Dual modifications on the gelatinization, textural, and morphology properties of pea starch by sodium carbonate and Mesona chinensis polysaccharide

Effect of carboxymethyl cellulose and/or wheat gluten on the pasting, rheological and quality properties of wheat starch-based batter for deep-fried products

This study aimed to investigate the effects of the individual and synergistic addition of wheat gluten (WG) and carboxymethyl cellulose (CMC) on the wheat starch (WS)-based batter characteristics to determine the molecular basis of texture formation in the actual batter system. Results showed that adding WG and/or CMC significantly increased the viscosity of WS during pasting. The rheological behavior showed that the WG-treated and CMC-treated group had the highest and lowest viscoelasticity. The addition of WG-CMC helped the WS-based batter obtain moderate viscoelasticity. These outcomes could be attributed to the enhancement of hydrogen bonding. The microstructure suggested that the addition of WG-CMC increased the density and integrity of the gel network. Overall, CMC competed for the binding sites of WG on WS, reducing the increase in viscoelasticity caused by the interaction between WG and WS. This might alleviate the unwanted springiness of fried products.

Effects of Premna microphylla turcz polysaccharide on rheological, gelling, and structural properties of mung bean starch and their interactions

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.

Effects of synergistic modification using alkalis and guar gum on the pasting, rheological, and microstructural properties of germinated highland barley starch gels

Germination treatment of highland barley enhances its nutritional value while weakening the starch gel properties. This study aims to enhance the characteristics of germinated highland barley starch (GBS) by exploring the synergistic effects of two alkalis (Na2CO3 and NaHCO3) and guar gum (GG) on GBS gel properties. The combined action of alkalis and GG significantly improved the peak viscosity, setback viscosity, and hardness compared with GG alone. The highest G' and G" reached 998 and 204 Pa at 0.4% Na2CO3 addition, which were increased by nearly 44% and 50%, respectively. Fourier-transform infrared spectral analysis revealed that the alkalis strengthened interaction forces, particularly with intensified absorption peaks at 3200-3700 cm-1 and 1550-1750 cm-1. The Na2CO3 and NaHCO3 reduced the spin-spin relaxation time (T2), resulting in a dense starch gel network. This study contributes to enhancing the market application of GBS and offers innovative insights for modifying other starches.

Effects of Stir-Frying and Heat-Moisture Treatment on the Physicochemical Quality of Glutinous Rice Flour for Making Taopian, a Traditional Chinese Pastry

Taopian is a traditional Chinese pastry made from cooked glutinous rice flour. The effects of heat-moisture treatment (110 °C, 4 h; moisture contents 12-36%, w/w) on the preparation of cooked glutinous rice flour and taopian made from it were compared with the traditional method of stir-frying (180 °C, 30 s). The color of heat-moisture-treated (HMT) flours was darker. HMT flours exhibited a larger mean particle size (89.5-124 μm) and a greater relative crystallinity of starch (23.08-42.92%) and mass fractal dimension (1.77-2.28). The flours exhibited water activity in the range of 0.589-0.631. Although the oil-binding capacity of HMT flours was largely comparable to that of stir-fried flours, HMT flours exhibited a lower water absorption index. Accordingly, the taopian produced with HMT flours exhibited a lower brightness, accompanied by a stronger reddening and yellowing. In addition, more firmly bound water was observed in the taopian produced with HMT flour. The taopian made with HMT flour with a moisture content of 24% exhibited moderate hardness, adhesiveness and cohesiveness and received the highest score for overall acceptability (6.80). These results may be helpful to improve the quality of taopian by applying heat-moisture treatment in the preparation of cooked glutinous rice flour.

New insights into the interaction between bamboo shoot polysaccharides and lotus root starch during gelatinization, retrogradation, and digestion of starch

In this study, the interaction between bamboo shoot polysaccharides (BSP) and lotus root starch (LS) during gelatinization, retrogradation, and digestion of starch was investigated. The addition of BSP inhibited the gelatinization of LS and decreased the peak viscosity, valley viscosity, and final viscosity. Amylose leaching initially increased and then decreased with the increase in BSP addition. The apparent viscosity and viscoelasticity of LS decreased with the increase in BSP addition. Moreover, 3 % BSP increased the hardness and cohesiveness of LS gel, whereas 6 %-15 % BSP decreased them. In addition, 3 %-6 % BSP promoted the uniform distribution of water molecules in the starch paste, whereas the addition of 12 % and 15 % BSP resulted in the inhomogeneous distribution of the water. The retrogradation degree of LS gel gradually increased with the increase in BSP addition from 3 % to 6 %, whereas 9 %-15 % BSP restricted the short-term and long-term retrogradation of LS. After 12 % BSP was added, the RDS content reduced by 11.6 %, the RS content significantly increased by 75 %, and the digestibility of starch decreased. This work revealed the interaction between BSP and LS during starch gelatinization, retrogradation, and digestion to improve the physicochemical properties and digestive characteristics of LS.

A review of starch swelling behavior: Its mechanism, determination methods, influencing factors, and influence on food quality

Swelling behavior involves the process of starch granules absorbing enough water to swell and increase the viscosity of starch suspension under hydrothermal conditions, making it one of the important aspects in starch research. The changes that starch granules undergo during the swelling process are important factors in predicting their functional properties in food processing. However, the factors that affect starch swelling and how swelling, in turn, affects the texture and digestion characteristics of starch-based foods have not been systematically summarized. Compared to its long chains, the short chains of amylose easily interact with amylopectin chains to inhibit starch swelling. Generally, reducing the swelling of starch could increase the strength of the gel while limiting the accessibility of digestive enzymes to starch chains, resulting in a reduction in starch digestibility. This article aims to conduct a comprehensive review of the mechanism of starch swelling, its influencing factors, and the relationship between swelling and the pasting, gelling, and digestion characteristics of starch. The role of starch swelling in the edible quality and nutritional characteristics of starch-based foods is also discussed, and future research directions for starch swelling are proposed.

Enhancement of functional activity and biosynthesis of exopolysaccharides in Monascus purpureus by genistein treatments

The exopolysaccharides (EPS) produced by the edible medicinal fungus Monascus purpureus (EMP) become the center of growing interest due to their techno-functional properties and their numerous applications in the food industries; however, the low EPS yields limit its application. In this study, the effect of genistein supplementation on the production, rheological and antioxidant properties of EPS by M. purpureus and its biosynthesis mechanism were explored. The results indicated that the addition of genistein (3 g/L) generated a 110% and 59% increase in the maximum mycelial biomass and EPS yield, respectively. The genistein supplementation group (G-EMP) had higher molar percentages of Xyl and Man, and significantly decreased molecule weight and particle size of EPS, which resulted in stronger antioxidant effect and cell growth promotion. Rheological analysis showed that both EMP and G-EMP demonstrated pseudoplastic fluid behavior and G-EMP exhibited strong gel-like elastic behavior (G' > G"). Furthermore, genistein not only facilitated the production of EPS by regulating cell membrane permeability, enhancing cellular respiratory metabolism and monosaccharide precursor synthesis pathways, and enhancing antioxidant enzyme activity to reduce oxidative stress damage, but also affected the composition of the monosaccharides by increasing enzyme activity in the underlying synthesis pathways. These findings expand the application of M. purpureus resources and provide a paradigm for future study of the structural and functional characteristics of EPS.

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Genistein (3 g/L) significantly stimulate yield of biomass and exopolysaccharides (EPS) from M. purpureus.

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The physicochemical and rheological properties of EPS were significantly changed.

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Their antioxidant and cytoprotective effect were compared.

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A possible mechanism for the response of genistein to increase EPS yield is proposed.

Impact of Konjac Glucomannan with Different Molecular Weight on Retrogradation Properties of Pea Starch

The impact of konjac glucomannan (KGM) with different molecular weight (Mw) on the retrogradation properties of pea starch, such as color, viscoelasticity, gel strength, water holding capacity (WHC), moisture distribution and crystallinity, was investigated. At the same time as the Mw of KGM decreased, the lightness, elastic modulus, gel strength, water freedom and crystallinity of pea starch showed an increasing trend, whereas the viscosity modulus and WHC showed a decreasing trend. At one day of storage, compared with single pea starch, KGM with low Mw made gel strength increase from 40 g to 45 g, WHC decrease from 82% to 65% and crystallinity increase from 21.3% to 24.0%. Therefore, KGM with low Mw could promote retrogradation of pea starch in the short-term. At 7 days or even 14 days of storage, KGM with medium-high Mw had smaller indices than those of pure pea starch, including the lightness, storage modulus, gel strength, water freedom and crystallinity. This indicated that KGM with medium-high Mw could inhibit the long-term retrogradation of starch. The larger the Mw of KGM, the more noticeable the inhibition effect.

Comparative transcriptome analysis of Monascus purpureus at different fermentation times revealed candidate genes involved in exopolysaccharide biosynthesis

Exopolysaccharides (EPS), metabolites of the medicinal edible fungus Monascus purpureus, have antioxidant, immunomodulatory, and anti-inflammatory effects. However, the biosynthetic mechanism of EPS from M. purpureus is still unclear, which hinders its utilization. In this study, the fermentation conditions of M. purpureus were optimized and comparative transcriptomic analysis was performed to understand the mechanisms and effects of fermentation on EPS synthesis. The optimal medium composition was 40 g/L mannose, 4 g/L yeast powder, 1 g/L MgSO4·7H2O, 0.8 g/L KH2PO4, 1.6 g/L K2HPO4·3H2O, and 2 mL/L Tween 80, and the optimal cultivation conditions were an inoculum of 7 %, culture temperature 30 °C, initial pH 6.0, and 180 rpm for 4 d. A total of 8095 unigenes were obtained, and 17 key enzymes for EPS synthesis were identified. Interestingly, 12 carbohydrate metabolism subcategories were enriched in the group with 4 days of fermentation compared to 2 days, with most of the differentially expressed genes (DEGs) being upregulated, but only nine carbohydrate metabolism subcategories were enriched with longer fermentation time, with all DEGs being downregulated. This study provides a theoretical basis for enhancing the EPS content and reveals the dynamics of EPS synthesis in M. purpureus, providing important targets for future EPS molecular modifications and gene knockdown studies.