The food situation today is undergoing remarkable changes due to the progress of science and technology, not only in Japan but also on a global scale, as well as environmental and health issues, and major political, economic, and social reforms. The effects of these changes are not only positive but also negative for mankind. Under these circumstances, it is significant to consider the future direction of measures to control microorganisms that cause food contamination, spoilage, and food poisoning, which are directly related to food production, storage, distribution, and hygiene. In this special feature, the four topics of predictive food microbiology, control of gas-phase microorganisms, control of interfacial microorganisms, and control of highly resistant microorganisms were addressed by the leading specialists in each of these areas. Furthermore, I also briefly discussed some other potential items that are expected to be managed in future microorganism control.

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Stochastic approaches for describing microbial death responses in foods have gained increased attention in the field of predictive microbiology and quantitative microbial risk assessment. Particularly, recent studies have focused on describing variability and uncertainty of microbial responses. Although variability due to individual cell heterogeneity is inherent in a small number of bacteria during the inactivation process, an appropriate theoretical stochastic description for the variability in individual cell heterogeneity has not been achieved. This article reviews recent advances in the development of models for describing the variability in individual cell heterogeneity from the perspective of bacterial inactivation, as a stochastic process of bacterial cell numbers. Large numbers of replicated experiments, computer simulations, and mathematical formulations have led to novel techniques for describing variability in individual cell heterogeneity during the microbial survival process. The proposed stochastic theory will enable reinterpretation of conventional bacterial behavior based on the average bacterial numbers. Advances in the modeling procedures described in this article will support the further development of predictive microbiology studies and their practical use in food processing and distribution environments.

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In the food industry, it is an important issue to prevent secondary contamination by airborne and attached microorganisms. Considering recent respiratory infections such as the influenza virus and the current Covid-19 Pandemic, controlling pathogens in indoor spaces has been emphasized. Especially the transmission of the virus indoors is a major concern. Hypochlorous acid (HOCl) has so far been used as a liquid-based disinfectant for treating things. Recently, the scope of objects to be treated with hypochlorite solution has been expanded to indoor spaces, including air and solid surfaces, and the use of gaseous hypochlorous acid (HOCl(g)) has been studied intensively. Safe utilization of HOCl(g) requires appropriate control and management of its concentration. It has been demonstrated that HOCl(g) is an effective disinfectant against various bacteria and viruses, including SARS-CoV-2, in aerosols and solid surfaces at low concentrations. The bactericidal efficacy of HOCl(g) depends on the product of the HOCl(g) concentration and time, and it increases with increasing the relative humidity. The use of HOCl(g) is of potential advantage to inactivate harmful microorganisms present in large indoor spaces without wetting the surface and without manual manipulation, i.e., no touch techniques. There are no safe disinfectants without accurate control of their concentration. It is crucial to imaginatively consider how to use HOCl(g) for the safe and effective disinfection of various settings for the foreseeable future.

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An essential point to be aware of when studying microbial cleaning and disinfection in food factories is the concept of biofilm. Biofilms are inhabited by a wide variety of microorganisms living in a kind of community, exchanging materials, energy, and information with other microorganisms around them. A biofilm is not simply an aggregate of microbial cells, but a network of macromolecular polymers in which the microbial cells are heterogeneously incorporated. The structure of a biofilm can be compared to a mushroom, but from the microorganism's point of view, it is a giant structure rich in irregularities and filled with "pore water". There are no special removal or sterilization methods for biofilms. The basic principle of microbial removal in food factories is cleaning, so the most important objective is to determine from where the biofilm is being generated. It is then essential to remove the biofilm using physical techniques and science-based cleaning approaches. In addition, the type of organic matter coexisting with the generated biofilm differs depending on the nature of the food plant involved (e.g. lipid-rich or protein-rich). Therefore, it is fundamental to perform cleaning according to the nature of a given instance of contamination. The idea of trying to simply sterilize the biofilm without cleaning is therefore an erroneous notion.

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Five types of durable dormant cells in bacteria are known, and they do not have evolutionary connections to each other. The endospore of Bacillus and Clostridium, the exospore of Streptomyces, the myxospore of Gram-negative bacteria Myxococcus xanthus, the cysts of Gram-negative bacteria Azotobacter, and the akinetes of the cyanobacterium Anabaena cylindrica are known. Although they are molds rather than bacteria, the ascospores of Talaromyces, Neosartorya, and Byssochlamys show the same level of heat resistance as endospores of bacteria, and food contamination accidents have occurred. Endospores of Bacillus and Clostridium show significant resistance to elevated temperature, high pressure, ultraviolet light, radiation, and chemical agents and are often used as biological indicators (BI) in sterilization. Spore-forming bacteria are found in diverse environments, including natural settings and the food industry. Some of them can cause health issues in animals and humans. The aim of this paper is to offer an overview of the most recent discoveries and remaining questions concerning exosporium and spore coat structure, dehydration in the spore core, DNA protection, DNA repair systems, and germination mechanisms, particularly those associated with spore resistance, which have been thoroughly investigated. Additionally, it provides a summary of techniques for investigating damaged spores. This information will be valuable for understanding the mechanisms underlying physical or chemical disinfection methods and for selecting the most suitable culture medium for colony counting.

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The term "health foods" refers to all foods that claim to have health benefits, but there are differences in the form of these foods, their scientific basis for efficacy and safety, and whether they make functional claims. From a regulatory perspective, they are divided into two categories: "Foods with Health Claims", which can be labeled with functional claims, and other foods, commonly known as "so-called health foods". Foods with Health Claims is a broad term encompassing Foods for Specified Health Uses, Foods with Nutrient Function Claims, and Foods with Function Claims. Among these three categories, there are also differences in terms of eligibility to use them, which ingredients can be labeled as functional, how functionality is evaluated, and how these foods are regulated and reported to the government. Product information and labeling play a significant role in the selection and proper use of a wide variety of health foods. If we do not correctly understand product information and labels, we may not only miss out on the claimed health benefits but also put our health at risk. Therefore, this article will focus on essential information to consider when dealing with health foods and will provide insights into product selection and effective usage.

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Food plays an important role in protecting people's health and providing a rich lifestyle. Food safety is supported by evidence. Food analysis is an important tool to obtain this evidence. Highly reliable analytical techniques support food safety. When abnormal values are observed, it is important to investigate the cause. Identification of the cause makes it possible to take appropriate measures and prevent recurrence. Developing and passing on analysis techniques in preparation for emergencies is important for improving operational efficiency and crisis management for organizations. When an inspection error occurs, it is important to view it as a problem of the organization's system management rather than as an individual's responsibility. In order to consistently produce accurate and reliable results, it is important that both the wheels of analysis technology (tangible) and analyst motivation (intangible) function in a well-balanced manner. Motivation is maintained through relationships of trust in the workplace. Relationships of trust are built through daily communication. Daily communication plays a major role in achieving the goals of an organization. Analysts protect people's lives and make great contributions to society. I hope that analysts will continue to produce highly reliable evidence with a sense of fulfillment and pride.

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Magnetic Resonance Imaging (MRI) is a technique widely used for visualizing the spatial distribution of signal intensity, relaxation time, diffusion coefficient and chemical shift obtained by nuclear magnetic resonance (NMR), and is also effectively used in food science. In this article, a brief explanation of the basic knowledge of MRI was provided, and research work on its application to several food products, including fish meat and wheat starch paste, were introduced. For the application of MRI in a study of fish meat, the mechanism of the salt penetration process was clarified by visualizing salinity changes in the fish meat. Water behavior in fish muscle after water perfusion was also revealed. In addition, gelatinization of wheat starch paste by localized laser heating and subsequent water migration was also elucidated by visualizing the spatial distribution of the gelatinization state in the paste using MRI. The results of these studies demonstrated that MRI has a great potential for visualizing and evaluating the movement of water and salt in food products. In conclusion, it has been shown that MRI has a great potential for visualizing and evaluating various food products as a non-invasive tool, and its application is expected to continue to be developed.

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