Study of some affecting factors in the production of instant nutritional powder from sea snail Indothais lacera (Born, 1778)

Sea snail Indothais lacera (Born, 1778) is found along coral reefs and rocky reefs in the coastal zone from the north to the south of Vietnam. Currently, most of this species are being used as fresh seafood, so their economic value is not high. This study aims to investigate some optimal conditions in the production of instant nutritional powder from Indothais lacera to diversify food varieties and create a high economic value for this sea snail species. Experiments were carried out to examine the conditions of boiling and drying, then some nutritional compositions of snail meat were analysed after being boiled and dried. The results showed that using phosphoric acid to adjust the pH level of water for boiling sea snail indicated the optimum pH level of boiling water was 5.5; the shells were boiled in 5 minutes after boiling. Under these conditions, the protein content of boiled snail meat was 64.18±4.23%. The boiled snail meat was cut into small pieces then dried. The optimal drying condition was the temperature at 50oC for 15 hours, when the snail meat contained the highest content of protein and vitamin C of 66.07±4.81% and 0.66±0.036 mg/g, respectively; the moisture content of dried snail meat was 4.28±0.48% suitable for producing instant nutritional powder

Arsenic Accumulation in Rice Grain as Influenced by Water Management: Human Health Risk Assessment

Rice is a staple food for humans and a key source of soil arsenic (As) transfer to the human food chain. As a result, it is critical to develop ways for reducing As accumulation in rice. A pot experiment with seven different water management practices was done to examine the impacts of water management on rice (cv. BRRI dhan28) growth, yield, and As accumulation in rice grain. Any health risk due to As accumulation in rice grain was also determined. The soil used in the experiment was artificially contaminated with As and the source of As was sodium arsenate (Na2HAsO4 7H2O). Water management practices affect different plant growth and yield parameters including filled grains per panicle, unfilled grains per panicle, 1000-grain weight, grain yield and straw yield of rice. The number of filled grains per panicle and 1000-grain weight were found to be at their highest in the T7 (alternate wetting and drying) condition, whereas the number of unfilled grains per panicle was at its lowest in the same treatment. The T7 also demonstrated the highest grain yield (21.08 g/pot) and straw yield (22.02 g/pot), whereas the lowest values were noted in T1 (flooding throughout the growth period). The highest As concentration in rice grain (0.52 mg kg−1) was found in T1 and the lowest As concentration in grain (0.27 mg kg−1) was found in T7. Estimation of the human health risk revealed that the non-carcinogenic risks (HQ > 1) and carcinogenic risks (CR > 1.0 × 10−4) were greatly affected by different water regimes. The rice plant grown under alternate wetting and drying condition (T7) showed the lowest health risks compared to other water management practices. Thus, alternate wetting and drying conditions are a good water management strategy for increasing rice output while reducing arsenic buildup in rice grain.

Optimization of harvest and extraction factors by full factorial design for the improved yield of C-glucosyl xanthone mangiferin from Swertia chirata

Swertia chirata Buch.-Ham. ex C.B. Clarke is an important medicinal plant used in various herbal formulations as it shows significant biological activities such as hepatoprotective, hypoglycemic, anti-inflammatory, antimalarial, antioxidant and anti-parkinson. C-glucosyl xanthone glycoside (mangiferin) is known as bio-marker compound of genus Swertia L. Development of efficient extraction methods of C-glucosyl xanthone mangiferin from Swertia chirata was attempted by optimizing the pre-harvest, post-harvest and extraction techniques by full factorial design. Firstly, a full factorial design was implemented to evaluate the single and interactive effects of pre-harvest (growth stage and plant part), post-harvest (drying condition and storage periods) followed by selection of best extraction technique such as heat reflux extraction (HRE), microwave assisted extraction (MAE) and ultrasound assistant extraction (UAE) at different solvent types on mangiferin yield. HPTLC and HPLC techniques were used for the determination of mangiferin content in extracts generated from different plant samples. In addition, anti-oxidant and anti-diabetic properties were determined by using DPPH assay and percentage inhibition of α‑amylase enzyme. Substantial variation of mangiferin yield, ranged from 1.46 to 4.86% was observed, depending on the growth stage, plant part, drying condition, storage periods and extraction method. Results showed that drying of the leaves of Swertia chirata in the shade harvested at budding stage and stored for not more than 1 month was recommended for obtaining a higher mangiferin yield. Among different extraction techniques, MAE and UAE in 50% aqueous ethanol solvent were found to be efficient and cost-effective with better yield of mangiferin (4.82% and 4.86%, respectively) as compared to HRE (4.14%). Highest DPPH activity and percentage inhibition of α‑amylase was observed in the aqueous ethanol extract of S. chirata leaves harvested at bud-stage of plant followed by flowering stage. The study shows that optimization of various factors by full factorial design was found to be an effective procedure to improve mangiferin yield from Swertia chirata and can be used for extraction of mangiferin.

Study on the drying condition optimisation of the heating pump and the infrared radiation for the snakehead fish Channa maculata

The paper focused on the drying condition of the infrared radiation combining the heat pump for the snakehead fish basing on the level 1 multi-factor experimental planning model of Box-Wilson. The results showed the mathematical model (Y = 8.92 + 0.44X1 - 0.53X2 - 0.48X3 - 0.098X1X2 - 0.39X1X3 + 0.126X2X3) that expressed the relationship between the drying time (Y) and the impact factors (the sorbitol concentration (X1), the drying temperature (X2), and the wind speed (X3), in which the drying temperature (X2) affected the drying time stronger than other factors. The optimisation condition of drying was the sorbitol concentration of 2.5%, the drying temperature at 57.5oC, the wind speed of 1.6 m/s, and the drying time of 8.27 hours. Dried snakehead fish at the optimum condition got the sensory quality, food hygiene, and safety higher than the air drying and sun drying methods. The results are a scientific basis for completing the technology and widely deploying the drying method in production.

Long-Term Strength of Porous Geomaterials by a Micromechanical Model considering Alternate Wetting and Drying Condition

This study is devoted to determining the long-term strength of porous geomaterials under alternate wetting and drying condition by statical shakedown analysis. In the framework of micromechanics of porous materials, Gurson’s hollow sphere model with Drucker-Prager solid matrix is adopted as the representative volume element. The effects of alternate wetting and drying are considered as variable water pressure imposed on the inner boundary surface of the unit cell. The cyclic responses are separated as a pure hydrostatic part under compressive/tensive loads and an additional deviatoric part to capture shear effects. The reduction of the long-term strength due to inner water pressure is observed by the illustration of obtained macroscopic criteria with respect to various load parameters. In addition, the accuracy of the analytical solution is also verified by comparing to the results of FEM-based step-by-step computations.

Effect of fabric softener on crossing torque and compression properties of cotton yarn

The effect of a fabric softener treatment on the properties of the crossing torque–intersecting angle behavior of yarns and the transverse compression properties of single and crossing yarns, which are related to the shear properties of a fabric, is investigated. The crossing torque required to change the intersecting angle between two yarns, the hysteresis in the crossing torque–intersecting angle curve (i.e., crossing torque hysteresis), and the compression properties of cotton yarns after water treatment with and without softener were measured. To measure those properties, the drying condition was varied after the treatment to comprise crossed yarns with an applied load and parallel yarns in a bundled state. The average crossing torque value of the sample with a softener treatment was less than that with a water treatment for yarns from a bundle. For yarns dried while crossed, the average crossing torque value of the sample with a softener treatment was somewhat less than that with a water treatment. For both drying conditions, the average crossing torque hysteresis value decreased after a softener treatment. The compressional resilience value of the sample with a softener treatment was greater (bouncier) than that with a water treatment for yarns dried while crossed. The results suggest that the softener treatment reduces the crossing torque and increases the compressional resilience of yarns. This is due to the reduction of hydrogen bonding between surface fibers via the softener. The softener treatment also decreased the crossing torque hysteresis, corresponding to decreased friction between fibers.