Estimation of growth parameters of six different fungal species for selection of strains to be used in challenge tests of bakery products

Influence of Limosilactobacillus fermentum IAL 4541 and Wickerhamomyces anomalus IAL 4533 on the growth of spoilage fungi in bakery products

Fungi are the main microorganisms responsible for the spoilage of bakery products, and their control and subsequent reduction of food waste are significant concerns in the agri-food industry. Synthetic preservatives are still the most used compounds to reduce bakery product spoilage. On the other hand, studies have shown that biopreservation can be an attractive approach to overcoming food and feed spoilage and increasing their shelf-life. However, limited studies show the preservation effects on real food matrices. Therefore, this study aimed to investigate the influence of microorganisms such as lactic acid bacteria (LAB) and yeasts on the growth of spoilage filamentous fungi (molds) on bread and panettones. In general, on conventional and multigrain bread, treatments containing Limosilactobacillus fermentum IAL 4541 and Wickerhamomyces anomalus IAL 4533 showed similar results when compared to the negative control (calcium propionate) in delaying the fungal growth of the tested species (Aspergillus chevalieri, Aspergillus montevidensis, and Penicillium roqueforti). Different from bread, treatments with W. anomallus in panettones delayed the A. chevalieri growth up to 30 days, 13 days longer than observed on negative control (without preservatives). This study showed that biopreservation is a promising method that can extend bakery products' shelf-life and be used as an alternative to synthetic preservatives.

Innovative Biobased and Sustainable Polymer Packaging Solutions for Extending Bread Shelf Life: A Review

Sustainable packaging has been steadily gaining prominence within the food industry, with biobased materials emerging as a promising substitute for conventional petroleum-derived plastics. This review is dedicated to the examination of innovative biobased materials in the context of bread packaging. It aims to furnish a comprehensive survey of recent discoveries, fundamental properties, and potential applications. Commencing with an examination of the challenges posed by various bread types and the imperative of extending shelf life, the review underscores the beneficial role of biopolymers as internal coatings or external layers in preserving product freshness while upholding structural integrity. Furthermore, the introduction of biocomposites, resulting from the amalgamation of biopolymers with active biomolecules, fortifies barrier properties, thus shielding bread from moisture, oxygen, and external influences. The review also addresses the associated challenges and opportunities in utilizing biobased materials for bread packaging, accentuating the ongoing requirement for research and innovation to create advanced materials that ensure product integrity while diminishing the environmental footprint.

Strategies to improve the quality of wheat- flour- bread chain in Iran: the perspective of different stakeholders

Objective

Bread constitutes a significant energy source and provides protein and some essential micronutrients to a large population worldwide, including Iran. So, its quality characteristics are important for health. This study aimed to identify the views and experiences of various stakeholders involved in the wheat- flour- bread chain about factors affecting the quality of this chain and strategies for its improvement in Iran.

Results

Main suggested strategies in the field of raw materials were managing and planning for the production of high-quality wheat, measuring the quality factors of grain before purchasing by the government, allocating wheat quotas to flour mills based on the quality of the flour produced, and aerating and storing flour in silos to reduce its moisture. Holding training courses for bakery workers, improving the economic situation of bakers, and standardizing bread-making devices were the most important strategies in the bakery field. Assigning a specific unified management apparatus to deal with bread issues was also an effective and essential strategy. Findings show the need to implement strategies in various fields to improve wheat- flour- bread chain quality. This study provides helpful information to guide policy decisions and planning to enhance bread quality and promote public health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06225-7.

Water activity relations of spoilage fungi associated with smoke-dried catfish (Clarias gariepinus) sold in some open markets in Nigeria

Spoilage fungi were isolated from the skin and the muscle of smoke-dried catfish samples, which were products of traditional and improved processing methods. The samples significantly different mean a_w of 0.85 and 0.81 respectively [F (1, 3) = 0.014, P = 0.018], when they were checked immediately after purchase from selected open markets. The isolated spoilage fungi were identified by their phenotypic appearance and morphological features under microscope, with reference to standard identification guidelines. The isolates comprised of Aspergillus fumigatus, A. niger, A. flavus and Penicillium species. Effects of water activity (a_w) on growth and sporulation of these species at ambient temperature (25 ± 5 °C) were studied on standard media (a_w = 0.995) or media in which a_w was modified using NaCl as follows: 0.98, 0.94, 0.86 and 0.80. All the isolates could grow in the range of the a_w studied and there were statistically significant variabilities in the rates of growth among species [F (7, 50) = 63.34, P = 0.001] and in relation to media a_w [F (28, 50) = 4.055, P = 0.001]. There was no limitant a_w found in the studied conditions (0.995-0.80 a_w x fluctuating ambient temperature, 25 ± 5 °C), as all the isolates were fast growing. The a_w of the fish samples from the improved processing line was lower than those from the traditional processing lines. However, the a_w of all the tested the samples was above the Codex Standard for smoked fish, smoke-flavoured fish and smoke-dried fish, which is 0.75 a_w or less (10% moisture or less), as necessary to control bacteria pathogens and spoilage fungi. The results indicated that the open market fish samples may pose serious health risks if they are consumed after a short-term storage. Research Highlights Tolerance of smoke-dried fish spoilage fungi to water stress Effect of a_w on growth characteristics of smoke-dried fish spoilage fungi Water activity relations of some spoilage fungi from dried fish.

Impact of Storing Condition on Staling and Microbial Spoilage Behavior of Bread and Their Contribution to Prevent Food Waste

The high loss rate of bread is generally known to contribute to the alarmingly high numbers in worldwide food waste. Correct storage techniques are believed to enable the reduction of preventable food waste. Therefore, the influence of storage parameters on staling and spoilage behavior of German bread within the limits of common household methods was investigated in this study. The aim was to generate reliable data for staling and spoilage using different storage methods (PE-layered microperforated paper bag, plastic bag, and fridge and bread box) to bridge the gap between consumer’s needs and scientific research questions. Everyday routines of life, such as visual inspection, were compared with microbiological techniques and were found to represent an adequate tool for microbial safety control. Visually undetectable fungal growth has not been found to result in the production of mycotoxins (fumonisins B1 and B2 and ochratoxin A) in quantifiable or harmful concentrations. Thus, disgust should prevent any foodborne health risks as the visual appearance should lead to avoiding the consumption of spoiled food before mycotoxins are produced in amounts causing adverse health effects within the limits of this experimental setup. Additionally, the storage temperature especially was found to influence the kinetics of staling processes, as a reduction accelerated the staling process. Further, crumb moisture loss was found to contradict a long shelf life but, on the other hand, an elevated humidity was shown to provoke excessive microbial growth and should therefore be observed when designing suitable storage methods. Further, the correct choice of the bread type stored and a good sanitary practice represent simply accessible ways to prolong the storage period of bread loaves.

A quantitative study on growth variability and production of ochratoxin A and its derivatives by A. carbonarius and A. niger in grape-based medium

Aspergillus carbonarius and Aspergillus niger are the main responsible fungi for the accumulation of ochratoxin A (OTA) in wine grapes. Some strains are able to convert the parent mycotoxin into other compounds by means of hydrolysis and/or conjugation reactions through their defense mechanisms and enzymatic activity, leading to the formation of a modified mycotoxin. Thus, the variability of growth and metabolite production are inherent to the strain, occurring distinctively even when submitted to similar conditions. In this sense, this contribution aimed at determining the variability in multiplication and production of OTA by strains of A. carbonarius and A. niger isolated from grapes, as well as investigating the formation of modified mycotoxins. Strains were incubated in grape-based medium, and the diameter of the colonies measured daily. The determination of OTA was performed by high-performance liquid chromatography and the identification of modified mycotoxins was carried out using high-resolution mass spectrometry. Variabilities in terms of growth and OTA production were assessed across five different strains. Peak production of OTA was detected on day 15, and a decline on day 21 was observed, indicating that the observed reduction may be associated with the degradation or modification of the OTA over time by the fungus. Ethylamide ochratoxin A, a modified mycotoxin identified in this study, provides evidence that there may be underreporting of total mycotoxin levels in food, increasing uncertainty concerning health risks to the population.