Vo Quoc Tien’s research while affiliated with Can Tho University and other places

This study was conducted to optimize the foam-mat drying conditions to maximize quality [β-carotene and total polyphenol content (TPC)] and drying rate of “Gấc” aril powder by using two novel statistical techniques as Response Surface Methodology (RSM) and Artificial Neural Network (ANN) couple with Genetic Algorithm (GA). During production process, level of egg albumin (EA) used for foaming process and drying temperature mainly influenced the drying rate and content of antioxidant compounds in powder. ANN model of 3–10–3 showed more accuracy and faster prediction capacity than RSM model did. ANN-GA model predicted the optimal conditions to be 13.31 % EA, 0.26 % xanthan gum and drying temperature of 73.1 °C, with the drying rate of 1.89 g-water/g-dry matter/min, β-carotene content of 395.88 μg/g, TPC of 1.68 mgGAE/g. These results confirmed the suitability and promising of foam-mat drying for “Gấc” aril powder production, to be producing food ingredient containing highly bioactive compounds.

Two parts (arils and peel) of “Gấc” fruit (Momordica cochinchinensis Spreng) were analyzed for their physicochemical properties from the stage when the fruit reached maturity to the next ripening stages. Understanding these characteristics can help identify maturity indicators and use them most effectively. Research results show that “Gấc” fruit reaches maturity at the 7th week (A1) after fruit set (WAFS). At this time, the diameter and weight of the fruit no longer increase. Subsequent changes represent a gradual color change from completely blue (A1) to completely red (A5) and dark red (A6), through three intermediate stages (from A2 to A4). “Gấc” peel synthesizes the highest lycopene content (131.72 µg/g) at stage A5 (11 WAFS) and the highest β-carotene content at both stages A4 and A5 (10 and 11 WAFS) compared to fruit at stage A1 (7 WAFS). Meanwhile, lycopene and β-carotene in arils reached the highest concentrations (1672.04±9.1 μg/g and 582.45±3.4 μg/g, respectively) at stage A5 (11 WAFS). The total polyphenol content (TPC) in “Gấc” fruit arils/peel and total chlorophyll in “Gấc” fruit peel gradually decrease through the ripening stages, the highest value was achieved when the fruit was mature (A1) and the lowest value in fully ripened fruit (A5). Although showing a decrease, “Gấc” fruit still maintained TPC content in arils and peels of 89% and 73%, respectively (stages A4 and A5). The antioxidant activity of both “Gấc” fruit arils and peel also showed similar activity. In addition, “Gấc” arils also contain the highest vitamin C content in the fully ripe fruit stage compared to other stages. Thus, harvesting “Gấc” fruit at stages A4 and A5 will have beneficial ingredients (lycopene, β-carotene, total polyphenol content and vitamin C) that are good for human health.

Response surface methodology and Box-Behnken design (3 factors and 3 levels) were performed to optimize the effects of different egg albumin contents (5-15%), xanthan gum (0.1-0.5%) and drying temperature (50-70oC). Drying rate and β-carotene content are indicators observed through 18 experimental runs and 6 repetitions at the center point. Finally, the physical properties such as color, water solubility index, water absorption index and rehydration ratio together with moisture content, water activity and microstructural of OFSP powder were analysed. The total polyphenol content (TPC), DPPH scavenging activity and β -carotene were analysed. Research results revealed that the optimal egg albumin concentration, xanthan gum concentration and drying temperature of 10.73%, 0.33% and 65.48oC, respectively as foam-mat drying parameters were recorded. From those optimal parameters, the optimal values of drying rate and β-carotene were determined to be 2.34 g water/g dry matter/min (maximize) and 51.82 µg/g (maximize), respectively. Foam-mat dried powder contained low moisture content and water activity, 4.15% and 0.343, respectively, along with water solubility index, water absorption index and rehydration ratio were respectively determined to be 45.87%, 2.36% and 3.97. The color of foam-mat dried OFSP powder was evaluated. According to the findings, the content of β-carotene (48.61±0.5 μg/g) and TPC (2.24±0.04 mgGAE/g) along with antioxidant activity (57.43±1.2%) of OFSP powder products were also determined. SEM analysis of OFSP powder particles at different magnifications showed that they have irregular surface morphology and flake-like structures, different from the structure of powder particles dried by convection drying method, the surface is quite smooth and the structure is intact.

Background. Egg noodles are a commonly consumed food in Asia and are increasingly eaten around the world. Consumers now have more new requirements concerning the quality and healthiness of products. Therefore, the objective of this study is to determine the effects of Moringa leaf powder (MLP), konjac glucomannan (KG), and acetylated starch (AS) on the quality of noodles. Materials and methods. The Box–Behnken design via the response surface methodology was used, and cooking quality, weight increase, and cooking loss were the main responses. Quadratic polynomial equations were established to determine the influence of 3 independent variables (MLP, KG, and AS) on the cooking quality of the studied noodles. Results. A significance test and analysis of variance results demonstrated that the MLP, KG, and AS contributed significantly to the increase in rehydration rate and reduction of cooking loss. The joint interaction effects of dependent variables were also significant for cooking quality. Increasing the percentage of MLP and AS resulted in an increase in weight increase and cooking loss, while increasing the percentage of KG resulted in an increase in the rehydration rate and a significant reduction in cooking loss. Based on the fitted model for two responses, simultaneous optimization was also carried out. The optimal values were MLP, KG, and MS at 5%, 4.89%, and 3%, respectively, which gave an estimated maximum value for weight increase (83.61%) and a minimum value for cooking loss (3.05%). A scanning electron micrograph of noodles containing these concentrations showed that the continuity of the gluten network was enhanced. Conclusion. In this study, the parameters of the input variables were optimized to increase the weight of noodles after cooking and reduce the cooking loss, using the response surface methodology. The accuracy of the model has been verified by actual experimental data. The results obtained may provide new insight into the addition of high bioactive compounds available in plants to the formulation of common food products and the development of new food products for the manufacturing industry.

Background. Egg noodles are a commonly consumed food in Asia and are increasingly eaten around the world. Consumers now have more new requirements concerning the quality and healthiness of products. Therefore, the objective of this study is to determine the effects of Moringa leaf powder (MLP), konjac glucomannan (KG), and acetylated starch (AS) on the quality of noodles. Materials and methods. The Box–Behnken design via the response surface methodology was used, and cooking quality, weight increase, and cooking loss were the main responses. Quadratic polynomial equations were established to determine the influence of 3 independent variables (MLP, KG, and AS) on the cooking quality of the studied noodles. Results. A significance test and analysis of variance results demonstrated that the MLP, KG, and AS contributed significantly to the increase in rehydration rate and reduction of cooking loss. The joint interaction effects of dependent variables were also significant for cooking quality. Increasing the percentage of MLP and AS resulted in an increase in weight increase and cooking loss, while increasing the percentage of KG resulted in an increase in the rehydration rate and a significant reduction in cooking loss. Based on the fitted model for two responses, simultaneous optimization was also carried out. The optimal values were MLP, KG, and MS at 5%, 4.89%, and 3%, respectively, which gave an estimated maximum value for weight increase (83.61%) and a minimum value for cooking loss (3.05%). A scanning electron micrograph of noodles containing these concentrations showed that the continuity of the gluten network was enhanced. Conclusion. In this study, the parameters of the input variables were optimized to increase the weight of noodles after cooking and reduce the cooking loss, using the response surface methodology. The accuracy of the model has been verified by actual experimental data. The results obtained may provide new insight into the addition of high bioactive compounds available in plants to the formulation of common food products and the development of new food products for the manufacturing industry.

Purple sweet potato (PSP) has the potential to be used to prepare functional foods due to its attractive color and high anthocyanin content. With completely randomized design experiments used, the study investigated the effect of the percentage of steamed PSP (25, 29, 33 and 37% of total batch weight) on the overall quality of sandwich bread. The results showed that the added PSP significantly affected the color (L*, a* and b*) and anthocyanin content of bread. The sandwich bread with 33% PSP had the most intense purple color, and a soft structure was found with a measured hardness of 92.12 and 25.11 g force in the bread crust and the centre of the bread, respectively. The expansion ratio was 5.86 times compared with the control sample (5.47 times), and the moisture and anthocyanin content were 38.23% and 55.14 mg%, respectively. The findings of this study also suggested that the preparation of sandwiches with the addition of PSP, in addition to providing a beautiful color, also has the potential to improve overall product quality, increase fiber content (2.4%) and DPPH free radical scavenging activity (28.80%) compared to the control sample.

Wine is a fermented product of fruit juice. Mulberry and apple juice can also be used to produce wine. Several factors influence the alcoholic fermentation of the must; therefore, the optimization of the mulberry wine fermentation conditions with the dry yeast strain Saccharomyces bayanus (concentration varied from 0.15 to 0.25 g/L), fermentation conditions as pH value (from 3.5 to 4.5), and total soluble solid (TSS) content (24–28°Brix) were performed in this study. To evaluate the influence of these factors, a Box–Behnken design was used to minimize the number of factor combinations required, which allows the determination of optimal fermentation conditions (pH, TSS content, and dry yeast concentration) to produce wines with high alcohol and bioactive compounds (total anthocyanin (TAC) and polyphenol content (TPC)). Based on the analysis of experimental data, the second-order response surface models were developed to describe the relationship between initial pH value, TSS, and dry yeast concentration on wine quality acquisition (ethanol content and bioactive compounds). The results of the analysis of variance (ANOVA) showed that the model setup by response surface quadratic regression was suitable for predicting the wine quality. It was observed that the quality of the apple-fortified mulberry wine was significantly affected by all variables. The optimal contents of ethanol, total anthocyanin, and total polyphenol were achieved at 12.97% (v/v), 171.85 mg/L, and 87.17 mgGAE/L, respectively, when fermented in juice medium with optimal values of pH, TSS, and yeast concentration of 3.9, 26°Brix, and 0.22 g/L, respectively.

This study aimed to produce waffles with increased quality by adding turmeric starch (1-2%), lecithin (0.6-1%), and canola oil (7.5-12.5%) to the recipe. The physicochemical characteristics and sensory values of the product were analyzed together with radical scavenging activity (DPPH% testing). Multiple regression was used to analyze the relationship between curcumin in waffles/firmness and three independent variables (turmeric starch, lecithin, and canola oil), with the goal of using the independent variables to predict the dependent variables. Response surface methodology was used to optimize the content of the dependent variables to obtain the highest curcumin content and the best firmness. Being formulated with the optimal values of turmeric starch (2%), lecithin (0.86%), and canola oil (11.2%), waffles contain the optimal curcumin content (5.84 mg/100 g) and a good texture (not too hard or too soft at 209.7 g force). An amount of 100 g of waffles contain 6.90 g of protein, 36.64 g of carbohydrates, 16.78 g of lipids, 3.8 g of resistant starch, 1.32 g of fiber, and 0.6 g of ash. Analysis results of total polyphenolic content and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) inhibition were also found, with 37.81 mg GAE/100 g and 27.25% DPPH inhibition, respectively. The product was also highly appreciated for its sensory properties. Practical Application: Canola oil, lecithin, and turmeric starch could improve the nutritional (high in antioxidant content and activity) as well as sensorial properties of the product in the desired direction. Adding the ingredients at appropriate content could be applied at different technological scales, helping the food industry to provide new foods with nutritional value to meet the diverse food consumption of consumers.

Pouzolzia zeylanica grows naturally in the forest and is quite popular in Vietnam. This study was designed to investigate the influence of extraction parameters and their effective application in the processing of mixed fruit juice from P. zeylanica and orange juice. A three-factor [i.e., solvent ratio and material (5:1-6:1), extraction temperature (85-95 °C), and extraction time (10-15)] and three-level Box-Behnken design consisting of 18 experimental runs with 6 center points was used for the extraction of P. zeylanica. The optimal conditions (maximum extraction yield) based on both individual and combinations of all responses (ratio of water: materials is 5.4:1 v/w, extraction temperature 91 °C, and time 13 min) were found. At these optimum conditions, the TAC and TPC were found to be 13.55 mg/L and 88.26 mgGAE/L with a desirability value of 0.91. The experimental values are in close agreement with the corresponding predicted values (R 2 =0.942). In addition, by adding orange juice as a natural ingredient that provides additional vitamin C, this study attempted to improve the mixed juice product quality and increase antioxidant capacity and organoleptic value. The mixed juice with the ratio of P. zeylanica extract and orange juice of 80% and 20%, respectively, for a product with high TPC and TAC contents (240.61 mgGAE/L and 10.84 mg/L), significantly improved vitamin C content (255.96 mg/L) and antioxidant activity (67.55% DPPH). Practical Application: Pouzolzia zeylanica (L.) Benn., a medicinal plant, was operated to extract the bioactive compound. The extraction was then combined with orange juice to produce high-quality mixed juice, which could increase the income of local farmers.

he objective of this study was to develop macaroni products from chickpea and green bananas flours by partial substitution wheat flour in order to improve the nutritional composition of the product in the direction of increasing the content of resistant starch, fiber, ash and high quality protein. Four macaroni formulas were established with the control recipe. In five designed recipes, the amount of flour used was gradually reduced from 100% to 70%, while the amount of chickpea and green banana flour substituted increased from 0% to 16% and 0% to 14%, corresponding. The physicochemical characteristics including cooking quality, microstructure, color and nutritional characteristics of macaroni were evaluated. Sensory evaluation of the products created from the formulations was also carried out. The research results have shown that substituting chickpea flour and green banana flour in macaroni formulations affected the physical and chemical properties of the final product. Among the 5 designed formulations, the F3 formula replacing wheat flour with 13% chickpea flour and 10% green banana flour was selected as this product improved the desired nutritional properties. The macaroni product made from the F3 formula contained higher levels of protein, resistant starch, lipids, ash and fiber than the control sample, while the lower carbohydrates have been noted. The rehydration rates, volume gain and cooking loss of F3 product were recorded at values of 67.3%, 91.45% and 3.77%, respectively. The highest number of sensory assessors preferred (80-100%) to the F3 product compared to the macaroni products made up of the remaining formulations.