production of functional cake powder using quinoa flour and isomalt

Cake powder is a semi-ready product consisting of wheat flour, sugar, baking powder and other additives. In this product, the ingredients are mixed to each other and the consumer must mix it with the water or milk, egg, butter or vegetable oil (solid or liquid) according to the manufacturer's instructions. The cake powder is considered a special product for people because of its ease to use for cake making. The cake produced from this powder is classified as a bakery product. One way to increase the nutritional characteristics of bakery products is the partial or complete replacement of wheat flour with other cereal flour with high functional characteristics. Among the various grain flours, wheat flour is unique to produce bakery products, mainly due to its gluten protein. Although the other cereals contain protein groups similar to gluten, their gas holding capacity is low. Since cakes are made from weak wheat flour, cake batter does not need to hold gas, so it is possible to use the flours of other cereals in its production. The seeds of quinoa plant are very digestible and a source of protein, fiber, copper, iron, phosphorus, magnesium, manganese, folate, thiamine, all kinds of vitamins and omega-3. The unusual combination of protein, oil, fat, minerals, fatty acids, antioxidants, and vitamins in quinoa has made it a nutritious food. It is also free of gluten and is recommended for people who use gluten-free diets. Depending on cake type, these products contain 10-40% sugar. Considering the health effects of cakes, by reducing its calories, it can be used by all people, even those who are under certain dietary and therapeutic conditions. Foods rich in sugar are a known risk factor for obesity, diabetes, and cardiovascular disease. Isomalt is the only sweetener that is derived from sucrose and consists of two glucopyranosyl sorbitol and glucopyranosyl mannitol isomers. Isomalt has a sweet taste without flavors and promotes the transfer of flavor in foods.

In this study, sugar and wheat flour substituted with isomalt and quinoa flour in cake powder formulation at four levels (25, 50, 75, and 100%). the effect of sugar and wheat flour replacement with isomalt and quinoa seed flour on the chemical, nutritional, and sensory properties of the prepared cakes from the cake powders were investigated.

The results showed that the replacement of wheat flour with quinoa flour caused a decrease in the moisture content, specific volume, total sugar content, lightness parameter (L*), redness parameter (a*) and yellowness parameter (b*) of cake and increased protein, fat percentage and calorie of the cake samples. While replacing sugar with isomalt reduced the specific volume, total sugar and calorie, and increased the lightness parameter (L*). The evaluation of texture of cake samples showed that the treatments in all days (first, second and third day after baking) and storage time in all treatments had a significant effect on the stiffness of the cakes. The type of treatment had a significant effect on each of the sensory characteristics including taste, smell, color, texture, and overall acceptance. Therefore, the replacement of quinoa and isomalt flour in cake formulation reduced the sensory scores, including flavor, aroma, smell, color, texture, and overall acceptance. The reason for the change in physical properties of the cakes with partial replacement of wheat flour with quinoa flour can be the reduction of gluten content in the formulation, which directly affects the formation of the network and the trapping of the air bubble and eventually the physical properties of the final product. The presence of sugar in the formulation of bakery products has led to an increase in starch gelatinization temperature, which directly affects the trapping of air bubbles and carbon dioxide and eventually the final properties of bakery products. Increasing the use of isomalt decreases the presence of sugar in the formulation, resulting in a decrease in the positive effect of sugar on the final properties of the cakes. In addition, increasing the protein and fat content of cake samples by using the quinoa flour was due to the high protein and fat content of quinoa seed flour (19.25%) compared to wheat flour (7-8.5%).

By considering all properties of the cake samples, it can be concluded that the color and texture of the cake samples have a significant effect on the overall acceptance of the cake samples. Therefore, according to the results of this study, 25% replacement of wheat flour with quinoa flour and 25% replacement of sugar with isomalt (T1 treatment) were determined as optimal treatment.