Effects of buckwheat, transglutaminase and sourdough on the quality of frozen bread

In this study; it was aimed to research the emerging quality criteria changes of part-baked frozen bread after different storage periods (0, 3, 15, 30 and 45 days) which is produced by using whole buckwheat flour (WBF) (0, %10, %20 and %30), transglutaminase (TG) (0, 50 and 100 ppm) and two different yeasts (fresh yeast and sourdough).It was determined that during the addition of WBF in increasing rate and the storage, loaf volume of breads with fresh yeast were decreased decreased but with the addition of 50 ppm TG, Loaf volume of all breads were decreased. While 100 ppm TG addition provided an extra loaf volume increase only in control bread, it did not make a significant difference (p>0.01) in the other bread samples. With the addition of WBF, the firmness increased significantly (p<0.01) in parallel with the volume increase. 100 ppm TG addition caused to the firmness value increase in bread samples generally. While the firmness value increased in control breads during the storage, it did not show a significant change in WBF containing bread. While the springiness value shown a decrease in control samples which were produced without TG, it was not observed an important difference (p>0.01) statistically in the other bread samples during the storage. It was seen that the storage had no effect on the chewiness value in the control group. While the cohesiveness value decreased with the addition of WBF in increasing rate, TG addition did not make any statistical difference (p>0.01) in this value. At the end of 45-day storage, the cohesiveness value of the control group significantly decreased (p<0.01), but there was not a statistical change in the value of the bread samples which were made with %10 and %20 WBF addition. It was determined that the Loaf volume of the sourdough bread samples decreased with the addition of WBF in increasing rate, and TG addition and İncrease of TG level had negative effects on the quality of the sourdough bread samples.The WBF decreased the loaf volume and increased the firmness in the fresh yeast and sourdough bread samples. But, the decrease in the loaf volume during the storage was more in the control bread which did not contain WBF than the ones that contained it. While 50 ppm TG addition had positive effect on the bread characteristics generally, making this rate 100 ppm caused to decline of them. The usage of sourdough in the production of part-baked frozen bread also increased the loaf volume.The decrease level in the loaf volume which was seen during the frozen storage was more than the ones in the buckwheat bread samples in the control group. Having a less volume decrease with the storage in the bread samples made with WBF bread shown that this flour could be used in the frozen bread production; nonetheless, it was also concluded that the loaf volume decrease caused in the first day due to containing no gluten should be increased by using different additives and it is needed to make new studies about this issue. Enzyme addition can be suggested to be used in 50 ppm level in the bread production made with fresh yeast. Sourdough can be recommended to be used in the frozen bread.