Effect of packaging materials and storage conditions on the microbial quality of pearl millet sourdough bread

Abstract

Sourdough is one of the oldest methods of cereal fermentation applied mainly for the sole purpose of baking and has been proven to enhance the production of microbiologically safe products. This study investigated the effect of packaging materials and storage conditions on the microbial quality and some intrinsic parameters of the sourdough bread. Pearl millet flour was naturally fermented for 72 h to obtain sourdough which was used with pearl millet flour to produce sourdough bread while the control bread was produced with pearl millet flour and yeast. The bread samples were packaged in low density polyethylene and aluminium foil and stored at -5, 4, 6, 28 and 37 °C. The total bacteria count (log cfu/g) and total fungal count (spore/g) increased with an increase in storage temperature and storage days. Fungi colonies isolated from stored bread samples include species of Rhizopus, Aspergillus, Penicillium and Mucor. A significant increase (p B 0.05) in the pH and decrease in the moisture content of the bread samples were observed as storage period and storage temperature increased. Sourdough fermentation improved the microbial qualities and extended the shelf life of bread.

Shelf life extension of bread using ethanol emitters with different packaging materials

“…As storage days increased, the moisture content of bread samples decreased. This could be due to moisture migration from the bread crumb to the bread crust followed by environment, which promotes mold growth and leads to successive increase as the storage days increases (Martins et al, 2021). The bread crust absorbs some of the water, while the majority of the water migrates from the crumb to the atmosphere, resulting in water loss during storage (Monteau et al, 2017).…”

Effect of fermentation methods on properties of dough and whole wheat bread

“…The SOD method is long, and the fermentation process produces large amounts of organic acids, ethanol, and other important metabolites that have positive effects on the texture of the product and the aging rate. 8 The prefermented dough method is usually referred to as the sponge dough (SPD) method and is conducted by mixing and fermenting part of the flour, water, and yeast immediately to form a sponge-like structure, followed by mixing with the remaining dough components. Like the SOD method, the SPD method requires a longer fermentation time than the STD method, but it generally produces bread with better aroma and flavor, higher volume, and better texture qualities than the STD method.…”

“…Spontaneous SOD fermentation, one of the oldest biological processing techniques, usually relies on the presence of naturally occurring microorganisms, such as yeast and lactic acid bacteria (LABs), whose fermentation activity plays an important role in the quality of SOD bread. The SOD method is long, and the fermentation process produces large amounts of organic acids, ethanol, and other important metabolites that have positive effects on the texture of the product and the aging rate 8 . The pre‐fermented dough method is usually referred to as the sponge dough (SPD) method and is conducted by mixing and fermenting part of the flour, water, and yeast immediately to form a sponge‐like structure, followed by mixing with the remaining dough components.…”

Preparation and characterization of zinc oxide nanoparticle, its migration, and toxicity evaluation

“…So, these are best consumed at room temperature, but it has a short shelf life (2–3 days) due to high water activity (Upasen & Wattanachai, 2018). Several studies have reported the use of bio‐nanocomposite film like carboxymethyl cellulose‐chitosan ‐ZnO (Martins et al, 2021), starch‐chitosan, and nanoclay (Jha, 2020) for elongation of shelf life of the bread.…”

“…It was stated that Aspergillus niger, Cladosporium, Rhizopus nigricans, Neurospora sitophila, Pichia anomala, and Candida parapsilosis were the most popular fungi responsible for the spoilage of bakery products. However, bread is more susceptible to bacterial and fungal growth at ambient temperature or more as compared to bread stored at refrigerated conditions (Martins et al, 2021), but low temperature shows a high level of undesirable starch retrogradation which is responsible for staling (Xi et al, 2022). So, these are best consumed at room temperature, but it has a short shelf life (2-3 days) due to high water activity (Upasen & Wattanachai, 2018).…”