanning microscopy analysis of the vegetative cells showed single stellate chloroplast in ambient and PAR samples, but in PAR+UVBR-exposed plants, the chloroplast showed alterations in the number and form of arms. Under PAR+UVBR treatment, the thylakoids of the chloroplasts were disrupted, and an increase in the number of plastoglobuli was observed, in addition to mitochondria, which appeared with irregular, disrupted morphology compared to ambient and PAR samples. After UVBR exposure, the formation of carpospores was also observed. Plants under ambient conditions, as well as those treated with PAR and PAR+UVBR, all showed different concentrations of enzymatic response, including glutathione peroxidase and reductase activity. In summary, the present study demonstrates that P. acanthophora var. brasiliensis shows the activation of distinct mechanisms against natural radiation, PAR and PAR+UVBR.

Carotenoid and anthocyanin contents of grains of Brazilian maize landraces

BACKGROUND

Carotenoid and anthocyanin contents of 26 maize landraces cultivated in southern Brazil were determined to evaluate their potential as natural colorants or functional food ingredients.

RESULTS

The major carotenoids detected in the whole grain flour were zeaxanthin and lutein. Anthocyanins of landraces with purple starchy endosperm (Lingua de Papagaio and Mato Grosso Palha Roxa) were more extractable in methanol-HCl (1%, v/v), exhibiting 2.45 and 0.94 g kg(-1) of whole grains flour, respectively. In contrast, butanol-HCl (30%, v/v) was more effective for the extraction of anthocyanins from the purple-colored landraces Roxo 29 and Roxo 41; genotypes with pigments localized in the outer parts (pericarp) of grains (2.60 and 2.19 g kg(-1)). The Roxo 41 landrace showed the highest concentration of pigments, e.g. 11.72 10(-3) g kg(-1) of total carotenoids and 2.16 g kg(-1) of total anthocyanins. Similarly, the yellow-colored MPA 1 and the purple-colored Roxo 29 landraces showed prominent amounts of carotenoids (10.86 10(-3) g kg(-1)) and anthocyanins (2.60 g kg(-1)), respectively.

CONCLUSION

Our findings suggest that the colored grains of maize landraces studied may hold promise for the development of grain-based functional foods or natural colorants regarding their carotenoid and anthocyanin contents and as genetic resource in breeding programs.

Carotenoids and their isomers: color pigments in fruits and vegetables

Fruits and vegetables are colorful pigment-containing food sources. Owing to their nutritional benefits and phytochemicals, they are considered as 'functional food ingredients'. Carotenoids are some of the most vital colored phytochemicals, occurring as all-trans and cis-isomers, and accounting for the brilliant colors of a variety of fruits and vegetables. Carotenoids extensively studied in this regard include β-carotene, lycopene, lutein and zeaxanthin. Coloration of fruits and vegetables depends on their growth maturity, concentration of carotenoid isomers, and food processing methods. This article focuses more on several carotenoids and their isomers present in different fruits and vegetables along with their concentrations. Carotenoids and their geometric isomers also play an important role in protecting cells from oxidation and cellular damages.

Influence of pre- and postharvest factors on beta-carotene content, its in vitro bioaccessibility, and antioxidant capacity in melons

Fresh and stored melons were analyzed for total and bioaccessible beta-carotene content, as well as total antioxidant potentials, to investigate the effects of genotype, season, sowing time, and storage on nutritional quality. There were significant cultivar effects on beta-carotene content (P < 0.001), ranging from 1 to 23 mg kg(-1) of fresh weight (FW), its bioaccessibility (P < 0.005), ranging from 79 to 94.5%, and for antioxidant potential (P < 0.001), ranging from 1569 to 2267 micromol of Fe(2+) kg(-1) of FW of melons. Sowing time significantly affected beta-carotene contents (P < 0.017) and antioxidant potentials (P < 0.001), but these were highly cultivar dependent, with season having no effect. Postharvest storage over 4 weeks at 7 degrees C resulted in losses of antioxidant potential and beta-carotene content independent of cultivar. Cultivar and postharvest management were major determinants of nutritional quality of the melons evaluated.

Biofortification of crops with seven mineral elements often lacking in human diets--iron, zinc, copper, calcium, magnesium, selenium and iodine

The diets of over two-thirds of the world's population lack one or more essential mineral elements. This can be remedied through dietary diversification, mineral supplementation, food fortification, or increasing the concentrations and/or bioavailability of mineral elements in produce (biofortification). This article reviews aspects of soil science, plant physiology and genetics underpinning crop biofortification strategies, as well as agronomic and genetic approaches currently taken to biofortify food crops with the mineral elements most commonly lacking in human diets: iron (Fe), zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iodine (I) and selenium (Se). Two complementary approaches have been successfully adopted to increase the concentrations of bioavailable mineral elements in food crops. First, agronomic approaches optimizing the application of mineral fertilizers and/or improving the solubilization and mobilization of mineral elements in the soil have been implemented. Secondly, crops have been developed with: increased abilities to acquire mineral elements and accumulate them in edible tissues; increased concentrations of 'promoter' substances, such as ascorbate, beta-carotene and cysteine-rich polypeptides which stimulate the absorption of essential mineral elements by the gut; and reduced concentrations of 'antinutrients', such as oxalate, polyphenolics or phytate, which interfere with their absorption. These approaches are addressing mineral malnutrition in humans globally.

Carotenoid content of underutilized tropical fruits

This study was conducted to evaluate the total carotene content (TCC) and beta carotene (BC) in the selected underutilized tropical fruits. TCC of underutilized fruits estimated by spectrophotometric method was in the range of 1.4-19.8 mg/100 g edible portion. The TCC of these fruits decreased in the order: Jentik-jentik > Durian Nyekak 2 > Durian Nyekak 1 > Cerapu 2 > Cerapu 1 > Tampoi Kuning > Bacang 1 > Kuini > Jambu Mawar > Bacang 2 > Durian Daun > Bacang 3 > Tampoi Putih > Jambu Susu. BC contents estimated by HPLC method were highest in Jentik-jentik, followed by Cerapu 2, Durian Nyekak 2, Tampoi Kuning, Durian Nyekak 1, and Cerapu 1, which had a range of 68-92% of BC in TCC. These underutilized fruits have an acceptable amount of carotenoids that are potential antioxidant fruits.