Improving the textural and nutritional properties in restructured meat loaf by adding fibers and papain designed for elderly.

This study aimed to evaluate the effects of dietary fibers (apple, oat, pea, and inulin) in meat loaves treated with papain enzyme. In the first step, dietary fibers were added to the products at the level of 6%. All dietary fibers decreased the cooking loss and improved the water retention capacity throughout the shelf life of the meat loaves. Besides, the dietary fibers increased the compression force of meat loaves treated with papain, mainly oat fiber. The dietary fibers decreased the pH, especially the treatment with apple fiber. In the same way, the color was changed mainly by the apple fiber addition, resulting in a darker color in both raw and cooked samples. TBARS index increased in meat loaves added with both pea and apple fibers, mostly for the last one. In the next step, the combination of inulin, oat, and pea fibers was evaluated in the meat loaves treated with papain, combining fibers up to 6% total content likewise decreased cooking and cooling loss and increased the texture of the papain-treated meat loaf. The addition of fibers improved the acceptability of the texture-related samples, except for the three-fiber mixture (inulin, oat, and pea), which was related to a dry, hard-to-swallow texture. The mix of pea and oat fibers conferred the best descriptive attributes, possibly related to improved texture and water retention in the meat loaf, and comparing the use of isolated oat and pea, the perception of negative sensory attributes was not mentioned, such as soy and other off-flavors. Considering these results, this study showed that dietary fibers combined with papain improved the yielding and functional properties with potential technological use and consistent nutritional claims for elderly.

Oat fiber supplementation alleviates intestinal inflammation and ameliorates intestinal mucosal barrier via acting on gut microbiota-derived metabolites in LDLR-/- mice.

OBJECTIVE: Gut microbiota-derived metabolites are involved in intestinal inflammation, which can affect the development of atherosclerotic plaques. Previous studies have shown that oat fiber can delay the progression of atherosclerosis via improving lipid metabolism. The aim of this study was to evaluate how oat fiber acted on gut microbiota-derived metabolites, inhibited intestinal inflammation, and protected the intestinal mucosal barrier. METHODS: Male low-density lipoprotein receptor knock-out (LDLR-/-) mice were fed a high-fat/cholesterol diet with or without oat fiber for 14 wk. Histopathology of the aorta was detected by Oil Red O staining, and the small intestine mucosal pathology was measured through hematoxylin and eosin staining. Non-targeted metabolomics of feces was performed using liquid chromatography-mass spectrometry. Western blot method was used to assess the relative levels of the proteins involved in the toll-like receptor (TLR)4 signal pathway and intestinal mucosal barrier in interest tissues. RESULTS: Pathologically, oat fiber reversed the increment of the atherosclerotic lesion and ameliorated intestinal mucosal barrier in LDLR-/- mice. Oat fiber regulated the levels of gut microbiota-derived metabolites along with a decrease in isobutyrylcarnitine, valerylcarnitine, 1-methylguanosine, and 2-methylguanosine, and an increase in l-tyrosine and niacinamide. Notably, oat fiber blocked the TLR4 signal pathway and decreased the expression of nuclear factor-κB p65 in both the aorta and gut tissues. Also, oat fiber raised the expression of tight junction proteins including ZO-1 and occludin. CONCLUSION: Taken together, the present study revealed that oat fiber feeding effectively attenuated the development of atherosclerosis, at least partly via affecting gut microbiota-derived metabolites, inhibiting the intestinal inflammatory response, and maintaining the integrity of the intestinal mucosal barrier.

Oat Fiber Modulates Hepatic Circadian Clock via Promoting Gut Microbiota-Derived Short Chain Fatty Acids.

The biological alteration of circadian rhythm was found to be related to the development of metabolic disorders. Our previous studies reported that impaired lipid metabolism caused by a high-fat diet was improved by oat fiber, but did not attempt to answer whether the improvement is mechanistically linked to circadian rhythm. By focusing on circadian alteration, the present study aimed to elucidate the effect of gut microbiota-derived short chain fatty acids (SCFAs) on circadian rhythm in a high-fat diet experimental paradigm with and without dietary oat fiber feeding. The results showed that oat fiber prevented the production of obesity and dyslipidemia caused by a high-fat diet in C57BL/6 mice. From a circadian perspective specifically, a high-fat diet disrupted the hepatic circadian protein expressions of the liver clock genes, which were in parallel with the altered oscillation of serum triglycerides, low-density lipoprotein cholesterol, fasting insulin, and the homeostasis model assessment-insulin resistance index. Oat fiber, by contrast, reversed these disrupted diurnal oscillations. Most interestingly, what a high-fat diet induced and what oat fiber prevented were dictated in a close oscillation pattern resembling that of SCFA production facilitated by the intestinal microbiome. Given the results from the present study and from others that demonstrated the role played by SCFAs in regulating circadian rhythm, we conclude that the beneficial effects of oat fiber are likely mediated by complex processes involving multiple mechanisms including a signal transduction pathway of gut microbiota-derived SCFAs to hepatic circadian protein expression to lipid and other metabolic oscillations. The latter warrants more investigation to further determine whether the circadian rhythm pathway has any major and causal significance for the outcome measures in the prevention and treatment of metabolic disorders in humans.

Effects of Oat Fiber Intervention on Cognitive Behavior in LDLR-/- Mice Modeling Atherosclerosis by Targeting the Microbiome-Gut-Brain Axis.

It is known that cardiovascular disease can result in cognitive impairment. However, whether oat fiber improves cognitive behavior through a cardiovascular-related mechanism remains unclear. The present work was aimed to elucidate the potential of oat fiber on cognitive behavior by targeting the neuroinflammation signal and microbiome-gut-brain axis in a mouse model of atherosclerosis. Male low-density lipoprotein receptor knock-out (LDLR-/-) mice were treated with a high fat/cholesterol diet without or with 0.8% oat fiber for 14 weeks. Behavioral tests indicated that LDLR-/- mice exhibited a significant cognitive impairment; however, oat fiber can improve cognitive behavior by reducing latency to the platform and increasing the number of crossing and swimming distance in the target quadrant. Oat fiber can inhibit Aß plaque processing in both the cortex and hippocampus via decreasing the relative protein expression of GFAP and IBα1. Notably, oat fiber inhibited the nod-like receptor family pyrin domain-containing 3 inflammasome activation and blocked the toll-like receptor 4 signal pathway in both the cortex and hippocampus, accompanied by a reduction of circulating serum lipopolysaccharide. In addition, oat fiber raised the expressions of short-chain fatty acid (SCFA) receptors and tight junction proteins (zonula occludens-1 and occludin) and improved intestinal microbiota diversity via increasing the contents of gut metabolites SCFAs. In summary, the present study provided experimental evidence that dietary oat fiber retarded the progression of cognitive impairment in a mouse model of atherosclerosis. Mechanistically, the neuroprotective potential was related to oat fiber and its metabolites SCFAs on the diversity and abundance of gut microbiota that produced anti-inflammatory metabolites, leading to repressed neuroinflammation and reduced gut permeability through the microbiome-gut-brain axis.

Extrusion of a Curcuminoid-Enriched Oat Fiber-Corn-Based Snack Product.

Extruded snack products were made from an oat fiber-corn flour matrix fortified with 1.5% (w/w) curcuminoids (750 mg curcuminoids/100 g) to improve the solubility and stability of curcuminoids. The effects of extruder feed moisture content (21%, 28%, and 35%) and screw speed (200 and 300 rpm) on the extrusion parameters and physical properties of final snacks were investigated. Curcuminoids lost during extrusion and curcuminoids loss during subsequent drying of extrudates were analyzed, to separate the losses occurring in each unit process. Drying post extrusion (at 50 °C for 4 hr) was essential to obtain a crunchy shelf stable product (5% moisture). Curcuminoids loss during extrusion was from 17% to 84%, with high loss for the extrusion with low feed moisture content (21%). A further curcuminoids loss of 4% to 44% occurred during drying, with much higher loss for the extrudate with high moisture content. Total curcuminoids retained after extrusion and drying was 12% to 41% (59% to 88% loss), equivalent to 180 to 616 mg curcuminoids retained per 100 g snack, levels within recommended daily dose. Curcuminoids retained after drying was stable during 80 days of storage at 25 °C. The results highlighted the importance of understanding the impact of each unit process separately (for example, extrusion and drying) on the stability of curcuminoids for the development of healthier extruded snacks. PRACTICAL APPLICATION: Extruded snacks products were developed by fortifying the snacks with oat fiber and curcuminoids in order to address the need for a healthy ready to eat food products. Some extrusion characteristics were selected to produce snack products which have favorable properties in terms of consumer acceptance.

Processed cheese as a polymer matrix composite: A particle toolkit for the replacement of milk fat with canola oil in processed cheese.

In this study, we show that the replacement of milk fat with canola oil in a model caseinate-based imitation cheese product to increase its nutritional value can be done by treating processed cheese as a particle filled gel network. Using microscopy, model imitation cheese products with different lipid phases were found to have similar microstructures where fat or oil appears as inert particle fillers in a continuous protein network. Using a texture profile analyzer, we show that the textural properties of model imitation cheese are dependent on the material properties of the inert filler. Addition of rigid particle fillers generally results in greater reinforcement of the matrix (i.e., increased hardness). The addition of oat fiber particles at 5% volume fraction to model cheese containing 51% milk fat and 49% canola oil resulted in a product with similar functionalities (i.e., hardness, oil stability, and meltability) as that of model cheese containing 100% milk fat. The current study therefore shows that the addition of edible non-fat particles for matrix reinforcement can be used as an alternative method for reducing saturated fats in foods while keeping other desirable properties of the product.

Oat fiber as a carrier for curcuminoids.

The curcuminoid-carrying potential of oat fiber was examined as a potential route to overcome the low aqueous solubility of curcuminoids. Aqueous dispersions of oat fiber were mixed with curcuminoids solubilized in ethanol to obtain curcuminoids-oat fiber (1% w/w) dispersions in aqueous ethanol (2% v/v). Centrifugation of the curcuminoids-oat fiber dispersions resulted in a supernatant (95.3% w/w: 0.11% w/w protein, 0.17% w/w ß-glucan) and precipitate (4.74% w/w: 0.18% w/w protein, 0.11% w/w ß-glucan) with the curcuminoids being almost equally partitioned into both fractions. Curcuminoids solubility in the supernatant was markedly greater than that in aqueous ethanol and water. The curcuminoids were in the amorphous state in the precipitated fraction and were more stable to degradation than the curcuminoids in the supernatant. These studies show the potential of oat fiber as a carrier for curcuminoids into functional foods.

Effect of dietary fibers on physico-chemical, sensory and textural properties of Misti Dahi.

Misti dahi, a popular ethnic delicacy of eastern India analogous to caramel coloured set style sweetened yoghurt, besides several therapeutic virtues, contains high fat and sugar. Alike people elsewhere in the world, people in India too are now becoming health conscious and are aware of the relation between diet and health. Hence, high fat and sugar contents are causes of concern for the successful marketing of misti dahi in India. With a view to enhance the health attributes of misti dahi and improve marketability, three commercial dietary fiber preparations (inulin, soy fiber and oat fiber) were incorporated and their effect on the product's quality in terms of physicochemical, sensory and textural quality was assessed. Standard method was followed for the preparation of fiber fortified misti dahi (FFMD). Among the three dietary fibers, inulin significantly decreased viscosity and instrumental firmness and increased lightness (L*), redness (a*), yellowness (b*), syneresis and work of shear values of FFMD. Oat fiber settled at the bottom and gave a poor appearance. Soy fiber did not affect the flavor of FFMD. Although overall acceptability scores of inulin and soy fiber containing FFMD were significantly lower than control, they were still above the minimum acceptable score. Based on the results obtained in the present study, it was concluded that acceptable quality FFMD could be prepared using inulin and soy fiber at 1.5 % level of fortification.