New starch preparations resistant to enzymatic digestion

Hypoglycemic effect of orally administered resistant dextrins prepared with different acids on type 2 diabetes mice induced by high-fat diet and streptozotocin

A comparative study was performed to investigate the physicochemical properties and protective effects of hydrochloric acid-resistant dextrin (H-RD), citric acid-resistant dextrin (C-RD) and tartaric acid-resistant dextrin (T-RD) on the metabolic disorders and intestinal microbiota for type 2 diabetes mellitus (T2DM) mice. T-RD had the minimum molecular weight, with the highest short chain (DP 6-12) proportion and resistant starch content. After 4-week intervention with the three resistant dextrins, the body weight and fasting blood glucose of T2DM mice were improved significantly, accompanied by the reduction of serum indexes (TG, TC, LDL-C, ALT, AST, CRE, BUN, FINS, and GSP), but the serum HDL-C and liver glycogen levels increased. Among the three RDs intervention groups, T-RD showed the most significant improvement, followed by C-RD and finally H-RD. The 16 s rDNA results indicated that oral administration of resistant dextrins favored the proliferation of specific gut microbiota, including Faecalibaculum, Parabacteroides and Dubosiella, and reduced the ratio of Firmicutes/Bacteroidota, which is beneficial for reducing insulin resistance. Herein, the findings supported that the resistant dextrins exhibited a remission effect on T2DM, providing a basis for the development of functional food adjuvants for T2DM treatment.

Effects of Soluble Dextrin Fiber from Potato Starch on Body Weight and Associated Gut Dysbiosis Are Evident in Western Diet-Fed Mice but Not in Overweight/Obese Children

BACKGROUND

The study investigated the impact of starch degradation products (SDexF) as prebiotics on obesity management in mice and overweight/obese children.

METHODS

A total of 48 mice on a normal diet (ND) and 48 on a Western diet (WD) were divided into subgroups with or without 5% SDexF supplementation for 28 weeks. In a human study, 100 overweight/obese children were randomly assigned to prebiotic and control groups, consuming fruit and vegetable mousse with or without 10 g of SDexF for 24 weeks. Stool samples were analyzed for microbiota using 16S rRNA gene sequencing, and short-chain fatty acids (SCFA) and amino acids (AA) were assessed.

RESULTS

Results showed SDexF slowed weight gain in female mice on both diets but only temporarily in males. It altered bacterial diversity and specific taxa abundances in mouse feces. In humans, SDexF did not influence weight loss or gut microbiota composition, showing minimal changes in individual taxa. The anti-obesity effect observed in mice with WD-induced obesity was not replicated in children undergoing a weight-loss program.

CONCLUSIONS

SDexF exhibited sex-specific effects in mice but did not impact weight loss or microbiota composition in overweight/obese children.

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).

Characterization, health benefits, and food applications of enzymatic digestion- resistant dextrin: A review

Resistant dextrin or resistant maltodextrin (RD), a short-chain glucose polymer that is highly resistant to hydrolysis by human digestive enzymes, has shown broad developmental prospects in the food industry and has gained substantial attention owing to its lack of undesirable effects on the sensory features of food or the digestive system. However, comprehensive fundamental and application information on RD and how RD improves anti-diabetes and obesity have not yet been received. Therefore, the characterization, health benefits and application of RD in various fields are summarized and discussed in the current study. Typically, RD is prepared by the acid thermal method and possesses excellent physicochemical properties, including low viscosity, high solubility, storage stability, and low retro-gradation, which are correlated with its low molecular weight (Mw) and non-digestible glycosidic linkages. In contrast, RD prepared by the simultaneous debranching and crystallization method has low solubility and high crystallinity. The ingestion of RD can positively affect metabolic diseases (diabetes and obesity) in animals and humans by producing short-chain fatty acids (SCFAs), and facilitating the inflammatory response. Moreover, RD has been widely used in the beverage, dairy products, and dessert industries due to its nutritional value and textural properties without unacceptable quality loss. More studies are required to further explore RD application potential in the food industry and its role in the management of different chronic metabolic disorders.

A Comparative Study of Resistant Dextrins and Resistant Maltodextrins from Different Tuber Crop Starches

The anti-digestibility of resistant dextrin (RD) and resistant maltodextrin (RMD) is usually significantly affected by processing techniques, reaction conditions, and starch sources. The objective of this investigation is to elucidate the similarities and differences in the anti-digestive properties of RD and RMD prepared from three different tuber crop starches, namely, potato, cassava, and sweet potato, and to reveal the associated mechanisms. The results show that all RMDs have a microstructure characterized by irregular fragmentation and porous surfaces, no longer maintaining the original crystalline structure of starches. Conversely, RDs preserve the structural morphology of starches, featuring rough surfaces and similar crystalline structures. RDs exhibite hydrolysis rates of approximately 40%, whereas RMDs displaye rates lower than 8%. This disparity can be attributed to the reduction of α-1,4 and α-1,6 bonds and the development of a highly branched spatial structure in RMDs. The indigestible components of the three types of RDs range from 34% to 37%, whereas RMDs vary from 80% to 85%, with potato resistant maltodextrin displaying the highest content (84.96%, p < 0.05). In conclusion, there are significant differences in the processing performances between different tuber crop starches. For the preparation of RMDs, potato starch seems to be superior to sweet potato and cassava starches. These attributes lay the foundation for considering RDs and RMDs as suitable components for liquid beverages, solid dietary fiber supplements, and low glycemic index (low-GI) products.

Structural characterization of slow digestion dextrin synthesized by a combination of α-glucosidase and cyclodextrin glucosyltransferase and its prebiotic potential on the gut microbiota in vitro

Starch-based dietary fibers are at the forefront of functional ingredient research. In this study, a novel water-soluble slow digestion dextrin (SDD) was synthesized by synergy of α-glucosidase and cyclodextrin glucosyltransferase and characterized. Results showed that SDD exhibited high solubility, low viscosity, and resistance to digestive enzymes, and also showed an increased dietary fiber content of 45.7% compared with that of α-glucosidase catalysis alone. Furthermore, SDD was used as the sole carbon source to ferment selected intestinal strains and human fecal microflora in vitro to investigate its prebiotic effects. It was found that SDD could markedly enriched the abundance of Bifidobacterium, Veillonella, Dialister, and Blautia in human gut microflora and yielded higher total organic acid. The combination of α-glucosidase and cyclodextrin glucosyltransferase in this study showed valuable potential for the preparation of a novel slow digestion dextrin with good physicochemical properties and improved prebiotic effects.

Interactions between structure and function of resistant glucans for alleviating type 2 diabetes mellitus (T2DM) and its complications in mice

Resistant glucan, a functional dietary fiber, has been shown to alleviate type 2 diabetes mellitus (T2DM) and its complications in clinical studies. However, the interactions between the special structure of resistant glucan and the metabolism-related pathways in T2DM have not yet been systematically studied. This study identified the structural differences between resistant glucans prepared by new and old methods. Oral gavage with two resistant glucans in T2DM mice, led to significant improvements in glucose and lipid metabolism as measured by related indicators (including gut microbiota, fecal metabolites, and physiological and biochemical indexes). According to these results, in addition to van der Waals forces, micelle formation, and hydrogen bonding, the branching structures of resistant glucans produced more hydroxyl, carbonyl, and keto groups that linked cholesterols, cholesterol esters, and low-density lipoprotein intermediates. Moreover, after lipid clearing, the metabolic environment was more conducive to the proliferation of specific gut microbiota (including Phascolarctobacterium, Prevotella, Butyricicoccus, Weissella, and Anaerostipes) with decreasing abundance ratios of Firmicutes and Bacteroides. This facilitated the synthesis of high-density lipoprotein, conversion of cholesterol into coprostanol, and production of short-chain fatty acids and bile acids. Our findings provide a foundation for comprehensive investigation of the structure of resistant glucan in the promotion and prevention of T2DM.

Preparation and characterization of type 3 resistant starch by ultrasound-assisted autoclave gelatinization and its effect on steamed bread quality

In this study, we aimed to establish an innovative and efficient preparation method of potato resistant starch (PRS). To achieve this, we prepared type 3 resistant starch (RS3) from native potato starch (PS) using an ultrasonic method combined with autoclave gelatinization and optimized by the response surface method to study the structure and properties of potato RS3 (PRS3) and its effect on the quality of steamed bread. Under optimal treatment conditions, the PRS3 content increased from 7.5% to 15.9%. Compared with PS, the B-type crystal structure of PRS3 was destroyed, and the content of hydroxyl groups was increased, but no new chemical groups were introduced. PRS3 had a rougher surface and a lower crystallinity, gelatinization temperature, viscosity, setback value, and breakdown value. The low content (5%) of PRS3 had a stable viscosity and was easily degraded by bacteria, which can improve the quality of steamed bread to a certain extent. When the PRS3 content was over 10%, it competed with the gluten protein to absorb water, which reduced the contents of β-turn and α-helix in the dough, increased the contents of β-fold, and weakened the structure of the gluten network. It also decreased the specific volume and elasticity of the steamed bread and increased the spreading rate, hardness, and chewiness. Steamed bread prepared with a flour mixture containing 5% PRS3 was similar to the presidential acceptance of control flour. In this study, a new sustainable and efficient PRS3 preparation method was established, which has certain guiding significance for the processing of Functional steamed bread with high-resistant starch.

Molecular structure and properties of cassava-based resistant maltodextrins

In-depth molecular structure and properties of cassava-derived resistant maltodextrins (RMDs) were determined. Cassava starch was dextrinized with 0.04% or 0.06% HCl at 120 °C for 60-180 min to obtain resistant dextrins (RDs), which were further hydrolyzed by α-amylase to produce RMDs. Prolonging dextrinization duration decreased proportion of α-1,4 linkages and α-/β-reducing ends but increased fraction of indigestible α-/β-1,6, β-1,4, β-1,2 linkages, degree of branching (DB), degree of polymerization, relative molecular weight, and total dietary fiber (TDF) content of the RMDs. Moreover, RMDs had greater proportion of β-glycosidic linkages, α-/β-reducing end, DB, TDF, and low molecular weight dietary fiber (LMWDF) content than their RD counterparts. Potential prebiotic activity score was higher in RMDs with abundant LMWDF fraction but low DB. Slight difference in the glass transition temperature of maximally freeze-concentrated unfrozen phase (T_g') and unfrozen water content was found among RMDs. However, RMDs had lower T_g' than their RD counterparts.

Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

Assessment of physicochemical and thermal properties of soluble dextrin fiber from potato starch for use in fruit mousses

BACKGROUND

Fruit mousses are products with a relatively low amount of dietary fiber in a single portion, but with additional portions of soluble fiber they may be good alternative to fiber-rich snacks as take-away food. In the present study, the properties of new soluble dextrin fiber (SDexF) from potato starch were assessed to establish whether it could be used to enrich fruit mousses. The properties of SDexF that can affect processing and storage stability of enriched mousses were studied and compared with those of native potato starch and semiproducts (resulting from various drying temperatures). The effect of the addition of SDexF on the pasting properties of mousse was also analyzed.

RESULTS

The application of food-grade hydrochloric and citric acids as catalysts in the dextrinization of food-grade potato starch allowed to SDexF to be obtained. Despite the differences in characteristics of the semiproducts, the final SDexF preparations were very similar in the meaning of solubility, dextrose equivalent (DE), retrogradation, and pasting properties. SDexF preparations were characterized by a significantly lower retrogradation tendency, peak viscosity, final viscosity, and gelatinization enthalpy in comparison with both native starch and semiproducts. Soluble dextrin fiber was successfully added to banana-apple mousse. The addition of SDexF to mousse did not cause any undesirable changes to the viscosity of the product, and surprisingly even resulted in mousse with lower viscosity. Turbidity and RVA studies revealed that SDexF was stable and retrogradation processes can be negligible during storage.

CONCLUSION

The SDexF obtained from potato starch can be a novel functional substance to increase the dietary fiber content of fruit or fruit and vegetable mousses. © 2020 Society of Chemical Industry.

Effect of water-soluble dietary fiber resistant dextrin on flour and bread qualities

A new water-soluble resistant dextrin (WSRD), fabricated by thermal-acid treatment following amylase hydrolysis from corn starch, was expected to strengthen the dietary fibers intake of flour products. This study was to investigate the effects of WSRD on flour processing quality, and further dissect its improvement mechanisms by farinographic and rheological analysis, SDS-PAGE, Fourier transform infrared spectroscopy, texture analyzer, etc. Results showed that WSRD greatly improved the viscoelasticity and strength of dough, which was predominantly contributed by its formation of gel-like networks. Meanwhile, the WSRD-induced increase of gluten aggregates and β-sheet conformation provided the structural basis for enhancing dough quality. Notably, WSRD greatly promoted the sensory appearance and crumb quality of baked breads. Moreover, the WSRD-treated breads resisted the hydrolysis of digestive fluid and enzymes. Therefore, WSRD can strengthen the processing qualities and nutritional values of flour products, which will broaden the application of the novel dietary fiber in flour industry.

In-depth study of the changes in properties and molecular structure of cassava starch during resistant dextrin preparation

Physical, chemical and thermal properties, as well as molecular structure of cassava-based resistant dextrins prepared under different dextrinization conditions (0.04-0.10% HCl, 100-120 °C, 60-180 min) were determined. Increasing acid concentration, temperature and heating time resulted in the products with darker color, higher solubility, reducing sugar content, total dietary fiber and proportion of high molecular weight fiber fraction. An endothermic peak at 45-70 °C, having enthalpy of 1.66-2.14 J/g, was found from the samples processed under mild conditions (0.04-0.08% HCl, 100 °C, 60 min). However, harsher dextrinization conditions eliminated this endotherm. Dextrinization led to 1000-fold decrease in weight-average molecular weight (M_w) of the products, comparing to the native starch. Stronger processing conditions yielded the resistant dextrins with slightly higher M_w but composing of shorter branched chains. During dextrinization, hydrolysis was a predominant step, while transglucosidation and repolymerization played key roles in modifying molecular structure and properties, especially dietary fiber content, of resistant dextrins.

Some Nutritional Characteristics of Enzymatically Resistant Maltodextrin from Cassava (Manihot esculenta Crantz) Starch

Cassava (Manihot esculenta Crantz) native starch was treated with pyroconversion and enzymatic hydrolysis to produce a pyrodextrin and an enzyme-resistant maltodextrin. Some nutritional characteristics were quantified for both compounds. Pyroconversion was done using a 160:1 (p/v) starch:HCl ratio, 90 °C temperature and 3 h reaction time. The resulting pyrodextrin contained 46.21% indigestible starch and 78.86% dietary fiber. Thermostable α-amylase (0.01%) was used to hydrolyze the pyrodextrin at 95 °C for 5 min. The resulting resistant maltodextrin contained 24.45% dextrose equivalents, 56.06% indigestible starch and 86.62% dietary fiber. Compared to the cassava native starch, the pyrodextrin exhibited 56% solubility at room temperature and the resistant maltodextrin 100%. The glycemic index value for the resistant maltodextrin was 59% in healthy persons. Its high indigestible starch and dietary fiber contents, as well as its complete solubility, make the resistant maltodextrin a promising ingredient for raising dietary fiber content in a wide range of foods, especially in drinks, dairy products, creams and soups.

Enzyme-resistant dextrins from potato starch for potential application in the beverage industry

The objective of this study was to produce soluble enzyme-resistant dextrins by microwave heating of potato starch acidified with small amounts of hydrochloric and citric acids and to characterize their properties. Twenty five samples were initially made and their solubility was determined. Three samples with the highest water solubility were selected for physico-chemical (dextrose equivalent, molecular weight distribution, pasting characteristics, retrogradation tendency), total dietary fiber (TDF) analysis, and stability tests. TDF content averaged 25%. Enzyme-resistant dextrins practically did not paste, even at 20% samples concentration, and were characterized by low retrogradation tendency. The stability of the samples, expressed as a percentage increase of initial and final reducing sugar content, at low pH and during heating at low pH averaged 10% and 15% of the initial value, respectively. The results indicate that microwave heating could be an effective and efficient method of producing highly-soluble, low-viscous, and enzyme-resistant potato starch dextrins.

Prebiotics and age, but not probiotics affect the transformation of 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ) by fecal microbiota - An in vitro study

Heterocyclic aromatic amines (HAAs) are carcinogens which are formed in meat cooked using high-temperature methods. The human gastrointestinal (GI) microbiota plays a crucial role in maintaining health in humans of different ages, and especially in the elderly. However, the GI microbiota, whose metabolism and composition changes with age, may also be responsible for the activation of mutagenic substances reaching the colon with diet. Probiotics and prebiotics are promising in terms of reducing the destructive effects of HAAs. The aim of the study was to determine if fecal microbiota derived from the feces of 27 volunteers: infants (up to 18 months), adults (aged 23-39 years), the sub-elderly (aged 64-65 years), and the elderly (aged 76-87 years), and the presence of probiotics or prebiotics, affected the transformation of IQ (2-amino-3-methylimidazo[4,5-f]quinoline) to 7-OH-IQ (2-amino-3,6-dihydro-3-methyl-7H-imidazo[4,5-f]quinoline-7-one). The compounds were identified using LC-MS(n), NMR, and FTIR. Their genotoxicity was compared in the comet assay. Individual strains capable of IQ transformation were also identified. 7-OH-IQ was detected in six persons (two children and four elderly individuals). The degree of IQ conversion ranged from 26% (4-month-old girl) to 94% (81-year-old woman) of the initial quantity. Four Enterococcus isolates: two Enterococcus faecium and two Enterococcus faecalis strains, as well as one Clostridium difficile strain (LOCK 1030, from the culture collection) converted IQ to 7-OH-IQ. The genotoxicity of samples containing 7-OH-IQ was even three times higher (P < 0.05) than those with IQ and was correlated with the degree of IQ conversion and 7-OH-IQ concentration.