Balci Fatih, Bayram Mustafa
Faculty of Engineering, Department of Food Engineering, Gaziantep University, 27310 Gaziantep, Turkey.
J Food Sci Technol. 2015 Sep;52(9):5579-89. doi: 10.1007/s13197-014-1687-x. Epub 2014 Dec 24.
Color (CIE b*; yellowness) is an important parameter for bulgur quality. Color of bulgur is mainly due to natural pigments (carotenoids) that are present at different levels in wheat. In order to increase the customer acceptability, the producers try to obtain yellowish color in bulgur. In this study, two different tempering methods (spray and steam) were used before sun and UV- light polishing applications. Sun and UV-light were applied to tempered bulgur for 12, 24, 36, 48, 60 and 72 h. Moisture content (%, d.b.), ash content (%, d.b.), protein content (%, d.b.), total carotenoid content in terms of lutein equivalent (TCC) and color values (CIE L*; lightness, CIE b*; yellowness, CIE a*; redness and CIE YI; yellowness index) were determined. It was found that UV-light was more effective (P < 0.05) on the CIE L* and CIE b* values compared to sunlight. Both tempering methods were significantly (P < 0.05) increased the CIE L*, CIE b* and CIE YI values. Steam tempering has a significant effect (P < 0.05) on the CIE b* values as well as UV and time of UV exposure. The highest value of TCC i.e. 6.31 μg/g was obtained by using spray tempering and UV-light exposure. As a conclusion, as proposed methods steam tempering and UV-light have an obvious positive effect on the color of bulgur.
颜色（CIE b*；黄度）是碎粒小麦品质的一个重要参数。碎粒小麦的颜色主要归因于小麦中不同含量的天然色素（类胡萝卜素）。为了提高消费者的接受度，生产商试图使碎粒小麦呈现淡黄色。在本研究中，在进行日晒和紫外线抛光处理之前，使用了两种不同的调湿方法（喷雾和蒸汽）。对调湿后的碎粒小麦进行12、24、36、48、60和72小时的日晒和紫外线照射。测定了水分含量（%，干基）、灰分含量（%，干基）、蛋白质含量（%，干基）、以叶黄素当量计的总类胡萝卜素含量（TCC）以及颜色值（CIE L*；亮度、CIE b*；黄度、CIE a*；红度和CIE YI；黄度指数）。结果发现，与阳光相比，紫外线对CIE L和CIE b值的影响更显著（P < 0.05）。两种调湿方法均显著（P < 0.05）提高了CIE L*、CIE b和CIE YI值。蒸汽调湿对CIE b值以及紫外线和紫外线照射时间均有显著影响（P < 0.05）。通过喷雾调湿和紫外线照射获得了最高的TCC值，即6.31μg/g。总之，如所提出的方法，蒸汽调湿和紫外线对碎粒小麦的颜色有明显的积极影响。
