Effect of heating and acidicpHon characteristics of wheat gluten suspension

Effect of multiple-frequency ultrasound-assisted transglutaminase dual modification on the structural, functional characteristics and application of Qingke protein

Qingke protein rich in restricted amino acids such as lysine, while the uncoordination of ratio of glutenin and gliadin in Qingke protein has a negative impact on its processing properties. In this study, the effect of multiple-frequency ultrasound combined with transglutaminase treatment on the functional and structural properties of Qingke protein and its application in noodle manufacture were investigated. The results showed that compared with the control, ultrasound-assisted transglutaminase dual modification significantly increased the water and oil holding capacity, apparent viscosity, foaming ability, and emulsifying activity index of Qingke protein, which exhibited a higher storage modulus G' (P < 0.05). Meanwhile, ultrasound combined with transglutaminase treatment enhanced the cross-linking degree of Qingke protein (P < 0.05), as shown by decreased free amino group and free sulfhydryl group contents, and increased disulfide bond content. Moreover, after the ultrasound-assisted transglutaminase dual modification treatment, the fluorescence intensity, the contents of α-helix and random coil in the secondary structure of Qingke protein significantly decreased, while the β-sheet content increased (P < 0.05) compared with control. SDS-PAGE results showed that the bands of Qingke protein treated by ultrasound combined with transglutaminase became unclear. Furthermore, the quality of Qingke noodles made with Qingke powder (140 g/kg dual modified Qingke protein mixed with 860 g/kg extracted Qingke starch) and wheat gluten 60-70 g/kg was similar to that of wheat noodles. In summary, multiple-frequency ultrasound combined with transglutaminase dual modification can significantly improve the physicochemical properties of Qingke protein and the modified Qingke proteins can be used as novel ingredients for Qingke noodles.

Development of a highly efficient ion-ozone cavitation technology for accelerated bread production

The bakery market is one of the most capacious in Kazakhstan. Manufacturers of bread products are in dire need of the introduction of intensive technologies for improving product quality and safety. This article presents the results of research to develop technology for accelerated production of bread with ion-ozone cavitation treatment. The influence of various modes of exposure to ion-ozone cavitation has been investigated. After baking, bread samples were examined for organoleptic, physicochemical, rheological and microbiological indicators. The optimal method is treatment with ion-ozone at a concentration of 0.0025 units/mg, at a pressure of 1.0 atm for 1 min. As a result, it was proved that this mode accelerates the process of obtaining dough and shortens the fermentation time, and baking bread increases the qualitative and quantitative indicators according to the control method. The results showed that the ion-ozone technology reduces the length of the process of making dough and bread by three times compared to traditional technologies. The developed products with existing analogues in the Kazakhstan market will differ due to their high taste and consumer properties, product safety, long shelf life and low cost.

Simultaneous Refolding of Wheat Proteins and Soy Proteins Forming Novel Antibiotic Superstructures by Carrying Eugenol

Essential oils (EOs) are natural antibiotic chemicals for food preservation; however, their use is challenging due to low solubility and high volatility. In this study, hybrid protein particles with hydrophobic interiors and colloidal stability were designed to carry hydrophobic eugenol with enhanced storage and thermal stability. Stable self-emulsified delivery systems (SEDSs) were facilitated by simply mixing eugenol with wheat proteins (WPs) and soy proteins (SPs) at pH 12 prior to neutralization. This strategy enabled protein co-folding that permitted the entrapment of eugenol with a high entrapment capacity of ca. 500 mg/g protein. Control over the SP/WP ratios contributed to tunable microstructural conformations, which in turn modulated the stability of SEDSs with prominent bacteriostatic properties against fungi when applied to rice cakes during long-term storage. These results underline the feasibility of properly utilizing EOs by binary protein structures, where the antibacterial properties of EOs could be manipulated coherently.

Significance of Sodium Bisulfate (SBS) Tempering in Reducing the Escherichia coli O121 and O26 Load of Wheat and Its Effects on Wheat Flour Quality

The occurrence of recalls involving pathogenic Escherichia coli-contaminated wheat flours show the need for incorporating antimicrobial interventions in wheat milling. The objectives of this study were to assess the efficacy of sodium bisulfate (SBS) tempering in reducing E. coli O121 (ATCC 2219) and O26 (ATCC 2196) wheat load and to evaluate the impact of effective (≥3.0 log reductions) SBS treatments on wheat flour quality. Wheat grains were inoculated with E. coli (~6 log CFU/g) and tempered (17% moisture, 24 h) using the following SBS concentrations (%wheat basis): 0, 0.5, 0.75, 1.0, 1.25, and 1.5% SBS. Reductions in E. coli O121 and O26 wheat load at different time intervals (0.5, 2, 6, 12, 18, and 24 h) during tempering were evaluated. The addition of SBS during tempering resulted in E. coli (O121 and O26) log reductions of 2.0 (0.5% SBS) to >4.0 logs (1.5% SBS) (p ≤ 0.05). SBS tempering (1.25 and 1.5% SBS) produced acidic wheat flours (pH = 4.51–4.60) but had comparable wheat flour properties in terms of composition, dough, and bread-making properties relative to the control (0% SBS). SBS tempering reduced the E. coli O121 and O26 load of wheat after tempering with minimal effects on wheat flour quality.

Lime juice and enzymes in clean label pan bread: baking quality and preservative effect

Clean label breadmaking is a challenge for the bakery industry, considering the removal of additives, especially preservatives. Through dough acidification and the use of enzymes, shelf-life of breads may be extended in terms of sensory quality and preservation against microbiological deterioration. This study aimed to evaluate the effect of lime juice (0, 10.2 or 20.4 g.100 g^-1, flour basis, f.b.) on technological characteristics and preservation of clean label pan breads, with and without enzymes (0.0015 and 0.0050 g.100 g^-1 of phospholipase and fungal xylanase, f.b., respectively). The technological parameters of dough (high-speed mixing time, temperature, pH before and after proofing) and pan bread (specific volume, firmness, crust and crumb color, a_w, pH and mold occurrence) were evaluated. Doughs with lime juice required a longer mixing time, and produced breads with lower volume, firmer crumb, lighter crust and lower mold occurrence, when compared to the market standard. Pan breads with 10.2 g.100 g^-1 of lime juice and enzymes showed a higher volume and softer crumb, compared to those with only lime juice. Thus, the joint use of lime juice and enzymes may be suitable for clean label pan breads, maintaining a soft crumb and longer shelf life without additives.