Slow Digestion Research Articles

α-Gal present on both glycolipids and glycoproteins contributes to immune response in meat-allergic patients

The α-Gal syndrome is associated with the presence of IgE directed to the carbohydrate galactose-α-1,3-galactose (α-Gal) and is characterized by a delayed allergic reaction occurring 2 to 6 hours after ingestion of mammalian meat. On the basis of their slow digestion and processing kinetics, α-Gal-carrying glycolipids have been proposed as the main trigger of the delayed reaction. We analyzed and compared the invitro allergenicity of α-Gal-carrying glycoproteins and glycolipids from natural food sources. Proteins and lipids were extracted from pork kidney (PK), beef, and chicken. Glycolipids were purified from rabbit erythrocytes. The presence of α-Gal and IgE binding of α-Gal-allergic patient sera (n= 39) was assessed by thin-layer chromatography as well as by direct and inhibition enzyme-linked immunosorbent assay. The invitro allergenicity of glycoproteins and glycolipids from different meat extracts was determined by basophil activation test. Glycoprotein stability was evaluated by simulated gastric and intestinal digestion assays. α-Gal was detected on glycolipids of PK and beef. Patient IgE antibodies recognized α-Gal bound to glycoproteins and glycolipids, although binding to glycoproteins was more potent. Rabbit glycolipids were able to strongly activate patient basophils, whereas lipid extracts from PK and beef were also found to trigger basophil activation, but at a lower capacity compared to the respective protein extracts. Simulated gastric digestion assays of PK showed a high stability of α-Gal-carrying proteins in PK. Both α-Gal-carrying glycoproteins and glycolipids are able to strongly activate patient basophils. In PK and beef, α-Gal epitopes seem to be less abundant on glycolipids than on glycoproteins, suggesting a major role of glycoproteins in delayed anaphylaxis upon consumption of these food sources.

Effects of dietary fibre and soybean oil on the digestion of extruded and roller‐dried maize starch

SummaryThe effects of soybean dietary fibre (SDF), microcrystalline cellulose (MCC), konjac glucomannan (KGM), soluble soybean polysaccharide (SSPS) and soybean oil (SO) on in vitro digestion of extruded maize starch (EMS) and roller‐dried maize starch (RDMS) samples were investigated. Adding MCC, particularly in high doses, induced slow digestion in EMS and RDMS samples, but not after adding SDF. KGM and SSPS addition reduced starch hydrolysis of RDMS but did not have a significant effect on EMS, whereas SO addition reduced starch hydrolysis of EMS but had no effect on RDMS. Principal component analysis demonstrated that the addition of MCC, SO, KGM (0.51%), and SSPS (0.51%) to EMS and KGM (0.51%) to RDMS were the best choices to slow the hydrolysis of starch, compared with that of other additives. These findings provide useful information on the selection of exogenous additives in the development of low glycaemic index products for maize starch.

Therapeutic potential of Seabuckthorn (Hippophae rhamnoides L.) in medical sciences

Seabuckthorn has multiple-use properties. This review explores the medicinal applications of Hippophae rhamnoides in healing ailments. The plant is being used in different parts of the world for its nutritional and medicinal properties. Sea buckthorn-based preparations have been extensively exploited in folklore treatment of slow digestion, stomach malfunctioning, cardiovascular problems, liver injury, tendon and ligament injuries, skin diseases and ulcers. In recent years, the medicinal and pharmacological activities of Seabuckthorn have been well investigated using limited clinical trials. Homeopathy is a well-respected modality to assist wellness. Traditional and modern medicinal experts have been applied this plant to treat various diseases. Seabuckthorn is an important plant because of its immense medicinal and therapeutic potential. However, several knowledge gaps identified in this paper would give impetus to new academic and R&D activities, especially for the development of Sea buckthorn-based herbal medicine and nutraceuticals. Its full application in dermatology may be attributed to the presence of a variety of flavonoids, vitamins, and unsaturated fatty acids. Great use of the plant in the traditional system for dermatological aspects, demands further comprehensive phytochemical work based on its actual use by the traditional population. Anti-inflammation is the most important applicable ingredient of this miracle berry.

Analysis of the Factors Affecting Static In Vitro Pepsinolysis of Food Proteins.

In this meta-analysis, we collected 58 publications spanning the last seven decades that reported static in vitro protein gastric digestion results. A number of descriptors of the pepsinolysis process were extracted, including protein type; pepsin activity and concentration; protein concentration; pH; additives; protein form (e.g., ‘native’, ‘emulsion’, ‘gel’, etc.); molecular weight of the protein; treatment; temperature; and half-times (HT) of protein digestion. After careful analysis and the application of statistical techniques and regression models, several general conclusions could be extracted from the data. The protein form to digest the fastest was ‘emulsion’. The rate of pepsinolysis in the emulsion was largely independent of the protein type, whereas the gastric digestion of the native protein in the solution was strongly dependent on the protein type. The pepsinolysis was shown to be strongly dependent on the structural components of the proteins digested—specifically, β-sheet-inhibited and amino acid, leucine, methionine, and proline-promoted digestion. Interestingly, we found that additives included in the digestion mix to alter protein hydrolysis had, in general, a negligible effect in comparison to the clear importance of the protein form or additional treatment. Overall, the findings allowed for the targeted creation of foods for fast or slow protein digestion, depending on the nutritional needs.

Identifying targets for increased biogas production through chemical and organic matter characterization of digestate from full-scale biogas plants: what remains and why?

BackgroundThis study examines the destiny of macromolecules in different full-scale biogas processes. From previous studies it is clear that the residual organic matter in outgoing digestates can have significant biogas potential, but the factors dictating the size and composition of this residual fraction and how they correlate with the residual methane potential (RMP) are not fully understood. The aim of this study was to generate additional knowledge of the composition of residual digestate fractions and to understand how they correlate with various operational and chemical parameters. The organic composition of both the substrates and digestates from nine biogas plants operating on food waste, sewage sludge, or agricultural waste was characterized and the residual organic fractions were linked to substrate type, trace metal content, ammonia concentration, operational parameters, RMP, and enzyme activity.ResultsCarbohydrates represented the largest fraction of the total VS (32–68%) in most substrates. However, in the digestates protein was instead the most abundant residual macromolecule in almost all plants (3–21 g/kg). The degradation efficiency of proteins generally lower (28–79%) compared to carbohydrates (67–94%) and fats (86–91%). High residual protein content was coupled to recalcitrant protein fractions and microbial biomass, either from the substrate or formed in the degradation process. Co-digesting sewage sludge with fat increased the protein degradation efficiency with 18%, possibly through a priming mechanism where addition of easily degradable substrates also triggers the degradation of more complex fractions. In this study, high residual methane production (> 140 L CH4/kg VS) was firstly coupled to operation at unstable process conditions caused mainly by ammonia inhibition (0.74 mg NH3-N/kg) and/or trace element deficiency and, secondly, to short hydraulic retention time (HRT) (55 days) relative to the slow digestion of agricultural waste and manure.ConclusionsOperation at unstable conditions was one reason for the high residual macromolecule content and high RMP. The outgoing protein content was relatively high in all digesters and improving the degradation of proteins represents one important way to increase the VS reduction and methane production in biogas plants. Post-treatment or post-digestion of digestates, targeting microbial biomass or recalcitrant protein fractions, is a potential way to achieve increased protein degradation.

Influence of gardenia yellow on in vitro slow starch digestion and its action mechanism.

This study aimed to explore the influence of gardenia yellow on in vitro wheat starch digestion. The influence of gardenia yellow on the digestion properties of starch was determined through in vitro digestion, and its action mechanism on slow starch digestion was revealed by laser scanning confocal microscopy, enzymatic inhibition dynamics, and other means of characterization. Results showed that gardenia yellow could inhibit starch digestion, significantly increase the resistant starch and slowly digestible starch contents in starch (P < 0.05), and trigger the decrease in glycemic and hydrolysis indices. Furthermore, gardenia yellow could spontaneously bind to the catalytic sites of α-amylase and α-glucosidase, affect their secondary structures through vdW force and hydrophobic interaction, and reduce their catalytic abilities to inhibit the digestion process of wheat starch. Therefore, the interactions of gardenia yellow with starch and digestive enzymes jointly promote the slow digestion of starch.

Characterization and in vitro digestibility of potato starch encapsulated in calcium alginate beads

In this study, potato starch granules were encapsulated in calcium alginate beads (PS@CAB) with the aim of slowing starch digestion. The microstructure, gelatinization property, and in vitro digestibility of PS@CAB were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and in vitro simulated digestion experiment. The size of the fresh beads was about 2 mm and reduced to about 1 mm after drying. The encapsulation efficiency of starch was over 98%. Compared to the potato starch, the swelling power of PS20@CA2B decreased from 31.1 ± 0.4 g/g to 6.6 ± 0.4 g/g at 95 °C. DSC results showed that the peak gelatinization temperatures of potato starch encapsulated in the beads increased significantly (p < 0.05) with a maximum value a 69.87 °C, compared with potato starch (62.76 °C). The maximum value of enthalpy change was 11.47 J g−1, which was much higher than that of unencapsulated potato starch (7.56 J g−1). SEM images showed that potato starch granules were coated in beads by calcium alginate films. Moreover, slowly digestible starch and resistant starch contents in the beads increased to 27.5% and 18.3%, respectively, which were remarkably higher than those of potato starch without encapsulation (9.2%, 3.4%, respectively). This study proposes a new strategy for the slow digestion of starch by encapsulating starch granules in calcium alginate beads, which benefits people with type 2 diabetes or obesity.

Effect of heat-moisture treatment to raw paddy rice (Oryza sativa L.) on cooked rice properties

Heat moisture treatment is safe and non-chemical use method for modifying physicochemical properties and digestibility of starch. Slow starch digestion in rice product would provide numerous health benefits for the consumers. This study investigated the heat-moisture treatment to the raw paddy rice at 60 and 80 °C for 4 and 24 h, and their effects on the attributes of cooked rice. The firmness, adhesiveness, starch hydrolysis and morphological changes during in vitro digestion were examined. Results showed that heat-moisture treatment to raw paddy rice for 24 h significantly reduced the moisture content and could increase the total starch content of the rice grain. The apparent amylose content ranged from 23.83% to 25.65% at the variation in the values between treated and untreated rice. Enhancement in the firmness and reduction in the starch hydrolysis was found in rice treated by longer heating time of 24 h. Meanwhile, the adhesiveness of cooked rice was decreased when increasing the heating temperature. The morphological observation showed that the treated rice exhibited a honey-comb-like structure during simulated gastric digestion, while the untreated rice displayed a non-uniform structure. Noteworthy, the porous structure observed in all digested rice grains during simulated small intestinal digestion could favor the starch hydrolysis. This study showed that the heat-moisture treatment to the raw paddy rice at certain conditions obviously influenced the attributes of cooked rice, especially on the starch hydrolysis, which would provide a fundamental knowledge to enable development and improvement of slow digestion rice products.

Redistribution of nutritionally important starch fractions beneficial to diabetic population by using oats as a functional ingredient in a wheat-based food product – Jereesh

Oats being important sources of β-glucan were incorporated at 10, 20 and 30% level in a wheat-based traditional Arabian breakfast cereal called Jereesh and evaluated for sensory acceptability. Sensory analysis reflected that the products with 10 and 20% oats incorporation were acceptable in terms of color, appearance, taste, aroma, mouthfeel, after taste and overall quality as indicated by the sensory scores which revealed no substantial differences between control jereesh (CJ) and oats incorporated jereesh (OJ). However, jereesh with 30% oats incorporation was very sticky (viscous) and scored low in sensory evaluation. Thus, nutritionally important starch fractions were measured in jereesh with 20% oats incorporation using a controlled in vitro multi-enzymatic method. Results indicated that, addition of oats at 20% level resulted in a substantial decrease (p&lt;0.05) in total starch (TS), rapidly available glucose (RAG), and resistant starch content (RS), as well as a significant increase (p&lt;0.05) in slowly digestible starch (SDS) compared to the control jereesh. The starch digestibility index remained unchanged. The findings of the study suggest that incorporation of oats helps in value addition of jereesh in terms of slow digestibility with increased soluble dietary fiber content that might lower glycemic index.

Functional sourdough millet bread rich in dietary fibre -an optimization study using fuzzy logic analysis

Sourdough bread has been beneficial due to its slow starch digestibility and low glycaemic responses. In the present work sourdough breads are prepared from millet flours (kodo, barnyard, little and foxtail). Low bulk density of millet flours can make them an excellent ingredient to be incorporated in sourdough bread. Chemical composition and technological properties of millet flours showed a higher dietary fibre in kodo and more protein in foxtail. Fermentation parameters like total acidity, pH and dough raising capacity were studied. The fuzzy logic sensory score of foxtail sourdough bread was found to be the highest (0.9895), therefore further study was carried for bread made of different foxtail concentrations (20%, 30%, 40%, 50%). It was observed that total dietary fibre in sourdough bread (foxtail- 20–50%; refined flour- 65-35%; chickpea flour (10%), tapioca flour (5%); guar gum and salt 1% each; starter culture (20%) and water 53–55%) was found to be in the range of 5.64 ± 0.23 to 9.27 ± 0.19. The glycaemic index of optimized bread was found to be in the range of 40.79–42.35 that falls under the group of Low GI food (GI < 55). The fuzzy logic sensory score of sourdough bread made from 20% foxtail flour containing 1% guar gum was found to have the best sensory score (0.7221).

Structural requirements of flavonoids for the selective inhibition of α-amylase versus α-glucosidase

In the present study, 14 structurally unique flavonoids were screened to systematically investigate structural requirements for selectively inhibiting human α-amylase versus α-glucosidase to obtain a slow but complete starch digestion for health benefit. The selective inhibition property of three flavonoids chosen against the two classes of starch digestive enzymes was confirmed through various analytical techniques - in vitro inhibition assay, fluorescence quenching, kinetic study, and molecular modeling. Considering the chemical structure of flavonoids, the double bond between C2 and C3 and OH groups at A5 and B3 are critical for the inhibition of α-amylase allowing flavonoids to lie parallel on the α-amylase catalytic active site, whereas the OH groups at B3 and C3 are important for α-glucosidase inhibition causing B-ring specific entry into the catalytic active site of α-glucosidase. Our findings provide insights into how to apply flavonoids to effectively control digestion rate for improving physiological responses.

Inhibition Effect of Extract of Psychotria viridiflora Stem on α-Amylase and α-Glucosidase and Its Application in Lowering the Digestibility of Noodles.

A collection of tropical medicinal plants from East Malaysia's rainforests are used by indigenous tribes for their curative properties. Despite their purported healing properties, these forest plant species are largely unexplored and hence remain virtually unknown to the outside world. In this study, antidiabetic properties of Psychotria viridiflora, a plant used to treat diabetes by a local community in Sarawak, Malaysia were investigated. Ethyl acetate (EA) extract of P. viridiflora stem was found to exhibit high starch hydrolase inhibition activity with an IC50 value of 15.4 ± 2.1 μg/ml against porcine α-amylase and an IC50 value of 32.4 ± 3.7 μg/ml against rat intestinal α-glucosidase. A complex mixture of A-type oligomeric proanthocyanidins containing (epi)fisetinidol, (epi)afzelechin, (epi)guibourtinidol, and (epi)catechin were found. These compounds may be responsible for the starch hydrolase inhibition activity. Ethyl acetate (EA) extract of P. viridiflora stem was incorporated into wheat and rice flour to reformulate noodles with slow digestibility and was assessed under in vitro simulated gastrointestinal conditions. A dose-dependent effect on digestibility was observed for both noodles upon incorporation of 1-6% (w/w) of EA extract, with noodles containing 6% (w/w) extract exhibiting the greatest reduction in digestibility. As compared to rice noodles containing 6% extract (31.16% inhibition), wheat noodles with the same extract concentration had a smaller decline in digestibility (27.25% inhibition) after 180 min. Overall, our findings highlight the potential of P. viridiflora in the prevention of postprandial hyperglycaemia.

Slow digestion-oriented dietary strategy to sustain the secretion of GLP-1 for improved glucose homeostasis.

Dysregulated glucose metabolism is associated with many chronic diseases such as obesity and type 2 diabetes mellitus (T2DM), and strategies to restore and maintain glucose homeostasis are essential to health. The incretin hormone of glucagon-like peptide-1 (GLP-1) is known to play a critical role in regulating glucose homeostasis and dietary nutrients are the primary stimuli to the release of intestinal GLP-1. However, the GLP-1 producing enteroendocrine L-cells are mainly distributed in the distal region of the gastrointestinal tract where there are almost no nutrients to stimulate the secretion of GLP-1 under normal situations. Thus, a dietary strategy to sustain the release of GLP-1 was proposed, and the slow digestion property and dipeptidyl peptidase IV (DPP-IV) inhibitory activity of food components, approaches to reduce the rate of food digestion, and mechanisms to sustain the release of GLP-1 were reviewed. A slow digestion-oriented dietary approach through encapsulation of nutrients, incorporation of viscous dietary fibers, and enzyme inhibitors of phytochemicals in a designed whole food matrix will be implemented to efficiently reduce the digestion rate of food nutrients, potentiate their distal deposition and a sustained secretion of GLP-1, which will be beneficial to improved glucose homeostasis and health.

Structural and digestion properties of potato starch modified using an efficient starch branching enzyme AqGBE

Modified potato starch with slower digestion may aid the development of new starch derivatives with improved nutritional values, and strategies to increase nutritional fractions such as resistant starch (RS) are desired. In this study, a correspondence between starch structure and enzymatic resistance was provided based on the efficient branching enzyme AqGBE, and modified starches with different amylose content (Control, 100%; PS1, 90%; PS2, 72%; PS3, 32%; PS4, 18%) were prepared. Through SEM observation, NMR and X-ray diffraction analyses, we identified that an increased proportion of α-1,6-linked branches in potato starch changes its state of granule into large pieces with crystallinity. Molecular weight and chain-length distribution analysis showed a decrease of molecular weight (from 1.1 × 106 to 1.1 × 105 g/mol) without an obvious change of chain-length distribution in PS1, while PS2-4 exhibited an increased proportion of DP 6-12 with a stable molecular weight distribution, indicating a distinct model of structural modification by AqGBE. The enhancement of peak viscosity was related to increased hydrophobic interactions and pieces state of PS1, while the contents of SDS and RS in PS1 increased by 37.7 and 49.4%, respectively. Our result provides an alternative way to increase the RS content of potato starch by branching modification.

Effects of dairy processing on phospholipidome, in-vitro digestion and Caco-2 cellular uptake of bovine milk

Present work investigated the effects of processing (homogenization, sterilization) and cold storage on physicochemical properties, in vitro digestion and Caco-2 cellular uptake of bovine milk. Extreme heat sterilization and low temperature storage have significant impact on particle size and phospholipidome of bovine milk. In addition, cold storage of bovine milks led to formation of β' polymorphs crystals and endothermic peak with Toffset higher than body temperature. Processing and cold storage also increased the initial digestibility but reduced the overall digestibility of bovine milk. This might be related to the decreased particle size of the milk fat globules, changed in the phospholipidome of the MFGM and formation of β' polymorphs crystals in frozen milk. It is interesting to note that PE has relatively faster digestion meanwhile SM has relatively slower digestion. HTST milk which demonstrated lesser changed in terms of phospholipidome demonstrated highest cellular uptakes of most fatty acids.

Expression and characterization of 1,4-α-glucan branching enzyme from Microvirga sp. MC18 and its application in the preparation of slowly digestible starch

Nutraceuticals containing modified starch with increased content of slowly-digestible starch (SDS) may reduce the prevalence of obesity, diabetes and cardiovascular diseases due to its slow digestion rate. Enzymatic methods for the preparation of modified starch have attracted increasing attention because of their low environmental impact, safety and specificity. In this study, the efficient glucan branching enzyme McGBE from Microvirga sp. MC18 was identified, and its relevant properties as well as its potential for industrial starch modification were evaluated. The purified McGBE exhibited the highest specificity for potato starch, with a maximal specific activity of 791.21 U/mg. A time-dependent increase in the content of α-1,6 linkages from 3.0 to 6.0% was observed in McGBE-modified potato starch. The proportion of shorter chains (degree of polymerization, DP < 13) increased from 29.2 to 63.29% after McGBE treatment, accompanied by a reduction of the medium length chains (DP 13–24) from 52.30 to 35.99% and longer chains (DP > 25) from 18.51 to 0.72%. The reduction of the storage modulus (G’) and retrogradation enthalpy (ΔHr) of potato starch with increasing treatment time demonstrated that McGBE could inhibit the short- and long-term retrogradation of starch. Under the optimal conditions, the SDS content of McGBE-modified potato starch increased by 65.8% compared to native potato starch. These results suggest that McGBE has great application potential for the preparation of modified starch with higher SDS content that is resistant to retrogradation.

OPTIMISATION OF CONDITIONS FOR BARNYARD MILLET GERMINATION

Development of foods that promote health and wellbeing is one of the key priorities of food industry. Barnyard millet, important minor millet is highly digestible (81.13 per cent) and contains fair amount of protein (12 per cent) coupled with low carbohydrate (58.56 per cent) of slow digestibility (25.88 per cent). The nutritive value and taste of barnyard milled can be improved by germination. The present study concentrates in the optimization of conditions for barnyard millet germination to maximise the nutritive value and overall acceptance. The barnyard millet was cleaned, soaked in water with varying time intervals followed by 24 hrs germination. The dried grains were powdered, sieved and then subjected to organoleptic evaluation. The parameters such as moisture absorption, sprout length, malt yield and germination percentage were worked out. Based on organoleptic evaluation, the germinated barnyard millet flour, 10hrs soaking and 24 hrs germination was found to be the best and utilized for the production of value added products. As the soaking time increases (4 to 18hrs) the moisture absorption increases from 35.16 and 54.12 per cent. The sprout length reaches a maximum of 0.4 cm at 18hrs of soaking. The malt yield differs from 59.62 to 71.54 per cent with respect to soaking time.

Physiological Impact of a Single Serving Slow Absorption Carbohydrate on Metabolic, Hemodynamic, and Performance Markers in Endurance Athletes During a Bout of Exercise.

Davitt, PM, Saenz, C, Hartman, T, Barone, P, and Estremera, S. Physiological impact of a single serving slow absorption carbohydrate on metabolic, hemodynamic, and performance markers in endurance athletes during a bout of exercise. J Strength Cond Res 35(5): 1262-1272, 2021-The purpose of this study was to determine how a slow-absorbing carbohydrate affected markers of metabolism, hemodynamics, and performance in well-trained endurance athletes. We examined total and exogenous carbohydrate oxidation (CHO ox), glucose, and performance after consuming different glucose beverages, before a treadmill run. Ten male runners (32.4 years; V̇o2max, 55.9 ml·kg-1·min-1) participated on 3 occasions: slow digestion CHO (S), fast digestion CHO (F), and water (W). Subjects consumed a 50 g dose of either S or F before a 3-hour treadmill run at 57% V̇o2max. Variables were assessed at -15, 0, 30, 60, 90, 135, and 180 minutes. Immediately postrun, subjects completed a time-to-fatigue test at 110% V̇o2max. There was a significant difference in CHO ox for W vs. F and S (C,1.14; S,1.52; F,1.66 ± 0.2 g·min-1, p < 0.05). Fat ox was significantly higher in S vs. F (S,0.54; F,0.47 ± 0.08 g·min-1, p < 0.05). Exogenous CHO ox was significantly higher in F vs. S (F,0.26; S,0.19 + 0.04 g·min-1, p < 0.05). There was a significant difference in average blood glucose for trial (F,94.5; S,97.1 vs. W,88.4 + 2.1 mg·dl-1) and time × trial for F vs. S (0 minutes, p < 0.05). There were no significant performance differences. Consumption of a single bolus of CHO beverage before a 3-hour run elicits significant alterations in energy metabolism compared with just water, with S CHO oxidizing significantly more fat than a rapidly digested carbohydrate. These findings suggest that slow-digesting modified starch provides a consistent blood glucose level and sustained exogenous energy supply during a sustained, 3-hour endurance run. Significance was set at p < 0.05.

Effect of removal of endogenous non-starch components on the structural, physicochemical properties, and in vitro digestibility of highland barley starch

Highland barley (HB) is a kind of slow-digesting grain. The effects of endogenous non-starch components on the digestibility of highland barley starch (HBS) are worth exploring. In this study, the effects of non-starch components on the structure, physicochemical and digestibility of HBS were studied by removing β-glucan, proteins and lipids individually and in pairs. The results showed that, all removal treatments led to an increase in the swelling power of the HBS and changes in its pasting properties, causing its easier gelatinisation and subsequent digestion. The effects of the removal of multiple components on the digestion and physicochemical properties of HBS were more significant than those corresponding to that of a single. The effect order of a single non-starch component on starch digestibility is: lipids < β-glucans < proteins. Regarding the multiple, the lowest SDS was induced by the removals of lipid and protein (actually, the protein, β-glucan and lipids were all removed), and the lowest RS was induced by the removal of proteins. The changes in the physiochemical and digestion properties caused by the removal of the non-starch components were significantly correlated; the swelling power was significantly and positively correlated with the glucose concentration at the end of digestion, and the sum of SDS and RS content was positively correlated with the ratio of 1022/995 cm−1. In conclusion, these results reveal the internal factors affecting the slow digestion characteristics of HB from the perspective of endogenous non-starch components while providing important reference values of these components in slow-digesting diets.

Long chains and crystallinity govern the enzymatic degradability of gelatinized starches from conventional and new sources

Slowly digestible starches have received interest due to their lower increase of postprandial blood glucose and insulin levels and, hence, modification of starches towards slower digestibility has commercial interest. However, chemical characteristics driving enzymatic (digestive) degradation are not fully unraveled. The digestion properties of starches have been linked to their crystalline type, chain length distribution, amylose content or degree of branching, but content and length of relatively long side-chains in amylopectin has not been paid attention to. Therefore, this research focusses on the unique content and length of amylopectin side-chains from conventional and new starch sources (potato, corn, pea, and tulip) correlated to the enzymatic digestion. The rate of hydrolysis was found to be correlated with the crystalline type of starch, as previously suggested, however, the complete hydrolysis of all starches, independent of the crystalline type and source, was shown to be governed by the content of longer amylopectin chains.