Search Results (8)

Leafy sweet potato is a new type of sweet potato, whose leaves and stems are used as green vegetables. However, sweet potato tips can be affected by pre-harvest factors, especially the intensity of light. At present, intercropping, greenhouse planting, and photovoltaic agriculture have become common planting modes for sweet potato. Likewise, they can also cause insufficient light conditions or even low light stress. This research aimed to evaluate the influence of four different shading levels (no shading, 30%, 50%, and 70% shading degree) on the growth profile of sweet potato leaves. The net photosynthetic rate, chlorophyll pigments, carbohydrates, and polyphenol components were determined. Our findings displayed that shading reduced the content of the soluble sugar, starch, and sucrose of leaves, as well as the yield and Pn. The concentrations of Chl a, Chl b, and total Chl were increased and the Chl a/b ratio was decreased for the more efficient interception and absorption of light under shading conditions. In addition, 30% and 50% shading increased the total phenolic, total flavonoids, and chlorogenic acid. Transcriptome analysis indicated that genes related to the antioxidant, secondary metabolism of phenols and flavonoids, photosynthesis, and MAPK signaling pathway were altered in response to shading stresses. We concluded that 30% shading induced a high expression of antioxidant genes, while genes related to the secondary metabolism of phenols and flavonoids were upregulated by 50% shading. And the MAPK signaling pathway was modulated under 70% shading, and most stress-related genes were downregulated. Moreover, the genes involved in photosynthesis, such as chloroplast development, introns splicing, and Chlorophyll synthesis, were upregulated as shading levels increased. This research provides a new theoretical basis for understanding the tolerance and adaptation mechanism of leafy sweet potato in low light environments. Full article

The phosphorus chemical plant (PCP) production process leads to the substantial discharge of fluoride into the surrounding environment. However, there is limited research data regarding the pollution levels and ecological safety thresholds of farmland fluoride around PCPs in karst areas. This study evaluates the local contamination status and health risks by determining the fluoride content in farmland and vegetables in vicinity of a PCP in a karst area of Southwestern China. Farmland ecological security threshold was derived based on the species sensitivity distribution (SSD) model. Results showed that the fluoride contents in the soil ranged from 529.36 to 1496.02 mg kg⁻¹, with the median value of 823.93 mg kg⁻¹, which was higher than the national background value in China (478 mg kg⁻¹) by 172.37%. Fluoride contents in vegetables ranged from 0.01 to 25.21 mg kg⁻¹, with the median value of 1.29 mg kg⁻¹, which was higher than the limits of contaminants in food (1 mg kg⁻¹) by 129.00%, and 53.85% of vegetable samples were contaminated. Leafy vegetables showed a higher tendency of fluoride enrichment compared to non-leafy vegetables. Despite there being no significant health risk to the residents via the intake of vegetables overall, there may be potential health risks from the intake of sweet potato leaves. Based on the SSD model, the ecological safety thresholds of fluoride in local farmland was classified into the suitable for planting category (≤174.13 mg kg⁻¹), safe plant utilization category (174.13–4005.42 mg kg⁻¹), and strict control of planting category (≥4005.42 mg kg⁻¹). These findings will provide valuable insights to facilitate the safe cultivation of local agricultural products and optimize the utilization of soil resources. Full article

Malabar spinach (Basella alba), amaranth (Amaranthus tricolor), and sweet potato (Ipomoea batatas) are leafy vegetables found in Southwest China. The variation of chlorophyll, carotenoids, ascorbic acid, total flavonoids, phenolic compounds, and antioxidant capacity was studied in the leaves and stems of the three vegetables. The content of main health-promoting compounds and the antioxidant capacity in the leaves were higher than that in the stems, indicating that the leaves of the three vegetables possess greater nutritional value. The trend of total flavonoids in all three vegetables was similar to the trend of antioxidant capacity, suggesting that the total flavonoids may be the major antioxidants wihin these vegetables. Eight individual phenolic compounds were detected in three different vegetables. The most abundant levels of individual phenolic compounds in the leaves and stems of malabar spinach, amaranth, and sweet potato were 6′-O-feruloyl-d-sucrose (9.04 and 2.03 mg g⁻¹ DW), hydroxyferulic acid (10.14 and 0.73 mg g⁻¹ DW), and isorhamnetin-7-O-glucoside (34.93 and 6.76 mg g⁻¹ DW), respectively. Sweet potato exhibited a higher total and individual phenolic compound content compared to malabar spinach and amaranth. Overall, the results demonstrate that the three leafy vegetables possess high nutritional value, and could be used not only for consumption but also in various other fields, including medicine and chemistry. Full article

Leafy sweet potato (Ipomoea batatas L.) is an excellent source of nutritious greens and natural antioxidants, but reports on antioxidants content and activity at buds, leaves, petioles, and stems are scarce. Therefore, the total phenolics content (TPC), total anthocyanins content (TAC), and antioxidant activity (assessed by DPPH and ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP)) were investigated in four aerial parts of 11 leafy sweet potato varieties. The results showed that varieties with pure green aerial parts, independently of the part analyzed, had higher TPC, FRAP, and ABTS radical scavenging activities. The green-purple varieties had a significantly higher TAC, while variety GS-17-22 had the highest TAC in apical buds and leaves, and variety Ziyang in petioles and stems. Among all parts, apical buds presented the highest TPC and antioxidant capacity, followed by leaves, petioles, and stems, while the highest TAC level was detected in leaves. The TPC was positively correlated with ABTS radical scavenging activity and FRAP in all parts studied, whereas the TAC was negatively correlated with DPPH radical scavenging activity. Collectively, the apical buds and leaves of sweet potato had the higher levels of nutritional values. These results would provide reference values for further breeding of leafy sweet potatoes. Full article

Once in soil and water, metals can enter the food chain, and the consumption of contaminated crops can pose a serious risk to human health. This study used pot experiments to evaluate the accumulation of metal elements and their influence on levels of antioxidants in vegetables. The current study clearly demonstrates that metals accumulated in the five vegetables that were planted in the contaminated soils, especially so for water spinach. Cd accumulation of all of the vegetables planted in the contaminated soils was greater Cu. The low accumulation rate that was seen in sweet potato leaf, potato, and tomato indicated their suitability for planting in suspected contaminated soil, such as at farms nearby metal industries, in replacement of high accumulators, such as leafy vegetables. The non-carcinogenic HI of Cd exposure from water spinach and sweet potato were >1, whereas those for Cu were <1. This study suggests that residents may experience health risks due to vegetable consumption, and that children are vulnerable to the adverse effects of heavy metal ingestion. Full article

Initial evidence suggests that lithium might affect life expectancy and the risk for different disease conditions, but most studies were conducted in patients on lithium medication. Little is known about the association of blood lithium levels within the physiological range with cardiometabolic risk factors and diet. We measured plasma lithium in a community-based sample from Northern Germany (samples taken between 2010 and 2012). All participants (aged 25–82 years) underwent standardized examinations and completed a semi-quantitative food frequency questionnaire. Of several variables tested, the estimated glomerular filtration rate (eGFR) was statistically significantly (inversely) associated with lithium levels, mainly in individuals with slightly impaired renal function (eGFR < 75 mL/min/1.73 m²). Besides, lithium levels were positively associated with age and alcohol intake. Using reduced rank regression, we identified a dietary pattern explaining 8.63% variation in plasma lithium levels. Higher lithium levels were associated with higher intakes of potatoes, leafy vegetables, root vegetables, fruits, tea, beer, wine and dietetic products and lower intakes of pasta, rice, pork, chocolate, sweets, soft drinks, other alcoholic beverages, sauces and snacks. Our observations suggest that plasma lithium levels are associated inversely with kidney function, particularly in individuals with slightly impaired renal function, and positively with age and alcohol intake. Lithium at physiological levels was moderately related to an exploratory dietary pattern. Full article

Pacific Islanders have paid dearly for abandoning traditional diets, with diabetes and other non-communicable diseases (NCD) widespread. Starchy root crops like sweet potato, taro, and cassava are difficult to grow on the potassium-deficient soils of atolls, and high energy, low nutrient imported foods and drinks are popular. Nutritious, leafy food plants adapted to alkaline, salty, coral soils could form part of a food system strategy to reduce NCD rates. This project targeted four atolls south of Tarawa, Kiribati, and was later extended to Tuvalu. Mineral levels in diverse, local leafy food plants were compared to reveal genotype–environment interactions. Food plants varied in ability to accumulate minerals in leaves and in tolerance of mineral-deficient soils. Awareness activities which included agriculture, health, and education officers targeted atoll communities. Agriculture staff grew planting material in nurseries and provided it to farmers. Rejuvenation of abandoned giant swamp taro pits to form diversified nutritious food gardens was encouraged. Factsheets promoted the most suitable species from 24 analyzed, with multiple samples of each. These included Cnidoscolus aconitifolius (chaya), Pseuderanthemum whartonianum (ofenga), Polyscias scutellaria (hedge panax), and Portulaca oleracea (purslane). The promoted plants have been shown in other studies to have anti-NCD effects. Inclusion of the findings in school curricula and practical application in the form of demonstration school food gardens, as well as increased uptake by farmers, are needed. Further research is needed on bioavailability of minerals in plants containing phytates and tannins. Full article

Dark green leafy vegetables (DGLVs) are considered as important sources of iron and vitamin A. However, iron concentration may not indicate bioaccessibility. The objectives of this study were to compare the nutrient content and iron bioaccessibility of five sweet potato cultivars, including three orange-fleshed types, with other commonly consumed DGLVs in Ghana: cocoyam, corchorus, baobab, kenaf and moringa, using the in vitro digestion/Caco-2 cell model. Moringa had the highest numbers of iron absorption enhancers on an “as-would-be-eaten” basis, β-carotene (14169 μg/100 g; p < 0.05) and ascorbic acid (46.30 mg/100 g; p < 0.001), and the best iron bioaccessibility (10.28 ng ferritin/mg protein). Baobab and an orange-fleshed sweet potato with purplish young leaves had a lower iron bioaccessibility (6.51 and 6.76 ng ferritin/mg protein, respectively) compared with that of moringa, although these three greens contained similar (p > 0.05) iron (averaging 4.18 mg/100 g) and β-carotene levels. The ascorbic acid concentration of 25.50 mg/100 g in the cooked baobab did not enhance the iron bioaccessibility. Baobab and the orange-fleshed sweet potato with purplish young leaves contained the highest levels of total polyphenols (1646.75 and 506.95 mg Gallic Acid Equivalents/100 g, respectively; p < 0.001). This suggests that iron bioaccessibility in greens cannot be inferred based on the mineral concentration. Based on the similarity of the iron bioaccessibility of the sweet potato leaves and cocoyam leaf (a widely-promoted “nutritious” DGLV in Ghana), the former greens have an added advantage of increasing the dietary intake of provitamin A. Full article