Carotenoid and mineral content of Micronesian giant swamp taro (Cyrtosperma) cultivars

A Concise Review on Taro Mucilage: Extraction Techniques, Chemical Composition, Characterization, Applications, and Health Attributes

Taro (Colocasia esculenta) is an important source of carbohydrates as an energy source and is used as a staple food throughout the world. It is rich in mucilage and starch granules, making it a highly digestible ingredient. Mucilage can act as a matrix and a thickening, binding, emulsifying, or foaming agent in food, pharmaceutical, and several other fields of research. Moreover, mucilage can be extracted from several living organisms and has excellent functional properties, such as water-holding, oil-holding, and swelling capacities. Therefore, these remarkable functional properties make mucilage a promising ingredient with possible industrial applications. Furthermore, several extraction techniques, including enzyme-assisted, ultrasonication, microwave-assisted, aquatic, and solvent extraction methods, are used to obtain quantitative amounts of taro mucilage. Coldwater extraction with ethanol precipitation can be considered an effective and cost-effective technique to obtain high-quality mucilage with suitable industrial applications, whereas the ultrasonication method is more expensive but results in a higher amount of mucilage than other emerging techniques. Mucilage can also be used as a fat replacer or reducer, dye remover, coating agent, and antioxidating agent. Therefore, in this review, we detail the key properties related to the extraction techniques, chemical composition, and characterization of taro mucilage, along with its suitable applications and health benefits.

Exploring the Potential of Indigenous Foods to Address Hidden Hunger: Nutritive Value of Indigenous Foods of Santhal Tribal Community of Jharkhand, India

Traditional foods of indigenous communities can be explored as a sustainable means of addressing undernutrition. Our study aimed at identifying indigenous foods of the Santhal tribal community of Godda district of Jharkhand, India, assessing their nutritive value, and appraising their potential role in addressing hidden hunger. A cross-sectional survey using qualitative methods like focus group discussions with women of childbearing age (15-49 years), adult males, and elderly people was conducted for food identification. This was followed by taxonomic classification and quantitative estimate of nutritive value of the identified foods either in a certified laboratory or from secondary data. The community was well aware of the indigenous food resources in their environment. More than 100 different types of indigenous foods including a number of green leafy vegetables were identified. Taxonomic classification was available for 25 food items and an additional 26 food items were sent for taxonomic classification. Many indigenous foods (more than 50% of which were green leafy vegetables) were found to be rich sources of micronutrients like calcium, iron, vitamin A as beta carotene, and folate. Maximizing utilization of indigenous foods can be an important and sustainable dietary diversification strategy for addressing hidden hunger in this indigenous community.

Essential and toxic metals in taros (Colocasia esculenta) cultivated in the Canary Islands (Spain): evaluation of content and estimate of daily intake

Taros are a staple in the diet of many people around the world, and they are an excellent source of minerals. Monitoring the levels of metals in food provides basic information that is useful from the perspectives of safety, regulation, and nutrition. Forty-two samples of taros were randomly obtained from supermarkets, vegetable markets, and farmer's plots on the island of Tenerife (Canary Islands, Spain). The edible portion (pulp) was the only part considered for analysis. Flame atomic absorption spectrometry (FAAS) was used to determine the contents of Na, K, Ca, Mg, Cu, Fe, Mn, and Zn. The levels of Cr, Ni, Cd, and Pb were determined using graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations (mg/kg) were 565.6 Na, 2947 K, 231.4 Ca, 364.5 Mg, 1.224 Cu, 3.818 Fe, 1.408 Mn, 2.242 Zn, 0.044 Cr, 0.021 Ni, 0.003 Cd, and 0.006 Pb. The mean concentrations of Cd and Pb were well below the accepted European Commission limits (0.1 mg/kg weight for both metals, respectively). Daily consumption of taro (10.41 g taro/person/day) contributes to the dietary intake of essential metals and trace elements, mainly Mg (1.265% in adult women and 1.084% in adult men) and Cu (1.182% for adult men and women). The average daily intakes of Cd (0.031 μg/day) and Pb (0.062 μg/day) from taro were below the legislated respective tolerable weekly intakes (TWIs). Thus, the samples analyzed were considered safe to eat based on their metal concentrations and legislated allowable intakes.

Antioxidant activity and cytotoxicity of Cyrtosperma johnstonii extracts on drug sensitive and resistant leukemia and small cell lung carcinoma cells

CONTEXT

The number of patients with cancer is increasing. New therapeutic agents to overcome drug-resistant tumors are urgently needed. Cyrtosperma johnstonii N.E. Br. (Araceae) is used for treatment of cancer in Thai traditional medicine. This study aimed to evaluate antioxidant activity and cytotoxicity of C. johnstonii extracts on human cancer cells.

MATERIALS AND METHODS

Dried powder of C. johnstonii rhizomes was extracted with several solvents. The 0.1 mg/ml extract solution was tested for antioxidant activity by 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. Color formation from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to determine cell viability. Standardization of the extract was performed by high-performance liquid chromatography (HPLC) with photodiode array detector at 254 and 360 nm. Cell cycle arrest was evaluated by flow cytometry after 5 min, 12 h and 24 h treated with 20 µg/ml of the acetone extract.

RESULTS

The acetone extract exhibited the highest phenolic content and antioxidant activity (TEAC and EC values = 19.2 ± 0.14 and 19.2 ± 0.31 mM/mg, respectively). The IC₅₀ values for leukemia ranged from 11 ± 1 to 29 ± 3 µg/ml and from 5 ± 2 to 6 ± 0 µg/ml for small cell lung carcinoma cells. Cell cycle arrest occurred at the G2/M phase followed by apoptosis. HPLC analysis revealed that rutin is the major constituents of the extract.

DISCUSSION AND CONCLUSION

The acetone extract of C. johnstoni is a promising source of natural antioxidants and anticancer. The extract inhibits cancer cells effectively with less effect on normal cells.

Mucilage chemical profile and antioxidant properties of giant swamp taro tubers

The yellow (YP) and white (WP) sections of giant swamp taro (GST) contain 40.0 g/kg and 51.5 g/kg (dry wt) respectively of pure mucilage made up of D-glucose (44.95-78.85 %), D-galactose (8.70-25.35 %), D-mannose (3.20-10.45 %), D-arabinose (2.45-5.20 %) and small amounts of glucuronic acid and rhamnose. Arabinogalactan-proteins (5.30-8.83 g/kg) contain mainly arabinose and galactose (in a 1:1 proportion) and also significant amounts of rhamnose, xylose, glucuronic acid and mannose. Antioxidant activity of YP was higher than those of WP while chelating ability and reducing power increased with mucilages content. Generally YP and WP showed better reducing power (1.06 ± 0.35 at 5 mg/mL) than ascorbic acid (0.89 ± 0.22). WP and YP chelated ferrous ions by 20.0-76.0 % and 16.4-71.0 % respectively. Effective concentrations (EC50) of mucilages (WP 1.28 ± 0.05 mg/mL; YP 1.42 ± 0.04 mg/mL) were lower than those of citric acid (1.58 ± 0.04 mg/mL). Generally mucilage from the WP and YP sections are excellent sources of chelating agents.

A systematic review on the contributions of edible plant and animal biodiversity to human diets

The sustainable use of natural and agricultural biodiversity in the diet can be instrumental to preserve existing food biodiversity, address malnutrition, and mitigate adverse effects of dietary changes worldwide. This systematic review of literature summarizes the current evidence on the contribution of plant and animal biodiversity to human diets in terms of energy intake, micronutrient intake, and dietary diversification. Peer-reviewed studies were searched in ten databases using pre-defined search terms. Only original studies assessing food biodiversity and dietary intake were included, resulting in a total of 34 studies. 7, 14, and 17 studies reported information in relation to energy intake, micronutrient intake, and dietary diversification, respectively. In general, locally available foods were found to be important sources of energy, micronutrients, and dietary diversification in the diet of particularly rural and forest communities of highly biodiverse ecosystems. The current evidence shows local food biodiversity as important contributor of nutritious diets. Findings are, however, limited to populations living in highly biodiverse areas. Research on the contribution of biodiversity in diets of industrialized and urban settings needs more attention. Instruments are needed that would more appropriately measure the dietary contribution of local biodiversity.