In vitro and in vivo hydrolysis of legume starches by α-amylase and resistant starch formation in legumes—a review

Enhancing enzymatic resistance of pea type 3 resistant starch through pressure heating and annealing

Type III resistant starch (RS3) is an important functional food ingredient. In this study, RS3 was prepared by retrogradation of pea starch after acid hydrolysis and pullulanase debranching. Heat-moisture treatments, including annealing (90 °C, 40-70 % moisture content) and pressure heating (121 °C, 10-40 % moisture content), were employed to further enhance the RS content of pea RS3. The relationship between the structural changes and digestibility of pea RS3 was investigated. The results showed significant increases in relative crystallinity, particle size, gelatinization temperature, and RS content, while swelling power, pasting viscosity, and rapidly digestible starch content were markedly decreased after heat-moisture treatment. A strong positive correlation (r = 0.94*) was observed between relative crystallinity and RS content. The highest RS content of 85.6 % was achieved after pressure heating at 20 % moisture content, which was notably higher than the 45.6 % RS content before heat-moisture treatment. This study highlights the beneficial effects of annealing and pressure heating in enhancing RS content in pea RS3, providing valuable insights for developing RS3 with high RS content after cooking.

The Effect of Cooking and Cooling Chickpea Pasta on Resistant Starch Content, Glycemic Response, and Glycemic Index in Healthy Adults

Background/Objectives: Legume seeds, such as chickpeas, are a rich source of resistant starch (RS) and have a low glycemic index (GI). The aim of this study was to evaluate the effect of cooking and cooling chickpea pasta on the RS content, glycemic response, and GI in healthy subjects. Methods: Twelve healthy subjects of both sexes, aged 18-65 years, participated in this study. Each person consumed two standardized portions of chickpea pasta: (i) freshly cooked (FCP) and (ii) cooked chickpea pasta which was cooled for 24 h at 4 °C and reheated before consumption (CCP). Glucose solution was provided as a reference food. Participants consumed chickpea pasta in a random order. GI measurements were completed using the standard methodology and calculated according to the ISO 2010 standard. Results: The cooling and reheating process significantly increased the RS content of boiled chickpea pasta (from 1.83 g/100 g to 3.65 g/100 g) and had a beneficial effect on postprandial glycemia in healthy individuals. The CCP pasta had a significantly lower GI value than the FCP pasta (33 vs. 39, p = 0.0022). A significant difference in the glucose, as identified by the incremental area under the curve (IAUC), was observed between the CCP and FCP (1327.9 ± 414.8 mg/dL/min vs. 1556.1 ± 456.9 mg/dL/min, p = 0.0022). The cooling-reheating process did not affect the sensory attributes of the chickpea pasta. In general, the overall acceptability of the CCP pasta was similar to that of the FCP pasta. Conclusions: The results of our study support the hypothesis that a reduced glycemic response after simple changes in technological intervention leads to a decrease in postprandial blood glucose and GI. This can be helpful for people who need to control postprandial glycemia.

In vitro digestion and fermentation characteristics of eight kinds of pulses and suggestions for different populations

Pulse-based diets are attracting attention for their potential in combating diet-related non-communicable diseases. However, limited research studies have focused on the digestive and fermentative properties of pulses, which are crucial for exerting benefits. Here, we investigated the in vitro digestibility of starch/protein, along with the fermentation characteristics, of eight pulses and their pastes, including white kidney beans, adzuki beans, cowpeas, broad beans, mung beans, chickpeas, white lentils, and yellow peas. The findings indicated that pulse flours and pastes were low GL food (estimated GL < 10) and had a low degree of protein hydrolysis during simulated gastrointestinal digestion. During in vitro fermentation, pulses flours and pastes decreased the fermentation pH, increased the level of short-chain fatty acids (mainly consisting of valeric acid, followed by acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid), and positively modulated the microbiota composition over time, specifically reducing the ratio of Firmicutes to Bacteroidetes. In addition, we found that boiling could affect the in vitro digestion and fermentation characteristics of pulses, possibly depending on their intrinsic nutrient characteristics. This research could provide a comprehensive summary of the nutrient content, digestibility, and fermentation of eight pulses and their pastes. Guided by factor analysis, for different individuals' consumption, pulses, cowpeas, broad beans, white lentils, and white kidney beans were preferred for diabetic individuals, yellow peas and white lentils were preferred for intestinal homeostasis disorders, and white lentils, broad beans, white kidney beans, and cowpeas were suitable for obese individuals, in which white lentils were considered healthier and suggested for healthy adults.

Unveiling Diversity for Quality Traits in the Indian Landraces of Horsegram [Macrotyloma uniflorum (Lam.) Verdc.]

Horsegram (Macrotyloma uniflorum [Lam.] Verdc.) is an underutilized pulse crop primarily cultivated in South Asian countries like India, Nepal, and Sri Lanka. It offers various nutraceutical properties and demonstrates remarkable resilience to both biotic and abiotic stresses. As a result, it has emerged as a promising crop for ensuring future food and nutritional security. The purpose of this study was to assess the nutritional profile of 139 horsegram germplasm lines obtained from 16 Indian states that were conserved at the National Gene Bank of India. Standard analytical methods, including those provided by the Association of Official Analytical Chemists (AOAC), were used for this investigation. The study revealed substantial variability in essential nutrients, such as protein (ranging from 21.8 to 26.7 g/100 g), starch (ranging from 26.2 to 33.0 g/100 g), total soluble sugars (TSSs) (ranging from 0.86 to 12.1 g/100 g), phenolics (ranging from 3.38 to 11.3 mg gallic acid equivalents (GAEs)/g), and phytic acid content (ranging from 1.07 to 21.2 mg/g). Noteworthy correlations were observed, including a strong positive correlation between sugars and phenols (r = 0.70) and a moderate negative correlation between protein and starch (r = -0.61) among the studied germplasm lines. Principal component analysis (PCA) highlighted that the first three principal components contributed to 88.32% of the total variability, with TSSs, phytates, and phenols emerging as the most significant contributors. The cluster analysis grouped the accessions into five clusters, with cluster III containing the accessions with the most desirable traits. The differential distribution of the accessions from north India into clusters I and III suggested a potential geographical influence on the adaptation and selection of genes. This study identified a panel of promising accessions exhibiting multiple desirable traits. These specific accessions could significantly aid quality breeding programs or be directly released as cultivars if they perform well agronomically.

Unveiling the Evidence for the Use of Pulses in Managing Type 2 Diabetes Mellitus: A Scoping Review

Management of type 2 diabetes mellitus (T2DM) is a pressing global healthcare challenge. Innovative strategies that integrate superior medical and nutritional practices are essential for holistic care. As such, pulse consumption is encouraged for its potential benefit in reducing hypercholesterolaemia, dyslipidaemia, and triglyceride levels, as well as enhancing glycaemic control. This scoping review aims to assess the depth of evidence supporting the recommendation for pulse consumption in T2DM management and to identify gaps in the existing literature. We conducted a comprehensive search across the databases MEDLINE, Global Health, EMBASE, CINAHL, Web of Science, and the Cochrane Library (up to July 2023). We included population-based studies of any design, and excluded review-style articles. Articles published in languages other than English were also excluded. From the 2449 studies initially identified, 28 met our inclusion criteria. Acute postprandial trials demonstrated improved glucose responses and enhanced insulin responses to pulse-based intervention. Meanwhile, long-term trials reported meaningful improvements in T2DM indicators such as haemoglobin A1C (HbA1c), fasting glucose, fasting insulin, C-peptide, and markers of insulin resistance like homeostatic model assessment (HOMA). Integrating more pulses into the diets of diabetic individuals might offer an efficient and cost-effective strategy in the global initiative to combat T2DM.

Proso Millet (Panicum miliaceum L.) as Alternative Source of Starch and Phenolic Compounds: A Study on Twenty-Five Worldwide Accessions

Proso millet has been proposed as an effective anti-diabetic food thanks to the combined action of polyphenols and starch. This study aimed to characterize the chemical composition of twenty-five accessions, in order to enhance this cereal as an alternative to available starch for food applications or to propose new food ingredients with health benefits. Proso millet contained a high percentage of starch, reaching values of 58.51%. The amylose content showed high variability, with values ranging from 1.36 to 42.70%, and significantly higher values were recorded for the white accessions than for the colored ones. High-resistant starch content (13.41-26.07%) was also found. The HPLC-MS analysis showed the same phenolic pattern in all the samples. Cinnamic acids are the most abundant compounds and significant differences in their total content were found (0.69 to 1.35 mg/g DW), while flavonoids were only detected in trace amounts. Statistical results showed significantly higher antiradical activity in the colored accessions than in the white ones.

Upscaling of alkaline pea protein extraction from dry milled and pre-treated peas from laboratory to pilot scale: Optimization of process parameters for higher protein yields

The upscaling of pea protein extraction from laboratory scale with a centrifuge to pilot scale with a decanter centrifuge was investigated, and the pea protein extraction efficiency from dry milled and pre-treated peas was compared. Upscaling from laboratory to pilot scale is possible since starch was under the limit of detection (< 0.5%). The protein banding pattern of a sodium-dodecyl-sulfate polyacrylamide gel electrophoresis confirmed that albumins and globulins were extracted by alkali extraction. Protein yield increased from 59.5% to 67.1% for dry milled peas due to constant and quick discharge of dry matter in the decanter centrifuge. For pre-treated peas, the protein yield increased from 60.3% to 94.3%, which is explained by an improved cutting and improved separation in pilot scale compared to laboratory scale. The impact of acceleration, mass flow, differential speed and their respective interactions in the decanting process was determined with a design of experiments. For dry milled peas, only the mass flow exceeded the significance level. However, a mass flow of 5 kg h−1, an acceleration of 1000 g$$\times$$ × and a differential speed of 50 min−1 led to the highest protein yield of 75.6%. The obtained protein yields for the pre-treated peas were in the range of 83 to 96% and therefore did not show significant differences in protein yield.

Physiochemical and thermal characterisation of faba bean starch

The structure and physicochemical properties of starch isolated from the cotyledon and hull of faba beans and from wheat (as reference) were examined using 16 different methods. The amylose content in faba bean cotyledon and hull starch was 32% and 36%, respectively, and that in wheat starch was 21%. The faba bean cotyledon and hull starch were structurally alike both displaying C-polymorphic pattern, a similar degree of branching and similar branch chain length distributions. Wheat starch had a significantly greater prevalence of short amylopectin chains (DP < 12) and a higher degree of branching. Granules in both faba bean starches exhibited surface cracks and were more homogenous in size than the smoother wheat starch granules. Gelatinisation temperature was higher for the faba bean starches, likely as an effect of high amylose content and longer starch chains delaying granular swelling. Cotyledon starch produced pastes with the highest viscosities in all rheological measurements, probably owing to larger granules. Higher prevalence of lipids and resistant starch reduced the viscosity values for hull starch. For all starches, viscosity increased at faster heating rates. During the rheological analyses, the samples were exposed to different instruments, heating rates and temperatures ranges, differing from standard rheological procedures, which could help predict how different processing techniques effect the final starch textures.

Graphical abstract

Enzymatic synthesis, structure of isomalto/malto-polysaccharides from linear dextrins prepared by retrogradation

Isomalto/malto-polysaccharides (IMMPs) with degree of polymerization (DP) 10-100 have novel potential applications, including enhanced solubility and anti-inflammatory. However, there are minimal synthetic methods for preparing IMMPs with a relatively higher DP, which is due to the lack of suitable molecular weight linear dextrins (I-LDs). The existing I-LDs preparation methods have disadvantages, such as low yield and uncontrollable molecular weight. Therefore, this study proposes a method for preparing soluble linear dextrins (S-LDs, M_w = 2.1 kDa) by low-temperature retrogradation from debranched waxy corn starch (M_w = 3.0 kDa). S-LDs reacted with 4,6-α-glucanotransferase GtfB-ΔN from Limosilactobacillus reuteri 121 to yield IMMPs with 12.3 kDa M_w and 83.8% α1 → 6 linkages content. Process monitoring revealed the synthesis mechanism and a detailed reaction process. Finally, IMMPs were identified by enzyme fingerprinting as α1 → 6 chains with α1 → 4 fragments inlaid at the reducing, non-reducing end, and middle part. This study provides a new synthesis method and more structural information for IMMPs.

Effect of feeding mid- or zero-tannin faba bean cultivars differing in vicine and covicine content on diet nutrient digestibility and growth performance of weaned pigs

To prioritize what cultivars to grow to feed pigs, 5 faba bean cultivars including 3 zero-tannin, high vicine and covicine cultivars (Snowbird, Snowdrop, Tabasco) and 2 medium-tannin, lower vicine and covicine cultivars (Fabelle, and Malik) were fed to compare effects on diet nutrient digestibility and growth performance of weaned pigs. A total of 260 pigs (8 ± 1.2 kg), weaned at 20 ± 1 d of age housed 2 barrows and 2 gilts/pen were fed 1 of 5 dietary regimens starting 1-week post-weaning for 4 weeks in a randomized complete block design. Diets including each cultivar at 20% or 30% provided 10.2 and 10.1 MJ net energy (NE)/kg and 1.3 and 1.2 g standardized ileal digestible (SID) lysine (Lys)/MJ NE in phase 1 and phase 2, respectively. Digestibility data were analyzed using PROC GLIMMIX and growth performance data were analyzed using PROC MIXED with pen as experimental unit. Fabelle contained the most condensed tannins (CT; 0.53%) but the least vicine (0.04%) and covicine (0.01%). Zero-tannin cultivars contained little CT (&lt; 0.2%) but had the greatest vicine (0.5%) and covicine content (0.4%). For phase 1, diet apparent total tract digestibility (ATTD) of dry mater (DM), gross energy (GE), crude protein (CP), digestible energy (DE), and NE values did not differ among cultivars. For phase 2, diet ATTD of DM and GE were greatest (P &lt; 0.05) for Snowdrop and Tabasco, intermediate for Fabelle, and lowest for Malik; Snowbird was not different from Fabelle or Malik. Diet ATTD of CP was greatest (P &lt; 0.05) for Tabasco, intermediate for Snowbird, and lowest for Malik; Snowdrop was not different from Tabasco or Snowbird, and Fabelle was not different from Snowbird or Malik. Diet DE and NE values were greatest (P &lt; 0.05) for Tabasco, intermediate for Fabelle and Snowdrop, and lowest for Snowbird; Malik was not different from Fabelle or Snowbird. For the entire trial (d 0 to 28), daily feed disappearance and weight gain for pigs fed Fabelle were 10% greater (P &lt; 0.05) than those fed Malik; pigs fed zero-tannin cultivar diets were intermediate. Pigs fed Fabelle were 1.6 kg heavier (P &lt; 0.05) than those fed Malik at the end of the trial; pigs fed zero-tannin cultivar diets were intermediate. In conclusion, growth performance of pigs fed faba bean cultivar diets was more related to feed disappearance than diet nutrient digestibility. Vicine and covicine instead of condensed tannin content of faba bean cultivars seemed more relevant to growth performance in weaned pigs.

Pressure moisture treatment and hydro-thermal treatment of starch

Starch is often subjected to denaturation treatment to improve its useful properties and eliminate its shortcomings. Various methods have been developed to produce modified starches with different properties and for a variety of uses. Because physically modified starch can be produced without chemical substances or biological agents, the modification method is very simple and inexpensive, and the resulting material can be used as clean label starch. Among these physical modification technologies, heat moisture treatment (HMT) is a universally valid technology, but little is known about pressure moisture treatment (PMT)-related technology. Physical modification of starch using PMT results in new functions and value-added characteristics required by industry, and PMT has the potential to produce starch with new functions. In this paper, PMT-related technologies for physically modified starch, the difference between PMT and the hydro-thermal treatment, and clean label starch manufacturing using HMT and PMT were investigated.

Effect of hermetic Purdue Improved Crop Storage (PICS) bag on chemical and anti-nutritional properties of common Bean (Phaseolus vulgaris L.) varieties during storage

Storage conditions influence the nutritive value and quality of many legumes. The aim of this study was to evaluate the quality of beans stored under hermetic conditions as a strategy for preserving the quality of beans post-harvest. Three bean varieties [Rosecoco, small red (Wairimu)], and red mottled (Nyayo)] were adjusted to three moisture levels (12%, 15% and 18%) and stored in hermetic bags and ordinary polypropylene bags and sampled after 0, 45, 90, 135,180, 225 and 270 days for chemical and anti-nutritional analysis. Total soluble sugars, in-vitro starch and protein digestibility, free amino nitrogen, tannin content and phytic acid content of the beans were determined using standard methods. Results showed that the beans in hermetic bags had 22%, 23% and 18% higher total soluble sugars, in-vitro starch and protein digestibility, respectively, than those in polypropylene bag during storage. On day 225 of storage, beans in hermetic bags had the optimal in-vitro starch and protein digestibility, and tannin content. Principal component analysis indicated that nutrient and anti-nutrient retention of the beans was achieved with lower storage moisture and duration in hermetic bags. The results of this study can be used to explain the superiority of the hermetic storage technology over ordinary methods of beans storage, and by extension other legumes, in nutrient retention during storage.

Effects of Auricularia auricula-judae polysaccharide on pasting, gelatinization, rheology, structural properties and in vitro digestibility of kidney bean starch

Auricularia auricula-judae polysaccharide (AP) has unique molecular structures and multiple bioactivities with excellent gel-forming property and thermal tolerance. However, few researches focus on the interactions between AP and legume starches. In this study, the effects of AP on the pasting, gelatinization, rheology, microstructure, and in vitro digestibility of kidney bean starch (KBST) were evaluated. The pasting, gelling and structural properties of AP-KBST mixtures were characterized by rapid visco analyzer, rheometry, texture analyzer, laser particle analyzer, low-field nuclear magnetic resonance, Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. And an in vitro method was employed to measure the digestibility of AP-KBST composites. The pasting viscosity, swelling degree of starch granules, viscoelasticity, gel strength, cold storage stability and water-retention capacity of KBST were enhanced with increasing AP concentration. The combination of AP and KBST exhibited a higher short-range ordered and a firmer and denser structure than that of KBST alone. Moreover, AP increased the contents of resistant starch and slowly digestible starch, which were positively correlated with the storage modulus and the degree of order, thereby suggesting that the formation of strong and ordered gel network structure by synergistic interactions between AP and KBST was responsible for the reduced starch digestibility.

Hindgut fermentation of starch is greater for pulse grains than cereal grains in growing pigs

The nutritive value of starch, the major source of dietary energy in pigs, varies depending on its susceptibility for digestion. The botanical origin of starch determines starch structure, and therefore, digestibility. To compare digestibility of starch, fiber, gross energy (GE), crude protein, and amino acid (AA), and to characterize undigested starch of grains in growing pigs, seven ileal-cannulated barrows (initial body weight, 30 kg) were fed six diets containing 96% of one of six test ingredients (three pulse grains: zero-tannin faba bean, green field pea, or mixed-cultivar chickpea; three cereal grains: hulled barley, hard red spring wheat, or hybrid yellow, dent corn), or a N-free diet in a 7 × 7 Latin square at 2.8 × maintenance digestible energy. Grain samples were ground with a hammer mill through a 2.78-mm screen. Amylose content ranged from 29% to 34% for pulse grains and from 22% to 25% for cereal grains. The apparent ileal digestibility (AID) of starch was greater (P < 0.05) in cereal (94% to 97%) than pulse grains (85% to 90%) and was lowest (P < 0.05) in faba bean (85.3%) followed by field pea (87.2%) and chickpea (90.1%). However, apparent total tract digestibility (ATTD) of starch of all tested grains was close to 100%. Apparent hindgut fermentability (AHF, as ATTD - AID) of starch was greater (P < 0.05) in pulse grains (9.9% to 15%) than cereal grains (3.3% to 4.8%). The AHF of total dietary fiber tended to be the greatest (P < 0.10) for corn (43.5%) and lowest for wheat (25.3%). The AHF of GE was greater (P < 0.05) in pulse grains (17% to 20%) than in cereal grains (9% to 11%) and resulted in greater (P < 0.05) digestible energy (DE) contribution from hindgut fermentation for pulse grains than cereal grains (0.9 vs. 0.5 Mcal/kg). Wheat had the greatest standardized ileal digestibility of total AA (90.2%; P < 0.05). Confocal laser scanning microscopy images revealed that 20% to 30% of starch granules of pulse grains were entrapped in protein matrixes. In scanning electron microscopy images, starch granules were larger in faba bean and field pea than cereal grains. Digesta samples revealed pin holes and surface cracks in starch granules of corn and wheat, respectively. In conclusion, hindgut fermentation of starch and fiber was greater in pulse grains than cereal grains resulting in a greater DE value despite lower ileal DE for pulse grain than cereal grains. Defining the digestible and fermentable fractions of starch may enhance the accuracy of equations to predict the net energy value of these feedstuffs.

Efficiency of Resistant Starch and Dextrins as Prebiotics: A Review of the Existing Evidence and Clinical Trials

In well-developed countries, people have started to pay additional attention to preserving healthy dietary habits, as it has become common knowledge that neglecting them may easily lead to severe health impairments, namely obesity, malnutrition, several cardiovascular diseases, type-2 diabetes, cancers, hypertensions, and inflammations. Various types of functional foods were developed that are enriched with vitamins, probiotics, prebiotics, and dietary fibers in order to develop a healthy balanced diet and to improve the general health of consumers. Numerous kinds of fiber are easily found in nature, but they often have a noticeable undesired impact on the sensory features of foods or on the digestive system. This led to development of modified dietary fibers, which have little to no impact on taste of foods they are added to. At the same time, they possess all the benefits similar to those of prebiotics, such as regulating gastrointestinal microbiota composition, increasing satiety, and improving the metabolic parameters of a human. In the following review, the evidence supporting prebiotic properties of modified starches, particularly resistant starches and their derivatives, resistant dextrins, was assessed and deliberated, which allowed drawing an interesting conclusion on the subject.

Cellulose Nanofibers Improve the Performance of Retrograded Starch/Pectin Microparticles for Colon-Specific Delivery of 5-ASA

Cellulose nanofibers (CNF) were employed as the nanoreinforcement of a retrograded starch/pectin (RS/P) excipient to optimize its colon-specific properties. Although starch retrogradation ranged from 32 to 73%, CNF addition discretely disfavored the RS yield. This result agrees with the finding that in situ CNF reduces the presence of the RS crystallinity pattern. A thermal analysis revealed that the contribution of pectin improves the thermal stability of the RS/CNF mixture. Through a complete factorial design, it was possible to optimize the spray-drying conditions to obtain powders with high yield (57%) and low moisture content (1.2%). The powders observed by Field Emission Gum Scanning Electron Microscopy (FEG-SEM) had 1–10 µm and a circular shape. The developed methodology allowed us to obtain 5-aminosalicilic acid-loaded microparticles with high encapsulation efficiency (16–98%) and drug loading (1.97–26.63%). The presence of CNF in RS/P samples was responsible for decreasing the burst effect of release in simulated gastric and duodenal media, allowing the greatest mass of drug to be targeted to the colon. Considering that spray-drying is a scalable process, widely used by the pharmaceutical industry, the results obtained indicate the potential of these microparticles as raw material for obtaining other dosage forms to deliver 5-ASA to the distal parts of gastrointestinal tract, affected by inflammatory bowel disease.

Preliminary Investigations into the Use of Amylases and Lactic Acid Bacteria to Obtain Fermented Vegetable Products

Legumes are valuable sources of proteins and other functional components. However, the high starch content can be an impediment in developing new vegan food formulations. Enzyme-assisted hydrolysis was used to hydrolyze the starch from chickpea and broad bean vegetable milk to further develop vegetable lactic acid-fermented products. The antioxidant activity of legumes was tested, and it was observed that the overall antioxidant activity (DPPH radical scavenging ability) significantly increased after enzyme-assisted hydrolysis while total phenols content decreased. The obtained vegetable milk was then fermented using exopolysaccharides-producing lactic acid bacteria. A significant decolorization was observed after fermentation in the case of broad bean-based products. Rheological behavior of the fermented products was determined using small amplitude oscillatory measurements and the three-interval thixotropy test. Results showed higher complex viscosity values for broad bean-based products, which displayed a weak gel-like structure. The starter cultures used for vegetable milk samples fermentation influenced the resistance to flow.

A current review of structure, functional properties, and industrial applications of pulse starches for value-added utilization

Pulse crops have received growing attention from the agri-food sector because they can provide advantageous health benefits and offer a promising source of starch and protein. Pea, lentil, and faba bean are the three leading pulse crops utilized for extracting protein concentrate/isolate in food industry, which simultaneously generates a rising volume of pulse starch as a co-product. Pulse starch can be fractionated from seeds using dry and wet methods. Compared with most commercial starches, pea, lentil, and faba bean starches have relatively high amylose contents, longer amylopectin branch chains, and characteristic C-type polymorphic arrangement in the granules. The described molecular and granular structures of the pulse starches impart unique functional attributes, including high final viscosity during pasting, strong gelling property, and relatively low digestibility in a granular form. Starch isolated from wrinkled pea-a high-amylose mutant of this pulse crop-possesses an even higher amylose content and longer branch chains of amylopectin than smooth pea, lentil, and faba bean starches, which make the physicochemical properties and digestibility of the former distinctively different from those of common pulse starches. The special functional properties of pulse starches promote their applications in food, feed, bioplastic and other industrial products, which can be further expanded by modifying them through chemical, physical and/or enzymatic approaches. Future research directions to increase the fractionation efficiency, improve the physicochemical properties, and enhance the industrial utilization of pulse starches have also been proposed. The comprehensive information covered in this review will be beneficial for the pulse industry to develop effective strategies to generate value from pulse starch.

Interaction with longan seed polyphenols affects the structure and digestion properties of maize starch

This study investigated effects of longan seed polyphenols (LSPs) on the structure and digestion properties of starch, and discussed the interaction mechanism between starch and LSPs. The results showed cooking with 20 % LSPs did not change amylopectin chain length distribution of normal maize starch, however, the amylose content was reduced from 21.60 to 14.03 %. This suggests LSPs may interact with starch via non-covalent bond. Isothermal titration microcalorimetry and XRD results confirmed the existence of non-covalent interaction, and indicated that LSPs may enter the hydrophobic cavity of amylose, forming V-type inclusion complex. LSPs did not affect gelatinization temperatures of maize starch, whereas 20 % LSPs decreased the enthalpy change by about 26 %. The digestion results indicate significant inhibition effect of LSPs on the digestion of cooked starch, attributing to the interaction of LSPs with starch. These suggest potential applications of LSPs as functional ingredients in modulating postprandial glycemic response of starchy food.

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

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

Optimization of the autoclave preparation process for improving resistant starch content in rice grains

The autoclave preparation process to increase the content of resistant starch (RS) in rice grains was optimized, and the results showed that the optimal preparation process was obtained with a water content of 41.63%, a pH of 5.95, an autoclave time of 60.96 min, and a refrigeration time of 17.11 hr. Under these conditions, the theoretical value of RS content in rice grains reached 17.57%. After autoclaving, the estimated glycemic index (EGI) in rice grains was reduced from 78.35 to 66.08 measured after cooking, suggesting that autoclaving was capable of increasing the RS content in rice grains and reducing its EGI value. These results may help spark new concepts and methods for the development of specialized foods for specific populations, such as people with diabetes.

The Effect of Sprouting in Lentil (Lens culinaris) Nutritional and Microbiological Profile

Biological and vegetarian raw food products, in particular based on legume sprouts, are an increasing food trend, due to their improved nutritional value when compared to seeds. Herein, protein and mineral profiles were studied in 12 lentil varieties, with varieties Du Puy, Kleine Schwarze, Rosana, Flora, Große Rote and Kleine Späths II demonstrating the highest protein percentages. After sprouting, protein percentages increased significantly in 10 of the 12 varieties, with the highest increases ranging between 20–23% in Dunkelgrün Marmorierte, Du Puy, Große Rote and Kleine Späths II varieties. While Fe concentration was significantly decreased in three varieties (Samos, Große Rote and Kleine Späths II), Zn and Mn were positively impacted by sprouting (p ≤ 0.05). Magnesium concentration was not affected by sprouting, while Ca and K had percentage increases between 41% and 58%, and 28% and 30%, respectively, in the best performing varieties (Kleine Schwarze, Dunkelgrün Marmorierte, Samos and Rosana). Regardless of the associated nutritional benefits, issues pertaining to sprouts microbiological safety must be ensured. The best results for the disinfection protocols were obtained when combining the seed treatment with SDS reagent followed by an Amukine application on the sprouts, which did not affect germination rates or sprout length. The increasing levels of sprout consumption throughout the world require efficient implementation of safety measures, as well as a knowledge-based selection for the nutritional quality of the seeds.

Starch Digestion Enhances Bioaccessibility of Anti-Inflammatory Polyphenols from Borlotti Beans (Phaseolus vulgaris)

The consumption of beans has been associated with chronic disease prevention which may be attributed to the polyphenols present in the seed coat and endosperm. However, their bioaccessibility is likely to be limited by interactions with bean matrix components, including starch, protein and fibre. The aim of this project was to evaluate the effect of domestic processing and enzymatic digestion on the bioaccessibility of polyphenols from Borlotti beans (Phaseolus vulgaris) and to test their anti-inflammatory properties in a macrophage cell model. In vitro digestion of cooked beans released twenty times more polyphenols (40.4 ± 2.5 mg gallic acid equivalents (GAE)/g) than domestic processing (2.22 ± 0.1 mg GAE/g), with starch digestion contributing to the highest release (30.9 ± 0.75 mg GAE/g). Fluorescence microscopy visualization of isolated bean starch suggests that polyphenols are embedded within the granule structure. LC-MS analysis showed that cooked Borlotti bean contain flavonoids, flavones and hydroxycinnamic acids, and cooked bean extracts exerted moderate anti-inflammatory effects by decreasing mRNA levels of IL1β and iNOS by 25% and 40%, respectively. In conclusion, the bioaccessibility of bean polyphenols is strongly enhanced by starch digestion. These polyphenols may contribute to the health benefits associated with bean consumption.

Understanding the multi-scale structural changes in starch and its physicochemical properties during the processing of chickpea, navy bean, and yellow field pea seeds

This study aimed to isolate starch from three types of untreated and autoclaved pulse seeds including chickpea, navy bean, and yellow field pea and to characterize their multi-scale structure and the associated physicochemical properties. Autoclaving of pulse seeds tended to significantly decrease the relative crystallinity, the Mw value, and degree of order of starch samples measured by X-ray diffraction, size exclusion chromatography, and FT-IR. Simultaneously, double helix content, and degree of double helix obtained from solid-state 13CNMR and FT-IR were relatively higher (P < 0.05) for autoclaved pulse seeds than their native counterparts. The structural characteristics also corroborated well with the obtained results of resistant starch content, gelatinization behavior, swelling power, solubility, and bile acid binding capacity. This research gave insights into the structural characteristics of starch from pulses and their changes that occurred following processing of seeds, aiming to provide information for the future study on their processing-structure-function relationship.

Nutritional quality of fresh and stored legumes sprouts - Effect of Lactobacillus plantarum 299v enrichment

Nutrient content and digestibility as well as factors with a potentially negative effect on these parameters were studied in legume sprouts enriched with L. plantarum 299v. The nutrient digestibility and contents were not strongly affected by the co-culture of the probiotic and sprouts. The highest digestibility of starch was observed for adzuki bean preparations (from 91.6% to 95.5%), while the lowest value was noted for soybean preparations (from 49.6% to 60.8%). A slight decrease in starch digestibility was observed in adzuki and soybean sprouts enriched with the probiotic (by about 5% and 7% respectively). An increase in starch digestibility was noted in lentil and mung bean sprouts. A key influence on protein digestibility was exerted by the activity of trypsin and chymotrypsin inhibitors. Generally, there was no negative effect of the studied factors on starch digestibility. Most importantly, the control and probiotic-rich sprouts retained high quality after cold storage.

Plasticity in the Human Gut Microbiome Defies Evolutionary Constraints

The gut microbiome of primates, including humans, is reported to closely follow host evolutionary history, with gut microbiome composition being specific to the genetic background of its primate host. However, the comparative models used to date have mainly included a limited set of closely related primates. To further understand the forces that shape the primate gut microbiome, with reference to human populations, we expanded the comparative analysis of variation among gut microbiome compositions and their primate hosts, including 9 different primate species and 4 human groups characterized by a diverse set of subsistence patterns (n = 448 samples). The results show that the taxonomic composition of the human gut microbiome, at the genus level, exhibits increased compositional plasticity. Specifically, we show unexpected similarities between African Old World monkeys that rely on eclectic foraging and human populations engaging in nonindustrial subsistence patterns; these similarities transcend host phylogenetic constraints. Thus, instead of following evolutionary trends that would make their microbiomes more similar to that of conspecifics or more phylogenetically similar apes, gut microbiome composition in humans from nonindustrial populations resembles that of generalist cercopithecine monkeys. We also document that wild cercopithecine monkeys with eclectic diets and humans following nonindustrial subsistence patterns harbor high gut microbiome diversity that is not only higher than that seen in humans engaging in industrialized lifestyles but also higher compared to wild primates that typically consume fiber-rich diets.IMPORTANCE The results of this study indicate a discordance between gut microbiome composition and evolutionary history in primates, calling into question previous notions about host genetic control of the primate gut microbiome. Microbiome similarities between humans consuming nonindustrialized diets and monkeys characterized by subsisting on eclectic, omnivorous diets also raise questions about the ecological and nutritional drivers shaping the human gut microbiome. Moreover, a more detailed understanding of the factors associated with gut microbiome plasticity in primates offers a framework to understand why humans following industrialized lifestyles have deviated from states thought to reflect human evolutionary history. The results also provide perspectives for developing therapeutic dietary manipulations that can reset configurations of the gut microbiome to potentially improve human health.

Investigation of cell wall polysaccharides from flour made with waste peel from unripe banana (Musa sapientum) biomass

BACKGROUND

The peel from unripe banana biomass is an agroindustrial waste. The present study aimed: (i) to extract pectin from enzymatically-treated waste peel from unripe banana biomass (WPUBB) using a Box-Behnken design to optimize the extraction conditions (temperature, pH and extraction time) and obtain a maximum yield and (ii) to fractionate the polysaccharides from WPUBB employing sequential extractions using different solvents.

RESULTS

The optimized product was obtained at 86 °C, pH 2.00, for 6 h and it presented a yield of 11.63%. The optimized product had low galacturonic acid content and a high amount of glucose (82.3%), suggesting the presence of starch (as confirmed by the bi-dimensional heteronuclear single quantum coherence NMR spectrum). All of the fractionated polysaccharides had a high glucose content. Low amounts of pectin were found in the water, chelating and diluted alkali-soluble fractions. The fractions extracted using NaOH indicated the presence of glucuronoarabinoxylans.

CONCLUSION

Glucose was the main monosaccharide found in all the fractions extracted from the WPUBB. Although the present study suggests that WPUBB is still not suitable for pectin extraction using current technologies, other compounds, such as resistant starch and glucuronoarabinoxylans, were found, suggesting that WPUBB could be used in the development of food formulations. © 2019 Society of Chemical Industry.

Effect of Rice Processing towards Lower Rapidly Available Glucose (RAG) Favors Idli, a South Indian Fermented Food Suitable for Diabetic Patients

The Asian food pattern primarily embraces rice and rice-based products, which mainly comprise 90% starch. Among these various food products, Idli is mostly prepared through fermentation. It has high palatability, and the rapid and highly digestible nature of the food product results in a higher post-glucose level in diabetic patients. A heat-treated Idli rice sample was prepared by roasting parboiled rice at the temperature range of 155 to 165 °C for 65 to 75 s. Idli/rice-based Dokala made from heat-treated rice is better when compared to untreated rice in terms of its microbiological profile and physiochemical properties. The proximate composition of heat-treated parboiled rice Idli/Rice Dokala showed slightly higher values than the untreated parboiled rice Idli/Rice Dokala, which reveals that it has marginally higher nutritive value. Determination of the Rapidly Available Glucose (RAG) and Slowly Available Glucose (SAG) values, SEM analysis, resistant starch analysis, microbial assay, and in vivo studies were performed to determine the glycemic index (GI) and glycemic load in normal and diabetic persons. Sensory analysis also proved that heat-treated Idli/Rice Dokala is superior to untreated based on the color, flavor, appearance, taste, and texture.

Preparation and characterization of resistant starch type III from enzymatically hydrolyzed maize flour

Polysaccharides including resistant starch are categorized as dietary fiber and are used as an important prebiotic. Similar to soluble fibers, resistant starch also has a number of physiological effects that have been shown to be beneficial for health. Starch hydrolyzing enzymes, most importantly amylases, play essential roles in the production of resistant starch. This study aimed to develop α-amylase-treated maize flour with slow digestibility and unique physicochemical characteristics compared to native maize flour. In the current study, resistant starch type III from maize flour was prepared using α-amylase obtained from indigenously isolated Bacillus licheniformis. The α-amylase gene from B. licheniformis was amplified and cloned into the pET-24(a) vector, expressed in E. coli BL21 (DE3) cells and purified by metal ion affinity chromatography. The purified enzyme enhanced the yield of resistant starch 16-fold in maize flour. Scanning electron microscopy revealed that the granular structure of maize flour was disrupted into a dense network with irregular structure, and X-ray diffractograms confirmed the transformation from an amorphous to a crystalline structure upon α-amylase treatment. Thermogravimetric analysis revealed increased amylose content of α-amylase-treated maize flour. Moreover, α-amylase-treated maize flour resulted in a significant enhancement of the desired properties of maize flour, such as resistant starch content, amylose, milk absorption capacity, and iodine and fatty acid complexing ability, and a reduction in swelling power, water binding, oil absorption capacity, and in vitro digestibility compared to untreated maize flour. Resistant starch type III showed low digestibility and increased complexing ability with iodine and fatty acid and therefore could be a safe and beneficial alternative as a coating material for the delivery of active, sensitive ingredients to the colon.

Nutrients’ and Antinutrients’ Seed Content in Common Bean (Phaseolus vulgaris L.) Lines Carrying Mutations Affecting Seed Composition

Lectins, phytic acid and condensed tannins exert major antinutritional effects in common bean when grains are consumed as a staple food. In addition, phaseolin, i.e., the major storage protein of the bean seed, is marginally digested when introduced in the raw form. Our breeding target was to adjust the nutrient/antinutrient balance of the bean seed for obtaining a plant food with improved nutritional value for human consumption. In this study, the seeds of twelve phytohaemagglutinin-E-free bean lines carrying the mutations low phytic acid, phytohaemagglutinin-L-free, α-Amylase inhibitors-free, phaseolin-free, and reduced amount of condensed tannins, introgressed and differently combined in seven genetic groups, were analyzed for their nutrient composition. Inedited characteristics, such as a strong positive correlation (+0.839**) between the genetic combination “Absence of phaseolin + Presence of the α-Amylase Inhibitors” and the amount of “accumulated iron and zinc”, were detected. Three lines carrying this genetic combination showed a much higher iron content than the baseline (+22.4%) and one of them in particular, achieved high level (+29.1%; 91.37 µg g−1) without any specific breeding intervention. If confirmed by scientific verification, the association of these genetic traits might be usefully exploited for raising iron and zinc seed content in a bean biofortification breeding program.