Thermal Characterization and Phase Behavior of a Ready-to-Eat Breakfast Cereal Formulation and its Starchy Components

Abstract

Gelatinization in excess of water and melting transition for different moisture contents of a ready-to-eat cereal formulation (RTE blend) and its major components, (i.e., oat flour, rice flour, and an oat-rice flour blend) were studied by differential scanning calorimetry (DSC) and rapid visco-analyzer (RVA). The highest swelling power was exhibited by the rice flour and the lowest by the RTE blend. Two endothermic peaks under excess of water were exhibited by all materials, at 53-75°C and 80-102°C, and they were associated to gelatinization and cereal protein denaturation, respectively. A third peak appearing in all materials except in rice flour, at higher temperatures (102-116°C), was attributed to the melting of the amylose-lipid complexes. The effect of water in the melting of the flours and blends was well described by the Flory-Huggins equation and its parameters agreed well with those reported in the literature for starchy products. A theoretical value of the polymer-diluent (starchwater) interaction factor for starch of 0.36 was calculated from a combined model of Hildebrand empirical approach to solubility and the Flory-Huggins theory, and reasonably compared with the interaction parameter (χ) obtained for the materials considered in this work. State diagrams for the oat-rice flour blend and for the RTE blend going through an extrusion process were finally obtained.

Thermomechanical characterization of an amylose-free starch extracted from cassava (Manihot esculenta, Crantz)

“…The value for WXCS was 256 °C (Table 1), similar to the values reported for cassava starch with amylose (254 °C) (Garcia et al 1996), waxy rice starch (252 °C) , and higher than potato starch (221.5 °C), oatmeal (214 °C) and wheat (291 °C) (Núñez et al, 2009 ) and higher than rice, potato, and oatmeal. Predicted ΔH u for WXMS (47.6 kJ.mol For both WXCS and WXMS, T g decreased with increasing moisture contents ( Figure 4A), as predicted by the plasticizing effect of water (Kalichevsky et al, 1992;Bizot et al, 1997;Chaudhary et al, 2011).…”

“…Phase transitions such as melting are important parameters in starches since they explain aspects of their behavior in food products subject to heat treatments (Núñez, Sandoval, Müller, Della Valle, & Lourdin, 2009). The thermal characterization of starches was developed primarily using Differential Scanning Calorimetry (DSC) (Biliaderis, Page, Maurice, & Juliano, 1986;Contreras-Gallegos, Domínguez-Pachecho, Hernández -Aguilar, & Carballo-Carballo, 2015;Cruz-Orea, Pitsi, Jamée, & Thoen, 2002).…”

“…The thermal characterization of starches was developed primarily using Differential Scanning Calorimetry (DSC) (Biliaderis, Page, Maurice, & Juliano, 1986;Contreras-Gallegos, Domínguez-Pachecho, Hernández -Aguilar, & Carballo-Carballo, 2015;Cruz-Orea, Pitsi, Jamée, & Thoen, 2002). The transitions associated to the melting have shown one or two endotherms (P1 and P2) at different moisture contents for starches of different botanical origin (Biliaderis, 2009;Donovan, 1979;Garcia et al, 1996;Núñez et al, 2009). …”

“…However, other authors have stated that these starch phase transitions are processes in no equilibrium controlled by the glass transition of the amorphous domains. Despite some limitations identified in this theory, the Flory-Huggins analysis can be used to simulate the thermal behavior in practical applications such as extrusion and baking (Núñez et al, 2009). …”

Shear and elongational viscosities of a complex starchy formulation for extrusion cooking

“…140-160°C) was above the melting temperature of the samples and the second one (i.e. 100-120°C) below them; the melting temperature was previously determined by Differential Scanning Calorimetry in a preceding study (Núñez, Sandoval, Müller, Della Valle, & Lourdin, 2009); it ranged from 130 to 140°C, for the levels of moisture content considered in this work (25 to 17%).…”