The 5th International Conference on Food Digestion . Introduction

Unravelling the fate of food in the gastrointestinal tract is essential to better understand the health effects of the food and to fight against diet-related pathologies such as cardiovascular diseases and type-2 diabetes. Digestion is the process that transforms food into nutrients. The first step of digestion occurs in the mouth, where mastication transforms solid and semi-solid foods into particles while mixing with saliva allows bolus formation and initiates digestion of carbohydrates.Then the bolus is transferred into the stomach, where acid conditions and specific enzymes (pepsin, gastric lipase) start hydrolyzing macronutrients like proteins and triglycerides. The next step occurs in the small intestine, where other digestive enzymes further degrade macronutrients allowing their absorption. In the small intestine, proteins are hydrolyzed by trypsin, chymotrypsin, elastase, carboxypeptidase etc, lipids by pancreatic lipases, and carbohydrates by pancreaticamylase. Small intestinal digestion is completed by the enzymes of the brush border membrane that release macronutrients, which can be absorbed by enterocytes to reach the bloodstream. Undigested material,fiber for example, reaches the large intestine where it is further metabolized by the intestinal microbiota.Investigating food digestion requires the use of models and a myriad of in vitro (static and dynamic), animal and human models have been described in the literature with the objectives of understanding the fateof food in the gastrointestinal tract. In particular, static in vitro digestion simulations are extremely popular because they are very easy to use and do not require sophisticated equipment. They have been shown to beadapted for screening large series of similar samples in identical conditions or to understand interactions at the molecular scale (Bohn et al.,2017). However, they are too simple to study more complex phenomenaand the kinetics of food digestion for which dynamic in vitro models are more appropriate (Dupont et al., 2018).There was a high heterogeneity between the different static in vitro digestion models that were used by the research groups all around the world. Models were differing in the pH used in the different phases(gastric and intestinal), their duration, the digestive enzyme/substrate ratio, etc For that reason, comparing results obtained from one study to another was impossible and there was a crucial need for a harmonizedmethod that could be used by everyone allowing comparison between studies. This was one of the main objectives of the INFOGEST COST Action

Geology of the Shakespeare quadrangle (H03), Mercury

By using images acquired by the Mercury dual imaging system (MDIS) on-board the MESSENGER spacecraft during 2008–2015 and available DTMs, a new 1:3,000,000-scale geological map of the Shakespeare quadrangle of Mercury has been compiled. The quadrangle is located between latitudes 22.5°–65.0°N and longitudes 270.0°–180.0°E and covers an area of about 5 million km2. The mapping was based on photo-interpretation performed on a reference monochromatic basemap of reflectance at 166 m/pixel resolution. The geological features were digitized within a geographic information system with a variable mapping scale between 1:300,000 and 1:600,000. This quadrangle is characterized by the occurrence of three main types of plains materials and four basin materials (pertaining to the Caloris basin), whose geologic boundaries have been here redefined compared to the previous map of the quadrangle. The stratigraphic relationships between the craters were based on three main degradation morphologies. Furthermore, previously unmapped tectonic landforms were detected and interpreted as thrusts or wrinkle ridges

Short communication: Molecular genetic characterization of ovine αS1-casein allele H caused by alternative splicing

Abstract Sequencing of ovine CSN1S1*H cDNA showed an absence of exon 8 in comparison with GenBank sequences; the absence was confirmed by protein sequencing. We demonstrated that this allelic aberration is the result of a deletion of 4 nucleotides, the last 3 of exon 8 and the first 1 of intron 8, which are replaced by an insertion of 13 nucleotides in the DNA sequence. The insertion is a precise duplication of a part of the adjacent intronic sequence of CSN1S1*C″ . These sequence differences result in an inactivation of the splice donor sequence distal to exon 8, leading to upstream exon skipping during the serial splice reactions of the ovine CSN1S1*H pre-mRNA, and may affect the specific casein expression as well as protein characteristics

Encapsulated proanthocyanidins as novel ingredients

Proanthocyanidins (OPC) are polyphenolic compounds, derivatives of flavan-3-ol flavonoids. They are abundant in grape seeds and skins, and contribute to most of the polyphenols in red wine. Proanthocyanidins from grape seed have been reported to show various health as well as technological properties. Aim of the study was to investigate the coating efficiency of maltodextrin (MD) in different molecular ratios with arabic gum (AG) on encapsulation of phenolic compounds extracted from grape pomace. The present study was planned to examine the contributions of MD, AG and OPC to the structural architecture of encapsulated OPC by means of scanning electron microscopy (SEM), their encapsulation efficiency and their functionality (antioxidant activity and bioavailability) by spectrophotometric assays and mass spectrometry analysis (MALDI-TOF-MS). The effect of encapsulated OPC on in vitro polyphenol digestibility was also evaluated according to the Infogest protocol. Encapsulated products were obtained by a mild ultrasonication method in controlled conditions based on the phenomenon of acoustic cavitation, and then freeze-dried. The content of coating material had significant (p>0.05) impact on particle morphology of spray-dried suspensions. SEM analysis of samples of AG/MD and AG/MD/OPC were similar and exhibited cracks and sharp edges, but samples with OPC showed a more enclosed structure. Total and Surface phenolic content of microcapsules showed the best encapsulation efficiency for samples with 4% of AG and 12% of MD. MALDI-TOF-MS characterization of encapsulated samples showed integrity of OPC components in the microcapsules with no changes with respect to original OPC. The in vitro digestion experiments showed also that composition and functionality of encapsulated OPC were better preserved along gastrointestinal digestion process. In conclusion, OPC microcapsules could be utilized both as nutraceuticals and additives in various food application

Identification of hormonogenic tyrosines in fragment 1218-1591 of bovine thyroglobulin by mass spectrometry. Hormonogenic acceptor TYR-12donor TYR-1375.

A fragment of bovine thyroglobulin encompassing residues 1218-1591 was prepared by limited proteolysis with thermolysin and continuous-elution polyacrylamide gel electrophoresis in SDS. The reduced and carboxymethylated peptide was digested with endoproteinase Asp-N and fractionated by reverse-phase high performance liquid chromatography. The fractions were analyzed by electrospray and fast atom bombardment mass spectrometry in combination with Edman degradation. The post-translational modifications of all seven tyrosyl residues of the fragment were characterized at an unprecedented level of definition. The analysis revealed the formation of: 1) monoiodotyrosine from tyrosine 1234; 2) monoiodotyrosine, diiodotyrosine, triiodothyronine (T3), and tetraiodothyronine (thyroxine, T4) from tyrosine 1291; and 3) monoiodotyrosine, diiodotyrosine, and dehydroalanine from tyrosine 1375. Iodothyronine formation from tyrosine 1291 accounted for 10% of total T4 of thyroglobulin (0.30 mol of T4/mol of 660-kDa thyroglobulin), and 8% of total T3 (0.08 mol of T3/mol of thyroglobulin). This is the first documentation of the hormonogenic nature of tyrosine 1291 of bovine thyroglobulin, as thyroxine formation at a corresponding site was so far reported only in rabbit, guinea pig, and turtle thyroglobulin. This is also the first direct identification of tyrosine 1375 of bovine thyroglobulin as a donor residue. It is suggested that tyrosyl residues 1291 and 1375 may support together the function of an independent hormonogenic domain in the mid-portion of the polypeptide chain of thyroglobulin

Quantification of Protein "Biomarkers" in Wheat-Based Food Systems: Dealing with Process-Related Issues

Selected food proteins may represent suitable markers for assessing either the presence/absence of specific food ingredients or the type and intensity of food processes. A fundamental step in the quantification of any protein marker is choosing a proper protocol for solubilizing the protein of interest. This step is particularly critical in the case of solid foods and when the protein analyte is prone to undergo intermolecular disulfide exchange reactions with itself or with other protein components in the system as a consequence of process-induced unfolding. In this frame, gluten-based systems represent matrices where a protein network is present and the biomarker proteins may be either linked to other components of the network or trapped into the network itself. The protein biomarkers considered here were wheat gluten toxic sequences for coeliac (QQPFP, R5), wheat germ agglutinin (WGA), and chicken egg ovalbumin (OVA). These proteins were considered here in the frame of three different cases dealing with processes different in nature and severity. Results from individual cases are commented as for: (1) the molecular basis of the observed behavior of the protein; (2) the design of procedure aimed at improving the recovery of the protein biomarker in a form suitable for reliable identification and quantification; (3) a critical analysis of the difficulties associated with the plain transfer of an analytical protocol from one product/process to another. Proper respect for the indications provided by the studies exemplified in this study may prevent coarse errors in assays and vane attempts at estimating the efficacy of a given treatment under a given set of conditions. The cases presented here also indicate that recovery of a protein analyte often does not depend in a linear fashion on the intensity of the applied treatment, so that caution must be exerted when attributing predictive value to the results of a particular study

Metatranscriptomics reveals temperature-driven functional changes in microbiome impacting cheese maturation rate

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 6 (2016): 21871, doi:10.1038/srep21871.Traditional cheeses harbour complex microbial consortia that play an important role in shaping typical sensorial properties. However, the microbial metabolism is considered difficult to control. Microbial community succession and the related gene expression were analysed during ripening of a traditional Italian cheese, identifying parameters that could be modified to accelerate ripening. Afterwards, we modulated ripening conditions and observed consistent changes in microbial community structure and function. We provide concrete evidence of the essential contribution of non-starter lactic acid bacteria in ripening-related activities. An increase in the ripening temperature promoted the expression of genes related to proteolysis, lipolysis and amino acid/lipid catabolism and significantly increases the cheese maturation rate. Moreover, temperature-promoted microbial metabolisms were consistent with the metabolomic profiles of proteins and volatile organic compounds in the cheese. The results clearly indicate how processing-driven microbiome responses can be modulated in order to optimize production efficiency and product quality.F.D.F. was supported by a grant from Regione Campania within the program “POR CAMPANIA FSE 2007/2013” - project CARINA (Safety sustainability and competitiveness of the agro-food production in Campania) – CUP B25B09000080007

Sensory and Biochemical Characterization of Novel Drinks Based on Tomato Juice

In these last years, consumers’ choices are being directed towards healthier food and beverages with an increasing demand for functional products. In this study, we investigated the sensory and biochemical properties of novel drinks based on tomato juice. To this purpose, different blends were formulated mixing fresh tomato juice with other fruit juices and nectars in different proportions and then assayed to investigate their sensory (panel test), compositional and biochemical characteristics. Our results indicated that it is possible to formulate tasty drinks based on tomato juice with improved nutritional properties. The combinations of red fruits/tomato (60/40 v/v) and red fruits/orange/tomato (40/30/30 v/v/v) showed a sugar content lower than those of different soft drinks on the market including energy drinks, and suitable lycopene levels as well. Interestingly, the blended red fruits/orange/tomato had a greater number of polyphenols and vitamin C, a softer tomato flavour and high sensory appreciation. High pasteurization (90ºC,7 min), performed to increase storability, did not significantly affect sensory and biochemical properties of drinks. These achievements may be useful to modulate tomato flavour release and consumer acceptability of novel drinks based on tomato juice

Effect of added enzymes and quinoa flour on dough characteristics and sensory quality of a gluten free bakery product

The study is aimed at developing a new cereal-based product, with increased nutritional quality, by using quinoa flour. The effect of the use of transglutaminase (TGase) and proteolytic enzymes on the microstructure, properties and in vitro digestion of gluten-free bakery products based on quinoa flour was evaluated. Microstructural results evaluated by means of Scanning Electron Microscopy (SEM) showed that the quinoa starch granules are rather small (0.4–2 μm) and the presence of TGase induced significantly changes in dough and baked samples microstructures. The overall acceptability of the breads was improved by TGase addition. The results achieved showed that these enzymes have different effects on the bread characteristics and may improve properties of formulations, setting the basis for development of baked quinoa products

Differential Protein Expression in Berry Skin from Red Grapes with Varying Hybrid Character

Protein expression from the berry skin of four red grape biotypes with varying hybrid character was compared at a proteome-wide level to identify the metabolic pathways underlying divergent patterns of secondary metabolites. A bottom-up shotgun proteomics approach with label-free quantification and MaxQuant-assisted computational analysis was applied. Red grapes were from (i) purebred Vitis vinifera (Aglianico cv.); (ii) V. vinifera (local Sciascinoso cv.) grafted onto an American rootstock; (iii) interspecific hybrid (V. vinifera × V. labrusca, Isabel), and (iv) uncharacterized grape genotype with hybrid lineage, producing relatively abundant anthocyanidin 3,5-O-diglucosides. Proteomics supported the differences between hybrids and purebred V. vinifera grapes, consistently with distinct phenotypic metabolite assets. Methanol O-anthraniloyltransferase, which catalyses the synthesis of methyl anthranilate, primarily responsible for the "foxy" odour, was exclusive of the Isabel hybrid grape. Most of the proteins with different expression profiles converged into coordinated biosynthetic networks of primary metabolism, while many possible enzymes of secondary metabolism pathways, including 5-glucosyltransferases expected for hybrid grapes, remained unassigned due to incomplete protein annotation for the Vitis genus. Minor differences of protein expression distinguished V. vinifera scion grafted onto American rootstocks from purebred V. vinifera skin grapes, supporting a slight influence of the rootstock on the grape metabolism