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Recently, a static in vitro digestion (IVD) protocol was published by Minekus and coworkers (Minekus et al., 2014) within the COST INFOGEST network. The protocol, concentrating on physiological enzyme activities had the main goal to improve the comparability of experimental data between labs. The protocol was validated in several inter-laboratory studies using skim milk powder (SMP) and indeed demonstrated improved harmonization compared with previous experiments with individual IVD protocols (Egger et al., 2016). Although the enzyme activities and salt concentrations of the harmonized protocol are based on available human in vivo data, confirmation of the protocol's physiological relevance has been lacking until now. The main goal of the study was therefore to compare the harmonized IVD protocol with data from in vivo digestion. Towards this aim, an in vivo pig experiment with the same SMP as used for the validation of the IVD protocol was performed followed by a comparison of protein hydrolysis between in vivo and in vitro results. Protein hydrolysis at different levels was analyzed with gel electrophoresis, mass spectrometry, high performance liquid chromatography, and spectrophotometric o-phthaldialdehyde determination of free amino acids. Principle component analysis was used for graphical data comparison. Milk proteins detected after gastric IVD corresponded to gastric and duodenal in vivo samples and intestinal IVD samples corresponded to distal jejunal in vivo samples. Peptides identified after the gastric phase of IVD, correlated with in vivo gastric samples (r=0.8) and intestinal IVD peptides correlated best with in vivo samples collected from the median jejunum (r=0.57). Free amino acids were in both systems mainly released during the intestinal phase of digestion. Protein hydrolysis in the harmonized IVD was similar to in vivo protein hydrolysis in pigs at the gastric and intestinal endpoints. Therefore, the harmonized static in vitro protocol is suited to study protein hydrolysis at these endpoints.

Background: An adequate diet contributes to health and wellbeing in older age. This is nowadays more important than ever since in industrialised countries the elderly population is growing continually. However, information regarding the consumption behaviour of older persons in Switzerland is limited. Objective: The objective of this investigation was to explore how middle-aged and elderly Swiss view animal products in relation to diet and health, and what factors predict consumption frequency. Design: A representative consumer survey among 632 people over the age of 50 years, living in the German-, French- and Italian-speaking regions of Switzerland was conducted. Results: This paper presents the results related to meat and meat products consumption. Most participants consumed meat and meat products regularly. The majority of participants with low meat intake indicated that eating small amounts would be enough. Respondents judged fresh meat (except pork) to be healthier than meat products, and poultry to be the healthiest meat. Overall meat consumption frequency was predicted by language region, gender, household size, and BMI. Furthermore, participants’ opinion about healthiness, taste and safety of meat but not their adherence to the Swiss food pyramid was found to be correlated to the consumption frequency of individual types of meat. Conclusion: Several factors have an impact on consumption frequency of meat and meat products in the middle-aged and elderly Swiss population and the importance varies according to the individual types of meat and meat products. The results show that the traditional food pyramid is not one of these factors for which reason new tools must be explored to support elderly people in regard to a healthy dietary behaviour.

Different studies have shown that people are aware of the benefits of dairy products, but a sizeable part of the world's population still does not consume the recommended amount of dairy produce. The aims of the present research were to determine which dairy products are consumed by the middle-aged and elderly (50-81yr old) living in Switzerland and to explore why some of this population segment are actually reducing their consumption of dairy products. On average, older Swiss adults consumed 2.6 portions of dairy products per day, which is slightly less than the recommended 3 to 4 portions a day. Additionally, about one-quarter of the respondents indicated that they have reduced their milk or dairy consumption. The main reasons given for this decision were to reduce fat or cholesterol. A reported difficulty in digesting some dairy products may be a further reason for limiting dairy intake, particularly cheese. It follows that a need for the propagation of appropriate nutritional information about dairy products to the middle-aged and elderly exists.

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