Bioengineered Wheat Arabinoxylan - Fostering Next-Generation Prebiotics Targeting Health-Related Gut Microbes.

Dietary prebiotic fibers play an important role in modulating gut microbiota by enhancing the abundance of beneficial microorganisms and their bioactive metabolites. However, dietary fibers are a structurally heterogeneous class of polysaccharides, varying in molar mass, branching patterns, and monosaccharide composition, which could influence their utilization by various gut microorganisms. The present study aimed to investigate the effects of molar mass and chemical structure of wheat arabinoxylan fiber (AX) on the growth and metabolism of two key gut resident bacteria (Faecalibacterium prausnitzii and Lacticaseibacillus rhamnosus LGG), which are linked to human health. For this purpose, low, medium, and high molar masses of AX (LAX, MAX, and HAX, respectively) were modified with specific α-arabinofuranosidases to leave only singly substituted, only doubly substituted, or unsubstituted xylose units. Almost all the modified AX samples showed a better prebiotic score than unmodified AX for different molar masses. The modified LAX exhibited a better prebiotic effect than HAX and MAX. In addition, LAX, with doubly substituted xylose units, exhibited the highest prebiotic potential and SCFA production by both microorganisms. Furthermore, AX, either singly or doubly substituted, had a consistent impact on L. rhamnosus growth, whereas AX, with all arabinose residues removed, had a greater impact on F. prausnitzii. These findings support the potential of bioengineered AX as next-generation prebiotics targeting health-related gut microbes.

The clean label trend: An ineffective heuristic that disserves both consumers and the food industry?

What started around the late 2000s as the "Clean Label" (CL) trend has now become a meaningful segment of the food market, appealing to consumers who want foods made of a limited number of simple and recognizable ingredients. However, this description and tentative definitions of CL foods are vague, subject to multiple interpretations, and CL remains an informal denomination for foods, making consumers' demands and food manufacturers' offerings hardly compatible. Therefore, rather than attempting an illusory definition of CL foods, this narrative review aims to (1) show how CL appears to be a heuristic used by consumers to attempt to make safe and healthful food choices, (2) discuss how this heuristic overlooks many critical aspect of food safety and healthfulness and is consequently ineffective to guide consumers' choices, and (3) discuss the implications of the CL trend on the food chain's stakeholders and their relationships.

Instant Oatmeal Increases Satiety and Reduces Energy Intake Compared to a Ready-to-Eat Oat-Based Breakfast Cereal: A Randomized Crossover Trial.

BACKGROUND: Foods that enhance satiety can help consumers to resist environmental cues to eat and help adherence to calorie restriction. The objective of this study was to compare the effect of 2 oat-based breakfast cereals on appetite, satiety, and food intake. METHODS: Forty-eight healthy individuals, 18 years of age or older, were enrolled in a randomized, crossover trial. Subjects consumed isocaloric servings of either oatmeal or an oat-based ready-to-eat breakfast cereal (RTEC) in random order at least a week apart. Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. Lunch was served 4 hours after breakfast. The physicochemical properties of oat soluble fiber (ß-glucan) were determined. Appetite and satiety responses were analyzed by area under the curve. Food intake and ß-glucan properties were analyzed using t tests. RESULTS: Oatmeal increased fullness (p = 0.001) and reduced hunger (p = 0.005), desire to eat (p = 0.001), and prospective intake (p = 0.006) more than the RTEC. Energy intake at lunch was lower after eating oatmeal compared to the RTEC (p = 0.012). Oatmeal had higher viscosity (p = 0.03), ß-glucan content, molecular weight (p < 0.001), and radius of gyration (p < 0.001) than the RTEC. CONCLUSIONS: Oatmeal suppresses appetite, increases satiety, and reduces energy intake compared to the RTEC. The physicochemical properties of ß-glucan and sufficient hydration of oats are important factors affecting satiety and subsequent energy intake.

Orange pomace fibre increases a composite scoring of subjective ratings of hunger and fullness in healthy adults.

Dietary fibre has been shown to increase subjective satiating ratings. However data from human trials has produced mixed results, possibly due to different types of fibre which have diverse physicochemical properties and gastrointestinal transit behaviour. The aim of study 1 was to investigate whether orange juice (OJ) with 5.5 g of added orange pomace fibre (OPF) was as satiating as whole orange (WO, chopped and blended to a puree/liquid) compared with OJ. Study 2 was to evaluate the dose-dependent satiating effect of OPF delivered in an orange-flavoured beverage. Both studies were randomized, controlled, double blind, cross over in design with 4 intervention arms in study 1 including OJ, OPF, WO, and water, and 3 arms in study 2: orange-flavoured beverage with low (2.5 g) and high (5.5 g) dose of OPF (LD-OPF and HD-OPF), and orange-flavoured beverage without fibre (Control). Volunteers were asked to response to 8 questions relating to hunger, fullness, desire to eat, thirst and discomfort by visual analogue scale (VAS) for each question. Differences were detected in least squares mean estimates of composite satiety scores and each individual question with statistical modelling to adjust for differences in baseline scores. Addition of 5.5 g OPF either to OJ or to orange-flavoured beverage significantly increased the composite satiety scores compared with OJ (P < 0.0001) or Control (P < 0.0001), and the effect was comparative to WO. LD-OPF showed some satiating effect (less desire to eat) compared with Control (P = 0.038), though less effective than HD-OPF (P = 0.043). In conclusion, the addition of OPF to OJ was as effective at increasing satiety as WO consumption compared with OJ; and there was a trend of dose-dependent effect of OPF on satiety compared with the control.

The role of meal viscosity and oat ß-glucan characteristics in human appetite control: a randomized crossover trial.

BACKGROUND: Foods that enhance satiety can help consumers to resist environmental cues to eat, and improve the nutritional quality of their diets. Viscosity generated by oat ß-glucan, influences gastrointestinal mechanisms that mediate satiety. Differences in the source, processing treatments, and interactions with other constituents in the food matrix affect the amount, solubility, molecular weight, and structure of the ß-glucan in products, which in turn influences the viscosity. This study examined the effect of two types of oatmeal and an oat-based ready-to-eat breakfast cereal (RTEC) on appetite, and assessed differences in meal viscosity and ß-glucan characteristics among the cereals. METHODS: Forty-eight individuals were enrolled in a randomized crossover trial. Subjects consumed isocaloric breakfast meals containing instant oatmeal (IO), old-fashioned oatmeal (SO) or RTEC in random order at least a week apart. Each breakfast meal contained 218 kcal (150 kcal cereal, and 68 kcal milk) Visual analogue scales measuring appetite were completed before breakfast, and over four hours, following the meal. Starch digestion kinetics, meal viscosities, and ß-glucan characteristics for each meal were determined. Appetite responses were analyzed by area under the curve. Mixed models were used to analyze response changes over time. RESULTS: IO increased fullness (p = 0.04), suppressed desire to eat (p = 0.01) and reduced prospective intake (p < 0.01) more than the RTEC over four hours, and consistently at the 60 minute time-point. SO reduced prospective intake (p = 0.04) more than the RTEC. Hunger scores were not significantly different except that IO reduced hunger more than the RTEC at the 60 minute time-point. IO and SO had higher ß-glucan content, molecular weight, gastric viscosity, and larger hydration spheres than the RTEC, and IO had greater viscosity after oral and initial gastric digestion (initial viscosity) than the RTEC. CONCLUSION: IO and SO improved appetite control over four hours compared to RTEC. Initial viscosity of oatmeal may be especially important for reducing appetite.

Functional Model Beverages of Saffron Floral By-Products: Polyphenolic Composition, Inhibition of Digestive Enzymes, and Rheological Characterization.

Despite the rapid and dynamic evolution of research into dietary polyphenols, there is still a knowledge gap regarding their bioaccessibility since it could be influenced by the chemical and nutritional compositions of the food matrix. This study aimed to describe the impact of food thickeners (xanthan gum, guar gum, ß-glucan, pectin) on the bioactivity of flavonoids from saffron floral by-products in model beverages before and after thermal processing. The different beverage formulas were characterized in terms of polyphenolic composition using HPLC-DAD-ESI-MSn and rheological properties. The impact of food thickeners and thermal processing on the inhibition of digestive enzymes was also determined. The model beverages mainly presented glycosylated flavonols (of kaempferol, quercetin, and isorhamnetin), with a reduced content in some heat-treated samples. The inhibitory effect on α-amylase was only detected in heat-treated beverages, showing the formulation without any thickener to have the greatest inhibitory effect. Finally, the presence of saffron floral by-products in the beverages showed a tendency to decrease the flow consistency index (K) and an increase in the flow behavior index (n), most probably driven by the aggregation of phenolics with thickeners. Therefore, this research provides new insights into the development of flavonoid-rich beverages in order to ensure that they exert the expected beneficial effects after their ingestion.

Acute effect of oatmeal on subjective measures of appetite and satiety compared to a ready-to-eat breakfast cereal: a randomized crossover trial.

OBJECTIVE: The physicochemical properties of soluble oat fiber (ß-glucan) affect viscosity-dependent mechanisms that influence satiety. The objective of this study was to compare the satiety impact of oatmeal with the most widely sold ready-to-eat breakfast cereal (RTEC) when either was consumed as a breakfast meal. METHODS: Forty-eight healthy individuals ≥18 years of age were enrolled in a randomized crossover trial. Following an overnight fast, subjects consumed either oatmeal or RTEC in random order at least a week apart. The breakfasts were isocaloric and contained 363 kcal (250 kcal cereal, 113 kcal milk). Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. The content and physicochemical properties of oat ß-glucan were determined. Appetite and satiety responses were analyzed by area under the curve (AUC). Physicochemical properties were analyzed using t tests. RESULTS: Oatmeal, higher in fiber and protein but lower in sugar than the RTEC, resulted in greater increase in fullness (AUC: p = 0.005 [120 minute: p = 0.0408, 180 minute: p = 0.0061, 240 minute: p = 0.0102]) and greater reduction in hunger (AUC: p = 0.0009 [120 minute: p = 0.0197, 180 minute: p = 0.0003, 240 minute: p = 0.0036]), desire to eat (AUC: p = 0.0002 [120 minute: p = 0.0168, 180 minute: p < 0.0001, 240 minute: p = 0.0022]), and prospective intake (AUC: p = 0.0012 [120 minute: p = 0.0058, 180 minute: p = 0.006, 240 minute: p = 0.0047]) compared to the RTEC. Oatmeal had higher ß-glucan content, higher molecular weight (p < 0.0001), higher viscosity (p = 0.025), and larger hydration spheres (p = 0.0012) than the RTEC. CONCLUSION: Oatmeal improves appetite control and increases satiety. The effects may be attributed to the viscosity and hydration properties of its ß-glucan content.

Revisiting survival at sea from a nutrition and food perspective: rationalizing the rations.

This study examines the design of food rations for survival at sea required by the International Maritime Organization through the Life Saving Appliances (LSA) Code, as implemented by Transport Canada. Energy demand and body fat reserves were estimated for the Canadian population based on demographic and anthropometric data. It was determined that caloric content of food rations could be drastically decreased without potential harm to survivors of a marine abandonment. Coupled with ration reformulation, such decrease could be an opportunity to extend safe survival conditions to up to 5 days versus 2 days as currently provisioned by the LSA Code.

Probing the Mechanism of Action of Small-Molecule Ice Recrystallization Inhibitors Using Proton Nuclear Magnetic Resonance Relaxation.

N-2-Fluorophenyl-d-gluconamide (2FA) improves the recovery and function of cryopreserved biological materials by inhibiting ice recrystallization. However, as for many small-molecule ice recrystallization inhibitors, the mechanism of action of 2FA is not well-understood. In this study, the IC50 of 2FA for ice recrystallization was determined to be 3.5 mM (95% CI [3.41-3.52]). 1H transverse and longitudinal relaxations were then characterized by NMR at 2FA concentrations from 0 to 10 mM and at temperatures between -15 °C and +30 °C. Corresponding activation energy of water molecule motion (EAH2O) was calculated, showing that at each concentration 2FA did not affect EAH2O in the solid state, whereas in the liquid state EAH2O was significantly higher with 2FA than for pure water. Therefore, 2FA is excluded from the ice lattice upon freezing and concentrated in the interstitial liquid phase. This restricts the migration of water molecules between ice crystals via the liquid phase, inhibiting ice recrystallization.

Probing gallic acid-starch interactions through Rapid ViscoAnalyzer in vitro digestion.

Phenolic compounds are known inhibitors of starch digestion through binding with α-amylase. However, a growing body of research shows that phenolic-starch interactions at the molecular level may interfere with this inhibition potential. In this study, we evaluated the effect of Gallic Acid (GA) as a model phenolic compound on starch digestion kinetics carried out in vitro in a Rapid ViscoAnalyzer (RVA). The results showed that when GA was added before cooking of starch in order to promote starch-GA complexation, the rate of digestion of starch was similar to that of starch alone, and faster than when GA was added after cooking of starch. The results demonstrated that when GA was introduced after cooking of starch, GA inhibited α-amylase strongly and that inhibition increased with starch paste viscosity only for potato and wheat starches. No correlation was found between starch molecular characteristics and the inhibiting capacity of GA at different starch concentrations. However, the apparent influence of starch chain length distribution suggested that physical effects (such as the absorption of GA at the surface of the starch paste) may play a role in the capacity of GA to inhibit α-amylase.

Viscosity development from oat bran ß-glucans through in vitro digestion is lowered in the presence of phenolic compounds.

Dietary fibres have been shown to aggregate and lose viscosity and water binding capacity in solution in the presence of phenolic compounds. This study aimed to verify this observation in a complex grain system containing ß-glucans. The viscosity of uncooked and cooked oat bran digested in vitro was measured in the presence of 1-30 mM phenolic acids or flavonoids, and digestograms were modelled to understand the effects of phenolic compounds on the drivers of viscosity. The final viscosity of the digesta, driven by ß-glucans, underwent a significant decrease of up to 31% upon the addition of phenolic compounds. To account for the inhibitory activity of phenolic compounds on digestive enzymes, modelling of the digestograms was adjusted with reference to that from previous work. The models suggest that phenolic compounds can simultaneously: (1) slow down the release of ß-glucans by slowing down digestion through enzyme inhibition, and (2) decrease the viscosity of solubilised ß-glucans, likely through colloidal aggregation as observed in solution before. These in vitro results suggest that the health benefits of oats linked to digestive viscosity of ß-glucans may be altered by co-formulation with or co-ingestion of phenolic compounds.

Influence of polysaccharide concentration on polyphenol-polysaccharide interactions.

Non-covalent interactions between polysaccharides and phenolics affect the physical properties of polysaccharide solutions. These interactions may in turn be influenced by polysaccharide-polysaccharide interactions. To test this hypothesis, we studied the influence of polysaccharide concentration (with guar, ß-glucans, and xanthan) on the variations of rheological and water-binding properties upon addition of phenolics compounds (vanillin, caffeic acid, gallic acid, and epigallocatechin gallate). Addition of phenolics led to increased flow behavior index and decreased flow consistency index, with maximum effects at polysaccharide concentrations ranging between 0.6 × C* and 1.4 × C*, where C* is the critical overlap concentration of each polysaccharide. Water mobility was generally not significantly influenced by the addition of phenolics. The results showed that the ability of phenolic compounds to induce aggregation of polysaccharides in solution was strongly influenced by polysaccharide concentration around C* and therefore by polysaccharide-polysaccharide interactions.

Microwave-assisted synthesis of NaMnF3 particles with tuneable morphologies.

Here, the synthesis of sub-micron MMnF3 (M = Na or K) particles by a rapid microwave-assisted approach is reported. Adjustment of the Na+-to-Mn2+ ratio in the reaction mixture yielded tuneable morphologies, i.e., rods, ribbons, and plates. Relaxometric results indicated that poly(acrylic acid)-capped MMnF3 particles exhibited characteristic magnetic properties, which endows them with potential T1-weighted contrast agent capabilities.

Rheological and water binding properties of xanthan, guar and ultra-finely milled oatmeal in white birch sap: Influence of sap minor constituents.

White Birch Sap (WBS) contains appreciable amounts of mineral ions and phenolic compounds and can be used as alternate solvent for food applications. In this study, the effect of the mineral and phenolic composition of WBS was evaluated on the physical properties of xanthan gum, guar gum, ultra-finely milled oatmeal and their combinations in solution. Solutions were formulated with WBS and with solvents mimicking WBS without phenolic compounds and WBS without phenolics nor mineral ions. The influence of solvent composition was evaluated on flow properties and water mobility of the solutions. From WBS without mineral ions nor phenolics, the addition of mineral ions led to increased pseudo-plasticity and decreased flow consistency, and decreased water mobility. Addition of phenolic compounds through WBS led to opposite effects possibly due to phenolic-driven aggregation of the hydrocolloids which also seemed to inhibit guar/xanthan interactions.

Hydrophobization and antimicrobial activity of chitosan and paper-based packaging material.

This study reports the elaboration of water-resistant, antimicrobial, chitosan and paper-based materials as environmentally friendly food packaging materials. Two types of papers were coated with chitosan-palmitic acid emulsions or with a blend of chitosan and O,O'-dipalmitoylchitosan (DPCT). Micromorphology studies showed that inclusion of hydrophobic compounds into the chitosan matrix was enhanced by grafting them onto chitosan and that this led to their penetration of the paper's core. Compared to chitosan-coated papers, the coating of chitosan-palmitic emulsion kept vapor-barrier properties unchanged (239 and 170 g.m(-2).d(-1) versus 241 and 161 g.m(-2).d(-1)), while the coating of chitosan-DPCT emulsion dramatically deteriorated them (441 and 442 g.m(-2).d(-1)). However, contact angle measurements (110-120 degrees after 1 min) and penetration dynamics analysis showed that both strategies improved liquid-water resistance of the materials. Kit-test showed that all hydrophobized chitosan-coated papers kept good grease barrier properties (degree of resistance 6-8/12). Finally, all chitosan-coated materials exhibited over 98% inhibition on Salmonella Typhimurium and Listeria monocytogenes .

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Emerging science on benefits of whole grain oat and barley and their soluble dietary fibers for heart health, glycemic response, and gut microbiota.

The aim of this work is to review the major mechanisms by which consumption of whole grain oats and barley, and ß-glucans, reduces the risk of coronary heart disease, type 2 diabetes, and other noncommunicable chronic conditions. These effects have been predominantly explained by the role of soluble dietary fibers and smaller bioactive compounds, such as phenolic compounds, in oats and barley. These help to reduce the level of serum low-density lipoprotein cholesterol, decreasing postprandial blood glucose and modulating gut microbiota. In the present review, the role of viscosity development of the intestinal content by ß-glucans in these mechanisms is discussed, as well as the impact of processing conditions altering the composition or the physicochemical characteristics of ß-glucans.

Pine Bark Phenolic Extracts, Current Uses, and Potential Food Applications: A Review.

PURPOSE: To summarize the main findings from research on food uses of Pine Bark Phenolic Extracts (PBPE), their origin, methods of extraction, composition, health effects, and incorporation into food products. METHODS: A narrative review of all the relevant papers known to the authors was conducted. RESULTS: PBPE are mainly extracted from the bark Pinus pinaster. They are generally rich in procyanidins and their effects on health in the form of nutritional supplements include effect on some forms of cancer, on diabetes, on eye and skin health. Their method of extraction influences greatly their composition and yield, and commercially suitable methods are still to be developed. Incorporation into food products raises challenges related to bioavailability and subsequent bioactivity and sensory properties of the final products. CONCLUSION: PBPE represent an opportunity for the development of functional foods with phenolic-rich bioactive compounds.

Quantitative characterization of the digestive viscosity profile of cereal soluble dietary fibers using in vitro digestion in Rapid ViscoAnalyzer.

A standard method measuring viscosity (η) of cereal products through in vitro digestion in a Rapid ViscoAnalyzer has been developed previously and is predictive of some physiological effects of cereal foods. This paper proposes a simple mathematical model to analyze quantitatively the digestograms obtained by that method. Digestograms of twelve uncooked and cooked cereal products were generated and data quality was assessed. Experimental data were fitted with a viscosity model ηmodel=η1+η2, where [Formula: see text] and [Formula: see text] were respectively viscosity decrease and viscosity increase components. The model showed very good agreement with experimental data and enabled interpretation of the digestograms in relation to the composition of the products: η1 was interpreted as the decreasing viscosity of digestible polymeric nutrients whereas η2 was interpreted as the viscosity development of viscous dietary fibers. This model may be useful to investigate quantitatively the biological effects of soluble dietary fibers in cereal products and similar products.

Gallic acid reduces the viscosity and water binding capacity of soluble dietary fibers.

Water binding capacity and viscosity of soluble dietary fibers are known to be essential drivers of their nutritional benefits. Phenolic compounds, often found in the presence of dietary fibers, are also known to bind non-covalently with soluble dietary fibers. In this study, we characterized the impact of gallic acid (1-30 mM) on the physical properties of four soluble dietary fibers in solution (0.75% w/w oat ß-glucans with medium and high molecular weights, 0.75% w/w guar galactomannan and 0.5% w/w xanthan mannoglucuronoglucan). Isothermal titration calorimetry and particle size analysis showed that gallic acid and soluble dietary fibers formed poorly dissociable non-covalent complexes, leading to colloidal aggregation of the fibers. Upon complexation, the physical properties of the fibers changed dramatically with up to a 65% increase in water mobility (reflecting a dramatic decrease in water binding capacity), up to a 41% increase in pseudo-plastic behavior leading to near-Newtonian behavior, and up to a 95% decrease in viscosity. This suggests that combinations of free phenolic compounds and soluble dietary fibers may be detrimental to the physical and potentially the nutritional properties of the fibers.