Butterfly pea flower have great sensory attraction, but they have not yet been used widely in Vietnam. Extracts of butterfly pea flowers can be used conveniently as a natural blue colorant for food products. In this study, the identification of anthocyanin compounds in butterfly pea flowers was performed by UPLC coupled with a UV and Mass spectrometer instrument. Positive and negative ion electrospray MS/MS chromatograms and spectra of the anthocyanin compounds were determined. By analyzing the chromatograms and spectra for each ion, five anthocyanins were identified in the butterfly pea flower extract; these were delphinidin-3-(6”‐p-coumaroyl)-rutinoside, cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl) glucose in both cis- and trans- isomers, cyanidin-3-(p-coumaroyl-glucoside) and delphinidin-3-pyranoside. Additionally, based on their intensity, it was determined that cyanidin-3-(p-coumaroyl-glucoside) was the most abundant anthocyanin, followed by cyanidin 3-(6”-p-coumaroyl)-rutinoside, delphinidin-3-(p-coumaroyl-glucoside), delphinidin-3-(6”-p-coumaroyl)-rutinoside and delphinidin-3-pyranoside. In this study, cyanidin derivatives were discovered in butterfly pea flower extract, where these compounds had not been detected in previous studies.

Health problems associated with excess calories, such as diabetes and obesity, have become serious public issues worldwide. Innovative methods are needed to reduce food caloric impact without negatively affecting sensory properties. The interaction between starch and phenolic compounds has presented a positive impact on health and has been applied to various aspects of food. In particular, an interaction between polyphenols and starch is widely found in food systems and may endow foods with several unique properties and functional effects. This review summarizes knowledge of the interaction between polyphenols and starch accumulated over the past decade. It discusses changes in the physicochemical properties, in vitro digestibility, prebiotic properties, and antioxidant activity of the starch–polyphenol complex. It also reviews innovative methods of obtaining the complexes and their applications in the food industry. For a brief description, phenolic compounds interact with starch through covalent or non-covalent bonds. The smoothness of starch granules disappears after complexation, while the crystalline structure either remains unchanged or forms a new structure and/or V-type complex. Polyphenols influence starch swelling power, solubility, pasting, and thermal properties; however, research remains limited regarding their effects on oil absorption and freeze–thaw stability. The interaction between starch and polyphenolic compounds could promote health and nutritional value by reducing starch digestion rate and enhancing bioavailability; as such, this review might provide a theoretical basis for the development of novel functional foods for the prevention and control of hyperglycemia. Further establishing a comprehensive understanding of starch–polyphenol complexes could improve their application in the food industry.

Orange-fleshed sweet potato (OFSP) noodles were created by replacing a portion of the wheat flour with OFSP flour in a formulation. This study was performed to identify the physical and chemical characteristics as well as sensorial attributes of noodles prepared from OFSP with some flours (wheat flour and semolina). The addition of xanthan gum and incubation time was examined. Instrumental analyses of noodles (cooking loss, volume increase, rehydration ratio, structure and microstructure) were carried out to assess the impact of experimental factors. The obtained results revealed that noodles made with more OFSP flour had a more yellow color than those with less OFSP flour. The mixture of OFSP and wheat flour in the formula F2 (the percent of OFSP 18.79% and wheat flour 28.18%) produced noodles with high quality and was the most favorable in appearance, taste, texture, and acceptability among the four formulas. Cooking weight and volume were increased from 164.89 to 174.12% and from 184.74 to 194.81%, respectively when semolina was added to the formula. The supplemental semolina 10.57%, xanthan gum of 2% and the incubation time 30 mins were obtained to enhance dough binding properties. The results suggest that OFSP flour could be replaced up to 40% wheat flour for noodles to improve the nutritional value (i.e. increased b-carotene) and might be acceptable to consumers with health food.

With attractive flower colours ranging from dark green to purple, Butterfly pea (Clitoria ternatea L.) is grown year-round in Vietnam. The purpose of this study is to determine the effect of air temperature on drying time and antioxidant compounds of Butterfly pea flowers, fitting the drying curves and testing the goodness of fit. In this study, air drying characteristics of the Butterfly pea flowers were determined using drying air temperature from 55oC to 70oC at a constant air velocity of 1 m/s. The data of experimental moisture loss were fitted to selected seven thin-layer drying models. The effect of drying conditions on the anthocyanin and total phenolic compound changes of Butterfly pea flower were compared. The effect of temperature on the diffusivity was described using the Arrhenius equation with an activation energy of 71.63 kJ.mol- ¹. At increasing temperature, the effective moisture diffusivity values ranged from 2.39×10-12 and 7.76×10-12 m²s - ¹. The mathematical models were compared according to the three statistical parameters such as the coefficient of determination (R2 ), reduced chi-square (χ 2 ) and root mean square error (RMSE) between the observed and predicted moisture ratios. The highest value of R2 (99.8%) and the lowest values of χ 2 (0.0004) and RMSE (0.0178) were observed for drying air temperature of 70oC. Among the seven mathematical models tested with experimental data, the Page model could sufficiently be described the drying characteristics of the Butterfly pea flower.

This work was carried out to determine the physical and chemical properties of goldenberry fruit (Physalis peruviana L.) grown in Lam Ha and Don Duong of Lam Dong province in Viet Nam. The shelf-life and quality of fruits during storage time at ambient temperature (28±2 o C) were also analysed. The analysis results recorded that most of the physical properties of the fruit grown in the two locations (Lam Ha and Don Duong of Lam Dong province, Viet Nam) yielded no significant differences, except the volume, density, hardness and colour of the fruit. The fruit grown in Lam Ha has a lighter colour and yellow intensity (higher a* and C value) than the ones grown in Don Duong, while the fruits are grown in Don Duong are darker (lower L* and higher H o ). In addition to its attractive properties in terms of colour, aroma and taste, they also contain moderate levels of vitamins (C and A), antioxidants (polyphenols), minerals (especially high content of phosphorus) and fibre. Fruit grown in Don Duong had a higher sweetness than those grown in Lam Ha (the ratio of sugar and acid was 2.7 times more). The concentration of bioactive compounds in the goldenberry fruits grown in Lam Ha and Don Duong were almost similar. The shelf-life of goldenberries up to 20 to 22 days at the ambient temperature of about 28±2 o C and 75-80% RH but the quality and sensory characteristics of goldenberry raw materials were declined.