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The aim of the present work was to assess the effect of an innovative oleogelation strategy, the aerogel-template approach, on protein and lipid digestibility. Whey protein isolate (WP) was converted into aerogel particles

Ageing is an unavoidable progressive process causing many changes of the individual life. However, if faced in an efficient way, living longer in a healthy status could be an opportunity for all. In this context, food consumption and dietary patterns are pivotal factors in promoting active and healthy ageing. The development of food products tailored for the specific needs of the elderly might favour the fulfilment of nutritionally balanced diets, while reducing the consequences of malnutrition. To this aim, the application of a food structure design approach could be particularly profitable, being food structure responsible to the final functionalities of food products. In this narrative review, the physiological changes associated to food consumption occurring during ageing were firstly discussed. Then, the focus shifted to the possible role of food structure in delivering target functionalities, considering food acceptability, digestion of the nutrients, bioactive molecules and probiotic bacteria.

In this study an in vitro static digestion method mimicking the elderly gastrointestinal conditions was designed by adapting the physiological parameters described in the INFOGEST standardized static in vitro digestion protocol, i.e., pH, digestive phase duration, concentrations of enzymes and bile salts, to the aged GI transit. The digestibility of proteins from different sources (pea, rice, wheat, and milk whey) was then assessed. Protein digestive behaviour was monitored after gastric and intestinal phases by BCA assay and SDS-PAGE to assess protein hydrolysis both from a quantitative and a qualitative point of view. Digested samples were also analysed for physical characteristics in terms of particle size and zeta potential. Data acquired under elderly gastrointestinal conditions were compared to those obtained by using the INFOGEST protocol designed to study adult digestion. Results clearly showed that the elderly gastrointestinal conditions deeply affected proteolysis leading to a general reduction of protein digestibility in comparison to the adult model. The proteolysis extent depended on the protein source with whey and rice proteins showing about 20% reduction using the model mimicking the elderly gut, followed by pea (about 10% reduction) and wheat (about 4% reduction) proteins. The knowledge of protein digestibility under elderly gastrointestinal conditions generated in this study could be useful in the attempt to develop age-tailored products.

This research was conducted to evaluate the potential use of saturated monoglyceride (MG)-based gels in the protection of probiotics upon in vitro digestion. For this purpose, a Lactobacillus rhamnosus strain was inoculated into binary and ternary systems, containing MGs, a water phase composed of an aqueous solution at controlled pH or UHT skimmed milk, and in ternary gels, sunflower oil. Gel structure characterization was initially performed just after preparation and after 14 days of storage at 4 °C by rheological, mechanical, thermal, and microscopy analyses. Afterwards, probiotic viability upon in vitro digestion was evaluated. The results highlighted that all freshly prepared samples showed good capability to protect L. rhamnosus with the exception of the binary system containing milk. However, the digestion of samples after 14 days of storage showed that the ternary system containing skimmed milk exhibited the best protection performance ensuring a L. rhamnosus viability of almost 106 CFU g-1 at the end of the gastrointestinal passage. Confocal microscopy results demonstrated that bacterial cells were located prevalently within the aqueous domain near the monoglycerides and protein aggregates. Under these conditions, they can simultaneously achieve physical protection and find nutrients to survive environmental stresses. These findings suggest that MG-based gels can be proposed as efficient carriers of probiotic bacteria not only during food processing and storage but also upon digestion.

BACKGROUND The effect of high-pressure homogenization (HPH) on the rheological and thermal properties, water retention capacity (WRC), morphology and in vitro digestion of wheat starch was evaluated. Starch suspensions (50 g kg-1 , w/w) were treated at increasing pressures (up to 100 MPa) and numbers of cycles (up to 5) to generate a wide range of energy densities (70-500 MJ m-3 ) delivered to the sample during processing. RESULTS High-pressure homogenization induced a partial starch gelatinization confirmed by higher digestibility. Gelatinization degree (GD) was between 13% and 83%, causing a wide range of functional properties. High-pressure homogenization-treated starch samples showed WRC values of 810-1910 g kg-1 . Storage modulus (G') and complex viscosity (η* ) of starch dispersions were almost two and three times higher than the control at 13% and 83% GD, respectively. Positive linear relationships between GD (R = 0.98, P

This work aimed to design high-pressure homogenization process able to improve pea protein functionalities. To this purpose, pea protein concentrate suspensions (5% w/w) were homogenised at increasing pressures (up to 150 MPa) and number of passes (up to 3). Samples were analysed for protein structural and conformational modifications, technological functionalities, and in vitro digestibility. As HPH intensity increased, protein unfolding was favoured, leading to solubility and oil holding capacity increase and generating emulsions with rheological properties shifting from liquid-like pseudo-plastic behaviours to gel-like plastic characteristics. The best performing HPH treatment included 3 passes at 70 MPa and leaded to a novel plant-protein based ingredient with improved techno-functionalities and digestibility comparable to original pea proteins. A further increase in HPH intensity at 150 MPa for 3 passes caused protein aggregation with detrimental effects on technological functionalities and digestibility. Results demonstrate the remarkable effect of HPH in tailoring protein functionalities, highlighting the need of a process design step to define HPH process parameters allowing to generate novel high-added value.

Background This study aimed to evaluate the protective effect of different biopolymer systems on the viability of two probiotics (Lactobacillus rhamnosus and Streptococcus thermophilus) during storage and in vitro digestion. Methylcellulose (MC), sodium alginate (SA), and whey protein (WP)-based structures were designed and characterized in terms of pH, rheological properties, and visual appearance. Results The results highlighted that the WP-system ensured probiotic protection during both storage and in vitro digestion. This result was attributed to a combined effect of the physical barrier offered by the protein gel network and whey proteins as a nutrient for microbes. On the other hand, surprisingly, the viscous methylcellulose-based system was able to guarantee good microbial viability during storage. However, this was not confirmed during in vitro digestion. The opposite results were obtained for sodium alginate beads. Conclusion The results suggest that the capacity of a polymeric structure to protect probiotic bacteria is a combination of structural organization and system formulation. © 2020 Society of Chemical Industry.

In recent years, consumer awareness of the importance of proper nutrition has translated into a rapid increase on the market of functional foods, especially those containing probiotic microorganisms. Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” Probiotic foods, as such, must contain at the time of consumption a sufficiently high number of probiotic microorganisms to guarantee a beneficial effect to the host. The ability of these organisms to survive can be critical due to the poor tolerance to certain food characteristics, such as acidity and oxygen concentration, as well as to processing and storage conditions. In addition, probiotics exhibit a high sensitivity to stress encountered during the gastrointestinal transit. For these reasons, it is necessary to develop new technologies that provide an improvement in the viability of probiotics, without negatively affecting the chemical, physical, or sensory characteristics of the food. In recent decades, several attempts have been made to improve the viability of probiotics in food. In this context, the main areas of intervention concern the selection of the most suitable strains, the application of proper culture conditions, the use of probiotic-protecting ingredients, and the use of encapsulation strategies.

AimThe effect of moderate-intensity pulsed electric fields (MIPEF) was evaluated on vegetable protein concentrates from pea, rice, and gluten.MethodsFive percent (w/w) suspensions of protein concentrates (pH 5 and 6) were exposed to up to 60,000 MIPEF pulses at 1.65 kV/cm. Both structural modifications (absorbance at 280 nm, free sulfhydryl groups, FT-IR-spectra) and functional properties (solubility, water and oil holding capacity, foamability) were analyzed.ResultsMIPEF was able to modify protein structure by inducing unfolding, intramolecular rearrangement, and formation of aggregates. However, these effects were strongly dependent on protein nature and pH. In the case of rice and pea samples, structural changes were associated with negligible modifications in functional properties. By contrast, noticeable changes in these properties were observed for gluten samples, especially after exposure to 20,000 pulses. In particular, at pH 6, an increase in water and oil holding capacity of gluten was detected, while at pH 5, its solubility almost doubled.ConclusionThese results suggest the potential of MIPEF to steer structure of proteins and enhance their technological functionality.

The present research aimed at enriching short dough biscuits with apple pomace to reduce their glycemic index. Apple pomace produced on a laboratory scale was dehydrated and milled to a powder, which was characterized for soluble and insoluble dietary fiber, and for phenolic content. Apple pomace was used to partially replace wheat flour (10 and 20% w/w) in biscuits, which were characterized for their sensory properties and submitted to in vitro digestion to predict the glycemic index. Results indicated that apple pomace contained impressive amounts of dietary fiber (nearly 40%), mainly represented by insoluble fiber (more than 25%). Apple pomace led to a significant reduction in the expected glycemic index of reformulated biscuits. The conventional biscuit presented a glycemic index of 70 and was thus classified as high glycemic index food. Substituting wheat flour by 10 and 20% with apple pomace reduced biscuit glycemic index to 65 and 60 respectively, thus ranking the product within the intermediate glycemic index foods. Using industrial apple pomace led to analogous results, demonstrating that this by-product could be exploited to reduce the glycemic index of bakery foods, thus concomitantly satisfying the need for strategies to manage type 2 diabetes and to valorize food by-products.

Correction for ‘Effect of the formulation and structure of monoglyceride-based gels on the viability of probiotic Lactobacillus rhamnosus upon in vitro digestion’ by Sofia Melchior et al., Food Funct., 2021, DOI: 10.1039/D0FO01788D.