Characteristics and Relationships between Total Polyphenol and Flavonoid Contents, Antioxidant Capacities, and the Content of Caffeine, Gallic Acid, and Major Catechins in Wild/Ancient and Cultivated Teas in Vietnam.

Vietnam has diverse and long-established tea plantations but scientific data on the characteristics of Vietnamese teas are still limited. Chemical and biological properties including total polyphenol and flavonoid contents (TPCs and TFCs), antioxidant activities (DPPH, ABTS, FRAP, and CUPRAC), as well as the contents of caffeine, gallic acid, and major catechins, were evaluated for 28 Vietnamese teas from North and South Vietnam. Higher values of TPCs and TFCs were found for green (non-oxidised) and raw Pu'erh (low-oxidised) teas from wild/ancient tea trees in North Vietnam and green teas from cultivated trees in South Vietnam, as compared to oolong teas (partly oxidised) from South Vietnam and black teas (fully oxidised) from North Vietnam. The caffeine, gallic acid, and major catechin contents depended on the processing, geographical origin, and the tea variety. Several good Pearson's correlations were found (r2 > 0.9) between TPCs, TFCs, the four antioxidant capacities, and the content of major catechins such as (-)-epicatechin-3-gallate and (-)-epigallocatechin-3-gallate. Results from principal component analysis showed good discriminations with cumulative variances of the first two principal components varying from 85.3% to 93.7% among non-/low-oxidised and partly/fully oxidised teas, and with respect to the tea origin.

Progress on maternal health care in Vietnam: Findings from Vietnam Multiple Indicator Cluster Survey 2000, 2006, 2011, and 2014.

This paper aims to describe a trend in coverage of maternal care services, and provides a detailed analysis of socio-economic correlations to the existing inequities. The paper uses data from the Vietnam Multiple Indicator Cluster Survey 2000, 2006, 2011, and 2014. In the MICS, there were 9,117 women in 2000, 9,473 women in 2006, 11,614 women in 2011, and 9,827 women in 2014 participated in. We found the coverage of antenatal care increase from 68.6% in 2000 to 95.9% in 2014. Similarly, the percentages of women who gave birth with the assistance of skilled staff increased during the studied period ( from 69.9% in 2000, 87.7% to 94.5% in 2014). However, improvements in antenatal care and skilled birth attendance in Vietnam have been uneven across different segments of the population. In all the four surveys, the proportions of women who received ANC by a skilled staff and percentages of women who gave birth with the assistance of a skilled health personnel were much higher among those with higher education, belonged to Kinh majority tribe, had better economic status, and lived in an urban area. The degrees of inequity in both antenatal and delivery care in Vietnam are likely to increase over time.

Smartphone-based digital images as a low-cost and simple colorimetric approach for the assessment of total phenolic contents in several specific Vietnamese dried tea products and their liquors.

The total phenolic contents (TPCs) represent the bioactive substances and antioxidant capacities of flora products. The present study employed digital images from a smartphone to determine the TPCs in tea products and their liquors. Various parameters related to the portable home-made colorimetric analysis box design were optimized to achieve the most favorable capturing condition. The proposed method performance was evaluated, which agreed with the Appendix F of AOAC (2016). In comparison with the standard UV-vis, no statistical differences (t-tests, P = 95 %) were observed, and there were advantages of simplicity, portability, sample volume reduction, decreased analysis time, low-cost operation, especially the potential to be used by tea producers, managers, and consumers to quickly analyze the TPCs. The results demonstrate the descending TPCs orders of green > white > oolong > black teas (recoveries of 95-98 %) and the increase of TPCs in tea liquors regarding the rising brewing temperature and duration.