Comparison of structural and physicochemical properties of starches from five coarse grains

Multi-scale structural heterogeneity of glutinous rice starch in different varieties: A determinant of physicochemical properties and digestibility

This study systematically investigated the multi-scale structure of glutinous rice starches (WK1, WK2, WK3, TN2072, and HY) from five varieties, and analyzed physicochemical properties and in vitro digestibility to reveal structure-property relationships. TN2072 starch exhibited distinctive structural characteristics showing a lower gyration radius (245.77 nm) and crystalline lamellar thickness (5.7249 nm), demonstrating a more compact molecular structure than those of the other starches. The proportion of short chains of amylopectin (DP 6-12, 32.9-42.16 %) was negatively correlated with both ΔH (7.91-11.23 J/g) and gelatinization temperature (70.15-80.70 °C), while showed positive correlation with peak viscosity (2185-2866 cP). Structural parameters of starch such as high double helix content, high relative crystallinity, and low lamellar thickness were associated with lower enzymatic hydrolysis rates in starch and a high content of resistant starch. Meanwhile, a high proportion of medium and long chains (DP ≥ 13) was conducive to the formation of ordered, compact crystal and lamellar structures, which was the key determinant for high gelatinization temperature and low digestibility. These findings revealed that the multi-scale structure of glutinous rice starch varied with different varieties, and determined the physicochemical properties and digestibility, providing a theoretical foundation for variety selection for specific industrial applications.

Sorghum starch review: Structural properties, interactions with proteins and polyphenols, and modification of physicochemical properties

Sorghum, a gluten-free carbohydrate source with high antioxidants and resistant starch, contains anti-nutrients like phytic acid, tannin, and kafirin. Interactions with starch and proteins result in polyphenol-starch, starch-kafirin, and tannin-protein complexes. These interactions yield responses such as V-type amylose inclusion complexes, increased hydrophobic residues, and enzyme resistance, reducing nutrient availability and elevating resistant starch levels. Factors influencing these interactions include starch composition, structure, and Chain Length Distribution (CLD). Starch structure is impacted by enzymes like ADP-glucose pyrophosphorylase, starch synthases, and debranching enzymes, leading to varied chain lengths and distributions. CLD differences significantly affect crystallinity and physicochemical properties of sorghum starch. Despite its potential, the minimal utilization of sorghum starch in food is attributed to anti-nutrient interactions. Various modification approaches, either direct or indirect, offer diverse physicochemical changes with distinct advantages and disadvantages, presenting opportunities to enhance sorghum starch applications in the food industry.

Characterization and Comparison of Structure and Physicochemical Properties of Highland Barley Starch of Different Colors

Domesticated highland barley is an important starch reserve and has differently colored grains, owing to different genotype backgrounds and cultivation environments. In this study, black, purple, blue, and yellow highland barley varieties were planted under the same cultivation conditions, and their starch distribution, structural characteristics, and physicochemical properties were analyzed. The apparent amylose content was highest in the purple variety (20.26%) and lowest in the yellow variety (18.58%). The different varieties had three subgroups and A-type crystalline structures, but the particle size and relative crystallinity (25.67-27.59%) were significantly different. In addition, the weight average molecular weight (6.72 × 107 g/mol), area ratio of APs to APL (2.88), relative crystallinity (27.59%), and 1045/1022 (0.730 cm-1) of starch were higher in yellow highland barley (YHB), forming a stable particle structure and increasing the Tp and PV of its starch. A cluster heat map showed that starches from differently colored highland barley vary in fine structure, water solubility, swelling power, and thermal and pasting properties. This study provides a reference for the high-quality breeding of colored highland barley and its utilization in food and non-food industries.

Sorghum starch: Composition, structure, functionality, and strategies for its improvement

Sorghum (Sorghum bicolor L. Moench) is increasingly recognized as a resilient and climate-adaptable crop that holds significant potential to enhance global food security sustainably. Compared to other common cereal grains, sorghum boasts a more diverse nutritional profile. The starch component accounts for more than 80% of total sorghum grain weight. Sorghum starch functionality and diverse industrial applications are determined by its physiochemical properties, including pasting, gelatinization, retrogradation, texture, and digestion kinetics. This review provides a comprehensive evaluation of the morphology, minor composition, crystalline structure, fine molecular structure, and structure-function relationships of sorghum starch. It further explores how these properties can be optimized through chemical, physical and enzymatic modifications to extend the applications of sorghum starch. Additionally, the review highlights the role of key enzymes in the biosynthesis of sorghum starch and discusses how biological modifications, enabled by advanced genetic and molecular breeding strategies, can modify starch quality. This review also provides a foundation for developing tailored sorghum varieties with enhanced starch properties that can expand applications of sorghum both in food and non-food industries, potentially contributing to global food security and sustainable agriculture.

Supramolecular structure and in vitro digestive properties of plasma-treated corn starches varying in amylose content

The effects of plasma treatment on the multi-scale structure and in vitro digestibility of maize starch with different amylose contents were systematically evaluated. The results demonstrated that all maize starches' molecular weights (MW) decreased when treated with plasma, among which the MW of waxy maize starch displayed the largest reduction. Plasma treatment led to an increase in the thickness of the semi-crystalline lamellae and double helix proportions of waxy and normal maize starches. However, high-amylose maize starch presented a less ordered structure by plasma treatment. Additionally, larger pores and channels were observed on the surface of plasma-treated waxy and normal maize starch granules. Moreover, deposits were displayed on the surface of high-amylose maize starch granules. These changes increased the in vitro digestibility and hydrolysis rate of three starches after plasma treatment. Notably, plasma treatment caused diverse alterations in the structure and functionality of maize starch varying in amylose content, leading to maize starch with better digestibility, therefore being used as an ingredient for functional foods.

Structural, properties and digestion in vitro changes of starch subjected to high pressure homogenization: An update review

High pressure homogenization (HPH) is considered as a promising method for improving the ideal metabolic reaction of starch-based foods in the body, but there is still no comprehensive understanding of the structure-property relationship of starch treated with HPH. This study reviews the advantages and limitations of HPH in starch-based foods processing in recent years. It also elaborates the bidirectional regulation of HPH on starch structure-property and its potential in improving nutritional quality, which includes the regular modification effects of HPH on the multi-scale structure, physicochemical properties, and digestion characteristics of starch. It was found that HPH could lead to the degradation of amylopectin, destruction of amorphous structure, and homogenization of fine particles, promoting gelatinization and ultimately endowing starch with good solubility and digestibility. Moreover, it could reorganize and reorder the internal starch chains, or cause the particles to disintegrate into an amorphous state, thereby enhancing the anti-digestibility of starch. The interaction of starch with different nutrients during the HPH process could be further investigated in future studies and explored with other techniques for structure-property modifications, which would help expand the development of personalized starch foods to meet growing consumer demands.

Study on Quality and Starch Characteristics of Powdery and Crispy Lotus Roots

Nine varieties of lotus root (Suining, Xinhe, Zaohua, Zhonghua, L0014, L0013, Cuiyu, L0011, and Zhenzhu) were selected as the research materials to compare their differences in physical, chemical, and starch characteristics before and after boiling, frying, and microwaving. The results showed that Zhenzhu, Xinhe, L0013, Cuiyu, and Zhonghua belong to the crispy lotus root type, while L0011, L0014, Zaohua, and Suining belong to the powdery lotus root type. Furthermore, the nine varieties were characterized for their starch by optical micrograph (OM), polarized micrograph (PM), scanning electron micrograph (SEM), attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), carbon-13 cross-polarization/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR), and differential scanning calorimetry (DSC). The starch granule of powdery lotus root appeared to be larger than that of crispy lotus, and ATR-FTIR studies revealed that the outer layer of starch granules from nine different varieties of lotus root had a highly organized structure. Moreover, XRD and 13C CP/MAS NMR analyses revealed that starch from eight lotus varieties (Suining, Xinhe, Zaohua, Zhonghua, L0014, L0013, Cuiyu, L0011) belong to the A-crystal type, while starch from Zhenzhu belongs to the CA-crystal type. The starch from powdery lotus root exhibited higher crystallinity, as well as increased gelatinization temperature and enthalpy, indicating that its crystal structure was relatively superior compared to that of crispy lotus starch. The short-range order degree, crystallinity, gelatinization temperature, and heat enthalpy of lotus starch decreased after boiling and frying but increased to varying extents after microwaving. Additionally, the heat resistance and stability of starch particles from crispy lotus root were improved after microwave treatment.

Enhancing the nutritional value and antioxidant properties of foxtail millet by solid-state fermentation with edible fungi

Foxtail millet is typically dehulled before consumption or processing. However, foxtail millet bran also contains abundant phenolic compounds and other nutrients. Edible fungi have rich extracellular enzyme systems; are environmentally friendly and safe for consumption; and have been shown to effectively degrade lignin and cellulose. This study aimed to screen edible fungi that can effectively ferment undehusked foxtail millet, improving its nutritional value and antioxidant properties through solid-state fermentation (SSF). The results demonstrated that fermentation utilizing Pleurotus geesteranus exhibited significant improvements in both the phenolic compound content and antioxidant properties of foxtail millet, with the optimal fermentation period determined to be 30 days. The physical and functional properties of fermented undehusked foxtail millet (FFM) flour were effectively improved, increasing crude protein, vitamin C, and crude polysaccharide contents by 11.46%, 27.78%, and 54.17%, respectively. In vitro scavenging activities of FFM were 73.19%, 93.86%, and 63.75% for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+), and superoxide anion radicals (O2 -), respectively. The total antioxidant capability (T-AOC) and superoxide dismutase (SOD) activity of FFM were 1.01 mM Trolox equivalents (TE)/g and 89.05 U/g, respectively. Additionally, T-AOC, SOD, and glutathione peroxidase (GSH-Px) activities increased, whereas malondialdehyde (MDA) levels decreased in the heart, liver, and kidneys of mice treated with FFM flour, indicating enhanced antioxidant capacity. Therefore, fermentation with edible fungi is suitable for improving the nutritional composition and antioxidant properties of foxtail millet.

Value addition of mango kernel for development and characterization of starch with starch nanoparticles for packaging applications

The present research was conducted to explore the potential of mango kernel starch from the Chaunsa variety to develop starch and starch nanoparticles (SNPs) based films. The investigation included starch isolation from mango kernel followed by the preparation of SNPs by acid hydrolysis and a thorough examination of various physicochemical properties for film formation. The properties of SNPs were found to be distinctly different from those of native starch. SNPs exhibited an aggregated form with an irregular surface, whereas native starch had an oval and elongated shape with a smooth surface. X-ray diffraction (XRD) analysis confirmed that the starch type in SNPs was of the A-type. Additionally, the pasting properties of SNPs were minimal due to the acid hydrolysis process. SNP-based composite film was developed with (5 %) SNP concentration added. This successful incorporation of SNPs enhanced biodegradability, with complete degradation occurring within three weeks. Moreover, the composite films displayed increased burst strength, measuring 1303.51 ± 73.7 g, and lower water vapor transmission rates (WVTR) at (7.40 ± 0.50) × 10-3 g per square meter per second and reduced water solubility at 35.32 ± 3.0 %. This development represents a significant advancement in the field of eco-friendly packaging materials.

Rod-Shaped Starch from Galanga: Physicochemical Properties, Fine Structure and In Vitro Digestibility

This work investigated the physicochemical properties, structural characteristics, and digestive properties of two non-conventional starches extracted from Galanga: Alpinia officinarum Hance starch (AOS) and Alpinia galanga Willd starch (AGS). The extraction rates of the two starches were 22.10 wt% and 15.73 wt%, which is lower than widely studied ginger (Zingiber officinale, ZOS). But they contained similar amounts of basic constituents. AOS and AGS showed a smooth, elongated shape, while ZOS was an oval sheet shape. AOS and ZOS were C-type starches, and AGS was an A-type starch. AOS showed the highest crystallinity (35.26 ± 1.02%) among the three starches, possessed a higher content of amylose (24.14 ± 0.73%) and a longer amylose average chain length (1419.38 ± 31.28) than AGS. AGS starch exhibits the highest viscosity at all stages, while AOS starch shows the lowest pasting temperature, and ZOS starch, due to its high amylose content, displays lower peak and trough viscosities. Significant differences were also found in the physicochemical properties of the three starches, including the swelling power, solubility, thermal properties, and rheological properties of the three starches. The total content of resistant starch (RS) and slowly digestible starch (SDS) in AOS (81.05%), AGS (81.46%), and ZOS (82.58%) are considered desirable. These findings proved to be valuable references for further research and utilization of ginger family starch.

Effects of soaking glutinous sorghum grains on physicochemical properties of starch

Glutinous sorghum grains were soaked (60-80 °C, 2-8 h) to explore the effects of soaking, an essential step in industrial processing of brewing, on starch. As the soaking temperature increased, the peak viscosity and crystallinity of starch gradually decreased, while the enzymatic hydrolysis rate and storage modulus first increased and then decreased. At 70 °C, the content of amylose, the enzymatic hydrolysis rate of starch, and the final viscosity first increase and then decrease with the increase of soaking time, reaching their maximum at 6 h, increased by 53.1 %, 11.0 %, and 10.4 %, respectively, as compared with the non-soaked sample. At 80 °C (4 h), the laser confocal microscopy images showed a network structure formed between the denatured protein chains and the leached-out amylose chains. The molecular weights of starch before and after soaking were all in the range of 3.82-8.98 × 107 g/mol. Since 70 °C is lower than that of starch gelatinization and protein denaturation, when soaking for 6 h, the enzymatic hydrolysis rate of starch is the highest, and the growth of miscellaneous bacteria is inhibited, which is beneficial for subsequent processing technology. The result provides a theoretical basis for the intelligent control of glutinous sorghum brewing.

Gluten-starch microstructure analysis revealed the improvement mechanism of Triticeae on broomcorn millet (Panicum miliaceum L.)

Understanding the mechanism by which Triticeae improves the quality of broomcorn millet (BM) is key to expanding the use of this crop to address food crises and food security. This study aimed to explore the effects of Triticeae on the disulfide bonds, secondary structures, microstructure, and rheological properties of BM dough, and to investigate the potential food applications of BM. Gluten protein, intermolecular SS, and β-Sheets content of the reconstituted doughs were significantly improved compared with BM dough, which improved disorderly accumulation of starch and gluten-starch interaction in BM dough. CLSM analysis showed that broomcorn millet-common wheat (BM-CW) and broomcorn millet-durum wheat (BM-DW) also possessed larger protein areas, smaller lacunarities, and better gluten-starch interactions in the reconstituted doughs. Disulfide bonds were positively correlated with the gluten network structure, and more disulfide bonds were formed in BM-CW (3.86 μmol/g), which promoted stronger mechanical resistance in BM-CW. Therefore, the combination of BM flour with CW and DW flours had better dough elasticity and stability. Finally, a potential evaluation and optimization scheme for BM as a cooked wheaten food is proposed to improve the reference for future food security and dietary structure adjustment of residents.

Comparison of the fine structure and physicochemical properties of proso millet (Panicum miliaceum L.) starch from different ecological regions

Field experiments were conducted to evaluate the morphology, granule size, fine structure, thermal properties, and pasting properties of starch from a waxy (139) and a non-waxy (297) varieties of proso millet grown in Yulin (YY) and Yangling (YL). Compared with the starches from the two varieties grown in YY, the starches from the two varieties grown in YL exhibited higher relative crystallinities, 1045/1022 cm-1 ratio, and amounts of amylopectin long branch chains (APL) but lower 1022/995 cm -1 ratio, amounts of amylopectin short branch chains (APs), and APs/APL ratios. Starches from YL also synthesized long branch-chain amylopectin to enhance intermolecular interactions and form a stable granular structure, which resulted in increased starch gelatinization temperature, enhanced shear resistance, and reduced setback viscosity. Starch from the waxy (139) variety has good application prospects in the food industry because of its high gelatinization temperature and light transmittance and low setback value, which can be ascribed to its extremely low amylose content, polydispersity index, high molecular weight, and dispersed molecular density. It may serve as a reference for applying proso millet starches in the food industry and developing breeding programs to improve starch quality.

Native and modified starches from underutilized seeds: Characteristics, functional properties and potential applications

Seeds represent a potential source of starch, containing at least 60-70% of total starch, however many of them are treated as waste and are usually discarded. The review aim was to analyze the characteristics, functional properties, and potential applications of native and modified starches from underutilized seeds such as Sorghum bicolor L. Moench (WSS), Chenopodium quinoa, Wild. (QSS), Mangifera indica L. (MSS), Persea americana Mill. (ASS), Pouteria campechiana (Kunth) Baehni (PCSS), and Brosimum alicastrum Sw. (RSS). A systematic review of scientific literature was carried out from 2014 to date. Starch from seeds had yields above 30%. ASS had the higher amylose content and ASS and RSS showed the highest values in water absorption capacity and swelling power, contrary to MSS and PCSS while higher thermal resistance, paste stability, and a lower tendency to retrograde were observed in MSS and RSS. Functional properties such as water solubility, swelling power, thermal stability, low retrogradation tendency, and emulsion stability were increased in RSS, WSS, QSS, and MSS with chemical modifications (Oxidation, Oxidation-Crosslinking, OSA, DDSA, and NSA) and physical methods (HMT and dry-heat). Digestibility in vitro showed that WSS and QSS presented high SDS fraction, while ASS, MSS, PCSS, and HMT-QSS presented the highest RS content. Native or modified underutilized seed starches represent an alternative and sustainable source of non-conventional starch with potential applications in the food industry and for the development of healthy foods or for special nutritional requirements.

Structure and genetic regulation of starch formation in sorghum (Sorghum bicolor (L.) Moench) endosperm: A review

This review focuses on the structure and genetic regulation of starch formation in sorghum (Sorghum bicolor (L.) Moench) endosperm. Sorghum is an important cereal crop that is well suited to grow in regions with high temperatures and limited water resources due to its C4 metabolism. The endosperm of sorghum kernels is a rich source of starch, which is composed of two main components: amylose and amylopectin. The synthesis of starch in sorghum endosperm involves multiple enzymatic reactions, which are regulated by complex genetic and environmental factors. Recent research has identified several genes involved in the regulation of starch synthesis in sorghum endosperm. In addition, the structure and properties of sorghum starch can also be influenced by environmental factors such as temperature, water availability, and soil nutrients. A better understanding of the structure and genetic regulation of starch formation in sorghum endosperm can have important implications for the development of sorghum-based products with improved quality and nutritional value. This review provides a comprehensive summary of the current knowledge on the structure and genetic regulation of starch formation in sorghum endosperm and highlights the potential for future research to further improve our understanding of this important process.

Effect of environment and variety on the physicochemical properties of Tartary buckwheat starch

BACKGROUND

Starch is a major nutrient in the human diet and has been widely used as an ingredient in many food and non-food applications. However, the research on the quality characteristics of Tartary buckwheat is lagging behind, and there is a lack of high-quality special varieties, which makes it difficult to become a popular food. The physicochemical properties of Tartary buckwheat starch may be affected by different environments and varieties, and the stability of planted varieties in different regions is also an important issue in current research.

RESULTS

The average amylose content and pasting properties of Dingxi Tartary buckwheat were lower, while the solubility, transparency, relative crystallinity and gelatinization enthalpy were higher compared with the other two regions, and there were significant differences between different varieties. All samples showed typical A-type structure, and the starch short-range order structure changed slightly. Amylose content, solubility, transparency, granule size distribution, pasting properties and thermal properties were significantly affected by environment and variety.

CONCLUSION

When choosing high-quality special varieties and products for processing, it contributes to select different buckwheat varieties and planting areas based on various objectives by understanding the effects of environment and varieties on the physicochemical properties of Tartary buckwheat starch. In this study, the four varieties planted in Dingxi and the two varieties in Zhaojue were easy to digest, and the differences of pasting properties and thermal properties are helpful to improve the application of Tartary buckwheat starch in the food industry. © 2023 Society of Chemical Industry.

Individual or mixing extrusion of Tartary buckwheat and adzuki bean: Effect on quality properties and starch digestibility of instant powder

Introduction

Tartary buckwheat and adzuki bean, which are classified as coarse grain, has attracted increasing attention as potential functional ingredient or food source because of their high levels of bioactive components and various health benefits.

Methods

This work investigated the effect of two different extrusion modes including individual extrusion and mixing extrusion on the phytochemical compositions, physicochemical properties and in vitro starch digestibility of instant powder which consists mainly of Tartary buckwheat and adzuki bean flour.

Results

Compared to mixing extrusion, instant powder obtained with individual extrusion retained higher levels of protein, resistant starch, polyphenols, flavonoids and lower gelatinization degree and estimated glycemic index. The α-glucosidase inhibitory activity (35.45%) of the instant powder obtained with individual extrusion was stronger than that obtained with mixing extrusion (26.58%). Lower levels of digestibility (39.65%) and slower digestion rate coefficient (0.25 min^-1) were observed in the instant powder obtained with individual extrusion than in mixing extrusion (50.40%, 0.40 min^-1) by logarithm-of-slope analysis. Moreover, two extrusion modes had no significant impact on the sensory quality of instant powder. Correlation analysis showed that the flavonoids were significantly correlated with physicochemical properties and starch digestibility of the instant powder.

Discussion

These findings suggest that the instant powder obtained with individual extrusion could be used as an ideal functional food resource with anti-diabetic potential.

Effect of Frozen Treatment on the Sensory and Functional Quality of Extruded Fresh Noodles Made from Whole Tartary Buckwheat

Extruded noodles made from whole Tartary buckwheat are widely known as healthy staple foods, while the treatment of fresh noodles after extrusion is crucial. The difference in sensory and functional quality between frozen noodles (FTBN) and hot air-dried noodles (DTBN) was investigated in this study. The results showed a shorter optimum cooking time (FTBN of 7 min vs. DTBN of 17 min), higher hardness (8656.99 g vs. 5502.98 g), and less cooking loss (5.85% vs. 21.88%) of noodles treated by freezing rather than hot air drying, which corresponded to better sensory quality (an overall acceptance of 7.90 points vs. 5.20 points). These effects on FTBN were attributed to its higher ratio of bound water than DTBN based on the Low-Field Nuclear Magnetic Resonance results and more pores of internal structure in noodles based on the Scanning Electron Microscopy results. The uniform water distribution in FTBN promoted a higher recrystallization (relative crystallinity of FTBN 26.47% vs. DTBN 16.48%) and retrogradation (degree of retrogradation of FTBN 34.67% vs. DTBN 26.98%) of starch than DTBN, strengthening the stability of starch gel after noodle extrusion. FTBN also avoided the loss of flavonoids and retained better antioxidant capacity than DTBN. Therefore, frozen treatment is feasible to maintain the same quality as freshly extruded noodles made from whole Tartary buckwheat. It displays significant commercial potential for gluten-free noodle production to maximize the health benefit of the whole grain, as well as economic benefits since it also meets the sensory quality requirements of consumers.

Comparative assessment of nutritional and functional properties of different sorghum genotypes for ensuring nutritional security in dryland agro-ecosystem

The cultivation of unique sorghum (resistant to abiotic stresses and re-recognized as healthy food) has attracted interest as an environmentally friendly minor cereal and may be a solution to food and nutritional security. However, information about how the use of selected sorghum grains affects nutritive values and its functional properties from sorghum flours is still lacking. To address this question, we selected six sorghum varieties (i.e., JinZa 34, LiaoZa 19, JinNuo 3, JiZa 127, JiNiang 2, and JiaXian) for the comprehensive analysis of the relationship among nutritional compositions, energy value contributions, and functional properties of sorghum grains. Results showed that Carr's index (CI) and angle of repose (AR) of all sorghum flours indicated good flow and compressibility properties in terms of micrometric parameters. All sorghums were considered free of tannin. Based on the scatterplot analysis, the proportions of energy contributions due to protein, fat, and carbohydrate (CHO), were highly positively correlated with protein, fat, and CHO, respectively. The significantly different flours of six sorghum varieties resulted in different functional properties. The amylose content showed a highly negative association with light transmittance and water and oil absorption capacities. In addition, amylose had a highly positive relationship with water solubility (WS) and swelling power (SP). JinNuo 3 had the highest nutritional compositions [proximate, mineral, anti-nutritional values, and amino acid (AA) profiles] and functional properties indicating that it could be used as a brewing liquor. Our findings will provide a new opportunity to cultivate sorghum as an environment friendly minor cereal crop in dryland agro-ecosystems of arid and semi-arid regions of northern China for nutritional security, agriculture processing, and non-food industry in the future.

Integrated Starches and Physicochemical Characterization of Sorghum Cultivars for an Efficient and Sustainable Intercropping Model

Sorghum has good adaptation to drought tolerance and can be successfully cultivated on marginal lands with low input cost. Starch is used in many foods and nonfood industrial applications and as a renewable energy resource. Sorghum starches with different amylose contents affect the different physicochemical properties. In this study, we isolated starches from six sorghum varieties (i.e., Jinza 34, Liaoza 19, Jinnuo 3, Jiza 127, Jiniang 2, and Jiaxian) and investigated them in terms of their chemical compositions and physicochemical properties. All the starch granules had regular polygonal round shapes and showed the characteristic “Maltese cross”. These six sorghum starches showed an A-type diffraction pattern. The highest amylose content of starch in Jinza 127 was 26.90%. Jiaxian had a higher water solubility at 30, 70, and 90 °C. From the flow cytometry analysis based on six sorghum starch granules, Liaoza 19 had a larger and more complex granules (particle percentage (P1) = 66.5%). The Jinza 34 starch had higher peak (4994.00 mPa∙s) and breakdown viscosity (4013.50 mPa∙s) and lower trough viscosity (973.50 mPa∙s). Jinnuo 3 had higher onset temperature, peak temperature, conclusion temperature, gelatinization enthalpy, and gelatinization range. The principal component analysis and hierarchical cluster analysis based on classification of different sorghum starches showed that Jiniang 2 and Jinnuo 3 had similar physicochemical properties and most divergent starches, respectively. Our result provides useful information not only on the use of sorghum starches in food and non-food industries but for the great potential of sorghum-based intercropping systems in maintaining agricultural sustainability.

New Type of Food Processing Material: The Crystal Structure and Functional Properties of Waxy and Non-Waxy Proso Millet Resistant Starches

Resistant starch (RS) is widely used in the food industry because of its ability to regulate and protect the small intestine, but their distinct effects on the structural and functional properties of waxy and non-waxy proso millet starches are not completely understood. The crystalline structure and physicochemical properties of waxy and non-waxy proso millets' starch samples were analyzed after heat-moisture treatment (HMT). The analysis revealed significant differences between the RS of waxy and non-waxy proso millets. The crystal type of proso millets' starch changed from type A to type B + V. The relative crystallinity of the RS of waxy proso millet was better than that of non-waxy proso millet. The gelatinization temperature and thermal stability of RS significantly increased, and the pasting temperature (PTM) of the RS of waxy proso millet was the highest. The water solubility and swelling power of the RS in proso millet decreased, and the viscoelasticity improved. The correlation between the short-range ordered structure of RS and ΔH, and gelatinization properties has a stronger correlation. This study provides practical information for improving the nutritional benefits of waxy and non-waxy proso millet in food applications.

Antimicrobial Activity and GC-MS Profile of Copaiba Oil for Incorporation into Xanthosoma mafaffa Schott Starch-Based Films

The present study evaluated the effect of the incorporation of copaiba oil, in direct and in microencapsulated form, into films based on Xanthosoma mafaffa Schott starch. Initially, the characterization of copaiba oil by gas chromatograph coupled with mass spectrometry (GC-MS) and its antimicrobial activity against gram-positive and gram-negative bacteria was performed. The films were produced by the casting technique and characterized in relation to physical, chemical, structural, and antimicrobial activity. Sesquiterpenes, mainly β-caryophyllene, were the predominant compounds in copaiba oil, showing antimicrobial activity against B. subtilis and S. aureus. The films showed forming capacity, however, was observed a decrease in solubility and revealed an increase in hydrophobic characteristics. However, the oil reduced the tensile strength and elongation, while the microcapsules did not influence the mechanical properties in comparison to the control film. From microstructure analysis, changes in the films roughness and surface were observed after the addition of oil both directly and in microencapsulated form. Films incorporated with microparticles were able to inhibit the gram-positive bacteria tested, forming inhibition zones, indicating that the encapsulation of copaiba oil was more efficient for protecting bioactive compounds from the oil, suggesting the possible application of mangarito starch-based films incorporated with copaiba oil as biodegradable packaging.

Morphological and physicochemical characterization of starches from underground stems of Trimezia juncifolia collected in different phenological stages

In this study, starches from underground stems of Trimezia juncifolia were evaluated during dry season (DSS), wet season (WSS) and sprouting (SS). Results evidenced that drought stress did not interfere with the yield, amylose content and degree of polymerization (DP) of amylopectin. However, the extraction yield in SS was 58% lower, being observed and increase of 7.5% in the content of amylose, and 13.5% in DP values for SS amylopectin, with a predominance of A-chains. The amount of total sugar, the starch granules size as well as solubility and swelling properties varied as function of the phenological status. Also, starch granules changed from A-type polymorph in DSS and SS to a C_A-type in WSS. Nevertheless, it was observed a crystallinity reduction from 56% in DSS to 37.1% in SS. In addition, thermograms evidenced the presence of amylose-lipid complexes, with endothermic transition temperatures being affected by drought stress and sprouting. Finally, results demonstrate that underground stems from T. juncifolia have adaptative strategies involving changes in the morphological and physicochemical properties of the starch granules.

Structural, pasting and thermal properties of common buckwheat (Fagopyrum esculentum Moench) starches affected by molecular structure

Common buckwheat starch (CBS) has extensive using value in the human diet. In this study, the molecular structure and physicochemical properties of CBS isolated from five cultivars collected from three regions of China were studied. Variations in molecular structure, crystalline structure, complexity, water solubility (WS), swelling power (SP), pasting properties, and thermal characteristics were recorded among the starches. The CBS had both similarities and differences in its properties by comparison with maize starch (MS) and potato starch (PS). The average molecular weight (M_W) and amylopectin average chain length (ACL) of CBS ranged from 3.86 × 10⁷ g/mol to 4.68 × 10⁷ g/mol and from 21.29% to 22.68%, respectively. CBS and MS were divided into one subgroup and showed typical A diffraction patterns, while PS was divided into two subgroups and exhibited a typical B polymorphic pattern. The WS and SP of all the starches significantly increased with increasing temperature and had great variation at 70 °C and 90 °C. Pearson's correlation analysis showed that the molecular structure of starches greatly affected the physicochemical properties. This study revealed that the physicochemical properties of CBS could be affected by the molecular structures.

Changes in Morphological and Physicochemical Properties of Waxy and Non-waxy Proso Millets during Cooking Process

Proso millet, a grain which is principally consumed in cooked form, is favored by consumers because of its rich nutritional value. However, the changes in morphological and physicochemical properties of proso millet grains occurring during the cooking process have rarely been reported. In this study, we investigated the changes in morphological and physicochemical properties of cooked waxy and non-waxy proso millets. During the cooking process, starch granules in the grains were gradually gelatinized starting from the outer region to the inner region and were gelatinized earlier in waxy proso millet than in non-waxy proso millet. Many filamentous network structures were observed in the cross sections of cooked waxy proso millet. As the cooking time increased, the long- and short-range, ordered structures of proso millets were gradually disrupted, and the ordered structures were fully disrupted by 20 min of cooking. In both waxy and non-waxy proso millets, thermal and pasting properties significantly changed with an increase in the cooking time. This study provides useful information for the processing of proso millet in the food industry.