Starch Research Articles

Plant use at Funnel Beaker sites: combined macro- and microremains analysis at the Early Neolithic site of Frydenlund, Denmark (ca. 3600 bce)

AbstractUnderstanding the neolithisation process in northern Europe requires detailed knowledge of both the type of crop plants as well as gathered food plants from Neolithic Funnel Beaker sites (4000–2800 bce). However, although many sites from this culture are known, significant gaps remain in our knowledge on which taxa were used as well as on how plant food was prepared. Here, we present the results of combined plant macro- and microremains from the Early Neolithic site of Frydenlund in present-day Denmark. The macroremains include carbonised seeds, fruits and underground storage organs from a variety of contexts. The microremains are phytoliths and starch granules recovered from 14 grinding stones that are among the oldest from Denmark as well as the first from this region analysed using state-of-the-art methods. The data are discussed in the context of an updated overview of crop spectra, evidence of gathered plants and of plant food preparation techniques at Funnel Beaker sites in the Netherlands, Germany, Denmark and Sweden. The results from the Early Neolithic site of Frydenlund show that the macroremains assemblage was dominated by Triticum turgidum ssp. durum (durum wheat), T. turgidum ssp. dicoccum (emmer wheat) and Hordeum vulgare var. nudum (naked barley), which apart from durum wheat fits the observed pattern from other Funnel Beaker sites in northwestern Europe. These crops were presumably cultivated separately as summer crops. Corylus avellana (hazel), Rubus fruticosus (blackberry) and R. idaeus (raspberry) were probably consumed as well, and possibly R. caesius (dewberry). While cereals were abundant in the macroremains assemblage, the microremains from the grinding stones indicate that these were used for grinding solely wild plants. The carbonised cereal grain fragments are therefore interpreted as possible evidence of cereal consumption mainly in the form of porridge or gruel, which corresponds well to comparable finds at other contemporary northwestern European sites. Future analysis of comparable high-quality data on combined macro- and microremains analysis is necessary to further refine our understanding of plant diets and plant food preparation techniques of the Funnel Beaker Culture as well as during the neolithisation process.

Effect of High-Pressure Processing Pretreatment on the Textural Properties of Cooked Nuovo Maratelli Rice

Nuovo Maratelli, a japonica rice with an intermediate amylose content, is suitable for paella (a traditional Spanish dish) due to its ability to withstand cooking and absorb flavors. In this study, high-pressure processing (HPP) at 400 and 600 MPa (10 min) was used as a pretreatment to improve the properties of rice cooked by either boiling or microwaving. The microstructure and pasting properties of unpressurized and pressurized rice were examined. Also, the cooking time and cooking kinetics were determined for each cooking method. Overall, the pasting properties of the rice were not impacted by the HPP treatments, but the typical polyhedral form of the rice starch granules was lost, especially at 600 MPa. Cooking times were reduced from 14 and 10 min for unpressurized samples to 12 and 8 min (400 MPa) and 8 and 6 min (600 MPa) for boiling- and microwave-cooked rice, respectively. The rice pretreated at 400 MPa (10 min) and microwaved (8 min) had lower hardness and adhesiveness, which was linked to the release of amylose during cooking. In summary, HPP could be an effective pretreatment for the improvement of the cooking and textural properties of Nuovo Maratelli rice, particularly when cooked by microwaving.

Multiscale structural characterization, physicochemical properties, and in vitro digestibility of pea starch produced by two different processes

AbstractBackground and ObjectivesDry grinding pea starch (DG) and wet grinding pea starch (WG) are two primary industrial starches with significantly different structures, physicochemical properties, and application potentials. To date, there have been no detailed studies examining these differences. Therefore, the aim of this study was to (i) investigate the effects of dry grinding and wet grinding on the structure of pea starch, and (ii) examine how the structure of pea starch influences its physicochemical properties and digestibility.FindingsThe crystallinity (35.75%), medium and long amylopectin (AP) chains (22.00%), swelling power (17.23 g/g), gelatinization temperature (76.4°C), and gelatinization viscosity (5585.0 cP) of WG were higher than those of DG (24.29%, 20.36%, 16.90 g/g, 75.9°C, and 5196.3 cP). In contrast, the average particle size (APS) (24.31 μm), resistant starch content (45.80%), and gel hardness (509.70 g) were lower than those of DG (25.68 μm, 52.13%, and 617.53 g).ConclusionsSignificant structural differences exist between WG and DG, with APS and AP chain length distribution being the primary factors contributing to the distinct physicochemical characteristics of the two pea starches.Significance and NoveltyThis is the first detailed comparison of the properties of commercial pea starch produced by two different processes. The results provide theoretical insights that underpin the use of pea starch in functional foods and promote the development of new starch‐based products.

Effects of partial precipitation and freeze-drying on morphology and physicochemical properties of rice starch hydrolysates

Agricultural bio-catalysis is of immense scientific interest due to its increasing importance in the efforts for more sustainable agriculture while optimizing environmental impacts. In our studies, native rice starch was hydrolyzed with various alpha-amylase concentrations (0, 0.1, 0.2, and 0.3% w/w of starch) at 50°C for 20 min; then purified by partial precipitation (PP) with organic solvents, or freeze-drying (FD) without further purification. The rice starch hydrolysates (RSH) produced by different methods (PP or FD) were determined for dextrose equivalent (DE), morphology, and some physicochemical properties including bulk density, moisture content, hygroscopicity, and water solubility. The results showed that at the same alpha-amylase treatment conditions, the RSH obtained by the PP method had lower DE values and production yields than those of RSH obtained by FD method. The FD-RSH had higher DE values, lower bulk densities and moisture contents, higher hygroscopicity and water solubility. In morphology, the PP-RSH (DE 10.2) had a larger particle size and more condensed microstructure compared to the FD-RSH of almost similar DE 13.5. These findings showed that the PP method resulted in lower-DE RSH with different morphological and physicochemical properties compared to those obtained by the FD method.

Tailored culture strategies to promote antimicrobial secondary metabolite production in Diaporthe caliensis: a metabolomic approach

BackgroundIn the search for new antimicrobial secondary metabolites of fungi, optimizing culture conditions remains a critical challenge, as standard laboratory approaches often result in low yields. While non-selective methods, such as modifying culture media, have been effective in expanding the chemical diversity of fungal metabolites, they have not yet established a direct link to key process parameters crucial for further optimization. This study investigates the capacity of Diaporthe caliensis as a biofactory for biologically active secondary metabolites, employing tailored culture media to explore the relationship between chemical diversity and critical process variables.ResultsThe metabolomic profiles, antibacterial activities, and production yields of the extracts were analyzed to progressively adjust the culture conditions. This study was conducted in five steps, evaluating carbon and nitrogen source concentration, nitrogen source type, salt supplementation, and pH adjustment. Altering the rice starch concentration affected biomass yield per unit of oxygen consumed, while modifications to the nitrogen source concentration influenced both the bioactivity and chemical space by Diaporthe caliensis. Despite changes at the metabolome level, the extracts consistently exhibited potent antibacterial activities, influenced by the nitrogen source, added salts and pH adjustments. For instance, when using corn steep liquor and rice starch, supplemented with micronutrients, different metabolites were produced depending on whether buffer or water was used, though both conditions showed similar antibacterial activities (IC50 ≈ 0.10 mg mL− 1 against Staphylococcus aureus and ≈ 0.14 mg mL− 1 against Escherichia coli). In the treatment where buffer was used to stabilize pH change, there was an increase in the production of phomol-like compounds which are associated with known antibiotic properties. In contrast, in the treatments using water, the drop in pH stimulated the production of previously unidentified metabolites with potential antimicrobial activity.ConclusionsThis study proposes a strategic methodology for the tailored formulation of culture media aiming to promote the biosynthesis of diverse secondary metabolites. This approach revealed the critical role of nutrient limitation and pH regulation in stimulating the production of polyketide-lactone derivatives, including the antibiotic phomol. Ultimately, the systematic, custom-designed culture conditions developed in this work offer a promising strategy for expanding the chemical diversity of Diaporthe caliensis, while providing valuable insights into the key parameters needed for optimizing this fungal biofactory.Graphical

Unraveling the changes of physical properties and nanostructures of rice starch incorporated with pregelatinized rice starch paste during gelatinization

In this study, we aimed to determine the influence of pregelatinized rice starch paste (PRSP) on the gelatinization of native rice starch, including its rheology and nanostructure. Gelatinization of PRSP-incorporated rice starch in excess water while heating at 5 °C/min was analyzed via rheometry, differential scanning calorimetry (DSC) and synchrotron small angle X-ray scattering (SAXS). Rheometry revealed that the addition of PRSP resulted in a more stable rice starch–water system at sub-gelatinization temperatures. A decrease from around 3000 Pa to lower than 1000 Pa in G′ was observed in the samples with PRSP after heating over 80 °C compared to that of the native starch. The sol-gel transition point of the starch–water system was altered by PRSP. DSC results showed no significant differences between the PRSP-incorporated and native starch. SAXS analysis revealed that the scattering invariant up to the gelatinization onset temperature was increased by the addition of PRSP due to the large volume fraction of the lamellar stacks. Correlation function-based structural parameters of the samples with PRSP changed earlier than those of native starch during heating due to the annealing effect. Moreover, the melting temperature of lamella of native starch was around 70 °C while those of the sample with PRSP were around 65 °C. Analysis of the radius of gyration (Rg) of the micellar structure after complete gelatinization indicated that Rg of native starch sample increased from 3.9 to 6.2 nm while that of the sample with 20% PRSP remained unchanged (≈ 4.3 nm). Overall, our results suggest that PRSP inhibits the swelling of rice starch during gelatinization and changes its rheological properties.

Effects of high hydrostatic pressure treatment on in vitro digestibility and in vivo glycemic response of sweet potato flour: Effects of HHP on digestibility and glycemic response of sweet potato starch

Sweet potato is a rich source of resistant starch, fibre, vitamins and minerals, which is associated with healthy benefits. In this study, the effects of high hydrostatic pressure (HHP) treatment at 200–600 MPa on the digestibility of sweet potato flour (SPF) through starch composition analysis, in vitro digestion assays, and glycemic index (GI) and response in diabetic mice. Changes in the morphology of starch granules post-treatment were observed using an scanning electron microscope (SEM). Treatments at 400 and 600 MPa increased amylose in sweet potato starch and significantly increased the proportion of slowly digestible starch (SDS), as indicated by in vitro digestion assays. Resistant starch content decreased, with no significant change in rapidly digestible starch. Peak glucose levels in diabetic mice post-consuming SPF treated at 400 and 600 MPa were 476 and 514, respectively, significantly lower than 608 in the control group. The area under the curve (AUC) of 400 MPa treated-SPF is 14% lower than control SPF. The GI of SPF in the control group was 78.6, reducing to 66.2 and 68.3 post-HHP treatment at 400 and 600 MPa, respectively, with no significant difference in the 200 MPa group from that of the control group. SEM observations showed that damage to starch granules increased with increasing processing pressure. HHP caused the starch granules to gelatinize and recoagulate, forming an irregular shape. The HHP treatment changed the composition of SPF, significantly increasing SDS content and it stabilized postprandial blood glucose levels and reduced GI, rendering it a potential method to develop processed products of sweet potatoes with a low GI, providing a novel technical option for developing health-promoting products.

Effect of cold plasma on the physicochemical characteristics of granular cold water swelling maize starch

Granular cold water swelling (GCWS) starch is a physically modified starch with several potential applications in instant foods. Recently, some studies have revealed the beneficial effects of cold plasma (CP) treatment on improving the functional properties of starch. However, the effects of CP on GCWS has not been addressed yet. Therefore, this study assessed the influence of dielectric barrier discharge (DBD) cold plasma treatment time (1, 2, 3, and 4 min) on various attributes of GCWS maize starch. Increasing the CP treatment time increased the water absorption, solubility, viscosity, and freeze-thaw stability of GCWS maize starch, while, decreased its relative crystallinity and turbidity. FTIR results indicated that the functional groups along backbone remained unchanged upon CP treatment. Morphological analysis revealed that the starch granules preserved their integrity during CP treatment. However, increasing the duration of CP treatment resulted in the formation of micro-cavities and fissures on the surface of GCWS starch granules. The textural and rheological characteristics of GCWS starch pastes were improved by CP treatment. It seems that CP treatment might lead to an interconnected structure within the starch network and reinforce the starch paste.

Effect of transglutaminase on the interaction of protein and rice starch

Effect of transglutaminase on the interaction of protein and rice starch

Inhibitory effect of different degree of polymerization inulin on the retrogradation of rice starch gels and fresh rice noodles

This experiment investigated the effects of inulin (IN) with different degrees of polymerization at various addition levels on the water distribution, textural properties, microscopic and molecular structure, cooking quality, and sensory evaluation of rice starch (RS) and fresh rice noodles (FRN) during storage. The results showed that the addition of three kinds of IN significantly reduced the transverse relaxation time T2 of the starch gels system during storage, effectively combined the water molecules in the system. Meanwhile, the addition of IN reduced the increase of starch gels hardness during storage, inhibiting the retrogradation of the starch gels. Fourier transform infrared results further confirmed that IN could suppress the retrogradation behavior of starch during storage by controlling the rearrangement or recrystallization of starch molecular chains. The scanning electron microscopy results of FRN after 7 d of storage showed that the addition of IN enhanced the water retention capacity of FRN during the retrogradation process, which was consistent with the water distribution results. Furthermore, all three kinds of IN improved the cooking and sensory quality of FRN during storage, and the lower the degree of polymerization, the better the anti- retrogradation effect and the quality of the FRN.

Development of starch-based films with enhanced hydrophobicity and antimicrobial activity by incorporating alkyl ketene dimers and chitosan for fruit preservation

Using hydrophobic antimicrobial food packaging films offers significant opportunities to extend the shelf life of food. This study developed a hydrophobically modified starch-based film incorporating alkyl ketene dimers (AKDs) and chitosan (CS) for mango preservation. The film's physicochemical properties and structural characteristics were comprehensively analyzed. The successful integration of AKDs into the starch (ST) matrix was confirmed through FT-IR, XRD, XPS, and SEM techniques, which revealed the establishment of β-ketoester linkages via esterification. The addition of AKDs significantly enhanced the film's hydrophobicity and mechanical properties, attributed to chemical cross-linking and the formation of intermolecular hydrogen bonds. In an eight-day room temperature storage test, the ST-AKD/CS films effectively extended the shelf life of mangoes by four days compared to the control and ST groups. As all components of the film are environmentally friendly and biodegradable, these hydrophobic films offer a promising solution for prolonging the freshness of mangoes while maintaining sustainability.

The molecular structure of leaf starch from three cereal crops

Plants produce storage and transient starches in seeds and in leaves, respectively. Understanding molecular fine structure and synthesis of transient starch can help improve plant quality (e.g. by helping breeders produce slowly digested amylopectin, which is beneficial for human nutrition). In the present study, leaf starches from rice, wheat and barley were isolated with cesium chloride gradient centrifugation. Starch fine structure was measured using size-exclusion chromatography and flurophore-assisted carbohydrate electrophoresis. The chain-length distribution (CLD) of amylopectin leaf starch was trimodal in wheat and barley leaf starch. The global peak of leaf starch was at degree of polymerization (DP) 22, and leaf amylopectin containeds more long branches, which are generally considered to hinder starch digestion, suggesting that leaf-specific starch synthesis enzymes could be expressed in the endosperm by genetic modification to produce amylopectin with more long chains, which would be more slowly digested, with advantages to human health. HypothesisThe biosynthetic processes for leaf starch and storage starch in a given plant species will show significant differences.

Effects of wheat cultivar, bran concentration and endoxylanase on the thermomechanical, viscoelastic and microstructural properties of whole wheat flour dough

Globally, it is challenging to promote the market of whole wheat product due to its undesirable product quality issues. To overcome this remarkable challenge, this research was to work on the constructive strategies for mitigating the negative impact of wheat bran. As such, the objective of this research was to investigate how the wheat cultivar, bran concentration and endoxylanase affected dough thermomechanical properties, viscoelasticity and microstructure by a combined use of mixolab, rheometry, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). A cultivar-dependent discrimination for the bran tolerance was observed to suggest the suitable wheat cultivars for whole wheat manufacturing. Bran addition positively affected dough mechanical and viscoelastic properties, i.e., larger dough mechanical weakening (C2) and gel strength, and it negatively affected starch gelatinization (C3) and retrogradation (C5). However, the main conclusions are below. The endoxylanase was incorporated to invert the bran impact on the above properties of dough. Endoxylanase was also used to develop a better integrity of gluten network, larger coverage of starch granules and even distribution of gas cells. Outcomes from this work will provide a practical guidance for improving the high-fibre product quality and promoting its market growth.

Comparative study on structure and properties of oxidized starch under combined treatments of ultrasound and enzyme.

The present study has developed a novel, eco-friendly method for the modification of potato starch by incorporating ultrasonic pretreatment, enzymatic hydrolysis, and oxidation with hydrogen peroxide. The technical parameters of the modification were optimized through response surface methodology to give optimum conditions. The results showed that the combination of ultrasound and enzyme disrupted the microstructure and crystalline structure of the starch granules, thus allowing for easier penetration of modifying agents and increasing the reactivity of the starch. Additionally, this starch exhibited higher thermal stability, with improved rheological properties compared to conventionally modified starch. This combined modification approach further reduced agglomeration of starch granules usually achieved by single-agent modification and increased the solubility of starch. Thus, this eco-friendly method is effective for the modification of potato starch.

Enhanced Stability, Quality and Flavor of Bread through Sourdough Fermentation with Nisin-Secreting Lactococcus lactis NZ9700

Sourdough bread is traditionally made fermenting a starter with high-gluten flour and water among other ingredients. However, the stability and safety of naturally fermented sourdough cannot always be fully guaranteed. In this study, Lactococcus lactis NZ9700, which actively secretes the bacteriocin nisin, was employed for sourdough fermentation and bread production. Three control groups were established to explore the complex and diverse changes occurring during sourdough fermentation, including a non-acidified dough group, a chemically acidified dough group, and a sourdough group fermented with L. lactis NZ9000 (which does not secrete nisin). The results demonstrate that fermentation with L. lactis leads to a rapid increase in colony-forming units (CFU) , stabilizing the pH of the sourdough at approximately 4.2 within 12 h. The in situ production of acids, sugars, and other metabolites during sourdough fermentation has a significant impact on the dough's microstructure. Microstructural analysis reveals that sourdough fermentation results in a more organized gluten network, with the L. lactis NZ9700 group exhibiting a more refined microstructure and fewer prominent starch granules. Furthermore, L. lactis NZ9700 produces stable nisin during fermentation, which persists even after baking, providing continuous antimicrobial protection to the final product. This reduced fungal contamination and extended the shelf life of the bread. Last, the growth of L. lactis NZ9700 during the early stages of fermentation provides more alcohols and ketones to the breads, endowing the sourdough breads with richer and more complex flavor profiles.

Gem-like starch granules engineered with different crystalline starches

Gem-like starch granules engineered with different crystalline starches

Micronized versus super-conditioned corn: Effects on starch digestion, performance, and blood metabolites of Holstein dairy calves.

Micronization, a dry-heat process, generates infrared electromagnetic short waves that can affect starch granules and gelatinization. A new method of corn processing, super-conditioned corn, a moisture-heat process, has potential to increase starch digestion and performance in calves. Therefore, incorporating super-conditioned or micronized corn in starter feed may enhance growth performance by improving total-tract starch digestion. This study aimed to evaluate the impacts of heat (micronizing and super-conditioning) and conventional processing method (grinding) of corn grain on the starch digestion, skeletal growth, feeding behavior, biochemical status of blood, and performance of dairy calves. Thirty-six Holstein female dairy calves [40 ± 1.8 kg of body weight (BW)] were assigned to 3 groups that starter feed contained 58% of one of the following corn types: the control group with dry ground corn (n = 12, GC), a group receiving micronized corn (n = 12, MC), or a group receiving super-conditioned corn (n = 12, CC). Three mash starter feeds with an identical nutritional composition were blended with 5% chopped alfalfa hay and fed to individually housed calves from wk 1 to 11 of their birth. All calves were fed 4 L/d of pasteurized whole milk twice daily since d 3 to wk 8, followed by 2 L/d of morning feeding from wk 10 to 11 of age. Calves were weaned on wk 9 and remained in the study until wk 11. Intake of feed was reported weekly and body measurements were recorded on d 3, wk 9, and 11 of age. Blood samples were collected from jugular vein on the last day of wk 11 of age. Behavioral data were recorded by direct observations of all the calves equal to 12 h before (d 61 to 63 of age) and 12 h after (d 75 to 77 of age) weaning. Final BW, average daily gain (ADG) and feed efficiency (FE) increased in calves fed CC compared with GC and MC in the overall period. An interaction of treatment × week was detected for total DMI on wk 10 and 11 of age where it was lower in the CC than in the GC and MC counterparts. However, feeding starter feed containing CC increased total-tract DM and starch digestibility compared with MC and GC. Rumination time and eating time decreased in CC calves than MC and GC calves. Moreover, significant treatment × week interactions were observed for the skeletal growth. On wk 11 of age, compared with the GC and MC, wither height and hip height was greater in calves fed CC. The CC formulation increased the concentrations of insulin and glucose fraction in blood while these parameters were not different between GC and MC. In conclusion, CC improved the ADG, FE, and skeletal growth, while reduced total DM intake during post-weaning period compared with MC and GC. Based on the positive changes in ADG, FE, and skeletal growth; CC was superior to the MC and GC, due to improved starch digestion.

Orange peel essential oil in rice starch encapsulating material for antimicrobial application against Escherichia coli

Orange peel essential oil in rice starch encapsulating material for antimicrobial application against Escherichia coli

Improved engineered fungal-bacterial commensal consortia simultaneously degrade multiantibiotics and biotransform food waste into lipopeptides

Resource utilization of food waste is necessary to reduce environmental pollution. However, antibiotics can enter the environment through food waste, resulting in antibiotic residues, which pose potential risks to human health. In this study, commensal artificial consortia were constructed through intercellular adaptation to simultaneously degrade antibiotics and bioconvert food waste into lipopeptides. The biodegradation efficiency of oxytetracycline in the three-strain consortium, which contained lipopeptide-producing Bacillus amyloliquefaciens HM618, high-level proline-producing Corynebacterium glutamate, and laccase-producing Pichia pastoris, was around 100% in the food waste medium at 72 h; this was higher than that in the pure culture of P. pastoris-Lac. Sulfamethoxazole could be removed at 48 h. However, the lipopeptide level in the three-strain consortium was only 77 mg/L. The four-strain consortium containing free fatty acid-producing Yarrowia lipolytica improved the lipopeptide level to around 218 mg/L. The degradation efficiency of oxytetracycline in the four-strain consortium was 100% at 48 h; however, only 56% of the sulfamethoxazole was removed over 96 h. Three five-strain consortia were formed by introducing recombinant manganese peroxidase-producing P. pastoris, recombinant HM618 with high-level amylase, and serine-producing C. glutamicum. In low starch food waste, the highest degradation efficiency of sulfamethoxazole was 71%, while oxytetracycline could be completely removed at 48 h. However, oxytetracycline inhibited starch degradation and lipopeptide production. The high level of starch improved lipopeptide synthesis to 1,280 mg/L. The results of this study provide a feasible strategy for the resource utilization of inferior biomass food waste.

Bioavailability of encapsulated rosmarinic acid and β-Carotene in beef Sausages: A Caco-2 cell study

In this study, we examined the bioavailability and functionality of rosmarinic acid and β-carotene in beef sausages using Caco-2 cell models. Digesta from enriched sausages showed high antioxidant activity, with 89.2% DPPH and 87.65% ABTS inhibition. Micrographs revealed the impact of co-delivery during digestion, with significantly higher levels of rosmarinic acid in sample B (80% rice starch & 20% rice protein) and β-carotene in sample C (60% rice starch & 40% rice protein) compared to the control digesta, attributed to the rice-starch network ensuring targeted release. During the total absorption of sample C, rosmarinic acid was more bioavailable than β-carotene. The carrier material structure plays a crucial role in the release of bioactive compounds into the mixed micellar phase. Encapsulation and incorporation into suitable food matrices such as meat can enhance the bioavailability of rosmarinic acid and β-carotene, potentially leading to the production of healthier meat products. Caco-2 cells, which resemble human intestinal cells, were used to study the absorption and transport of bioactive compounds post-gastrointestinal digestion. In-depth knowledge of the digestibility of specific dietary matrices is required to understand the metabolic dynamics of these substrates, which ultimately affect their bioavailability. The creation of functional meat products using rosmarinic acid and β-carotene ensures their complete utilisation.