[关键词]
[摘要]
甜菜汁富含生物活性物质,可作为食用色素和功能性食品原料的来源。本研究将澄清甜菜汁(clear beetroot juice; CBJ)加入面条配方中,以改善面条的营养价值、抗氧化性与颜色的丰富性。本研究以10% CBJ-面条为研究对象,探讨碱添加量(0~0.40%)对其质构、颜色和抗氧化性质的影响。使用质构仪和色差仪分别测定面条的质构和颜色,采用分光光度法测定总甜菜色素、总多酚含量和1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力。研究结果表明:与对照组干面条相比,增加碱添加量(0.10%~0.40%)会显著增加干面条的折断力(11.07%~33.35%)和游离态总多酚含量(2.26%~25.28%),但是显著减少总甜菜色素(3.77%~43.20%)和DPPH自由基清除能力(1.08%~18.20%)。此外增加碱添加量会显著增加熟面条的切断力(10.88%~29.23%)和拉伸强度(47.78%~137.21%)。在色泽上,添加0~0.40%碱的CBJ干面条的红色度(a*值)介于16.59至1.98,而相对应地熟面条的红色度介于7.39至1.76,这表明甜菜汁中的甜菜色素对高pH和高温不稳定。因此本研究建议以低碱添加量(0.10%)制备甜菜碱面条,不仅可呈现粉红色面条外观且可保留较多的甜菜色素、总多酚及较高的抗氧化性。
[Key word]
[Abstract]
Beetroot juice, rich in bioactive substances, is a good source of food colorings and functional ingredients. In this study, clear beetroot juice (CBJ) was added to the formulated noodle to improve the nutritional value, antioxidant properties and color of the noodle. The 10% CBJ-noodles was used as the research object to study the effects of added alkali level (0~0.40%) on the texture, color and antioxidant properties of the resultant noodles. Texture and color of the noodles were measured by a texture analyzer and a colorimeter, respectively. Total contents of betalains and polyphenols, and the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity were determined by spectrophotometry. The research results showed that compared with the control noodle (without alkali), increasing the alkali level (0.10~0.40%) significantly increased the breaking force (11.07~33.35%) and the content of free polyphenolics (2.26~25.28%) of the dried CBJ-noodles, whilst decreasing significantly total betalains (3.77~43.20%) and DPPH radical scavenging capacity (1.08~18.20%). In addition, increasing the level of added alkali increased significantly the cutting force (10.88~29.23%) and tensile strength (47.78~137.21%) of cooked noodles. In terms of color, the redness (a* value) of dried raw and cooked CBJ-noodle with 0~0.40% alkali ranged from 16.59 to 1.98 and from 7.39 to 1.76, respectively. These results indicate that the betalains in CBJ were unstable at a high pH and temperature. Therefore, this research proposes the use of a low alkali level (0.10%) for the preparation of alkaline noodles, which makes the noodles not only having a pink appearance but also possessing higher contents of retained betalains and polyphenols and higher antioxidant activity.
[中图分类号]
[基金项目]
中国台湾科技部专题研究计划项目(MOST-106-2221-E-127-002);广东石油化工学院人才引进项目(2019rc110)