Degree Of Gelatinization Research Articles

Comparison of different thermal treatments on the physicochemical properties of Apios fortunei used for yellow wine fermentation

A novel material (Apios fortunei), which has a high starch content and potential healthcare functions, was used for yellow wine fermentation. To determine how the tuber's composition would be modified by thermal treatments and how those modifications would affect fermentation, the changes in the physicochemical properties of the A. fortunei tuber after steam cooking, traditional extrusion (extrusion without enzyme) and enzymatic extrusion (introduce the amylase into the extrusion) were investigated. The results showed a low degree of gelatinization (70.56%) in the steam-cooked sample, and the fermentation broth of the traditionally extruded sample was dense. However, the enzymatically extruded sample was almost completely gelatinized (99.09%) with an amorphous starch structure measured via X-ray diffraction and Fourier-transform infrared spectroscopy. The high water solubility index (61.66%), low water absorption index (1.68 g/g) and viscosity (<60 cP), indicated that the broth of enzymatically extruded sample had a fine fluidity. The results of the final wines indicated that enzymatic extrusion significantly increased the fermentation efficiency, from 62.22% (steam cooking) and 63.87% (traditional extrusion) to 73.47%. Meanwhile, enzymatic extrusion improved the quality characteristics of the final wines, including total amino acid (4559.20 mg/L), soluble solid content (7.35 g/100 g) and total acid (10.66 g/L).

Modeling energy requirements in planetary ball milling of rice grain

Modified rice flours were obtained by high-impact milling. A factorial design was performed in a planetary ball mill varying rotational speed (450–650 rpm) and milling time (10–40 min) while milling energy (0.3–4.3 kJ/g), particle size distribution (PSD) of rice flour, and changes in starch structure were recorded. The effect of rotational speed and time on milling energy was satisfactorily modeled by the Response Surface Methodology. Modified flours presented bimodal PSD unlike that of the control flour, which was monomodal with a lower size dispersion. A significant reduction of D[4,3] (mean diameter) was observed as the milling energy increased. However, the effect of milling energy on PSD was dependent on milling speed. Classical milling equations provided a satisfactory fit of energy-size records at low speed (450 rpm), but at higher speed, a poor adjustment was obtained due to the increasing relevance of heat dissipation. The empirical milling equation based on linear or exponential relationships between milling energy and size reduction ratio provided a good fit for experimental data. Significant correlations between milling energy and damaged starch, crystallinity, and gelatinization degree were found. The proposed mathematical models are a contribution to the milling process design for specific modifications of rice flour.

Influence of acid treatment on flavonoid content and biological activity in tartary buckwheat grains and its application for noodles

Acid treatment is one of the most effective methods to convert flavonoid glycosides into their aglycones. In this study, the impacts of acid treatment of tartary buckwheat grains on the flavonoid composition and biological activities of tartary were investigated. The results indicated that acid treatment allowed the deglycosylation of rutin to quercetin in buckwheat grains, contributing to the enhancement of their antioxidant activity. Furthermore, as compared to the non-treated sample, acid-treated buckwheat grain samples showed stronger inhibition on tert-butyl hydroperoxide mediated the formation of intracellular reactive oxygen species in HepG2 cells, reduction in lipid accumulation and the related adipogenic transcription factors in 3T3-L1 cells, and reduction in inflammatory mediators in RAW 264.7 cells. Upon application to noodles making, noodles supplemented with acid-treated tartary buckwheat flours, which had weakened gluten strength and a low degree of gelatinization, displayed significantly improved antioxidant activity. These findings suggest that acid-treated buckwheat flours can be used to improve the health benefits of buckwheat products.

The effects of ultrasonic treatment on physicochemical properties and in vitro digestibility of semigelatinized high amylose maize starch

This study aimed to observe and quantify the high- and low-temperature ultrasonication impact of semigelatinized high amylose maize starch on physicochemical properties and in vitro digestibility. High- and low-temperature ultrasonication did not increase the degree of gelatinization, but generated cracks and pores on the starch granule surface and enhanced the short-range ordered molecular structure and apparent amylose content (AAC). Compared with incubation treatments, high-temperature ultrasonication gradually increased the slowly digestible starch (SDS) and resistant starch (RS), whereas low-temperature ultrasonication only decreased RS. Principal component analysis (PCA) and multivariate linear regression results showed that SDS and RS were significantly affected by the long-range ordered molecular structure, a molecular weight distribution of amylopectin, enthalpy change and AAC, whereas the short-range ordered molecular structure further dominated RS. Our results improved the understanding of physicochemical property changes in low- and high-temperature ultrasonication on semigelatinized high amylose maize starch and differentiated the significant principal components of SDS and RS formation.

Extrusion pregelatinization improves texture, viscoelasticity and in vitro starch digestibility of mango and amaranth flours

Non-conventional flours from unripe fruits and pseudocereals have potential as functional ingredients given their high protein contents and antioxidant activity. Pregelatinized starch and flours are increasingly used in gluten-free foods and as fat substitutes. The present work aimed to address the effect of extruding pregelatinization in the viscoelasticity and in vitro starch digestibility of amaranth and mango flours. Differences in starch, protein, and lipid contents between these flours were shown, which impacted the characteristics of the extruded flours. The gelatinization degree was 51% (amaranth) and 56% (mango). FTIR analysis showed that extrusion disrupted the hydrated and short-range ordered starch structure. Amaranth flour presented higher content of slowly digestible starch (41.13% raw and 49.39% extruded flour), which can be due to its higher protein conten (18.3%) with the potential of forming complexes with starch. A principal component analysis revealed that extrusion had a strong effect on the properties of both flours.

The Effect of Poly (Ethylene glycol) Emulation on the Degradation of PLA/Starch Composites.

As a hydrophilic renewable polymer, starch has been widely used in biocompatible plastics as a filler for more than two decades. The present study aimed at investigating the effects of polyethylene glycol (PEG), as a plasticizer, on the physicochemical properties of a hybrid composite—polylactic acid (PLA) and thermoplastic starch (TPS). A solvent evaporation process was adopted to gelatinize the starch and disparate PEG contents ranging from 3 to 15 wt.% (with respect to the sample weight) were examined. It was revealed that the increase in the PEG content was accompanied by an increment in the starch gelatinization degree. Referring to the microstructural analyses, the TPS/PLA mixture yielded a ductile hybrid composite with a fine morphology and a uniform phase. Nevertheless, two different solvents, including acetone and ethanol, were used to assess if they had any effect on the hybrid’s morphology, tensile strength and thermal properties. It was found that ethanol culminated in a porous hybrid composite with a finer morphology and better starch distribution in the PLA structure than acetone. As the result of PEG addition to the composite, the crystallinity and tensile strength were decreased, whereas the elongation increased. The hydrolytic degradation of samples was assessed under different pH and thermal conditions. Moreover, the microbial degradation of the PLA/TPS hybrid composite containing different PEG molar fractions was investigated in the soil for 45 days. The rate of degradation in both hydrolytic and biodegradation increased in the samples with a higher amount of PEG with ethanol solvent.

Methods of producing parboiled rice by hot air and combined microwave-hot air fluidized bed drying

Conventional parboiled rice requires many components such as boiler, steam pipe and auxiliary devices. To reduce the complexity of the process, in this work, the new method of producing parboiled rice by hot air fluidized bed (HAFB) and microwave-hot air fluidized bed (MWHAFB) was proposed and investigated. In the experiment, the soaked paddy with an initial moisture content of 47 ± 1% d.b. and initial grain temperatures of 32–65 °C were dried at the drying air temperatures of 110–170 °C with microwave powers of 0.8–4.0 W/gwet paddy (1.6–4.0 kW). The superficial air velocity at 4.6 m/s and bed depths of 5 cm (1 kgwet paddy) and 10 cm (2 kgwet paddy) were used. The experimental results showed that the drying time to reach an intermediate moisture content of 20 ± 2% d.b. was shorter with smaller bed depth, higher drying air temperature and higher microwave power. The MWHAFB and HAFB dryings could produce parboiled rice with a complete degree of starch gelatinization as the operating condition was suitable. The head rice quality of parboiled rice produced by MWHAFB and HAFB was not different. The parboiled rice had yellowish white for drying with excluding the tempering and had yellowish brown with including tempering as indicated by whiteness index (WI) with a value of 51–52. The consumption of energy was significantly lower in HAFB than that in the conventional process whilst the energy consumption between MWHAFB and conventional one was relatively comparable.

Evaluation of physico-chemical changes and FT-NIR spectra in fresh egg pasta packed in modified atmosphere during storage at different temperatures

Physico-chemical properties (i.e. water activity, colour, water absorption index and hardness) influence stability, quality and consumer acceptability of fresh pasta. The aim of this study was to investigate the effect of storage time on physico-chemical properties of fresh pasta stored at different temperatures (0, 5 and 10 °C). Storage time significantly affected the macroscopic properties (water absorption index and hardness) of fresh pasta and its water status (water activity, freezable water). During storage at all temperatures, water activity and freezable water decreased, confirming a reduction in water mobility in the product. Storage time increased pasta hardness and caused a reduction in the water absorption index. Fresh egg pasta retained its yellow colour, while lipid oxidation indices were only slightly affected. With the increase of storage temperature, the kinetic rate of water activity and gelatinisation degree decreased. In contrast, the kinetic rate of pasta hardness increased with the temperature. The Arrhenius relationship explained the temperature dependence of reaction constants, while FT-NIR analysis showed a structural reorganisation of pasta matrix during storage. Generally, pasta matrix reorganisation involved water, starch and proteins interactions, and storage temperature was an important factor affecting these modifications with specific effects on physico-chemical pasta properties (e.g. hardness).

Interactions between starch source and gelatinisation degree on performance and small intestinal digestion in broiler chickens

ABSTRACT 1. A 2 × 2 factorial arrangement was used to test the hypothesis that, in pelleted diets, legume starch is digested less rapidly and to a lesser extent than cereal starch, and that increased gelatinisation through extrusion would eliminate the differences between the starch sources. In addition, the trial examined whether a lower ratio of starch to nitrogen disappearance rate (SNDR) could improve feed conversion ratio (FCR). 2. At 17 d of age, male broilers were randomly distributed among four dietary treatments, consisting of either wheat or faba bean starch-rich fraction (FBS) as the sole starch source and pelleting or extrusion as processing methods. Each treatment had 10 replicate pens containing five birds each. 3. Extrusion resulted in a more extensive starch gelatinisation compared to pelleting, as expected. 4. No difference in weight gain at 29 d of age was observed between birds fed starch sources. However, birds fed wheat tended (P = 0.080) to have better FCR than those fed FBS, while the effect of processing methods was insignificant. Thus, there was no interaction between starch source and processing method on FCR. 5. In pelleted diets, FBS had lower and slower starch digestibility compared to wheat in all intestinal segments (P < 0.05). The interaction between starch source and processing method in all intestinal segments (P < 0.001) demonstrated that FBS responded more to gelatinisation through extrusion than did wheat. Thus, differences in starch digestibility between the wheat and FBS were eliminated with extrusion. 6. Feeding extruded diets significantly increased the upper jejunal expression of GLUT1, GLUT2 and SGLT1 compared to pelleted diets, which suggested that glucose absorption was less likely to be a limiting factor for starch utilisation. 7. Pelleting resulted in a lower ratio (P < 0.001) of SNDR compared to extrusion (on average 1.4-fold) but did not improve FCR.

Processing Matters in Nutrient-Matched Laboratory Diets for Mice-Energy and Nutrient Digestibility.

Simple SummaryThe processing of feed items has an impact on their nutritive properties, e.g., differences in the degree of starch gelatinization between pelleted and extruded diets are apparent. In many species, including humans, it is known that this influences the digestion process on enzymatic and microbial levels, and thus the animals´ ability to utilize the diet. Laboratory animal diets are often marketed as identical products, e.g., a standard maintenance diet, which can be purchased in pelleted or extruded form. The hypothesis that there are differences in energy and nutrient digestibility among such products, even though they are claimed to be the same diet, was investigated. The results of the digestibility trials confirm the hypothesis. Additionally, they show that even among batches of the same laboratory rodent diet in the same form, standardization is not always achieved.Starch gelatinization is a major determinant of carbohydrate digestibility and varies with diet processing. Laboratory rodent diets are often marketed as identical, but are sold in different forms, regardless of the markedly higher starch gelatinization in extruded than in pelleted diets. Our hypothesis was that this would impact energy and nutrient digestibility in mice fed pellets or extrudate, respectively. Trial 1 showed that feeding C57BL/6 mice a standard maintenance diet in extruded form results in a significantly higher digestibility of organic matter, energy, and carbohydrates than the identical diet in pelleted form. The replication of the experiment, however, revealed a variation between batches of the same pelleted diet regarding starch and total dietary fiber contents. Given the significant differences in diet digestibility and the potential impacts of digestibility on nutrient utilization, the intestinal microbiome, and intermediary metabolism, trials performed with differently processed diets are not comparable. This might partly explain failures to reproduce results, especially in gastrointestinal or microbiome research. Considering this impact on experimental animals, the degree of starch gelatinization should be declared in the diet information for laboratory animal diets. The differences between batches of laboratory animal diets as observed in the pellets are not acceptable.

In vitro digestibility and the characteristics of puffed products from different degrees of milling and moisture content of adlay grain (Coix lacryma – jobi L.)

Adlay (Coix lacryma–jobi L.) is one of the cereals that can be developed into slowdigesting instant food. The degree of milling and moisture content of cereals can affect the digestibility of the food products. The purpose of this study was to determine the proper degree of milling and moisture content of adlay seeds so that a puffing product with high slowly digestible starch (SDS) content and organoleptic characteristics acceptable to the panelists was produced. This study used an experimental method consisting of two main treatments: the degree of milling (whole grain and polished) and the moisture content of adlay seeds (10%, 13%, 16%, and 19%). In vitro digestibility was measured by used pancreatic porcine α-amylase. The results showed that puffed adlay with the highest SDS and organoleptic characteristics that were still acceptable to the panelists was puffed polished adlay with an initial moisture content of 13%. The adlay puffed had SDS of about 35.98%, hardness 2795.83 gf, degree of gelatinization 67.90%, the moisture content of 5.94%, and rehydration power of 59.40%. The preferences for color, taste, aroma, and after-taste of adlay puffed were in the normal category while the texture was in the preferred category.

In vitro digestibility of starches with different crystalline polymorphs at low α-amylase activity to substrate ratio

In this study, potato, lotus seed and wheat starch samples with different degree of gelatinization (DG) were prepared and their in vitro digestibility at low α-amylase activity evaluated by measuring the release of reducing sugar. The hydrolysis rate (k) and the final equilibrium concentration (C∞) of the three starches increased with increasing DG. Kinetic analyses showed that the Michaelis–Menten constant (Km) and the catalytic efficiency (kcat/Km) increased with increasing DG, indicative of the increasing affinity and catalytic efficiency of α-amylase with all three starch samples. Of the three starches, lotus seed starch showed a much greater increase in k and kcat/Km than potato and wheat starches as the DG of starch increased. From this study, we concluded that at low activity of α-amylase, DG is a major determinant for the binding affinity and catalytic efficiency of α-amylase to starch and in turn the digestion rate of starch.

Developing a new modification technology of oat flour based on differential pressure explosion puffing

This research developed differential pressure explosion puffing (DPEP) technology to modify oat. The effects of heating time, puffing temperature and differential pressure on gelatinization degree, water absorption, solubility, thermodynamics properties, gelatinization properties and crystal structure of oat flour were investigated. The gelatinization degree of starch in oats treated with DPEP was 99.73 g/100 g, and the solubility and water absorption of modified oat flour increased to 3.90 g/100 g and 2.81 g/g, respectively. Thermodynamic properties indicated that the gelatinization temperature and enthalpy of the modified oat flour decreased to 58.19 °C and 0.06 J/g respectively. The peak viscosity, trough viscosity and final viscosity of modified oat flour increased to 2.20 Pa s, 1.77 Pa s and 3.55 Pa s, respectively, oat flour had lower disintegration value and higher shear resistance. However, under long-term high temperature treatment, starch and lipid formed complex, leading to gradual transformation of the crystal structure from A-type to V-type, and water absorption, solubility and viscosity decreased.

Comparison of new and conventional processing methods for their effects on physical properties of fish feed

At present, aquafeed is made mainly by low-moisture extrusion cooking. To further improve feed quality, we developed a new process featuring high-moisture extrusion with a twin-screw extruder and a specially designed cooling die. In this study, aquafeed was made with two mash formulations (with or without wheat flour) by low moisture (conventional) or high moisture (new) extrusion under the same temperature (138 °C). Fresh and/or dried extrudates were evaluated for visual appearance, physical quality (water absorption and hardness with soaking time, bulk density, pellet durability, water stability and oil absorption capacity), chemical composition and degree of starch gelatinization. Results show that processing methods, feed formulation and post-extrusion drying all had significant effects on the visual appearance and physical quality of feed. The new feed (NF) was less expanded and less porous than conventional feed (CF), leading to significant reduction in oil absorption capacity, about 85 % of CF.Upon contact with water, fresh and dried CF absorbed water quickly and disintegrated easily, while NF absorbed water slowly and maintained a soft texture (around 50 g/mm2, comparable to fish fillet texture) even after 24 h of soaking. Dry matter loss from NF was significantly less than CF, after 6 h shaking in water. Due to its compact texture, NF had higher pellet durability than CF, with a bulk density greater than 1 g/cm3. Addition of wheat flour to the mash made CF more porous, harder in texture and less water stable but exerted a limited effect on NF. Therefore, the new process produced aquafeed that was soft in texture, durable, and extremely water-stable, while making addition of starch or other binder unnecessary. Although an increase in drying cost for NF is expected, the new method offers a good alternative to produce specialty feed and a promising strategy to reduce water pollution issues associated with aquaculture.

In vitro Digestibility of Starch from Ready-to-Eat Cassava and Corn Flours

HIGHLIGHTS Ready-to-eat flours, used without further processing, deliver raw starch to diet. Dry cassava flour had the best starch digestibility profile from all samples. Processing of the flours influences starch gelatinization degree and digestibility. Consumption of cassava flour can benefit nutritional quality of a meal.

The effect of dry heat parboiling processing on the short-range molecular order structure of highland barley

The crystalline structure and the physicochemical properties of highland barley under two different dry heat parboiling processing including low temperatures for a long time (LTLT) and high temperatures for a short time (HTST) and the relationship between them were studied. As measured by the techniques such as Fourier transform infrared spectroscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, differential scanning calorimetry, X-ray diffraction pattern, and the crystalline structure was shown that highland barley was rearranged and resulted β-sheet was the main influence on protein helical structure during dry heat parboiling processing. The aggregation of protein was degraded in LTLT processing. After dry heat parboiling processing, the crystal structure exhibited A, B, and V-style polymorphs, the peak temperatures of gelatinization were increased (from 64.18 °C to 71.58 °C), the enthalpy was decreased (from 5.99 J/g to 2.79 J/g), and the degree of gelatinization was up to 53.42%. LTLT dry heat parboiling was severe processing to highland barely.

Increased dimensional stability of alginate impression by addition cassava starch and sago starch

Background: Alginate impression material has a weakness about its dimensional stability being rapidly changing. Some na-tural ingredients contain polysaccharides namely amylose and amylopectin used to modify it. Comparison of amylose and ami-lopectin affects the degree of starch gelatinization; the greater the amylopectin content, the starch gel will be wetter, stickier and absorb less water. Objective: To determine the effect of the addition of cassava starch and sago starch to the dimensional stability of alginate impression. Method: Using a true experimental laboratory method with a cross-sectional design. Result: Based on the 1-way Anova test, the p-value was 0,000; smaller than 0.05. According to the post hoc multiple comparison test, the average difference between alginate plus cassava starch with controls was 0.35500, while alginate plus sago starch with controls was 0.75500. Conclusion: There is a significant change between the addition of cassava starch and sago starch to the dimen-sional stability of the alginate impression.

Addition of chickpea markedly increases the indigestible carbohydrate content in semolina pasta as eaten.

There is a growing interest in increasing dietary fiber (DF) consumption because of the health benefits associated with this nutrient. Pulses are considered a good source of non-digestible carbohydrates. The aim of this study was to investigate the possibility of substituting semolina with chickpea flour to increase indigestible carbohydrate content without altering the texture of the pasta. Pasta was prepared by extruding semolina-chickpea blends. The protein and DF content in the cooked pasta increased with the chickpea level, with an important contribution of resistant starch (RS) to the DF values. The optimum cooking time decreased as the chickpea content increased, which was related to the degree of starch gelatinization of the raw pasta. The in vitro digestible starch content decreased with the chickpea substitution level, concomitant with the increase in RS content. In general, the texture of the chickpea-containing pasta was similar to that of semolina pasta. Pending acceptability studies on these pastas may grant their promotion as good fiber sources, probably helpful in the fight against obesity and diet-related non-communicable diseases. © 2020 Society of Chemical Industry.

Structural and in vitro starch digestion properties of potato parenchyma cells: Effects of gelatinization degree

In the present study, intact potato cells as whole potato food model were isolated through soaking with mild acid and alkali solutions, followed by controlled hydrothermal treatment to reach 0–100% degree of gelatinization (DG). The morphological and structural changes of entrapped starch granules as well as in vitro starch digestion properties were investigated. Our results indicated that the changes of cell wall permeability induced by varied DG values dominated the in vitro starch digestion profiles of intact cells. The gelatinization of intracellular potato starch leads to cell wall expansion and high cell wall permeability, resulting in the accessibility changes of digestive enzymes to encapsulated starch substrates through cell wall barrier. This study suggests that starch digestibility of potato foods can be regulated through cell wall permeability induced by intracellular starch gelatinization degree.

Functional, Rheological, Morphological, and Micro‐Structural Properties of Extrusion‐Processed Corn and Potato Starches

AbstractThe purpose of this study is to investigate the effect of twin‐screw extrusion conditions on the properties and quality attributes of corn starch (CS) and potato starch (PS). Extrusion processing conditions used are—feed moisture level of 17% and 18%, screw speed level of 414 and 533 rpm, and barrel temperature of 131 and 135 °C for CS and PS, respectively. When compared with native starches, it is demonstrated that extrusion has a positive effect on the functional properties, that is, bulk density decreases, but water absorption index, water solubility index, degree of gelatinization, and in vitro digestibility increase significantly, and transform its native structure to a honeycomb‐like fine meshwork. Extrusion also results in a significant decrease in pasting temperature, peak viscosity, hold viscosity, final viscosity, breakdown viscosity, and setback viscosity of both the starches. In color profile, a decrease in luminosity, but increase in redness and yellowness are observed in extruded starches. Scanning electron microscopy and X‐ray diffractometry studies show that extrusion leads to complete destruction of structure along with reduced crystallinity and formation of V‐type polymorphs in starches. Compared to CS, PS shows more surface protrusions and formation of air cells leading to formation of a much more microporous structure.