Simulated gastro-intestinal digestion is widely employed in many fields of food and nutritional sciences, as conducting human trials are often costly, resource intensive, and ethically disputable. As a consequence, in vitro alternatives that determine endpoints such as the bioaccessibility of nutrients and non-nutrients or the digestibility of macronutrients (e.g. lipids, proteins and carbohydrates) are used for screening and building new hypotheses. Various digestion models have been proposed, often impeding the possibility to compare results across research teams. For example, a large variety of enzymes from different sources such as of porcine, rabbit or human origin have been used, differing in their activity and characterization. Differences in pH, mineral type, ionic strength and digestion time, which alter enzyme activity and other phenomena, may also considerably alter results. Other parameters such as the presence of phospholipids, individual enzymes such as gastric lipase and digestive emulsifiers vs. their mixtures (e.g. pancreatin and bile salts), and the ratio of food bolus to digestive fluids, have also been discussed at length. In the present consensus paper, within the COST Infogest network, we propose a general standardised and practical static digestion method based on physiologically relevant conditions that can be applied for various endpoints, which may be amended to accommodate further specific requirements. A frameset of parameters including the oral, gastric and small intestinal digestion are outlined and their relevance discussed in relation to available in vivo data and enzymes. This consensus paper will give a detailed protocol and a line-by-line, guidance, recommendations and justifications but also limitation of the proposed model. This harmonised static, in vitro digestion method for food should aid the production of more comparable data in the future.

https://hal.archives-ouvertes.fr/hal-01209876/document

A standardised static in vitro digestion method suitable for food – an international consensus

The popularity of fermented foods and beverages is due to their enhanced shelf-life, safety, functionality, sensory, and nutritional properties. The latter includes the presence of bioactive molecules, vitamins, and other constituents present in the initial food substrates. Many fermented foods also contain live microorganisms that may improve gastrointestinal health and provide other health benefits, including lowering the risk of type two diabetes and cardiovascular disease. The number of organisms in fermented foods can vary significantly, depending on how products were manufactured and processed, as well as conditions and duration of storage. In this review, we surveyed published studies in which lactic acid and other relevant bacteria were enumerated from the most commonly consumed fermented foods, including cultured dairy products, cheese, fermented sausage, fermented vegetables, soy-fermented foods, and fermented cereal products. Most of the reported data were based on retail food samples, rather than experimentally produced products made on a laboratory scale. Results indicated that many of these fermented foods contained 105-7 lactic acid bacteria per mL or gram, although there was considerable variation based on region and sampling time. In general, cultured dairy products consistently contained higher levels, up to 109/mL or g. Although few specific recommendations for what constitutes a relevant dose exist, the findings from this survey revealed that many fermented foods are a good source of live lactic acid bacteria, including species that reportedly provide human health benefits

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Fermented Foods as a Dietary Source of Live Organisms

The scientific evidence for the role of milk protein-derived bioactive peptides in humans: a review

Invited review: Microbial evolution in raw-milk, long-ripened cheeses produced using undefined natural whey starters.

Authenticity of dairy products has become an urgent issue for producers, researchers, governments, consumers and so on due to the increase of falsification procedures inducing lost large of money as well as the confidence of consumers. The determination of the authenticity and the detection of adulteration of milk and dairy products have been determined by several analytical techniques (e.g., physico-chemical, sensory, chromatography, and so on). Although these methods are considered as the reference ones, they required sophisticated analytical equipment's and skilled operators; they are also time consuming and need both the purchase and disposal of chemical reagents. Therefore, there is a need to find cheap and fast methods for the determination of the authenticity and the detection of adulteration of these products. Thus, spectroscopic techniques such as fluorescence spectroscopy, near infrared (NIR), mid infrared (MIR), nuclear magnetic resonance (NMR), among others, in combination with multivariate data analysis methods could be considered helpful tools in this domain. The advantages and disadvantages of each technique will be also discussed in this review.

Analytical methods coupled with chemometric tools for determining the authenticity and detecting the adulteration of dairy products: A review

Formation of lactulose, furosine, galactosyl-|*beta*|-pyranone and lysinoalanine was studied in UHT milk samples produced by either direct or indirect heating on industrial plants and by indirect heating on a pilot plant. In particular, the effects of severe sterilization conditions, different proportions of milk recirculation, and storage of the finished product (23 °C for up to 90 days) have been investigated on the levels of the above molecules in UHT milk. An extensive increase of the values of all the indicators occurred when severe heat process was applied, but no direct relation was found between their levels and the nominal time–temperature conditions. Lactulose and furosine levels confirmed to be strictly correlated in UHT milk. In case of overheating or high proportion (60%) of milk recirculation, galactosyl-|*beta*|-pyranone formation was strongly enhanced, proving that also the advanced Maillard reaction takes place extensively, which is not detected by furosine value. Formation of lysinoalanine in UHT drinking milk on storage was pointed out for the first time. Lysinoalanine proved to be the most sensitive index of storage conditions among the four parameters studied. Data suggest that a realistic defence of UHT milk quality can be achieved only by fixing upper limits to heat damage parameters. Besides avoiding unjustified milk overheating, this approach may allow manipulations, like reprocessing expired milk, to be pointed out.

Effects of overprocessing on heat damage of UHT milk

Occurrence and fate of ACE-inhibitor peptides in cheeses and in their digestates following in vitro static gastrointestinal digestion.

Sensitive determination of lysinoalanine for distinguishing natural from imitation Mozzarella cheese

Background hygienic and safe production is a high priority in the food industry. During processing, food may be subjected to bio-contamination. Accordingly, preservation of overall quality by keeping a clean environment is a goal to pursue. Among microbial vectors, air is considered a contributing factor to cross-contamination. Scope and approach nowadays, in food plants emphasis is paid to the assessment of air bioload in view of prevention of recontamination. Normally, air entering a processing plant is chilled and filtered to remove undesired microorganisms from outside. Nevertheless, apart from clean-room environments, uncontrolled factors (processes, personnel, structures, etc.) contribute to the release of microorganisms in indoor environments, resulting in generation of bioaerosols highly variable within and among plants, and on a daily basis within the same plant. Key findings and conclusions this review focuses on the relevance of bioaerosol monitoring in the food industry, providing an update of air sampling techniques and methods of analysis in view to strengthen preventive hygienic actions. Disinfection procedures to minimize microbial counts in the air as additional safeguard to the standard chemical sanitation protocols are reviewed. Benefits and limitations of air treatment by chemical fogging, ozonation, uv irradiation or cold plasma are outlined. Air bioload monitoring and the implementation of subsequent air disinfection procedures are a feasible and a routinely exploitable strategy to satisfy hygienic requirements in food plants. Further research is required to face technical challenges and optimize the feasibility of some disinfection technologies for the real-world of food environments.

/pdf/airborne-contamination-in-the-food-industry-an-update-on-4liwjaj1zz.pdf

Airborne contamination in the food industry : An update on monitoring and disinfection techniques of air

Background Cheese manufacturing consists of a dehydration process by which most of the whey is drained off. Whey proteins (WP) represent a nutritionally valuable fraction largely lost in the whey stream. The increasing consumer demand for food with novel texture and functionality prompted the dairy industry to exploit the valorization of WP. Scope and approach Cheese milk is considered a vehicle for the inclusion of WP. In this review, technological tools to fortify cheese with WP are discussed. Focus is addressed on both the pioneer approaches (the heat treatment of cheese milk, membrane separation technologies and the direct addition of milk- or whey-based derivatives) and on more recent techniques such as high hydrostatic pressure, ultra-high pressure homogenization, transglutaminase treatment of cheese milk and direct addition of buttermilk. Key findings and conclusions Milk fortification with WP influences the yield and overall properties of resulting cheeses. Processing conditions need to be adapted to successfully manufacture WP-fortified conventional cheeses as well as novel varieties (such as low-fat cheeses). Up to now, only some technological tools to include WP in cheese are exploited at industrial scale. The combination of different techniques is a strategy to overcome the impairment of cheese properties.

/pdf/technological-tools-to-include-whey-proteins-in-cheese-4kwxec7737.pdf

Fabio Masotti

Papers

Effects of overprocessing on heat damage of UHT milk

Occurrence and fate of ACE-inhibitor peptides in cheeses and in their digestates following in vitro static gastrointestinal digestion.

Sensitive determination of lysinoalanine for distinguishing natural from imitation Mozzarella cheese

Airborne contamination in the food industry : An update on monitoring and disinfection techniques of air

Technological tools to include whey proteins in cheese: Current status and perspectives