Major Nikola, Prekalj Bernard, Perković Josipa, Ban Dean, Užila Zoran, Ban Smiljana Goreta
Institute of Agriculture and Tourism, K. Huguesa 8, 52440 Poreč, Croatia.
Centre of Excellence for Biodiversity and Molecular Plant Breeding, Svetošimunska 25, 10000 Zagreb, Croatia.
Plants (Basel). 2020 Dec 17;9(12):1792. doi: 10.3390/plants9121792.
The extraction of glucosinolates in boiling aqueous methanol from freeze dried leaf tissues is the most common method for myrosinase inactivation but can be hazardous because of methanol toxicity. Although freeze drying is the best dehydration method in terms of nutritional quality preservation, the main drawbacks are a limited sample quantity that can be processed simultaneously, a long processing time, and high energy consumption. Therefore, the aim of this study is to evaluate the effects of applying high temperature for myrosinase inactivation via hot air drying prior to the extraction step, as well as the effects of cold aqueous methanol extraction on total antioxidant activity, total glucosinolates, total phenolic content, and sugar profile in 36 landraces of kale. The results from our study indicate that cold aqueous methanol can be used instead of boiling aqueous methanol with no adverse effects on total glucosinolate content. Our results also show that hot air drying, compared to freeze drying, followed by cold extraction has an adverse effect on antioxidant activity measured by DPPH radical scavenging, total glucosinolate content, as well as on the content of all investigated sugars.
从冻干叶片组织中用沸腾的甲醇水溶液提取硫代葡萄糖苷是使黑芥子酶失活的最常用方法，但由于甲醇毒性，该方法可能具有危险性。尽管就营养品质保存而言，冷冻干燥是最佳的脱水方法，但其主要缺点是可同时处理的样品量有限、处理时间长且能耗高。因此，本研究的目的是评估在提取步骤之前通过热风干燥应用高温使黑芥子酶失活的效果，以及冷甲醇水溶液提取对36个羽衣甘蓝地方品种的总抗氧化活性、总硫代葡萄糖苷、总酚含量和糖谱的影响。我们的研究结果表明，可以使用冷甲醇水溶液代替沸腾的甲醇水溶液，且对总硫代葡萄糖苷含量没有不利影响。我们的结果还表明，与冷冻干燥相比，热风干燥后进行冷提取对通过DPPH自由基清除法测定的抗氧化活性、总硫代葡萄糖苷含量以及所有研究糖类的含量都有不利影响。
