Effect of amylolysis on the formation, the molecular, crystalline and thermal characteristics and the digestibility of retrograded starches

Recent developments in enzymatic preparation, physicochemical properties, bioactivity, and application of resistant starch type III from staple food grains

Resistant starch (RS) was classified into five types and referred to the starch that cannot be digested and absorbed by the small intestine of healthy human beings. Among them, RS3 has received a lot of attention from researchers because of its good functional properties and greater application prospects. Meanwhile, the enzymatic method is widely used in the preparation of RS3 because of its high efficiency and environmental protection. α-Amylase and pullulanase as the main enzymes can effectively improve the yield of RS3. The physical properties of RS3 have an excellent potential for application in improving food crispness, texture and producing low glycemic index (GI) foods. It is more valuable because it has biological activities such as inducing apoptosis in tumor cells, lowering intestinal pH, and regulating blood glucose, etc. This paper summarized the current research progress of RS3 from different staple food grains, including current applications of enzymes commonly used in the preparation of RS3, physical properties and biological activities of RS3, and the application of RS3 in different areas to provide a theoretical basis for future research on RS3 as well as further development and applications based on the market requirement.

Processing and Utilization Technology of Root and Tuber Food

Roots and tubers make a great contribution to major staple foods and provide good sources of dietary carbohydrates for the nutrition supply and energy recharge of human [...].

Type 3 resistant starch from Canna edulis reduce lipid levels in patients with mild hyperlipidemia through altering gut microbiome: A double- blind randomized controlled trial

Type 3 resistant starch from Canna edulis (Ce-RS3) is an insoluble dietary fiber which could improve blood lipids in animals, but clinically robust evidence is still lacking. We performed a double-blind randomized controlled trial to assess the effects of Ce-RS3 on lipids in mild hyperlipidemia. One hundred and fifteen patients were included followed the recruitment criteria, and were randomly allocated to receive Ce-RS3 or placebo (native starch from Canna edulis) for 12 weeks (20 g/day). In addition to serum lipids, complete blood counts, serum inflammatory factors, antioxidant indexes, and dietary survey, 16 S rRNA sequencing technique was utilized to analyze the gut microbiota alterations. Targeted quantitative metabolomics (TQM) was used to detect metabolite changes. Compared with the placebo, Ce- RS3 significantly decreased levels of total cholesterol, lowdensity lipoprotein cholesterol, and non-high-density lipoprotein cholesterol, and increased the glutathione peroxidase. Based on the 16 S rRNA sequencing, TQM, the correlation analysis, as well as the Kyoto Encyclopedia of Genes (KEGG) and Genomes and Human Metabolome Database (HMDB) analysis, we found that Ce-RS3 could increase the abundances of genera Faecalibacterium and Agathobacter, while reduce the abundances of genera norank_f_Ruminococcaceae and Christensenellaceae_R-7_ group to regulate phenylalanine metabolism, which could reduce the fatty acid biosynthesis and fatty acid elongation in the mitochondria to lower blood lipids. Conclusively, we firstly confirmed the feasibility of Ce-RS3 for clinical application, which presents a novel, effective therapy for the mild hyperlipidemia. (Chictr. org. cn. Clinical study on anti-mild hyperlipidemia of Canna edulis RS3 resistant starch, ID Number: ChiCTR2200062871).

Differences and Mechanism of Waxy Corn Starch and Normal Corn Starch in the Preparation of Recrystallized Resistant Starch (RS3)

This study prepared resistant starch (RS) from waxy corn starch and normal corn starch and analyzed the effects of its molecular and microstructural characteristics on RS content. The RS content of waxy corn resistant starch (RS-WCS) was highest at 57.8%, whereas that of normal corn resistant starch (RS-NCS) was 41.46%. The short-chain amylose contents of RS-WCS and RS-NCS were 47.08% and 37.24%, respectively, proportional to their RS content. Additionally, RS content positively correlated with crystallinity, short-range order degree, and degree of polymerization (DP), exceeding 25. Electron microscopic images, before and after enzymolysis, revealed that RS-WCS was hydrolyzed from the surface to the center by pancreatic α-amylase, while RS-NCS underwent simultaneous hydrolysis at the surface and center. These results indicate that the higher RS content in RS-WCS, compared to RS-NCS, is attributable to the synergistic effects of molecular structure and microstructure.

Production of Resistant Starch by Roasting Retrograded Starch with Glucose

Starch is a natural plant raw material applicable in many areas of industry. In practice, it is most often used in a modified form, i.e., after various treatments aimed at modifying its properties. Modifications of native starch enable producing resistant starch, which, as a prebiotic with confirmed health-promoting properties, has been increasingly used as a food additive. The present study aimed to determine the effect of roasting retrograded starch with the addition of anhydrous glucose at different temperatures (110, 130 or 150 °C) and different times (5 or 24 h) on the modified starch's properties. The results of high-performance size-exclusion chromatography coupled with refractive index detector (HPSEC/RI) analysis and the changes observed in the solubility of starch roasted with glucose in DMSO, as well as in its other properties, confirm the changes in its molecular structure, including thermolytic degradation and the ongoing polymerization of starch with added glucose.

Effect of lecithin on the complexation between different botanically sourced starches and lauric acid

This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids.

Functionalization Methods of Starch and Its Derivatives: From Old Limitations to New Possibilities

It has long been known that starch as a raw material is of strategic importance for meeting primarily the nutritional needs of people around the world. Year by year, the demand not only for traditional but also for functional food based on starch and its derivatives is growing. Problems with the availability of petrochemical raw materials, as well as environmental problems with the recycling of post-production waste, make non-food industries also increasingly interested in this biopolymer. Its supporters will point out countless advantages such as wide availability, renewability, and biodegradability. Opponents, in turn, will argue that they will not balance the problems with its processing and storage and poor functional properties. Hence, the race to find new methods to improve starch properties towards multifunctionality is still ongoing. For these reasons, in the presented review, referring to the structure and physicochemical properties of starch, attempts were made to highlight not only the current limitations in its processing but also new possibilities. Attention was paid to progress in the non-selective and selective functionalization of starch to obtain materials with the greatest application potential in the food (resistant starch, dextrins, and maltodextrins) and/or in the non-food industries (hydrophobic and oxidized starch).

Lecithin enhances the complexation between pea starch and fatty acids in aqueous system, and affects the starch's structure and enzymatic hydrolysis

This paper investigates a newly found effect of lecithin on the complexation between starch and saturated fatty acids. Rapid visco analysis showed that adding lecithin to the pea starch-fatty acid mixtures resulted in a viscosity peak during the setback stage of the pasting curve. Subsequent differential scanning calorimetry showed that pea starch-fatty acid-lecithin systems formed more V-type structures than pea starch-fatty acid complexes. X-ray diffraction and Fourier transform infrared spectroscopy indicated the addition of lecithin developed the long-range and short-range order of the V-complexes. Small-angle X-ray scattering showed the ternary system had a more compact stack in nano-scale and smaller D bragg than the binary complex. In vitro enzymatic hydrolysis revealed higher hydrolysis resistance of ternary systems compared to binary complexes. The results of this research provide a mechanism for modifying starch-lipid complexes and contribute to scientific understanding of food ingredient interactions.

Recent preparation, modification and application progress of starch nanocrystals: A review

Due to the advantages of wide sources, high biocompatibility and favorable biodegradability, starch nanocrystals (SNCs) have gradually attracted attention and have bright development prospects in food, agriculture, materials, medicine and other fields. However, the traditional preparation method of SNCs is time-consuming and inefficient, and the physicochemical properties cannot fully meet the needs of multiple applications. Fortunately, the unique onion-like structure of starch granules and the large number of hydroxyl groups present on the surface entitle SNCs to efficient preparation and modification. This paper comprehensively reviewed the improvement methods of SNCs preparation process in recent years, and the advantages and disadvantages of the two improvement strategies were compared. Besides, the importance of introducing different pretreatment methods into the SNCs preparation process was emphasized. It also focused on the different modification treatment and application progress of SNCs, especially in the starch-based surface coating of fruits and vegetables. The information will contribute to further improve the preparation efficiency and physicochemical properties of SNCs, and ultimately expand the application field.

A novel method for obtaining high amylose starch fractions from debranched starch

High amylose starch shows wide applications in food and non-food-based industries. Traditional complex-precipitation approach for the amylose fractionation required a large volume of organic reagents and was possibly risky for food safety. The object of this work was to establish a novel method to obtain starch fractions rich in amylose from debranch starch through repeated short-term retrogradation and centrifugation. Four starch fractions were obtained with the amylose content of 52.08% (C1), 62.28% (C2), 63.58% (C3), and 64.74% (C4). The thermograms of samples displayed that multiple endothermic peaks were detected in C1 and C2 and only one endothermic peak with melting temperature over 120 °C were observed in C3 and C4, indicating their differences in retrogradation behavior. The chain length distribution results of sample exhibited that C1 and C2 contained more short chains (DP ≤ 24), while C3 and C4 consisted of mainly long chains (DP ≥ 25). Accordingly, the differences in fine structures could provide more choices for these fractionated high amylose starch to utilize in practical applications.

Effect of heat-moisture treatment (HMT) on thermal stability of starch gel and the surface adhesiveness of vermicelli

The molecular structure has an important influence on the surface adhesion of starch gel. In the present study, the surface adhesiveness of vermicelli after cooking was reduced by heat-moisture treatment (HMT), and the mechanism underlying the increased thermal stability was explored by measuring the changes in short-range order, crystallinity, the thickness of the crystalline layer, and the length of the double helix in the dry starch gel. The surface adhesiveness decreased by 72.12 % when the moisture content was 26 %. HMT increased the crystallinity, and the thickness of the crystalline layer of the starch gel increased from 14.61 nm to 14.83-17.30 nm at 20-26 % moisture content. The molecular rearrangement and destruction of unstable short double helixes increased the proportion of long double helixes, resulting in an increased crystallinity and layer thickness.

Optimization of the Sustainable Production of Resistant Starch in Rice Bran and Evaluation of Its Physicochemical and Technological Properties

In this study, the optimization of ultrasound (US) (850 kHz, 120 W) processing parameters (temperature, time, and power) for the enhanced production of resistant starch (RS) in rice bran (RB) matrixes was performed. The effect of US cavitation at different temperatures on the morphology, physicochemical properties, and mechanical performance of RS was evaluated. Ultrasonication at 40−70 °C temperatures affected the chemical structure, reduced the crystallinity of RS from 23.85% to between 18.37 and 4.43%, and increased the mechanical and thermal stability of RS pastes, indicating a higher tendency to retrograde. US treatment significantly (p < 0.05) improved the oil (OAC) and water (WAC) absorption capacities, swelling power (SP), solubility (WS), and reduced the least-gelation concentration (LGC). The mathematical evaluation of the data indicated a significant effect (p < 0.05) of the US parameters on the production of RS. The largest increment of RS (13.46 g/100 g dw) was achieved with US cavitation at 1.8 W/cm2 power, 40.2 °C temperature, and 18 min of processing time. The developed method and technology bring low-temperature US processing of rice milling waste to create a new sustainable food system based on modified rice bran biopolymers.

Comparison of structural and functional properties of maize starch produced with commercial or endogenous enzymes

To explore an effective and economic method to prepare higher contents of resistant starch (RS), different enzyme treatments including single pullulanase (PUL), commercial α-amylase (AA) or/and β-amylase (BA) with PUL, and malt endogenous amylase (MA) with PUL were used and the structural, physicochemical properties and digestibility of all modified starches (MS) were compared. All the enzyme-treated starches displayed a mixture of B and V-type diffraction patterns. The MA/PUL-MS showed higher V-type diffraction peak intensity as compared to other modified starches. Compared to the combination of commercial enzyme treatment, the combination of malt enzyme treatment led to higher apparent amylose contents (45.56%), RS content (53.93%) and thermal stability (302 °C), whereas it possessed lower solubility indices and predicted glycaemic index. The apparent viscosity and shear resistance of MA/PUL-MS were lower than that of AA/PUL-MS, whereas that of MA/PUL-MS was higher than that of BA/PUL-MS and BA/AA/PUL-MS. These findings would provide a theoretical and applicative basis to produce foods with lower GI in industrial production.

Insight into morphological, physicochemical and spectroscopic properties of β-chitin nanocrystalline structures

We systematically investigated the effect of β-chitin (BCH) particle size on the preparation of nanocrystals/nanowhiskers (CWH) by acid hydrolysis. Regardless this variable, CWH aqueous suspension exhibited outstanding stability and the average degree of acetylation remained nearly constant after the acid treatment. In contrast, the morphology, dimensions, crystallinity, and molecular weight of CHW were significantly affect by the particle size. Although needle-like crystals have predominated, BCH particles sizes significantly affected the dimensions and asymmetry of CWH, as confirmed by the rheological and NMR relaxation (T₂) behaviors. According to different SSNMR approaches, the acid hydrolysis meaningless affected the local chain conformation, while the spatial freedom of BCH intersheets, rated upon the mobility of methyl segments, was taken as evidence of higher permeability of acid into small particle sizes. Thus, this study demonstrated the importance of standardizing the surface/bulk proportions of β-chitin aiming to predict and control the CWH morphology and related properties.

Structural factors governing starch digestion and glycemic responses and how they can be modified by enzymatic approaches: A review and a guide

Starch is the most abundant glycemic carbohydrate in the human diet. Consumption of starch-rich food products that elicit high glycemic responses has been linked to the occurrence of noncommunicable diseases such as cardiovascular disease and diabetes mellitus type II. Understanding the structural features that govern starch digestibility is a prerequisite for developing strategies to mitigate any negative health implications it may have. Here, we review the aspects of the fine molecular structure that in native, gelatinized, and gelled/retrograded starch directly impact its digestibility and thus human health. We next provide an informed guidance for lowering its digestibility by using specific enzymes tailoring its molecular and three-dimensional supramolecular structure. We finally discuss in vivo studies of the glycemic responses to enzymatically modified starches and relevant food applications. Overall, structure-digestibility relationships provide opportunities for targeted modification of starch during food production and improving the nutritional profile of starchy foods.