Non-thermal emerging technologies as alternatives to chemical additives to improve the quality of wheat flour for breadmaking: a review

Wheat flour is the main ingredient used in the preparation of bread. Factors such as low gluten content and the addition of nontraditional ingredients in baking affect the quality of wheat flour and may limit its use in baking. With the increasing trend of "clean label" products, it may be interesting to develop and use physical processes to improve the quality of wheat flour and avoid the use of chemical additives. High hydrostatic pressure, non-thermal plasma, ultrasound, ozonation, ultraviolet light, and pulsed light treatments are non-thermal emerging technologies (NTETs) that have been studied for this purpose. They were originally developed to inactivate microorganisms and enzymes in foods. Additionally, these technologies can be used at low temperatures to modify the most important component of wheat flour, i.e., gluten and its fractions, which are responsible for the rheological properties of wheat flour dough. Thus, this review focuses on the effects of these NTETs by considering the following factors: (1) the technological properties of gluten, (2) gluten-starch interactions, (3) possible effects of NTETs on minor components of flours, and (4) the quality of wheat flour and the resulting final products.

The effect of redox agents on conformation and structure characterization of gluten protein: An extensive review

Gluten protein as one of the plant resources is affected by redox agent. Chemical modifications by redox agent have myriad advantages mainly short reaction times, no requirement for specialized equipment, low cost, and highly clear modification impacts. The gluten network properties could be influenced through redox agents (oxidative and reducing agents) which are able to alter the strength of dough via different mechanisms for various purposes. The present review examined the impact of different redox compounds on gluten and its subunits based on their effects on their bonds and conformations and thus with their impacts on the physico-chemical, morphological, and rheological properties of gluten and their subunits. This allows for the use of gluten for different of purposes in the food and nonfood industry.

Influence of pH, ionic strength and isoascorbic acid on the gel-forming ability of Jumbo squid muscle (Dosidicus gigas)

The effect of pH and ionic strength (μ) on the extraction capacity of myofibrillar proteins from Jumbo squid mantle muscle along with the addition of isoascorbic acid (IA) in its gel-forming ability (GFA) were evaluated. The results indicate that μ had a greater impact (p < 0.05) than pH on the extraction of muscle myofibrillar proteins. The effectiveness of IA, as the precursor of dehydro-isoascorbic acid (DIA), on the oxidation of sulfhydryl groups (-SH) to disulfide bonds (-SS-) of extracted proteins at 0.6 μ was also evaluated. During the sol-gel transition the -SH groups initially present in the protein system decreased (p < 0.05) due to the combined effect of heat treatment (90 °C/30 min) and the addition of IA; however, the oxidative effect of IA reduced (p < 0.05) the GFA of Jumbo squid muscle proteins. Results also indicated that NaCl at 2.8% rather than at 2.5% during gel preparation significantly (p < 0.05) improves its GFA.

Potassium bromate as a food additive: a case study of Tunisian breads

This study is the first investigation of potassium bromate as a food additive in Tunisian breads. In this study, levels of residual bromate were determined in 91 commercial breads from 31 bakeries randomly selected in two Tunisian cities. In total, 13 different types of bread were analyzed using a spectrophotometric method of bromate analysis. Bromate concentrations ranged from 5.95 to 49.31 μg g^-1, with an overall mean concentration of 19.92 μg g^-1. Significant differences were noticed between bromate levels in breads from bakeries of the two cities (P < 0.01). Based on the types of breads, Muffin contained the highest mean concentration of bromate residue (29.92 μg g^-1) as opposed to bread without salt, which had the lowest mean bromate level (13.53 μg g^-1). Compared to data available from other countries, our results showed relatively high bromate levels, which could potentially lead to long term toxic and carcinogenic effects in the Tunisian population.

Ozonation of whole wheat flour and wet milling effluent: Degradation of deoxynivalenol (DON) and rheological properties

The objective of this study was to evaluate the reduction on the levels of the mycotoxin deoxynivalenol (DON) in whole wheat flour (WWF) with different moisture levels, on the wet milling effluent through ozone (O₃) processing, as well as the impact of ozonation on the rheological properties of flour. The results have shown that the reduction of DON was improved with increasing moisture and exposure time of WWF and wet milling effluent to ozone. The maximum reduction was about 80%, proving that ozonation is an effective and promising technology in reducing mycotoxins in different products. However, the process altered the rheological profile of WWF. Therefore, further studies are needed to better understand the process.

Effects of ozone treatment on physicochemical properties of Korean wheat flour

The objective of this study was to investigate the effects of ozone treatment on the physicochemical properties of Korean wheat flour. Wheat flour samples were treated with ozone gas at 120 ppm for 15, 30, 45, and 60 min. Color b value, pH, and mold of flour decreased as exposure time to ozone increased. The water absorption index, peak viscosity, and final viscosity of flour increased by ozone treatment. Photomicrographs of flour suspensions under polarized light showed granules tended to lose birefringence owing to ozone during swelling. The result of SDS-PAGE showed that the intensity of protein bands at low molecular weights slightly increased in ozone-treated flours compared to the intensity in the control flour. The results of this study showed ozone gas affected the starch and protein of wheat flour, suggesting a need for further investigation on structural changes in starch and protein by ozone.