Institute of Food Technology and Analysis, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 2/22 Stefanowskiego Street, 90-537 Lodz, Poland.
Molecules. 2023 Mar 1;28(5):2299. doi: 10.3390/molecules28052299.
The nutritional value and health-promoting properties cause the fruits (acorns) of spp. to have great potential for use in the food industry as functional ingredients and antioxidants source. The aim of this study was to examine the bioactive compound's composition, antioxidant potential, physicochemical properties and taste characteristics of northern red oak ( L.) seeds subjected to roasting at different temperatures and times. The results indicate that the roasting markedly affects the composition of bioactive components of acorns. In general, the use of roasting temperatures greater than 135 °C causes a decrease in the total phenolic compound content of seeds. Furthermore, along with an increase in temperature and thermal processing time, a remarkable increase in melanoidins, which are the final products of the Maillard reaction, was also observed in processed seeds. Both unroasted and roasted acorn seeds had high DPPH radical scavenging capacity, ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity. Roasting at 135 °C caused negligible changes in total phenolics content and antioxidant activity of seeds. Almost all samples had lower antioxidant capacity along with an increase in the roasting temperatures. Additionally, thermal processing of acorn seeds contributes to the development of the brown color and the reduction of bitterness, and the creation of a more pleasant taste of the final products. Overall, the results of this study show that both unroasted and roasted seeds may be an interesting source of bioactive compounds with high antioxidant activity. Therefore, they can be used as a functional ingredient of beverages or food.
研究目的在于探讨不同烘焙温度和时间对北美红栎（Quercus rubra L.）种子生物活性化合物组成、抗氧化能力、理化性质和口感特征的影响。结果表明，烘焙显著影响栎果中生物活性成分的组成。一般来说，烘焙温度高于 135°C 会导致种子总酚含量降低。此外，随着温度和热加工时间的增加，加工后的种子中也观察到美拉德反应的最终产物——类黑素显著增加。未烘焙和烘焙的栎果种子均具有较高的 DPPH 自由基清除能力、铁还原抗氧化能力（FRAP）和亚铁离子螯合活性。135°C 烘焙对种子总酚含量和抗氧化活性的影响可忽略不计。几乎所有样品的抗氧化能力均随烘焙温度的升高而降低。此外，栎果种子的热加工有助于形成棕色色泽、降低苦味，并使最终产品具有更宜人的口感。总的来说，本研究结果表明，未烘焙和烘焙的北美红栎种子可能是具有高抗氧化活性的生物活性化合物的有趣来源。因此，它们可用作饮料或食品的功能性成分。
