Determining the qualitative, textural and sensory characteristics of oil cakes made with flaxseed and oat bran as a fat replacement

The cake is considered as the bakery products and has the different kinds with different calorie and often high calories in the kinds of cakes is due to the oil, eggs and sugar that is used in its formulation .In the present study the carbohydrate-based fat replacements are used instead of fats for consuming. The flaxseed with the scientific name of "Linum usitalissmum" is an annual plant from the family of flax and in terms of nutritional value it is a good source of omega-3 (alpha-linolenic acid, ALA), Lignans (such as phyto-estrogenic), fiber, protein, minerals and vitamins. The high amount of water absorption by flaxseed in bakery products leads to increase the volume and improve the quality of bread and also increase the shelf life of the product produced. The oat is a plant from the family of grains and from the genus of "Avena" called in English "Oat". One of the major compounds in the oat is β-glucan. The said compound is the common name of glucose polymers that is found in the endosperm cell walls of barley and oat and usually forms 3-7% of the seed weight and is classified as soluble dietary fiber and carbohydrate-based fat replacements. The purpose of this study was to add different levels of flaxseed and oat bran as a part of fat replacement in cake. Different Levels of shortening were replaced with Oat bran and flaxseed powder and their effects on the chemical characteristics, volume, color, staling and sensory characteristics of the cakes were examined. Raw materials needed to bake a cake included the null wheat flour (Mehbod Company) with extraction rate of 70%, sugar (Pardis Company), nonfat dry milk (IDI France Company), egg white powder (Talavang Company), table salt (Golha company), baking Powder (Golhan Company), oil (Ladan Company), flaxseed and oat bran (Sarv Company). Chemical tests performed on wheat flour, oat bran and flaxseed meal and samples of cakes included the measurement of moisture, ash, protein, fat, fiber, peroxide and pH were performed. For the production of cake the raw materials were prepared and were weighed. Then, the oil and sugar mixed for 2 minutes and then some water was added and mixed for 2 other minutes. Then, the null wheat flour, oat bran and flaxseed powder sieved with other materials were mixed. Finally, the cake was added to the mold and located in the tunnel oven at 170°C for 35 minutes for baking. in all the tests the control treatment (cake containing 100% fat and null wheat flour) with the code of C, the treatment containing the oat bran and flaxseed with the ratio of 20:40 (weight– weight of fat consumed) plus 40% of fat with the code of A1, the treatment containing the oat bran and flaxseed with the ratio of 40:20 (weight – weight of fat consumed) plus 40% of fat with the code of A2, the treatment containing the oat bran and flaxseed with the ratio of 30:30 (weight– weight of fat consumed) plus 40% of fat were determined with the codes of A3 revealed. The method proposed by Henry Simon British Company and device of volumeter were used to determine the volume of cake samples produced. The test of determining the color the Hunter Lab device was used. In order to determine the amount of staling of the cake samples, the device of evaluating the texture or Instron was used. In this study, examined by 10 trained evaluators was used for organoleptic test of samples. In determining the amount of staling in the cake samples produced the sensory method was used. This test was conducted at the intervals of 3, 7 and 10 days after baking of the samples. In order to investigate the quantitative characteristics of data considering to the presence of four treatments and three replications, randomized block design, the analysis of variance and the software "SPSS", version 16, were used. The amount of protein and fiber in treatment of A1 and in the control treatment was the highest and the lowest, respectively. In addition, the amount of ash and moisture in the treatment of A2 and in the control treatment was the highest and the lowest, respectively. The treatment of A1 and the control samples had the highest and the lowest amount of peroxide, respectively. Results of specific volume test indicated that the treatment of A2 and the control samples had the highest and the lowest amount of specific volume, respectively. The results of colorimetric test of cake samples indicated that the lightness (L*) in the control cake and in the treatment of A1 was the lowest and the highest amount, respectively. Moreover, the amount of redness in treatment of A1 and control treatment was the highest and the lowest, respectively. The amount of yellowness in the control treatments and treatment of A2 was the highest and the lowest, respectively. The results of evaluating the sensory characteristics of cake samples produced by panelists showed that most sensory characteristics of the cake samples containing flaxseed and oat bran compared with the control had higher rating. The results of staling test in the cake samples produced by sensory method showed that the control treatment had the highest amount of staling and the treatments of A1, A2 and A3 had the lowest amount of staling, respectively. The results of staling test using device method showed that the control treatment had the highest amount of staling and the treatments of A1 and A2 had the lowest amount of staling, respectively. Finally, the treatment of A2 was introduced as the best treatment. In the present study, oat bran and flaxseed seed were used as a part of carbohydrate-based fat replacements in the cake to produce a healthier products with less fat and better nutritional compounds while improving the qualitative characteristics.