Mugo Beatrice Muthoni, Kiio Juliana, Munyaka Ann
Department of Foods Nutrition and Dietetics, School of Health Sciences Kenyatta University Nairobi Kenya.
Food Sci Nutr. 2024 Apr 26;12(8):5403-5411. doi: 10.1002/fsn3.4186. eCollection 2024 Aug.
Hyperkalemia is common among patients with end stage kidney disease. Management involves diet modification. Hot water blanching is recommended to leach potassium in vegetables which results in losses of water-soluble and heat labile vitamins. Evidence on the effect of blanching in reducing potassium level of locally consumed vegetables in Kenya is limited. This study sought to establish effect of hot water blanching time-temperature on level of potassium, vitamin B1, B3 and C in kales () and spinach () on potassium and vitamins B1, B3 and C retention/loss. The study adopted a full factorial experimental design. Vitamins were determined using high performance liquid chromatography. Potassium was quantified using atomic absorption spectrophotometry. To compare nutrient content between samples, independent t-test and Analysis of Variance were used at 95% confidence level. Nutrient content of fresh kales and spinach were potassium (102 mg/100 g and 615 mg/100 g), vitamin B1 (124 μg/100 g and 51 μg/100 g), vitamin B3 (1165 μg/100 g and 812 μg/100 g) and vitamin C (102 mg/100 g and 116 mg/100 g) respectively. In kales, blanching for 20 min at 1000°C resulted to retention of 86.9%, 55.6%, 27.6% and 12.9% of vitamin B1, B3, C and potassium respectively. In spinach, blanching for 20 min at 1000°C resulted in retention of 79.9%, 88.6%, 12.2% and 40.6% retention of vitamin B1, B3, C and potassium respectively. Vitamin C and Potassium were the most sensitive to heat and leaching. Time had a greater effect than temperature in this study. This study recommends blanching of kale at 15.2 min at 800°C, spinach at 17.7 min at 840°C. Further research on optimal blanching time-temperature for potassium and vitamin retention/loss is recommended.
高钾血症在终末期肾病患者中很常见。治疗方法包括饮食调整。建议采用热水焯烫的方式去除蔬菜中的钾，但这会导致水溶性和热不稳定维生素的流失。关于在肯尼亚当地食用蔬菜中焯烫对降低钾含量效果的证据有限。本研究旨在确定热水焯烫的时间 - 温度对羽衣甘蓝和菠菜中钾、维生素B1、B3和C含量以及钾和维生素B1、B3和C保留/损失的影响。该研究采用了全因子实验设计。维生素通过高效液相色谱法测定。钾通过原子吸收分光光度法定量。为了比较样品之间的营养成分，在95%置信水平下使用独立t检验和方差分析。新鲜羽衣甘蓝和菠菜的营养成分分别为：钾（102毫克/100克和615毫克/100克）、维生素B1（124微克/100克和51微克/100克）、维生素B3（1165微克/100克和812微克/100克）以及维生素C（102毫克/100克和116毫克/100克）。在羽衣甘蓝中，在1000°C下焯烫20分钟后，维生素B1、B3、C和钾的保留率分别为86.9%、55.6%、27.6%和12.9%。在菠菜中，在1000°C下焯烫20分钟后，维生素B1、B3、C和钾的保留率分别为79.9%、88.6%、12.2%和40.6%。维生素C和钾对热和沥滤最为敏感。在本研究中，时间的影响大于温度。本研究建议羽衣甘蓝在800°C下焯烫15.2分钟，菠菜在840°C下焯烫17.7分钟。建议进一步研究钾和维生素保留/损失的最佳焯烫时间 - 温度。
