Effects of high hydrostatic pressure on the ordered structure including double helices and V-type single helices of rice starch

Recent advances in the impact of gelatinization degree on starch: Structure, properties and applications

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.

Impact of pre-meal immersion on multi-scale structural changes and starch digestibility of cooked dried noodles

Pre-meal immersion is a common process for both the consumption of dried noodles and development of takeaway noodles, but its impact on the structure and digestibility of dried noodles is still unclear. In this study, dried noodles cooked for the optimal time were immersed at 80 °C for different time durations. Multi-scale structural changes, including texture, molecular structure, microstructure, and in vitro starch digestibility were studied using a combination of kinetic (first-order exponential decay function, the Peleg model, and LOS plots), physicochemical, and microscopic analysis. The relationship between multi-scale structural changes and starch digestibility was derived. As the immersion progressed, the hardness first rapidly decayed and then reached equilibrium. The decay rate in the initial stage depended on the gluten content. In most cases, the immersion process caused depolymerization of gluten proteins and further gelatinization of starch granules, which was observed from an increase in the free -SH content and decrease in the short-range ordered structure, although there were fluctuations over immersion time. Structural changes resulted in the corresponding changes in substance migration. However, a high gluten content (∼15% w/w) imparted a denser microstructure to the noodles, weakening the deterioration effects compared with a low gluten content (∼10% w/w). In vitro digestion experiments proved that samples with higher gluten content had higher starch digestion rates and lower starch digestion extent during immersion. Correlation analysis revealed that there was a negative correlation between k1 and the tightness of the gel. This study helps to reveal the structural mechanisms of starch digestibility in cooked noodles during immersion.

Structure and functional properties of taro starch modified by dry heat treatment

Taro starch (TS) was modified by dry heat treatment (DHT) for different periods (1, 3, 5, and 7 h at 130 °C) and temperatures (90, 110, 130, and 150 °C for 5 h) to expand its applications in food and other industries. The structure and functional properties of DHT-modified TS were characterized. It was found that TS granules became agglomerated after DHT, and the particle size, amylose content, solubility, and retrogradation enthalpy change of TS increased with increasing dry heating time and temperature, whereas the relative crystallinity, molecular weight, swelling power, gelatinization temperature, and enthalpy change decreased. The absorbance ratio of 1047 cm-1/1022 cm-1 for DHT-modified TS (except at 7 h) was higher than that of native TS. DHT increased the contact angle of TS in a time- and temperature-dependent manner. At a moderate strength, DHT increased the pasting viscosity, relative setback value, and storage modulus but decreased the relative breakdown value. Moreover, DHT (except at 150 °C) caused a decrease in the rapid digestive starch content and estimated glycemic index of TS. These results suggested that DHT-modified TS could be used in foods with high viscosity requirements, gel foods, and low-glycemic index starch-based foods.

Evaluation of dual modification by high hydrostatic pressure and annealing on the physicochemical properties of bean starch

This study investigated the physical modifications by high hydrostatic pressure (HHP) at 600 MPa for 30 min/30 °C, annealing (AN) at 50 °C/24 h and the combination of both (HHP + AN and AN + HHP) applied to yellow bean starch to verify changes in morphology, X-ray diffraction, molecular order, thermal properties and pasting properties of native (NS) and modified starches. Morphological analysis showed loss of sphericity and increase in diameter with the appearance of pores on the surface after application of treatments. The AN starch showed lower values of syneresis, degree of double helix (DD), order (DO), and viscosity of the paste obtained by RVA. It exhibited a Vh-type classification with the appearance of the amylose-lipid complex. However, the gelatinization temperatures, as well as the enthalpy of gelatinization, were significantly higher. On the other hand, the starch treated with HHP showed a higher Setback (SB) value. The greatest modifications were found for the starches subjected to the combined treatments (AN + HHP) and (HHP + AN), where the order of the treatments was significant for the morpho-structural changes of yellow bean starch. According to the micrographs, the surface aspect was altered, with AN + HHP showing greater irregularities and flat yet irregular faces, as well as a larger granule diameter (147.05). The X-ray diffractogram showed a reduction in crystallinity from 28.14 % (NS) to 18.09 % (AN + HHP) and classified the starch as type "A". The double modification (HHP + AN and AN + HHP) reduced the gelatinization temperature and the enthalpy of gelatinization but had no effect on the bands of the FT-IR spectrum. There was only a reduction in the degree of order and the double helix. Finally, the treatment with AN + HHP is more effective as the gelatinization with AN facilitates the application of HHP. Both methods used are classified as physical (thermal and non-thermal), aiming to minimize environmental impacts and achieve faster and safer morpho-structural modification without leaving chemical residues in the products.

Effects of explosion puffing on the native structural organization and oil adsorption properties of starch

The effects of explosion puffing (EP) on the native structural organization (i.e., thermal properties, crystalline structure, short-range order, granule morphology and powder properties) and oil adsorption properties of puffed starch (PS) were investigated. The results showed that EP treatment could decrease the melting enthalpy of starch double helices and increase the V-type crystallinity. The highest V-type crystallinity (24.7 %) was obtained when the puffing pressure was 0.4 MPa and the starch:ethanol:water ratio was 1:2:1 (w/w). By controlling the puffing conditions, EP treatment can alter the morphology, and increase the particle size, flowability and specific surface area of PS. The high amorphous proportion and porous sheet structure of PS resulted in the highest oil adsorption capacity when the starch:ethanol:water ratio was 1:1:1 (w/w). Pearson correlation analysis showed that oil adsorption capacity was significantly and positively correlated with the 1022/995 cm-1 value and V-type crystallinity, but negatively correlated with bulk density and angle of repose. Furthermore, oil retention capacity was strongly dependent on V-type crystallinity. These findings demonstrated that EP is an innovative technology with the potential to enhance the V-type crystallinity and adsorption performance of starch.

Structural, rheological, and gelling characteristics of starch-based materials in context to 3D food printing applications in precision nutrition

Starch-based materials have viscoelasticity, viscous film-forming, dough pseudoplasticity, and rheological properties, which possess the structural characteristics (crystal structure, double helix structure, and layered structure) suitable for three-dimensional (3D) food printing inks. 3D food printing technology has significant advantages in customizing personalized and precise nutrition, expanding the range of ingredients, designing unique food appearances, and simplifying the food supply chain. Precision nutrition aims to consider individual nutritional needs and individual differences, which include special food product design and personalized precise nutrition, thus expanding future food resources, then simplifying the food supply chain, and attracting extensive attention in food industry. Different types of starch-based materials with different structures and rheological properties meet different 3D food printing technology requirements. Starch-based materials suitable for 3D food printing technology can accurately deliver and release active substances or drugs. These active substances or drugs have certain regulatory effects on the gut microbiome and diabetes, so as to maintain personalized and accurate nutrition.

The effect of non-thermal physical modification on the structure, properties and chemical activity of starch: A review

Non-thermal physical treatments has obvious advantages in regulating the structure and properties of starch compared with chemical treatment. Hance, this article summarized and compared the effects of three kinds of non-thermal physical treatments including grinding and ball milling, high hydrostatic pressure and ultrasonic on the structure, properties and chemical activity of starches from different plants. The potential applications of non-thermal physical modified starch were introduced. And strategies to solve the problems in the current research were put forward. It is found that although starch has a dense structure, the starch granules could be deformed under three kinds of non-thermal physical treatments, which could damage the granule morphology, microstructure, and crystal structure of starch, reduce particle size, increase solubility and swelling power, and promote starch gelatinization. Three kinds of non-thermal physical treated starch could be used as flocculant thickener, starch based edible films and fat substitutes. Non-thermal physical treatments caused the structure of starch to undergo three stages, which were similar to mechanochemical effects. When starch was in the stress stage and the transition stage from aggregation to agglomeration, its active sites significantly increase and move inward, ultimately leading to a significant increase in the chemical activity of starch.

Structural characterization of different starch-fatty acid complexes and their effects on human intestinal microflora

Resistant starch type 5 (RS5), a starch-lipid complex, exhibited potential health benefits in blood glucose and insulin control due to the low digestibility. The effects of the crystalline structure of starch and chain length of fatty acid on the structure, in vitro digestibility, and fermentation ability in RS5 were investigated by compounding (maize, rice, wheat, potato, cassava, lotus, and ginkgo) of different debranched starches with 12-18C fatty acid (lauric, myristic, palmitic, and stearic acids), respectively. The complex showed a V-type structure, formed by lotus and ginkgo debranched starches, and fatty acid exhibited a higher short-range order and crystallinity, and lower in vitro digestibility than others due to the neat interior structure of more linear glucan chains. Furthermore, a fatty acid with 12C (lauric acid)-debranched starches complexes had the highest complex index among all complexes, which might be attributed to the activation energy required for complex formation increased with the lengthening of the lipid carbon chain. Therefore, the lotus starch-lauric acid complex (LS12) exhibited remarkable ability in intestinal flora fermentation to produce short-chain fatty acid (SCFAs), reducing intestinal pH, and creating a favorable environment for beneficial bacteria.

The effects of high-pressure treatment on the structure, physicochemical properties and digestive property of starch - A review

High hydrostatic pressure (HHP) is a novel technology used in the food-processing industry. Starch is an important renewable natural resource. The applications of starch are determined by its properties, which in turn are determined by its structure. In this study, the effects of HHP treatment on starch structure (granular structure, crystalline structure, molecular structure, and molecular conformation) and properties (pasting, retrogradation, thermal, digestive, rheological, swelling, solubility, water absorption, and oil absorption properties) are summarised. Additionally, the mechanism of HHP-induced gelatinisation is discussed. First, the strong hydration ability of starch molecules under high pressure facilitates the binding of water molecules to starch molecules via hydrogen bonding. These bound water molecules may block the channels inside the starch granules, leading to the formation of a sealed space. Finally, the granules disintegrate because of the intra/extra pressure difference. This study provides a reference for the application of HHP to starch processing and modification.

Structural, functional and mechanistic insights uncover the role of starch in foxtail millet cultivars with different congee-making quality

Ten foxtail millet cultivars with different congee-making quality were investigated for relationships between starch structures, functional properties and congee-making qualities. Swelling power, pasting peak viscosity (PV) and setback (SB), gel hardness and resilience, and gelatinization onset (T_o), peak (T_p) and range (R) temperature were correlated with congee-making performance significantly. Good eating-quality cultivars with these parameters were in the range of 15.41-18.58 %, 3095-3279 cp, 1540-1745 cp, 430-491 g, 0.47-0.57, 64.43-65.28 °C, 69.97-70.32 °C and 23.38-24.52 °C, respectively. Correlation analysis showed that amylose, amylopectin B₂ chains and A₂₁ were essential parameters controlling the functional properties. Amylose molecules with linear molecular morphology would cause crystal defects and a wide range of molecular weight distribution. Additionally, they were more prone to re-association, which influenced the PV, SB, T_o, T_p and gel hardness. B₂ chains impacted the gelatinization temperature range (R), gel resilience and swelling behavior by affecting the alignment of double helices and the size of starch particles and pores. Starch with more binding sites of bound water (A₂₁) tended to leach from the swelling granules easily and contributed to higher values of PV. The content of amylose, B₂ chains and A₂₁ of good eating-quality cultivars were 16.19-18.46 %, 11.60-11.69 % and 96.50-97.02 %, respectively.

Effect of sucrose, trehalose, maltose and xylose on rheology, water mobility and microstructure of gluten-free model dough based on high hydrostatic pressure treated starches

Due to functional and physicochemical properties, starch in its native state has limited range of applications. Simultaneously, information on effects of different sugars and their interactions with modified starch on gluten-free model dough is also limited. To better overcome these restrictions, the effects of sucrose, trehalose, maltose and xylose on rheology, water mobility and microstructure of gluten-free dough prepared with high hydrostatic pressure (HHP) treated maize (MS), potato (PS) and sweet potato starch (SS) were investigated. MS, PS and SS dough with trehalose exhibited a lower degree of dependence of G' on frequency sweep (z'), higher strength (K) and relative elastic part of maximum creep compliance (J_e/J_max), suggesting stable network structure formation. Total gas production (V_T) of MS dough with maltose, PS dough with sucrose and SS dough with trehalose was increased from 588 to 1454 mL, 537 to 1498 mL and 637 to 1455 mL respectively. Higher weakly bound water (T₂₂) was found in the dough with trehalose at 60 min of fermentation, suggesting more hydrogen bonds and stable network. Thus, trehalose might be a potential improver in HHP treated starch-based gluten-free products.

A study on the structural, physicochemical, rheological and thermal properties of high hydrostatic pressurized pearl millet starch

Starch in native form has limited application due to functional and physicochemical characteristics. To overcome these limitations, starch can be modified by non-thermal technologies such as high hydrostatic pressure (HHP). This study investigates high-pressure-induced gelatinization and the effect of this process on the structural, functional, morphological, pasting, thermal, physical and rheological properties of millet starch. The suspension of millet starch and water was pressurized at 200, 400 and 600 MPa for 10, 20 and 30 min to modify the starch in terms of structure, morphology, some physicochemical and rheological properties. Swelling strength and starch solubility decreased as a result of treatment with HHP. All treatments caused to increase in water holding capacity of the starch (from 0.66 % for native starch to 2.19 % for 600 MPa-30 min). Thermal analysis showed a decrease in gelatinization temperature and enthalpy of gelatinization and the pasting properties showed a decrease in the peak viscosity after HHP treatment. In addition, HHP treatment caused to increase in the hydration ability of starch by creating porosity and gaps in the granule surface and increasing the specific surface area. HHP application resulted in an increase in the peak time and pasting temperature and a decrease in breakdown and peak viscosities, final viscosity and setback viscosity in comparison with native starch of millet. The starch sample treated with 600 MPa for 30 min had the lowest syneresis and retrogradation ability. Increasing pressure and the time led to an increase in the elastic nature of the starch samples. According to the results, it is possible to increase usage area of starches in the food industry by improving its technological with HHP. This green physical technology can influence the quality parameters of starch, which can provide benefits for product machining and economic purposes.

Effect of dual modification with citric acid combined with ultrasonication on hydrolysis kinetics, morphology and structure of corn starch dispersions

Corn starch dispersions (CSD) were hydrolyzed with citric acid and compared with CSD co-treated with citric acid combined with ultrasonication for 1 to 18 days, which are designated as single modification (CSD-SM) and dual modification (CSD-DM), respectively. The logistic functions monitor the dynamics of the hydrolysis advance (%) of the CSD-SM and CSD-DM as a function of time, where the zones most vulnerable to the single-treatment and/or co-treatment of the corn starch granules (CSG) are the amorphous or disordered regions. The characterization results of CSD-DM suggest that the structural changes caused by dual modification affected the morphology, sequence, and microstructure of the CSG. The heterogeneous changes caused by the dual modification changed the configuration of the CSG, generating a kind of destemming of the amorphous lamellae (depolymerization), an increase in the percentage of relative crystallinity of the CSD-DM and an active rearrangement of the intralamellar chains that promoted the relative amount of double helix for 18 days of double modification. The synergistic effect of the dual modification for CSD by the sequential combination of a chemical treatment followed by a physical one improved the hydrolyzed advance by 12 %, the relative crystallinity by 10 %, and the promotion of double helices by 25 % during 18 days of co-treatment.

Comparative study of thermo-mechanical, rheological, and structural properties of gluten-free model doughs from high hydrostatic pressure treated maize, potato, and sweet potato starches

Effects of high hydrostatic pressure (HHP, 100, 300 and 500 MPa for 30 min at 25 °C) treated maize (MS), potato (PS), and sweet potato (SS) starches on thermo-mechanical, rheological, microstructural properties and water distribution of gluten-free model doughs were investigated. Significant differences were found among starch model doughs in terms of water absorption, dough development time, and dough stability at 500 MPa. Total gas production of MS, PS and SS doughs was significantly increased from 541 to 605 mL (300 MPa), 527 to 568 mL (500 MPa) and 551 to 620 mL (500 MPa) respectively as HHP increased. HHP increased storage (G') and loss (G″) modulus in terms of rheological properties suggesting, the higher viscoelastic behavior of starch model doughs. The dough after 500 MPa treatment showed lower degree of dependence of G' on frequency sweep suggesting, the formation of a stable network structure. In addition, continuous abundant water distribution and uniform microstructure were found in MS (300 MPa), PS (500 MPa) and SS (500 MPa) doughs for 60 min fermentation. Thus, the starches after HHP show great application potential in gluten-free doughs with improved characteristics.

Nonthermal physical modification of starch: An overview of recent research into structure and property alterations

To tailor the properties and enhance the applicability of starch, various ways of starch modification have been practiced. Among them, physical modification methods (micronization, nonthermal plasma, high-pressure, ultrasonication, pulsed electric field, and γ-irradiation) are highly potential for starch modification considering its safety, environmentally friendliness, and cost-effectiveness, without generating chemical wastes. Thus, this article provides an overview of the recent advances in nonthermal physical modification of starch and summarizes the resulting changes in the multi-level structures and physicochemical properties. While the effect of these techniques highly depends on starch type and treatment condition, they generally lead to the destruction of starch granules, the degradation of molecules, decreases in crystallinity, gelatinization temperatures, and viscosity, increases in solubility and swelling power, and an increase or decrease in digestibility, to different extents. The advantages and shortcomings of these techniques in starch processing are compared, and the knowledge gap in this area is commented on.

Research and application of hydrostatic high pressure in tumor vaccines (Review)

It is well known that hydrostatic pressure (HP) is a physical parameter that is now regarded as an important variable for life. High hydrostatic pressure (HHP) technology has influenced biological systems for more than 100 years. Food and bioscience researchers have shown great interest in HHP technology over the past few decades. The development of knowledge related to this area can better facilitate the application of HHP in the life sciences. Furthermore, new applications for HHP may come from these current studies, particularly in tumor vaccines. Currently, cancer recurrence and metastasis continue to pose a serious threat to human health. The limited efficacy of conventional treatments has led to the need for breakthroughs in immunotherapy and other related areas. Research into tumor vaccines is providing new insights for cancer treatment. The purpose of this review is to present the main findings reported thus far in the relevant scientific literature, focusing on knowledge related to HHP technology and tumor vaccines, and to demonstrate the potential of applying HHP technology to tumor vaccine development.

Effects of ultra-high pressure on the morphological and physicochemical properties of lily starch

In this study, starch extracted from lily bulbs were modified using an ultra-high pressure (UHP) treatment at six different pressure levels (100, 200, 300, 400, 500, and 600 MPa). The effects of UHP treatment on the physicochemical and morphological properties of lily starch were investigated. The morphological observation revealed that UHP treatment led to particle expansion and aggregation. Compared with the native and lily starch treated at 100-500 MPa, the lily starch treated at 600 MPa exhibited almost completely disrupted morphology and a larger particle size, indicating nearly complete gelatinization of the starch. The relative crystallinity of the UHP-treated starch remarkably reduced. Gelatinization temperatures via differential scanning calorimetry decreased with increasing pressure. The rapid viscoanalyzer results revealed that the lily starch treated with UHP at 600 MPa showed low values of peak viscosity, trough viscosity, breakdown, final viscosity, and setback. These results indicated that UHP was an effective physical modification method for lily starch, UHP treatment (600 MPa, 30 min) caused nearly complete gelatinization of lily starch, and lily starch modified using UHP might expand the application of lily in the food field.