## 3 Results and Discussion

Table 2: Contents of RS in wheat starch (g\(\cdot\)100 g\({}^{-1}\) dm) depending on the type and dose of the polyphenol standard added. Starch-rich foods such as white bread, pasta, rice, cornflakes and other cereal-based products became the major contributors to the energy intake of the human daily diet and constitute a basis of nutrition for the world's population. In most of these foods, starch is rapidly digested and absorbed, which contributes to increased oxidative stress, high plasma glucose levels, increased insulin resistance and elevated hypertension [20], which consequently may favor weight gain and the development of type 2 diabetes, cardiovascular diseases and certain types of cancer, including colon tumors [3; 21]. At the same time, for the better part of the global population, it is impossible to give up consuming too much of the starchy food products, which are available at any time at a decent price. Therefore, important future goals for food designers should be to project starch-rich food products characterized by a delay in starch digestion without alterations of the desired organoleptic characteristics and specific features of the food expected by consumers. Hence, any efforts to slow down the digestibility of starch are highly desirable. Recently, leading strategies proposed to achieve this goal include: (_i_) modulating starch structure by preserving crystalline structure, to promote resistant starch production or reduce the mobility of gelatinized starch gel; (_ii_) favoring mashing over milling, to preserve intact cell walls and select large particle size flows (_iii_) modulating the Maillard reaction by, for example, converting starch to melanoidins [9]. The results of the present study clearly indicated that either the dose or the type of the polyphenolic compound had a statistically significant impact on the development of resistant starch in wheat starch gels (Tables 1 and 2, \(p\) < 0.05). However, the observed impact was dose-dependent, and interestingly, higher amounts of RS were found in the case of the lowest dose applied (5 mg--4.66% of starch gel; mean = 2.94 \(\pm\) 1.23 g\(\cdot\)100 g\({}^{-1}\) dm) as compared to the other doses: 10 mg--9.09% of starch gel (mean = 1.58 g\(\cdot\)100 g\({}^{-1}\) dm) and 20 mg--16.66% of starch gel (mean = 1.51 \(\pm\) 0.90 g\(\cdot\)100 g\({}^{-1}\) dm), which might suggest that the optimal dose in this matter might be 5 mg instead of 10 mg. There is a lack of knowledge in the available literature concerning the impact of single polyphenic compounds on wheat starch digestibility, measured by RS content. Generally, starch is composed of two types of polymers, namely amylose and amylopectin. amylose is typically a linear polyglucan consisting of D-glucose units linked by glycosidic bonds, while amylopectin is a relatively larger moiety than amylose and is highly branched [22]. amylose has long unbranched sections of glucose molecules linked together by sporadic branching points. Amylopectin has a high molecular weight with a large number of short-chain branching [20]. The starch of maize, rice, wheat and potato consists of about 70-80% amylopectin and 20-30% amylose. This genetically determined amylose-to-amylopectin ratio in starch has a great impact on its digestibility since amylose is less susceptible to gelatinization than the branched amylopectin. It has been evidenced so far that a greater amylose-to-amylopectin ratio contributes to lower starch digestibility, and hence, a lower glycemic index [20; 23]. It is known, however, that amylose tends to retrograde into resistant starch, while amylopectin retrogrades into slowly digestible starch [9]. Upon the presence of water and high temperature, the starch granules swell, and the hydrogen bonds between amylose and amylopectin chains are broken down. Subsequently, amylose and amylopectin moieties are released from the starch granules, forming spaces that allow water to enter inside, consequently leading to the loss of the starch crystalline structure in a process called gelatinization.