Basak Somnath, Singhal Rekha S
Food Engineering and Technology Department, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Carbohydr Polym. 2024 Jul 15;336:122091. doi: 10.1016/j.carbpol.2024.122091. Epub 2024 Apr 2.
In this study, konjac glucomannan (KG) was incorporated in high acyl gellan (HAG) and low acyl gellan (LAG) hydrogels in different ratios. The addition of KG increased pseudoplasticity and thermal hysteresis values of the hydrogels. Improvement in elasticity and water holding capacity (WHC) was observed in KG-LAG hydrogels. The highest WHC (98.5 %) was observed for 1K1H (KG:HAG = 1:1) and 3K7L (KG:LAG = 3:7) hydrogels. The crystallinity of the composite hydrogels was lower than hydrogels prepared from individual biopolymers. The hydrogels exhibited a rough surface with minute pores in the cross-section, due to the aggregation of glucomannan on the gellan network in the composite hydrogels. While HAG and 1K1H hydrogels exhibited greater swelling at low pH (3.0), LAG and 3K7L exhibited greater swelling at high pH (11.0). At pH 7.0, the hydrogels exhibited swelling indices >300 %. Incorporation of 1K1H hydrogel at 10 % (w/w) in sandy loamy soil under semi-arid conditions increased the germination of fenugreek microgreens from 60 % to 80 % on the 15th day. Furthermore, the moisture evaporation rate of the soil reduced from 35 % to <15 %, positively impacting the physicochemical properties of the microgreens. The composite hydrogels were successful in achieving a controlled release of phosphate fertilizer.
在本研究中，魔芋葡甘聚糖（KG）以不同比例掺入高酰基结冷胶（HAG）和低酰基结冷胶（LAG）水凝胶中。添加KG提高了水凝胶的假塑性和热滞后值。在KG-LAG水凝胶中观察到弹性和持水能力（WHC）有所改善。1K1H（KG:HAG = 1:1）和3K7L（KG:LAG = 3:7）水凝胶的WHC最高（98.5%）。复合水凝胶的结晶度低于由单一生物聚合物制备的水凝胶。由于复合水凝胶中葡甘聚糖在结冷胶网络上的聚集，水凝胶表面粗糙，横截面有微小孔隙。虽然HAG和1K1H水凝胶在低pH值（3.0）下表现出更大的溶胀，但LAG和3K7L在高pH值（11.0）下表现出更大的溶胀。在pH值为7.0时，水凝胶的溶胀指数>300%。在半干旱条件下，将10%（w/w）的1K1H水凝胶掺入砂壤土中，第15天胡芦巴嫩苗的发芽率从60%提高到80%。此外，土壤的水分蒸发率从35%降至<15%，对嫩苗的理化性质产生了积极影响。复合水凝胶成功实现了磷肥的控释。
