High moisture extrusion of a dietary protein blend impairs in vitro digestion and delays in vivo postprandial plasma amino acid availability in humans.

BACKGROUND: Industrial processing can alter the structural complexity of dietary proteins and, potentially, their digestion and absorption upon ingestion. High moisture extrusion (HME), a common processing method used to produce meat alternative products, affects in vitro digestion, but human data are lacking. We hypothesised that HME of a mycoprotein/pea protein blend would impair in vitro digestion and in vivo postprandial plasma amino acid availability. METHODS: In Study A nine healthy volunteers completed two experimental trials in a randomised, double-blind, cross-over design. Participants consumed a beverage containing 25 g protein from a 'dry' blend (CON) of mycoprotein/pea protein (39/61%) or a HME content matched blend (EXT). Arterialised-venous blood samples were collected in the postabsorptive state and regularly over a 5 h postprandial period to assess plasma amino acid concentrations. In Study B, in vitro digestibility of the two beverages were assessed using BCA assay and optical-fluorescence microscopy at baseline, during and following gastric and intestinal digestion using the INFOGEST model of digestion. RESULTS: Protein ingestion increased plasma total, essential (EAA), and branched-chain amino acid (BCAA) concentrations (time effect; P<0.0001), but more rapidly and to a greater magnitude in the CON compared with the EXT condition (condition x time interaction; P<0.0001). This resulted in greater plasma availability of EAA and BCAA concentrations during the early postprandial period (0-150 min). These data were corroborated by the in vitro approach which showed greater protein availability in the CON (2150 ± 129 mg·mL-1) compared with EXT (590 ± 41 mg·mL-1) during the gastric phase. Fluorescence microscopy revealed clear structural differences between the two conditions. CONCLUSIONS: These data demonstrate that HME delays in vivo plasma amino acid availability following ingestion of a mycoprotein/pea protein blend. This is likely due to impaired gastric phase digestion as a result of HME induced aggregate formation in the pea protein. CLINICAL TRIALS: NCT05584358.

Understanding the mechanism of high viscosity food delaying gastric emptying.

Controlling the structure and viscosity of food can influence the development of diet-related diseases. Food viscosity has been linked with health through its impact on human digestion and gastrointestinal transit, however, there is limited understanding of how the viscosity of food regulates gastric emptying. Here, we used model food preparations with different viscosities using guar gum, to explore the mechanism underlying the influence of viscosity on gastric motility, gastric emptying and postprandial blood glucose. Based on experiments in human volunteers and animals, we demonstrated that high viscosity meals increased gastric antrum area and gastric retention rate. Viscosity also affected gut hormone secretion, reduced the gene expression level of interstitial cells of Cajal, resulting in a delay of gastric emptying and limiting the increase in postprandial glucose. This improved mechanistic understanding of food viscosity during gastric digestion is important for designing new foods to benefit human health.

Postprandial lipid and vascular responses following consumption of a commercially-relevant interesterified palmitic acid-rich spread in comparison to functionally-equivalent non-interesterified spread and spreadable butter: a randomised controlled trial in healthy adults.

Background: Interesterification is an industrial processing technique used widely where hard fats are essential for functionality and consumer acceptability, e.g. margarines and lower fat spreads. Objective: The aim of this study was to compare acute cardiovascular effects of functionally equivalent spreads (similar solid fat content) made with interesterified (IE) or non-IE palm-based fats, or spreadable butter. Methods: A randomised, controlled, 4-armed crossover, double-blind study (25 men, 25 women; 35-75 years; healthy; mean BMI 24.5, SD 3.8), compared effects of mixed nutrient meals containing 50 g fat from functionally equivalent products [IE spread, non-IE spread and spreadable butter (SB), with rapeseed oil (RO) as a reference treatment: with 16.7%, 27.9%, 19.3% and 4% palmitic acid, respectively] on 8 h postprandial changes in plasma triacylglycerol (TAG) and endothelial dysfunction (flow-mediated dilatation; FMD). Circulating reactive oxygen species (estimated using a neutrophil oxidative burst assay), glucose, insulin, NEFA, lipoprotein particle profiles, inflammatory markers (glycoprotein acetylation (Glyc-A) and IL-6), and biomarkers of endotoxemia were measured. Results: Postprandial plasma TAG concentrations after test meals were similar. However following RO versus the 3 spreads, there were significantly higher postprandial apolipoprotein B concentrations, and small HDL and LDL particle concentrations, and lower postprandial extra-large, large, and medium HDL particle concentrations, as well as smaller average HDL and LDL particle sizes. There were no differences following IE compared to the other spreads. Postprandial FMD% did not decrease after high-fat test meals, and there were no differences between treatments. Postprandial serum IL-6 increased similarly after test meals, but RO provoked a greater increase in postprandial concentrations of glycoprotein acetyls (GlycA), as well as 8 h sCD14, an endotoxemia marker. All other postprandial outcomes were not different between treatments. Conclusions: In healthy adults, a commercially-available IE-based spread did not evoke a different postprandial triacylglycerol, lipoprotein subclass, oxidative stress, inflammatory or endotoxemic response to functionally-equivalent, but compositionally-distinct alternative spreads. Clinical trial registry number: NCT03438084 (https://ClinicalTrials.gov).

Pea protein extraction method impacts the protein (micro)structural organisation and in vitro digestion kinetics.

There is increasing interest in including pulse proteins into food products due to their nutrient-rich and sustainable character. However, little is known regarding the consequences of different extraction approaches on the pulse protein structure and the subsequent protein (micro)structural organization and protein digestion kinetics. Therefore, three green pea protein extracts were created: (i) cooking followed by cotyledon cell isolation, (ii) alkaline extraction followed by isoelectric precipitation, or (iii) salt extraction, and compared to the original pea flour as well as to sodium caseinate. The results showed that encapsulated, denatured protein inside pea cotyledon cells presented the (s)lowest digestion, while accessible and more native protein (e.g., pea flour, pea protein salt extract) presented much faster and higher digestion. Moreover, the alkali extracted pea protein was denatured to some extent, significantly lowering in vitro digestion kinetics. In the second part, three different in vitro approaches were applied to digest the salt extracted pea protein. Semi-dynamic gastric digestion approaches simulate in vivo conditions more closely which especially impacted the rate of digestion.

Mechanisms of interesterified fat digestibility in a muffin matrix using a dynamic gastric model.

Industrially generated trans-fats have been linked with cardiovascular disease (CVD) and have thus been replaced by interesterified (IE) fats, in foods. Interesterification rearranges fatty acids on the glycerol backbone of a triacylglycerol molecule. However, the impact of IE fat on health is unknown. We recently reported differences in lipid absorption kinetics between IE and rapeseed oil (RO). Here, we investigated the mechanisms underpinning IE fat digestion kinetics in the same muffins baked using an IE fat, non-IE fat [with the same fatty acid composition] and rapeseed oil (RO) under simulated conditions. IE and non-IE fats were largely solid in the gastric phase and strongly associated within the muffin matrix, whereas RO formed liquid droplets which separated from the matrix. No significant difference in lipolysis rates was detected between IE and non-IE fats. The lipolysis of the RO fat was slower, due to long-chain PUFAs. Interesterification itself did not affect digestibility, but the strong interaction between the hard fats and the muffin matrix resulted in extensive creaming of the matrix in the stomach, leading to delayed gastric emptying compared to the RO sample. The rate and extent of lipolysis were determined by the amount of fat available and the structure of the fat. This demonstrates the importance of the physical behaviour of the fats during digestion and provides a mechanistic understanding of the overall lipid digestion of IE fats, which relates to their physiological response.

The use of confocal Raman microscopy and microfluidic channels to monitor the location and mobility of ß-carotene incorporated in droplet-stabilized oil-in-water emulsions.

This study sought to explore the combined use of confocal Raman microscopy and microfluidic channels to probe the location and mobility of hydrophobic antioxidant (ß-carotene) incorporated at the interface of food-grade droplet-stabilized emulsions (DSEs). Microfluidic channels were used to isolate emulsion droplets for efficient investigation of antioxidant mobility. This approach proved more conclusive than fixing the sample in agarose, because a single layer of droplets could be obtained. Results also indicated that the migration of ß-carotene incorporated in shell droplets of olive oil and trimyristin DSEs to core droplets was minimal and beta-carotene remained mostly localised at the interface even after 3 days of production. This work demonstrates that microfluidic isolation of emulsion droplets combined with confocal Raman microscopy can give new insights into the spatial variation of chemical composition within emulsions. This study revealed that the migration of ß-carotene between shell and core was minimal and hence it may be possible to concurrently deliver two incompatible compounds by spatially segregating them between shell and core compartments of DSEs.

Assessment of Polyphenols Bioaccessibility, Stability, and Antioxidant Activity of White Mugwort (Artemisia lactiflora Wall.) during Static In Vitro Gastrointestinal Digestion.

White mugwort (Artemisia lactiflora Wall.), a traditional Chinese medicine, has been widely consumed in different forms for health care purposes. In this study, the in vitro digestion model of INFOGEST was used to investigate the bioaccessibility, stability, and antioxidant activity of polyphenols from two different forms of white mugwort, including dried powder (P 50, 100, and 150 mg/mL) and fresh extract (FE 5, 15, and 30 mg/mL). During digestion, the bioaccessibility of TPC and antioxidant activity were influenced by the form and ingested concentration of white mugwort. The highest bioaccessibility of the total phenolic content (TPC) and relative antioxidant activity were found at the lowest P and FE concentrations, as calculated relative to the TPC and antioxidant activity of P-MetOH and FE-MetOH based on the dry weight of the sample. Post-digestion, in comparison to P, FE had higher bioaccessibility (FE = 287.7% and P = 130.7%), relative DPPH radical scavenging activity (FE = 104.2% and P = 47.3%), and relative FRAP (FE = 673.5% and P = 66.5%). Nine compounds, 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-di-caffeoylquinic acid, sinapolymalate, isovitexin, kaempferol, morin, rutin, and quercetin, identified in both samples were modified during digestion, yet still provided strong antioxidant activity. These findings suggest that white mugwort extract possesses a higher polyphenol bioaccessibility, showing great potential as a functional ingredient.

Interaction of polymers with bile salts - Impact on solubilisation and absorption of poorly water-soluble drugs.

Formulating poorly soluble drugs with polymers in the form of solid dispersions has been widely used for improving drug dissolution. Endogenous surface-active species present in the gut, such as bile salts, lecithin and other phospholipids, have been shown to play a key role in facilitating lipids and poorly soluble drugs solubilisation in the gut. In this study, we examined the possible occurrence of interactions between a model bile salt, sodium taurocholate (NaTC), and model spray dried solid dispersions comprising piroxicam and Hydroxypropyl Methylcellulose (HPMC), a commonly used hydrophilic polymer for solid dispersion preparation. Solubility measurements revealed the good solubilisation effect of NaTC on the crystalline drug, which was enhanced by the addition of HPMC, and further boosted by the drug formulation into solid dispersion. The colloidal behaviour of the solid dispersions upon dissolution in biorelevant media, with and without NaTC, revealed the formation of NaTC-HPMC complexes and other mixed colloidal species. Cellular level drug absorption studies obtained using Caco-2 monolayers confirmed that the combination of drug being delivered by solid dispersion and the presence of bile salt and lecithin significantly contributed to the improved drug absorption. Together with the role of NaTC-HPMC complexes in assisting the drug solubilisation, our results also highlight the complex interplay between bile salts, excipients and drug absorption.

Cyanidin-3-O-glucoside protects intestinal epithelial cells from palmitate-induced lipotoxicity.

CONTEXT: Increased free fatty acids (FFAs) levels, typical in obesity condition, can contribute to systemic lipotoxicity and inflammation adversely influencing Inflammatory Bowel Disease development and progression. Anthocyanins possess health promoting properties mainly associated to the induction of Nrf2-regulated cytoprotective proteins. OBJECTIVE: Using a novel experimental model, we evaluated the in vitro intracellular mechanisms involved in FFAs modulation of intestinal epithelial lipotoxicity and the protective effects of cyanidin-3-O-glucoside (C3G) in Caco-2 cells. RESULTS: Caco-2 exposed to palmitic acid (PA) in the serosal (basolateral) side showed a combined state of epithelial inflammation, inducing NF-κB pathway and downstream cytokines, that was reverted by C3G apical pre-treatment. In addition, PA altered intracellular redox status and induced reactive oxygen species that were reduced by C3G via the redox-sensitive Nrf2 signalling. DISCUSSION AND CONCLUSION: Results suggest that anti-inflammatory properties of anthocyanins, mediated by Nrf2, could represent an interesting tool for intestinal inflammatory disorders.

An evolving view on food viscosity regulating gastric emptying.

Viscosity is a property of most foods. The consumption of the high-viscosity food is associated with a variety of physiological responses, one of which is their ability to regulate gastric emptying and modulate postprandial glycemic response. Gastric emptying has been proven to be a key step affecting the digestion and absorption of food, whereas, the relationship between viscosity and gastric emptying is still far away from being understood. Here, we reviewed the factors that influence food viscosity and food viscosity changes during digestion. Besides, the effect of food viscosity on gastric emptying and food-viscosity-physiological response were highlighted. Finally, "quantitative relationship" of viscosity and gastric emptying was discussed. This review can contribute to the understanding that how food viscosity affects gastric emptying, and help for developing foods that could control satiety and manage body weight for the specific populations.

Role of calcium on lipid digestion and serum lipids: a review.

Calcium is an essential nutrient for humans that can be taken as supplement or in a food matrix (e.g. dairy products). It is suggested that dietary calcium may have a beneficial effect on cardiovascular risk but the mechanism is not clear. In this review, the main mechanisms of the possible cholesterol-lowering effect of calcium, i.e. interaction with fatty acids and bile acids, are described and clinical evidences are presented. The observations from interventional studies of the possible cholesterol-lowering effect in terms of the main related mechanisms are variable and do not seem to fulfill all the related aspects. It seems that the interplay of calcium in blood lipid metabolism might be due to its complex and multiple roles in the lipid digestion in the small intestine. The interactions between calcium and, fatty acids and bile may lead to impaired mixed micelle formation and solubilization, which is crucial in the lipid absorption and metabolism. In addition, the calcium source and its surrounding matrix will have an influence over the physiological outcome. This research is important for the delivery and formulation of calcium, particularly with the move toward plant-based diets.

Anti-Inflammatory Activity of an In Vitro Digested Anthocyanin-Rich Extract on Intestinal Epithelial Cells Exposed to TNF-α.

BACKGROUND: The consumption of foods rich in anthocyanins (ACN) have been associated with beneficial properties in chronic inflammatory disorders such as intestinal bowel diseases (IBD). These effects were attributed not only to a direct antioxidant mechanism but also to the modulation of cell redox-dependent signaling. However, ACN bioavailability is low for their poor stability in the digestive tract, so ACN gastrointestinal digestion should be considered. METHODS: To have a more realistic knowledge of the effects of ACN, we performed an in vitro simulated gastrointestinal digestion of an ACN-rich purified and standardized bilberry and blackcurrant extract (BBE), followed by an evaluation of ACN composition modification (HPLC-DAD and pH differential method) and antioxidant activity (FRAP assay). Then, we studied the effects of BBE gastrointestinal extract on Caco-2 exposed to TNF-α. RESULTS: The results confirmed the high instability of ACN in the mild alkaline environment of the small intestine (17% recovery index). However, the digested BBE maintained part of its bioactivity. Additionally, BBE gastrointestinal extract inhibited the TNF-α-induced NF-κB pathway in Caco-2 and activated the Nrf2 pathway. CONCLUSIONS: Although ACN stability is affected by gastrointestinal digestion, the anti-inflammatory and antioxidant activity of digested extracts were confirmed; thus, the loss of ACN can probably be counterweighed by their metabolites. Then, ACN introduced by diet or food supplements could represent an approach for IBD prevention.

Colloidal dynamics of emulsion droplets in mouth.

The interaction of emulsions with the tongue is key to the sensory appeal of food and can potentially be exploited for oral/buccal pharmaceutical delivery. Whilst there is good understanding of the different mucoadhesive forces governing emulsion interaction with the tongue, their relative importance is not well understood. In addition, the physical location of emulsions within the saliva papillae on the tongue is not understood at all. A combination of ex vivo salivary film, and in vivo oral coating experiments were used to determine the importance of different mucoadhesive forces. Mucoadhesion of cationic emulsions was largely driven by electrostatic complexation. SDS-PAGE of the in vivo saliva coating highlighted that mucins were largely responsible for cationic emulsion mucoadhesion. Anionic emulsions were bound via hydrophobic/steric interactions to small salivary proteins typically located away from the mucin anchor points. The physical location and clustering of emulsions relative to the salivary film/papillae was probed via the invention of a fluorescent oral microscope. Cationic emulsions were densely clustered close to the papillae whilst anionic emulsions were suspended in the salivary film above the papillae. Interestingly, non-ionic emulsions were also trapped within the salivary film above the papillae as individual droplets. These findings highlight that whilst electrostatic complexation with saliva is a powerful mucoadhesive force, hydrophobic and steric interactions also act to induce oral retention of emulsions. The differences in physical location and clustering of emulsions within the salivary film hint at the 3D locations of the different salivary proteins driving each mucoadhesive interaction. This novel understanding of emulsion saliva/papillae interactions has potential to aid efficacy of buccal pharmaceutical delivery and the reduction of astringency in plant-based foods.

Anticholinesterase Activities of Different Solvent Extracts of Brewer's Spent Grain.

Cholinesterases, involved in acetylcholine catabolism in the central and peripheral nervous system, have been strongly linked with neurodegenerative diseases. Current therapeutic approaches using synthetic drugs present several side effects. Hence, there is an increasing research interest in naturally-occurring dietary polyphenols, which are also considered efficacious. Food processing by-products such as brewer's spent grain (BSG) would be a potential bio-source of polyphenols. In this study, polyphenol-rich BSG extracts using 60% acetone and 0.75% NaOH solutions were generated, which were further subjected to liquid-liquid partitioning using various organic solvents. The water-partitioned fractions of the saponified extracts had the highest total polyphenol content (6.2 ± 2.8 mgGAE/g dw) as determined by Folin-Ciocalteu reagent, while the LC-MS/MS showed ethyl acetate fraction with the highest phenolics (2.9 ± 0.3 mg/g BSG dw). The best inhibitions of acetyl- (37.9 ± 2.9%) and butyryl- (53.6 ± 7.7%) cholinesterases were shown by the diethyl ether fraction of the saponified extract. This fraction contained the highest sum of quantified phenolics (99 ± 21.2 µg/mg of extract), and with significant (p < 0.01) inhibitory contribution of decarboxylated-diferulic acid. Amongst the standards, caffeic acid presented the highest inhibition for both cholinesterases, 25.5 ± 0.2% for acetyl- and 52.3 ± 0.8% for butyryl-cholinesterase, respectively, whilst the blends insignificantly inhibited both cholinesterases. The results showed that polyphenol-rich BSG fractions have potentials as natural anti-cholinesterase agents.

Palmitic acid-rich oils with and without interesterification lower postprandial lipemia and increase atherogenic lipoproteins compared with a MUFA-rich oil: A randomized controlled trial.

BACKGROUND: Interesterified (IE) fats are widely used in place of trans fats; however, little is known about their metabolism. OBJECTIVES: To test the impact of a commonly consumed IE compared with a non-IE equivalent fat on in vivo postprandial and in vitro lipid metabolism, compared with a reference oil [rapeseed oil (RO)]. METHODS: A double-blinded, 3-phase crossover, randomized controlled trial was performed in healthy adults (n = 20) aged 45-75 y. Postprandial plasma triacylglycerol and lipoprotein responses (including stable isotope tracing) to a test meal (50 g fat) were evaluated over 8 h. The test fats were IE 80:20 palm stearin/palm kernel fat, an identical non-IE fat, and RO (control). In vitro, mechanisms of digestion were explored using a dynamic gastric model (DGM). RESULTS: Plasma triacylglycerol 8-h incremental area under the curves were lower following non-IE compared with RO [-1.7 mmol/L⋅h (95% CI: -3.3, -0.0)], but there were no differences between IE and RO or IE and non-IE. LDL particles were smaller following IE and non-IE compared with RO (P = 0.005). Extra extra large, extra large, and large VLDL particle concentrations were higher following IE and non-IE compared with RO at 6-8 h (P < 0.05). No differences in the appearance of [13C]palmitic acid in plasma triacylglycerol were observed between IE and non-IE fats. DGM revealed differences in phase separation of the IE and non-IE meals and delayed release of SFAs compared with RO. CONCLUSIONS: Interesterification did not modify fat digestion, postprandial lipemia, or lipid metabolism measured by stable isotope and DGM analysis. Despite the lower lipemia following the SFA-rich fats, increased proatherogenic large triacylglycerol-rich lipoprotein remnant and small LDL particles following the SFA-rich fats relative to RO adds a new postprandial dimension to the mechanistic evidence linking SFAs to cardiovascular disease risk.

Comparison of oral physiological and salivary rheological properties of Chinese Mongolian and Han young adults.

OBJECTIVES: Consumers' oral physiology and salivary properties are greatly dependent on dietary backgrounds, and this in turn may impact food perception and preferences. Scarce studies are available on the oral physiology and salivary rheology of Chinese participants with different dietary and ethnic backgrounds. DESIGN: This study examined two ethnic groups, Chinese Han and Chinese Mongolian healthy young adults, and explored the differences in oral physiology and salivary rheological properties. Official data suggested that Chinese Mongolians tend to consume more red meat and dairy, and Chinese Han tend to consume more carbohydrates. 200 Han and 104 Mongolian participants were evaluated for the oral physiological and salivary rheological parameters (maximum bite force of incisor and molar teeth, maximum tongue pressure and maximum oral volume; the surface tension, shear viscosity and extensional viscosity of unstimulated and stimulated whole saliva samples). RESULTS: Distinct differences between two ethnic groups were found, particularly in their bite forces and salivary physical properties. Chinese Mongolian participants had significantly higher incisor bite force (168 N) than Chinese Han (146 N). In addition, Chinese Han had significantly lower unstimulated whole saliva flow rate than Chinese Mongolians; and significantly higher salivary surface tension, shear viscosity and extensional viscosity, in both unstimulated and stimulated whole saliva samples. CONCLUSIONS: Chinese Han and Chinese Mongolian participants exhibited different oral physiological and salivary rheological properties; and considering the dietary differences between the two ethnicities, the findings from this study suggest possible associations between dietary habits and oral physiological & saliva rheological properties.

Mechanisms, physiology, and recent research progress of gastric emptying.

Gastric emptying refers to a process in which the stomach discharges its contents into the small intestine to further digest and absorb nutrients. Understanding the mechanisms of gastric emptying and relationships between food and individuals is of paramount importance for the design and manufacture of novel and healthy foods. For ethical and cost reasons, in vivo tests are not always possible. In vitro digestion models therefore play a key role in current exploration of gastric emptying. This review outlines the mechanisms and physiology of gastric emptying, including calories, viscosity, composition of the food, age and gender of the individual. In addition, recent progress on in vitro static and dynamic gastric digestion models and future research trends are included in this review.

Morphology of bile salts micelles and mixed micelles with lipolysis products, from scattering techniques and atomistic simulations.

HYPOTHESES: Bile salts (BS) are biosurfactants released into the small intestine, which play key and contrasting roles in lipid digestion: they adsorb at interfaces and promote the adsorption of digestive enzymes onto fat droplets, while they also remove lipolysis products from that interface, solubilising them into mixed micelles. Small architectural variations on their chemical structure, specifically their bile acid moiety, are hypothesised to underlie these conflicting functionalities, which should be reflected in different aggregation and solubilisation behaviour. EXPERIMENTS: The micellisation of two BS, sodium taurocholate (NaTC) and sodium taurodeoxycholate (NaTDC), which differ by one hydroxyl group on the bile acid moiety, was assessed by pyrene fluorescence spectroscopy, and the morphology of aggregates formed in the absence and presence of fatty acids (FA) and monoacylglycerols (MAG) - typical lipolysis products - was resolved by small-angle X-ray/neutron scattering (SAXS, SANS) and molecular dynamics simulations. The solubilisation by BS of triacylglycerol-incorporating liposomes - mimicking ingested lipids - was studied by neutron reflectometry and SANS. FINDINGS: Our results demonstrate that BS micelles exhibit an ellipsoidal shape. NaTDC displays a lower critical micellar concentration and forms larger and more spherical aggregates than NaTC. Similar observations were made for BS micelles mixed with FA and MAG. Structural studies with liposomes show that the addition of BS induces their solubilisation into mixed micelles, with NaTDC displaying a higher solubilising capacity.

Genetic variation in wheat grain quality is associated with differences in the galactolipid content of flour and the gas bubble properties of dough liquor.

Lipids affect the quality of wheat flour for breadmaking. One possible mechanism is stabilization of the gas cells which are formed during dough mixing and expanded during fermentation, leading to a greater loaf volume and evenness of texture. We therefore compared the lipidomic profiles of flour and dough liquor fractions (which contain surface-active components present at the gas bubble interface) from two sets of wheat lines differing in allelic variation at a QTL for loaf volume. Analyses of fractions from three field trials showed consistent increases in the contents of galactolipids (monogalactosyl diglyceride and digalactosyl diglyceride) in flour and dough liquor of the lines with the increasing (good quality) allele. Biophysical analysis showed that this was associated with greater elasticity of the dough liquor fraction. This is consistent with published studies reporting a relationship between galactolipids and breadmaking quality and suggests a mechanism of action for the QTL.

Protein bioaccessibility from mycoprotein hyphal structure: In vitro investigation of underlying mechanisms.

Mycoprotein is a food ingredient from filamentous fungi rich in protein and fibre. This study investigated the protein bioaccessibility from the fungal cells by colourimetric assays in different mycoprotein formulations, following extraction methods and in vitro gastrointestinal digestion. The methods effects were further analysed by static laser light scattering, SDS-PAGE and optical-fluorescence microscopy. The extraction methods released a comparable proportion of protein (30 wt%) independent of sample concentration (10 wt% and 25 wt%), whereas the simulated digestions endpoints released a higher proportion of protein from the less concentrated (46 wt%). Furthermore, mechanical/physical processing had only a minor impact. Intestinal proteases promoted the most efficient protein release but without causing any apparent damage to the cell walls when viewed by microscopy. This suggested that the enzymes can diffuse through the cell walls, due to its porosity/permeability, and are the main factors responsible for the hydrolysis and bioaccessibility of protein from mycoprotein.