Use of different hydrocoloids for the production of mixed structure of açaí, banana, peanut, and guarana syrup

Abstract

This work aims to develop mixed structure of açaí, banana, peanut, and guarana syrup with added agar and gellan gum. Five mixed structure formulations were prepared with the addition of hydrocolloid agar and gellan gum: 1% agar (A1), 1% gellan gum (G1), 0.5% agar and 0.5% gellan gum (A050/G050), 0.25% agar and 0.75% gellan gum (A025/G075), 0.75% agar and 0.25% gum (A075/G025). Drying kinetics was performed with the five mixed structure formulations developed, and the mathematical models of Page, Newton, Logarithmic, and Henderson and Pabis were adjusted to the experimental data. Then, an entirely completely randomized design was used, keeping the temperature (60 °C) and drying time (8h) fixed and varying the hydrocolloid concentration (mentioned above) to choose the most promising formulations through the moisture, texture, total phenolic compounds (TPC), and total antioxidant activity (TAA) variables response. As a result, the Logarithmic model is suggested as the most appropriate for all to the experimental data mixed structure formulations, as it presented a higher determination coefficient (99.79 < R2 < 99.99), lower values of the root mean square error (0.005<RMSE<0.018), and chi-square (0.000023<χ2<0.000339). It was found that hydrocolloids do not influence the dynamics of the drying process. Considering the lowest moisture value, the highest texture value, and the TAA, it is concluded that the mixed structure A050/G050, A075/G025, and A1 were chosen as the most promising preparations. Then, they were characterized according to their physical, chemical, physicochemical, and hygroscopic properties. The dietary fiber showed significant differences with the addition of 0.5% agar. The addition of 0.75% of agar presents a higher average for available carbohydrates (56.85 mg 100 g-1). Mixed structure was represented by larger quantities of K, Mg, and Na. The most negative effect of the in vitro digestion of the TPC, ABTS, and FRAP was determined in the case of A050/G050. For rupture strength, sample A1 showed the lowest value (2.42 N) among mixed structures. The drying process contributed to the concentration of some physicochemical parameters of a mixed structure that caused the shrinkage of the polymeric network of agar and gellan gum, resulting in a more compact mixed structure. In turn, this polymeric net trapped the lipid content and the TPC (after gastrointestinal digestion) of mixed structure A1, thus bringing beneficial effects to the body. The addition of agar and gellan gum in mixed structure in the proportions used in this work did not show any significant difference (p>0.05) for hygroscopicity and solubility. Henderson model has been adjusted better to experimental data of mixed structure at the temperatures considered, simulating the food distribution chain in temperature conditions. Based on the results obtained, it is possible to develop mixed structure of açaí, banana, peanut, and guarana syrup added with agar and gellan gum that meets consumers is demands looking for practical and nutritious food. Besides, the entire study supports the understanding of the factors that may influence the final product: processing, drying, and stability.