Falade Kolawole O, Ayetigbo Oluwatoyin E
Department of Food Technology, University of Ibadan, Ibadan, Nigeria.
J Food Sci Technol. 2017 May;54(6):1455-1466. doi: 10.1007/s13197-017-2568-x. Epub 2017 Mar 10.
The effects of tempering (annealing), acid hydrolysis and low-citric acid substitution on chemical and physicochemical properties of starches of four Nigerian yam cultivars were investigated. Crude fat and protein contents of the native starches decreased significantly after the modifications, while nitrogen-free extract increased significantly with acid hydrolysis and citric acid substitution. Acid hydrolysis and low-citric acid substitution reduced the least concentration for gel formation of the starches from 4 to 2% w/v, but tempering had no effect. Swelling power of the starches reduced significantly, and water solubility increased significantly at 75 and 85 °C, especially with acid hydrolysis and low-citric acid substitution. However, tempering significantly reduced starch solubility in the four cultivars. Paste clarity of starches of white (29.17%), water (18.90%), yellow (30.90%) and bitter (10.57%) yams reduced significantly with tempering to 14.43, 11.83, 16.93 and 7.27%, but increased significantly with acid hydrolysis to 41.40, 35.37, 28.77 and 32.33%, and low-citric acid substitution to 36.60, 44.17, 50.67 and 14.33%, respectively. Pasting properties such as peak, trough, breakdown, final, and setback viscosities and peak time of native starches reduced significantly with acid hydrolysis and low-citric acid substitution, however, tempering significantly increased their pasting temperature, peak time, setback and final viscosities.
研究了回火（退火）、酸水解和低柠檬酸替代对四种尼日利亚山药品种淀粉的化学和物理化学性质的影响。改性后，天然淀粉的粗脂肪和蛋白质含量显著降低，而无氮提取物在酸水解和柠檬酸替代后显著增加。酸水解和低柠檬酸替代将淀粉形成凝胶的最低浓度从4%（w/v）降至2%（w/v），但回火没有效果。在75和85℃时，淀粉的膨胀力显著降低，水溶性显著增加，尤其是酸水解和低柠檬酸替代时。然而，回火显著降低了四个品种淀粉的溶解度。白山药（29.17%）、水山药（18.90%）、黄山药（30.90%）和苦山药（10.57%）淀粉的糊透明度在回火后显著降低至14.43%、11.83%、16.93%和7.27%，但在酸水解后显著增加至41.40%、35.37%、28.77%和32.33%，在低柠檬酸替代后分别增加至36.60%、44.17%、50.67%和14.33%。酸水解和低柠檬酸替代使天然淀粉的峰值、谷值、破损值、最终值和回生粘度以及峰值时间等糊化特性显著降低，然而，回火显著提高了它们的糊化温度、峰值时间、回生值和最终粘度。
