About this Research Topic
The expansion of food markets throughout the world and the development of large retailers have made food preservation a crucial quality parameter for food products. Bread and bakery products are convenient, staple foods worldwide. Bread is a perishable good and its quality can be compromised by physicochemical spoilage referred to as staling, as well as by microbial contamination.
Starch retrogradation is the main cause of staling and it depends on the processing, packaging, moisture, distribution of water between starch and gluten in the crumb and the storage conditions. In addition, the quality of bakery products is compromised by the microbial contamination. The main bacterial spoilage is determined by Bacillus species present in raw materials whose spores survive the cooking process and cause the ropiness of bread due to the bacterial metabolic activities and amylase synthesis. After the baking of the bread, environmental yeast (Pichia and Zygosaccharomyces genera) and moulds (Penicillium, Aspergillus and Cladosporium genera) are able to colonize the surface of product. Rapid visible moldy structures appearing on the bread surface may also yield the production of mycotoxins or allergenic compounds.
Bakery products spoilage by the aforementioned processes causes it to become unsuitable to ingest by the consumer and large economic losses for industry. Various anti-aging agents are used in the baking industry, e.g., emulsifiers, enzymes, ascorbic acid and hydrocolloids can minimize this spoilage. Chemical preservatives have been used for decades to control microbial contamination. However, the trend of consumers for 'clean label' products requires innovative conservation strategies. Today, these chemical additives can be frequently substituted by bio-preservatives obtained by biotechnological approaches. The most important microorganisms used in the biotechnology of bakery products to provide a natural preservation are lactic acid bacteria (LAB) of sourdough. Some sourdoughs fermentation is effective in delaying starch retrogradation. On the other hand, these bacteria are known to produce bioactive molecules (such as organic acids, fatty acids, hydrogen peroxide, diacetyl and bacteriocins) that show antimicrobial activity against spoilage microorganisms and pathogens.
Biopreservation techniques should be complemented with other strategies, e.g., the prevention of the contamination risk, the destruction of contaminants, and the optimization of packaging/storage conditions. The systems to prevent the contamination risk that are widely used are the application of HACCP system, with the use of good microbiological quality raw material and/or the application of innovative physical/chemical technologies. Among the control strategies, also the packaging technologies are used and they include the Modified Atmosphere Packaging (MAP), the active packaging and more recently the edible coatings. Therefore, the combination of different preservation methods with the application of hurdle technologies can ensure the good quality of the bakery products. However, the continuous incorporation of new technological and functional ingredients poses new challenges in the formulations of products for the industry.
Taking into consideration the described complexity of the bread spoilage process it becomes evident that bakery products spoilage requires integrated approaches. This Research Topic will collect the current advances in research aimed towards understand the spoilage mechanisms, prevent and control the spoilage of bakery products and to thus optimize food processes, prolonging shelf life and ensuring food quality and safety. Manuscripts should include the following topics:
- understanding of spoilage mechanisms
- characterization of microorganisms responsible for spoilage
- use of predictive models to prevent spoilage
- use of microbial biotechnologies to control spoilage
- lactic acid bacteria as bioprotective starters
- novel technologies for spoilage control and prevention packaging solutions
- reformulation of products to prevent spoilage
Keywords: Microbial spoilage, lactic acid bacteria, predictive microbiology, hurdle technologies, microbial biotechnology, packaging
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