Anthocyanins Are Converted into Anthocyanidins and Phenolic Acids and Effectively Absorbed in the Jejunum and Ileum.

Anthocyanins have been known for their health benefits. However, the in vivo digestion and absorption of anthocyanins through the gastrointestinal tract have not been fully clarified, creating challenges for understanding why anthocyanins have high biological activities and purported low bioavailability in vivo. Twenty-seven male rats were intubated with a 500 mg/kg dose of cyanidin-3-glucoside (C3G). Samples from rats' stomach, duodenum, jejunum, ileum, colon, and serum were collected at 0.5, 1, 2, 3, 4, 5, 6, 12, and 24 h after intubation. Three rats without C3G were used as the control with samples collected at 0 h. C3G and its metabolites in each sample were analyzed using high-performance liquid chromatography-PDA-electrospray ionization-MS/MS. These in vivo studies' results unequivocally demonstrated that cyanidin and phenolic acids were the primary C3G metabolites absorbed, mainly in the jejunum and ileum, between 1 and 5 h post-ingestion. We speculate that C3G uses phloroglucinaldehyde and protocatechuic acid metabolic pathways in its metabolism in vivo.

Isolation and characterization of starch from light yellow, orange, and purple sweet potatoes.

Sweet potato is attracting increased research attention because of its high nutritional value (e.g., carotene, anthocyanin, and minerals) and the wide application of its starch in foods and nonfoods. Herein, eight Chinese sweet potato varieties were investigated in terms of the physicochemical properties of starches. The lightness values of the eight sweet potato starches were higher than 90, which was satisfactory for starch purity. The average molecular weight (MW) and amylopectin average chain length (ACL) of sweet potato starches ranged from 6.93 × 107 g/mol to 16.57 × 107 g/mol and from 21.85% to 23.00%, respectively. Su16 starch with low amylose content and a large amount of short chains exhibited low crystallinity and thermal properties. These results suggested that the molecular structure of amylose and amylopectin was the main influencing factor in determining sweet potato starch physicochemical properties. The swelling power and water solubility of the starches ranged within 20.14-30.51 g/g and 5.28%-11.71% at 95 °C, respectively. Regarding pasting properties, all the starch samples presented high peak viscosity (>5500 cP) and peak temperature (>78 °C), indicating that sweet potato starch can be used as a thickener. All eight sweet potatoes varieties showed great application potential in the food industry.

Identification of QTL for resistance to root rot in sweetpotato (Ipomoea batatas (L.) Lam) with SSR linkage maps.

BACKGROUND: Sweetpotato root rot is a devastating disease caused by Fusarium solani that seriously endangers the yield of sweetpotato in China. Although there is currently no effective method to control the disease, breeding of resistant varieties is the most effective and economic option. Moreover, quantitative trait locus (QTL) associated with resistance to root rot have not yet been reported, and the biological mechanisms of resistance remain unclear in sweetpotato. Thus, increasing our knowledge about the mechanism of disease resistance and identifying resistance loci will assist in the development of disease resistance breeding. RESULTS: In this study, we constructed genetic linkage maps of sweetpotato using a mapping population consisting of 300 individuals derived from a cross between Jizishu 1 and Longshu 9 by simple sequence repeat (SSR) markers, and mapped seven QTLs for resistance to root rot. In total, 484 and 573 polymorphic SSR markers were grouped into 90 linkage groups for Jizishu 1 and Longshu 9, respectively. The total map distance for Jizishu 1 was 3974.24 cM, with an average marker distance of 8.23 cM. The total map distance for Longshu 9 was 5163.35 cM, with an average marker distance of 9.01 cM. Five QTLs (qRRM_1, qRRM_2, qRRM_3, qRRM_4, and qRRM_5) were located in five linkage groups of Jizishu 1 map explaining 52.6-57.0% of the variation. Two QTLs (qRRF_1 and qRRF_2) were mapped on two linkage groups of Longshu 9 explaining 57.6 and 53.6% of the variation, respectively. Furthermore, 71.4% of the QTLs positively affected the variation. Three of the seven QTLs, qRRM_3, qRRF_1, and qRRF_2, were colocalized with markers IES43-5mt, IES68-6 fs**, and IES108-1 fs, respectively. CONCLUSIONS: To our knowledge, this is the first report on the construction of a genetic linkage map for purple sweetpotato (Jizishu 1) and the identification of QTLs associated with resistance to root rot in sweetpotato using SSR markers. These QTLs will have practical significance for the fine mapping of root rot resistance genes and play an important role in sweetpotato marker-assisted breeding.