New insights into the alleviating role of starch derivatives on dough quality deterioration caused by freeze

Short-clustered maltodextrin mediates stabilization of gluten proteins during frozen storage compared to trehalose and guar gum

To investigate impacts of short-clustered maltodextrin (SCMD), trehalose (TH), and guar gum (GUAR) on mediating stabilizations of gluten proteins against cold denaturation, we focused on conformational transformations of gluten protein during frozen storage and its molecular mechanism. Firstly, we found SCMD markedly improved hydration features and decreased the surface hydrophilicity of gluten proteins, with the integrity and continuity of gluten network improving after 8-week frozen storage, compared to TH and GUAR. Furthermore, SCMD and TH addition hindered the conversion of α-helix to disordered β-fold and β-turn, while GUAR did not. Similar outcomes were observed in results of amino acid microenvironment. Molecular mechanism mining indicated the SCMD could establish additional hydrogen bonds with water and protein molecules, suppressing cold denaturation of protein. Our findings found saccharide composition and size were important factors in mediating protein stabilization during frozen storage, which will offer novel insights into the mitigation of cold-induced protein denaturation.

Unlocking the potential of β-limit dextrin: Preparation, structure, properties, and promising applications

Starch is a widely used and economically important polymer; however, its industrial applications are limited by certain shortcomings, such as retrogradation and high digestion rate. To overcome these limitations, native starches can be hydrolyzed by β-amylase, resulting in the production of β-limit dextrin (β-LD) and maltose as a co-product. β-LD retains the original inner core structure of its parent amylopectin and contains truncated external chains that is not prone to form exterior chain helical. The described molecular structures of β-LD impart unique physicochemical attributes, including prevention of retrogradation, high solubility, relatively low digestibility, etc. Compared with other dextrins, β-LD has a more defined structure and a larger molecular weight, but it still maintains high solubility, which endows β-LD with a wider range of potential applications in food and pharmaceutical industries. The considerations for improving preparation efficiency of β-LD, identifying additional functional traits, and expanding its industrial applications have been outlined along with future research directions. The insights provided in this review will be advantageous for the commercial production and utilization of β-LD in food industry to create value from native starch.

Mitigating the Effects of Starch Derivatives on Cold Denaturation of Gluten Protein: Insights from Hydration Capacity and Conformation Behavior

Mitigating the cold denaturation of gluten protein during frozen storage is crucial for the quality improvement of frozen cereal products. Our previous study observed that starch derivatives, especially short-clustered maltodextrin (SCMD), could significantly improve frozen dough quality, alleviating the deterioration of gluten-network structure. To further reveal the cryoprotection mechanism of SCMD on gluten protein during frozen storage, the modulatory roles of SCMD in the hydration capacity and conformation behavior of gluten protein were explored, in comparison with DE2 maltodextrin (MD) and pregelatinized starch (PGS). Results demonstrated that SCMD significantly facilitated the reservation of bound water and decreased the surface hydrophobicity of gluten protein after 8 weeks of frozen storage. Remarkable effects of SCMD on stabilizing the secondary structure and microenvironment of aromatic amino acids of gluten protein were observed. Further mechanistic investigation showed that when the temperature dropped from 300 to 250 K, the short-clustered structure could stabilize the α-helixes more evidently than linear structures through hydrogen bonds with water and steric hindrance effect, rather than directly with protein. Our findings will provide novel insights into the cold denaturation of gluten protein and useful guidance in selecting the optimum structure to suppress this denaturation, improving the quality of frozen cereal products.