The study of the effect of sucrose replacement by sucralose- isomalt mixture on the qualitative characteristics of kermanshah's traditional baklava

Food science has meet new challenges in food production that could respond consumer’s tastes and at the same time improve. Lifestyle modifications related to change in the eating quality and quantity along with mental stress led to the prevalence of non-communicable diseases. Based on the consumer’s demand, food scientists are now focusing on developing low calorie/high-fiber functional foods. Baklava is one of the most important flour products with a widespread production due to its desirable sensory properties as well as high stability. Despite the benefits of sucrose as a natural sweetener with desirable performance characteristics, due to problems with blood pressure, heart disease, tooth decay, obesity and increased blood glucose and insulin levels, especially for harmful diabetics in addition, due to economic and technological issues, increasing research are under way to replace sugar with other sweeteners. One of the important issues regarding the replacement of sugar in food products is the choice of the type of sweetener to replace and how to preserve the quality of the product during the storage period (Gohari Ardabili et al 2005). Sugar is an essential ingredient in the preparation of various types of Baklava, which in addition to the role of sweetening has a great effect on the physical and chemical properties of the product (Specter and Setser 1994). There are many substitutes for sugar for use in baking products. For example, sucralose and isomalt are the natural substitutes for sugar in the baked goods. Considering the nutritional properties and high sugar content, sucralose and isomalt are used as a desirable substitute to sugar in food formulations to increase nutritional value and avoid sucrose complications. In this study, isomalt and sucralose were used as a replacement for sugar in Kermanshah's traditional Baklava production and physicochemical and sensory properties were studied. Physicochemical, textural and sensory analysis of Kermanshah's traditional Baklava including ash (Institute of Standards and Industrial Research of Iran 2015), sucrose (Institute of Standards and Industrial Research of Iran 2013), protein percentage (Institute of Standards and Industrial Research of Iran 2013), fat percentage (Institute of Standards and Industrial Research of Iran 2014), caloric (Institute of Standards and Industrial Research of Iran 2008) and texture hardness (Institute of Standards and Industrial Research of Iran 2013) & colorimetric (Saricoban and Yilmaz, 2010) for 20 days storage and sensory properties (Lee et al., 2008) on the first day of production, were studied. The results of the tests were analyzed using the Minitab 14 software using one-way analysis of variance Duncan's test.

In this study in order to produce Kermanshah's traditional Baklava first the dough Baklava. In the first stage solid materials which are egg (21.5 %), Milk (20.5 %), Peking powder (4 %), oil (16 %) and butter (4.2 %) were mixed in the mixer, then while mixer was working with a low speed, flour (33 %) and salt (0.8 %) was added so that the dough Baklava. After dough packaged in nylon bag and stored at refrigerator (4-6 °C) for about two hours. Then inner dough ingredients included pistachio powder (36.5%), almond powder (36.5%), cardamom (9%) and cinnamon (18%) pour in the dough and spread out material first by hand and then with a spoonful. Again the next layer of dough was applied to the material and the butter and liquid oil mixture was rubbed on it. Then the dough were placed in an oven Model TF1000 (Atlas Corporation) at 300C for 25 minute. Remove the beans from the oven to cool and add to the nectar and set the lid to allow the nectar to completely penetrate into the baklava (Institute of Standards and Industrial Research of Iran 2006). In order to produce nectar control first stage water (35 %), sugar (40 %), rose water (5 %), saffron (10 %) and lemon essence (1 %) were mixed then were placed in a stove for 15 minute and the syrup was poured hot on the baklava. For produce other treatment replacement of sugar in ratios of 0, 20, 40, 60, 80% by the low-calorie sucralose and isomalt mixture. It is worth mentioning sucralose was considered 650 times sweeter than sucrose (sugar) and isomalt is half times sweeter than sucrose and the rest compounds were considered as fixed compounds.

The results of this research study showed that with increasing sucrose replacement by sucralose and isomalt mixture, the amount of ash, sucrose, protein percentage, fat percentage and calorie decreased significantly (p≤0.05) and moisture rate increased. Assessment of color changes during 20 days of storage showed that with increasing the replacement ratio, the light (L*) parameter significantly increased and redness (a*) and yellowness (b*) parameters significantly decreased and increased, respectively. Hardness of texture is measured by inserting a punch or rod into the food. Texture hardness is directly proportional to the magnitude of force required. The hardness decreased significantly on the first day with increasing sucrose replacement by sucralose and isomalt mixtures. As observed, increasing the shelf life significantly increases the texture hardness, this trend decreased with increasing substitution so that the treatment (20% sugar + 80% sucralose and isomalt mixture) had the least hardness after 20 days of storage. This is primarily due to the increase in sucrose substitution by sucralose and isomalt, the increased water uptake in baklava pastry and the decrease in texture hardness. During the storage period due to the release of water and the equilibrium of moisture treatments with the environment of all samples, it becomes harder than the first day (Gallagher et al. 2003). On the other hand, the sensory properties assessment showed that after control, the treatments containing 20% and 40% of sucralose and isomalt mixture had the highest sensory acceptability, and they were selected as the superior treatments.

The results revealed that by using the mixture (60% sugar + 40% sucralose and isomalt), the rate of sucrose consumed in the formulation of the control sample can be replaced by a mixture of sucralose and isomalt up to 40% without any adverse effect on its physicochemical, texture and sensory properties.