# Enhancement of Wheat Flour and Dough Properties by Non-Thermal Plasma Treatment of Wheat Flour
## 1 Introduction  
Cereals and grains are abundantly used worldwide, constituting a major part of human food consumption. Cereals and their products are energy sources for humans and animals, and contain carbohydrates, proteins, fiber and vitamins (such as E and B), along with magnesium and zinc [1; 2; 3]. Grains are consumed either whole or in powder form, which forms exist in different granulations and have different chemical compositions [4]. Generally, a grain consists of three parts: (1) bran, i.e., the outer layer, mostly rich with dietary fiber; (2) germ, i.e., the inner layer, consisting of lipids and proteins; and (3) endosperm, i.e., the bulk of a kernel, full of starch, proteins and minerals [5]. A powder form, i.e., flour, is a blend of these parts in different proportions, leading to different flour classifications. Plant-based foods are often subjected to thermal or chemical processing prior to consumption [6]. However, nowadays, the customer requirement to preserve nutrient ratios by reducing the treatment temperatures for preserving food quality and reducing the use of chemical treatment agents have urged food engineers to search for other, suitable, non-chemical food processing methods. Modern consumers demand rich organoleptic,additive-free food, environmentally friendly processing, freshness and high sensory and nutritional attributes [7; 8]. On the other hand, insufficient processing of food products can lead to the proliferation of bacterial, parasitic and pathogenic infections in humans [9]. Food-borne illnesses have significantly increased in recent years due to consumption of food that has been inadequately processed and therefore correct storage is additionally important to prevent mould formation, pest infestation and grain germination [6]. Microorganisms and pathogens occur in grains stored in humid environments, in which bran absorbs a significant amount of water, thus lowering the concentration of gluten and starch in the kernel and ultimately affecting end product quality [5; 10]. Conventional thermal processing measures for food, for boosting shelf life, hygiene and structural properties, can be very detrimental to food nutrient ratios and sensory and organoleptic qualities [11]. Currently employed sterilization and processing techniques, such as chemical preservation [12; 13], addition of bio-preservatives [14], mild heat treatments [15], microwave processing [16], ultrasound processing [17], reduction of water activity [18], high hydrostatic pressure technology [19; 20] and vacuum and hurdle techniques [21], provide limited benefits in comparison with their adverse alterations of food properties, such as shape, color, taste, smell, structure, nutrient degradation, formation of toxic byproducts, etc. [9; 22]. GSSG, thus limiting the formation of PSSG. As a result, the number of S-S intermolecular bonds increases. \[\text{Ascorbic acid + 0.5 O}_{2}\rightleftharpoons\text{Dehydroascorbic Acid + H}_{2}\text{O} \tag{1}\]  
\[\text{Dehydroascorbic Acid + GSH}\rightleftharpoons\text{Ascorbic acid + GSSG} \tag{2}\]  
Although many other chemicals (KIO\({}_{3}\), KbrO\({}_{3}\), chlorine, etc.) and oxidizing bacteria have been used to modify wheat flour functionality, the food industry is moving towards restricting the use of chemicals, and therefore the need for non-chemical treatment methods increases. Ozone is an example of an oxidizing agent, acceptable for use in the food industry [29]. [PERSON] et al. [30] and [PERSON] et al. [31] investigated the effects of ozone on both wheat flour and grain functionality and suggested it as a good alternative to chemicals for improving wheat flour characteristics. The key features that are responsible for the superiority of ozone over commonly used chemicals are its high oxidation potential and the fact that no residues are left after the treatment [32]. Non-thermal plasma (NTP) has emerged as a new and effective method in food processing that retains food quality better than conventional methods [33].