Annealing improves paste viscosity and stability of starch

Characterisation and utilisation of nano-reduced starch from underutilised cereals for delivery of folic acid through human GI tract

Ball milling offers green approach for size reduction of starch granules to nano scale size. In this research work, the starch from two underutilised cereal varieties viz. foxtail starch (FS) and sorghum starch (SS) were milled to achieve the desired nanometric range with mean particle diameter of 467.98 and 271.12 nm for nano foxtail (FSN) and nano sorghum starch (SSN), which were highly stable as revealed by zeta potential analysis. Functional attributes like solubility, swelling index, apparent amylose content, emulsifying and pasting properties were evaluated. Scanning electron microscopy (SEM) clearly revealed damaged starch granules produed by the process of milling. X-ray diffraction (XRD) displayed decrease in crystallinity upon milling to 16.08% (SSN) and 18.56% (FSN) and disappearance of some peaks. Attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) also revealed reduced crystallinity as confirmed by the decreased absorbance ratio of 1047/1022 cm-1 in nano starch particles. Rheological analysis displayed shear thinning behaviour of nano starch samples as evaluated using Herschel-bulkely model and Power law. The nano starch samples exhibited comparatively low thermal gelatinisation temperatures as compared to native counter particles. Moreover, the nano-encapsulated starch samples offered more resistance to in-vitro digestion and showed control release of folic acid at target sites.

Effects of thermal properties and behavior of wheat starch and gluten on their interaction: A review

Starch and gluten, the most important macromolecules in wheat flour, vary in thermal properties. The thermal behavior of starch, gluten and their complexes during the manufacture and quality control of flour products need to be accurately understood. However, the high complexity of starch-gluten systems impedes the accurate description of their interactions. When heated within varying temperature ranges and when water molecules are involved, the behaviors of amylose and amylopectin change, and the properties of the starch are modified. Moreover, important indicators of starch granules such as gelatinization temperature, peak viscosity, and so on, which are encapsulated by the gluten matrix, are altered. Meanwhile, the high-temperature environment induces the opening of the intrachain disulfide bonds of gliadin, leading to an increase in the probability of interchain disulfide bond formation in the gluten network system. These behaviors are notable and may provide insights into this complex interaction. In this review, the relationship between the thermal behavior of wheat starch and gluten and the quality of flour products is analyzed. Several methods used to investigate the thermal characteristics of wheat and its flour products are summarized, and some thermal interaction models of starch and gluten are proposed.

PROFIL GELATINISASI DAN KOMPONEN ANTIOKSIDAN TEPUNG KETAN HITAM TERMODIFIKASI DENGAN ANNEALING

This research aims to study and characterize the effect of the annealing conditions (temperature and heating duration) on the gelatinization profile and antioxidant components of annealing-modified black glutinous rice flour (ABGRF). This experiment used a 2x3 factorial design consisted of temperature factor (54 and 58°C) and heating duration factor (4, 5, and 6 hours) with 2 replications. Research results showed that both factors and their interactions significantly affected all parameters of the gelatinization profile and antioxidant component of ABGRF (except through viscosity). Compared to its native, ABGRF showed an increase in peak viscosity, through viscosity (except treatment 54°C:5 hours), peak time and pasting tem-perature, indicated ABGRF resistance improvement to the heating process. Generally, the temperature treatment increment increased breakdown, setback, and final viscosity, but the heating duration increment decreased those values. The variation of ABGRF gelatinization profiles increased the diversification potential of BGRF-based food products. Annealing caused an overall decrease in ABGRF antioxidant ability. ABGRF produced by 54°C:4 hours treatment had the highest amount of antioxidant components (total anthocyanins contents 103.78±2.24 mg C3GE/100 g, total phenolic compounds 241.65±1.98 mg GAE/100 g, DPPH 267.14± 3.23 mg AAE/100 g, FRAP 473.94±1.43 mg AAE/100 g), thus using it as ingredients in functional food is more recommended, especially as composite flour for bread and cake.

Physicochemical and Digestion Properties of Potato Starch Were Modified by Complexing with Grape Seed Proanthocyanidins

Dietary intake of potato starch could induce a dramatic increase in blood glucose and is positively associated with chronic metabolic diseases (type II diabetes, cardiovascular disease, etc.). Grape seed proanthocyanidins (GSP) are known to decrease starch digestion by inhibiting digestive enzymes or changing the physicochemical properties of starch. In the present study, GSP were complexed with potato starch to prepare polyphenol-starch complexes. The physiochemical properties and digestibility of complexes were investigated by in vitro digestion model, X-ray diffraction, differential scanning calorimetry, rapid visco analyzer, Fourier transform infrared spectroscopy as well as texture profile analysis. Results indicated that the peak viscosity, breakdown, trough, and setback of the complexes disappeared, replaced by a special continuous increase in paste viscosity. The complexes showed a lower final viscosity and higher thermal stability with the increasing binding amount of GSP. GSP decreased the hardness of the complexes' gel significantly. FT-IR indicated that GSP might interact with potato starch through noncovalent forces. Additionally, the complexes also showed a higher content of slowly digestible starch and resistant starch than that of the native starch. Thus, we inferred that the addition of GSP could modify the digestibility of potato starch and be an optional way to modify the starch with lower digestion.

Understanding the impact of Pulsed Electric Fields treatment on the thermal and pasting properties of raw and thermally processed oat flours

The aim of this research was to investigate the effect of Pulsed Electric Fields (PEF) treatments (electric field strengths 2 and 4.4 kV/cm combined with specific energy inputs between 48 and 484 kJ/kg) on the thermal and pasting properties of oat flours. Colour, β-glucan content, particle size distribution, morphological characteristics, starch short-range molecular order, protein secondary structure, thermal, and pasting properties of raw (dehulled and milled) and thermally processed (kilned at 115 °C for 30 min and steamed at 100-104 °C for 18 min under industrial process condition) oat flours under the influence of PEF treatment were evaluated. Results showed that PEF treatment, applied at any intensity, led to considerable changes in the structural properties especially when applied on raw oat flour. Both types of oat flour experienced an increase in particle size (up to four-fold), damage of starch granule morphology, and modifications in starch short-range molecular order and protein secondary structures as a result of PEF treatment. These physical changes observed after PEF treatment, particularly at increasing specific energy input, coincided with the thermal and pasting behaviour of PEF-treated oat flours, which include a decrease in gelatinisation enthalpy (up to 80%), increase in thermal transition temperatures (at least 3 °C), decrease in overall viscosity profile, and reduction in pasting temperature (up to 12 °C). Overall results suggested that PEF treatment improved majorly on starch-related functionality of oat, such as increased the pasting stability of raw and thermally processed oat flours and at the same time enhanced the retrogradation property (reduced syneresis and hardness) of raw oat flour, under lower temperature requirement without affecting pasting time. This research demonstrated the potential of PEF treatment in modifying the thermal and pasting properties of oat flour, thereby offering opportunities for novel products for food industry.

The Comparison of Structural, Physicochemical, and Digestibility Properties of Repeatedly and Continuously Annealed Sweet Potato Starch

In order to investigate the varied effects of repeated annealing treatment (RANN) and continuous annealing treatment (CANN) on the structural, physicochemical, and digestibility properties of the sweet potato. The 75% starch-water suspensions were prepared and incubated at 65 °C for 8 cycles and 96 hr. The results exhibited that RANN and CANN did not influence the starch granules and polarization cross obviously. The crystal type of RANN and CANN starches still maintained A-type, while the relative crystallinity increased. The solubility, swelling power, peak viscosity and breakdown of RANN and CANN starches decreased, but the gelatinization transition temperatures, trough viscosity, final viscosity, setback, and pasting temperatures of starches increased after annealing treatments. Furthermore, RANN and CANN decreased the RS and RS + SDS contents with the increase of annealing cycles and time. The RANN was more effective in modification of the crystallinity, solubility, swelling power, pasting, gelatinization transition temperatures and enthalpy, and digestibility of starch before four times compared with the CANN ones. By and large, RANN may be a potential way for modification of structural, physicochemical and digestibility properties. PRACTICAL APPLICATION: The described RANN and CANN starch provide new ideas for the study of modified starch. Furthermore, this study revealed the mechanism of annealing treatment and it was concluded that the repeated annealing treatment could provide a new potential way for the modification of starch.

Effect of an Atmospheric Pressure Plasma Jet on the Structure and Physicochemical Properties of Waxy and Normal Maize Starch

In present study, a novel physical modification of waxy maize starch (WMS) and normal maize starch (NMS) was investigated by using an atmospheric pressure plasma jet (APPJ) treatment. The effect on the structure and physicochemical properties of both starches was demonstrated by treatment with a 5% starch suspension (w/w) with APPJ for short periods of time (1, 3, 5, or 7 min). The pH of WMS and NMS was decreased after APPJ treatment from 5.42 to 4.94, and 5.09 to 4.75, respectively. The water-binding capacity (WBC) (WMS: 105.19%⁻131.27%, NMS: 83.56%⁻95.61%) and swelling volume (SV) (WMS: 2.96 g/mL⁻3.33 g/mL, NMS: 2.75 g/mL⁻3.05 g/mL) of the starches were obviously increased by APPJ treatment. The surfaces of starch granules were wrecked, due to plasma etching. No changes in the crystalline types of both starches were observed. However, the relative crystallinities (RCs) of WMS and NMS were reduced from 46.7% to 42.0%, and 40.1% to 35.7%, respectively. Moreover, the short-range molecular orders of both starches were slightly reduced. In addition, APPJ treatment resulted in lower gelatinization temperature and enthalpies. Therefore, APPJ provides a mild and green approach to starch modification, showing great potential for applications in the food and non-food industry.

Kithul palm (Caryota urens) as a new source of starch: Effect of single, dual chemical modifications and annealing on the physicochemical properties and in vitro digestibility

The objective of this study was to determine the effect of physical and chemical modifications on the physicochemical and in vitro digestibility of kithul starch. Starch isolated from kithul flour (Caryota urens) was subjected to physical and chemical modifications. The starch modification was verified by the presence of functional groups using Fourier transform Infrared spectral analysis (FT-IR). X-ray Diffraction (XRD) pattern revealed that the kithul starch is A- type and the modifications did not change the crystalline pattern. However, the relative crystallinity showed significant changes. Chemical modifications increased the swelling and solubility. Pasting and thermal parameters of all modified starches showed significant changes as compared to native starch (NS). Acetylated oxidised starch (AOS) showed highest paste viscosities. Higher enthalpy of gelatinization (∆H_gel) and paste viscosity attributed to perfection and ordering of amorphous regions in annealed starch (ANS). All modifications significantly increased the resistant starch (RS) content than native starch (NS), which indicates its lower digestibility. The current study showed the single, dual chemical modifications and annealing, effectively modified the physicochemical and in vitro digestibility of kithul starch.

Effects of Dual Modification with Succinylation and Annealing on Physicochemical, Thermal and Morphological Properties of Corn Starch

The objective of this study was to investigate the effects of annealing, succinylation, and a dual modification process (succinylation⁻annealing) on the physicochemical, thermal, and morphological properties of corn starch. Specifically, the properties of interest were the water-binding capacity (WBC), swelling power, paste clarity, solubility, pasting properties, stability ratio, and thermal and morphological characteristics. The dual modification process increased the physicochemical properties (WBC, swelling power, peak viscosity, and paste clarity) and increased the gelatinization temperature and gelatinization enthalpy (∆H), but had no effect on the morphological properties and X-ray diffraction patterns. A comparison of samples, made using each of the processes, showed that dual modification increased the stability ratio (more stable viscosity under thermal and shear stress), which was 0.69 for dual modified starch, compared with 0.64, 0.58 and 0.44 for native, succinylated, and annealed starches, respectively. The findings of the present study are of potential use in the food industry.

Effect of single and dual-modifications on stability and structural characteristics of foxtail millet starch

Foxtail millet starch was modified by annealing (AS), ultra-sonication (US) and a combination of the two treatments (annealing and ultra-sonication (AUS) or ultra-sonication and annealing (UAS)) and they were characterized. Compared to the native starch (NS), modified starches particularly UAS contained the highest amylose (27.96%). Ultra-sonication prior to annealing had a predominant effect on resistant starch (RS) level (UAS-45.59%). Among the modified starches, UAS had exhibited superior resistance to acidic (0.94) and shear (0.68) stability. Sonication, when used as the second treatment (AUS) elevated the final viscosity compared to its counter ones possibly due to the effects of cavitation promoted by sonication treatment. UAS had showed an A-type diffraction pattern and dominant peaks in FT-IR spectra. It can be inferred that dual modification of starch by ultra-sonication followed by annealing had exhibited the most desirable properties such as high acid and shear resistance, high freeze-thaw stability and improved gel texture.

In vitro digestibility of hydrothermally modified Bambara groundnut (Vigna subterranean L.) starch and flour

In-vitro digestibility and functional properties of Bambara groundnut (Vigna subterranean) (BG) flour, and its native and hydrothermally modified starches were investigated. The isolated native starch (BNS) was modified by annealing at 50°C for 48 hr (BAS), and heat-moisture treated at 100°C for 16 hr at 25% moisture level (BHS). The crude protein of BG flour was 16.88%. The amylose content of the flour and native starch was 6.10% and 27.70%, respectively. Hydrothermal modification increased the gelatinization profile of the starch but reduces its pasting properties. Swelling and solubility of the flour and starches increased with increase in temperature. X-ray diffraction revealed BNS and BAS exhibited "Type C" crystallinity pattern while BHS was "Type A." The BNS granule was oval, its diameter between 22 and 30 μm, with no significant change in the morphology of BAS and BHS. The BG flour had 33% resistant starch and 11.63% digestible starch. Heat-moisture treatment enhanced the resistant starch content of the native starch significantly.