The effect of lamellar structure ordering on the retrogradation properties of canna starch subjected to thermal and enzymatic degradation

Retrogradation behavior of starch dough prepared from damaged cassava starch and its application in functional gluten-free noodles

A novel starch-based model dough used to exploit staple foods was demonstrated to be feasible, which was based on damaged cassava starch (DCS) obtained by mechanical activation (MA). This study focused on the retrogradation behavior of starch dough and the feasibility of its application in functional gluten-free noodles. Starch retrogradation behavior was investigated by low field-nuclear magnetic resonance (LF-NMR), X-ray diffraction (XRD), scanning electron microscope (SEM), texture profile and resistant starch (RS) content analysis. During starch retrogradation, water migration, starch recrystallization and microstructure changes were observed. Short-term retrogradation could significantly alter the texture properties of starch dough, and long-term retrogradation promoted the formation of RS. The damage level influenced starch retrogradation, and damaged starch with the increasing damage level was beneficial to facilitate the starch retrogradation. Gluten-free noodles made from the retrograded starch had acceptable sensory quality, with darker color and better viscoelasticity than Udon noodles. This work provides a novel strategy for the proper utilization of starch retrogradation for the development of functional foods.

Effect of pre-gelatinized temperature on physical and nutritional content of indonesian instant cassava leaves porridge: rowe luwa

Abstract Rowe luwa is a traditional porridge from Southwest Sumba, Indonesia, made from the steamed pulp cassava leaves pounded together with rice. This study examined the effect of pre-gelatinization temperature on the physical quality and nutritional content of instant rowe luwa porridge. The experimental design used in this study was a Completely Randomized Design (CRD) with pre-gelatinization temperature factors, viz., 60 °C (X1), 65 °C (X2), 70 °C (X3), 75 °C (X4) and 80 °C (X5). Physical properties were measured by analyzing color, viscosity, rehydration, and syneresis, while for nutritional compositions, water content, ash, fat, protein, carbohydrate, and energy were evaluated. The simple linear regression was employed to examine the correlation between pre-gelatinization temperature and physical properties or nutritional composition. The results showed that the pre-gelatinization temperature correlated with physical properties, such as: viscosity (r = 0.9924), rehydration (r = 0.807) and syneresis (r = 0.841). Furthermore, the pre-gelatinized temperature significantly affected protein and carbohydrate contents (p < 0.05), while the moisture, ash, and fat contents showed negligible effect (p > 0.05). Principal Component Analysis (PCA) showed that instant rowe luwa porridge prepared with the pre-gelatinization temperature of 80 °C (object X5) had the highest viscosity, rehydration, syneresis, and protein contents compared to the other cooking temperatures. These preliminary data are useful for further research to determine the method and optimization formula of the instant rowe luwa porridge.

Effects of honey types and heating treatment on the textural, thermal, microstructural, and chemical properties of glutinous rice flour gels

Hardening issue in starch-based products that arises during storage, is ascribed to the long-term starch retrogradation which involves the recrystallisation of amylopectin. Present study aimed to delay storage hardening with the addition of high diastase honey bee honey (HBH) and low diastase kelulut bee honey (KBH) into glutinous rice flour (GRF) gels. As compared to KBH, retardation of texture deterioration by HBH was more prominent as evidenced by the significantly (p < .05) lowest hardness and rate of hardening of GRF gel added with HBH (honeygel) throughout the 7-day storage. Heated honey and sugar solution did not reduce gel hardness that gel weakening was associated to the naturally occurring diastase in raw honey. Hence, only conventional GRF gel (congel), GRF gel added with KBH (kelugel) and honeygel were assessed for intrinsic viscosity, thermal, microstructural and chemical properties. The results were substantiated by the significantly (p < .05) lowest intrinsic viscosity (62.93 mL/g) and thermal enthalpy (333.7 J/g) of honeygel. A weak gel network structure was illustrated in honeygel with the significantly (p < .05) highest pore diameter (125.27 μm). In conclusion, the GRF gel has successfully demonstrated the potential of honey diastase in inhibiting the long-term retrogradation which could solve the industrial real problem.

Retrogradation and Digestibility of Rice Starch Gels: The Joint Effect of Degree of Gelatinization and Storage

Retrogradation affects acceptability of starchy foods; however, it is preferred in some products such as rice noodles. Amylose content, gelatinization temperature, and storage condition were reported to affect retrogradation but with disputed data. The joint effects of these parameters were interested in this study. Rice starch was gelatinized using different temperatures (77, 81, 95, and 121 °C) and stored isothermally with temperature cycles for 10 days. Results showed that the most important parameter that affected retrogradation was storage time followed by storage condition and gelatinization temperature. The recrystallization rate constant (k) and Avrami exponent (n) of retrograded starches stored under temperature cycle were higher than isothermal storage. All samples showed similar polymorphs of a mixture of B and V types. High-temperature gelatinized starch gel stored under temperature cycle condition produced higher yield of resistant starch. The study provided useful information on how to apply these parameters to control the retrogradation of starchy foods, especially rice noodle. PRACTICAL APPLICATION: Retrogradation is found to be more prominent at higher gelatinization temperature and longer storage time. Resistant starch produced from retrograded starch depended largely on storage time than storage condition. This finding can be applied to improve rice noodle qualities (by increasing retrogradation) with lower digestibility (by producing higher resistant starch).

The multi-scale structure, thermal and digestion properties of mung bean starch

Identification and selection one special variety mung bean for lower GI food is very useful, however, the fundamental study for mung bean starch is still insufficient to meet its demand. In this study, four varieties of mostly planted mung bean in China were selected as model materials. The multi-scale structure of mung bean starch was characterized by SEC, HPAEC, XRD, SAXS, and SEM. SEC and HPAEC give the amylose contents, amylose and amylopectin fine structure of mung bean starch. Mung bean starch from XRD spectrum display C_A type semi crystallinity. The crystalline lamellar thickness from SAXS curves were 7.34-7.60 nm. DSC indicated that the peak gelatinization temperature is at 67 °C-68 °C. Resistant starch in mung bean disappears rapidly after cooking, although the amount of slowly digested starch was still more than half of the total starch. Since the gene backgrounds of the mung bean starch samples are very close, there was no obvious difference in their molecular and aggregated state structure, and the digestion properties were similar, too. Unique SEC and HPAEC profiles of starch chain length distribution can be utilized to help find more genetic resources and cultivate variety to meet the needs for starch applications.