Anti-obesity effects of epigallocatechin-3-gallate,orange peel extract,black tea extract,caffeine and their combinations in a mouse model

The anti-obesity effects of epigallocatechin-3-gallate (EGCG), orange peel extract (OPE), black tea extract (BTE), and caffeine (CF) in female CF-1 mice were studied. Female CF-1 mice were fed high-fat diets containing 0.1% EGCG, 0.2% OPE, 0.2% BTE and 0.05% caffeine alone and in combination for 10 weeks. The body weight gain and weights of abdominal fat and brown adipose tissue were significantly reduced in mice whose diets contained OPE, BTE, caffeine, OPE + BTE and OPE + CF. Notably, mice fed a high-fat diet supplemented daily with 0.2% OPE + 0.2% BTE + 0.05% CF prevented body weight gain by 48.8%, parametrial fat pad weight by 88.2%, retroperitoneal fat pad weight by 82.8% and brown adipose tissue by 63.7% compared with mice fed a high-fat diet. On the basis of these findings, it was concluded that oral feeding of orange peel extract, black tea extract and caffeine had anti-obesity effects by suppressing body weight gain and adipose tissue formation.     

Effect of tomato by-products in the diet of Comisana sheep on composition and conjugated linoleic acid content of milk fat

To evaluate the effect of supplementing the diet of Comisana sheep with by-products from industrial tomato manufacture on the fat composition and conjugated linoleic acid (CLA) content of milk fat, two groups of 50 ewes each were fed either total mixed ration standard (TMRS) or total mixed ration with added tomato by-products (TMRA). Milk fat composition was determined by high-resolution gas chromatography (HRGC). The milk fat content for the animals fed the TMRA diet increased by 6.41% (P < 0.01) after six weeks, compared with the animals fed the TMRS diet. The CLA content in the milk fat for the group of animals fed the TMRA diet was 19.8% (P < 0.05) higher than for those fed the TMRS diet, and reached 1.33 g 100 g^?1 fat, while the polyunsaturated fatty acid (PUFA) content increased by a 6.43% (P < 0.05) and reached 7.12 g 100 g^?1 fat. The fatty acid composition showed an increase in the amount of polyunsaturated fatty acids. The n ? 3:n ? 6 ratio increased by 13% in the milk from sheep fed with the TMRA diet. These observations were confirmed by triglyceride analysis, which showed a decrease in the amount of short-chain (C₂₈–C₃₂) and medium-chain (C₃₄–C₄₂) triglycerides after six weeks, while the opposite was observed for the long-chain triglycerides (C₄₄–C₅₄).     

Effects of Adding Fat and Lasalocid to Diets of Dairy Cows

Holsteins (n = 12) and Jerseys (n = 12) averaging 90 d postpartum were fed 70 d in a 2 × 2 × 2 factorial arrangement of breeds and diets containing 3.0 or 6.8% ether extract with or without 36.7 mg/kg lasalocid in the diet DM. For many variables, the breeds responded differently. Holsteins usually performed better on high fat diets without lasalocid and Jerseys responded better to lasalocid. Influence of increased dietary fat generally was small except when fat acted synergistically with lasalocid. Dry matter intake was depressed substantially only when lasalocid was added to the higher fat diet. This detrimental effect precipitated a reduction in milk production. Dietary lasalocid reduced 4% FCM yield, milk fat percent, and milk fat yield without any lasalocid × fat interactions on these variables; however these reductions were much larger with Holsteins than Jerseys. Feeding lasalocid decreased ruminal acetate and increased ruminal propionate, but the changes were smaller with Jerseys. Higher fat diets increased serum cholesterol, but increases were less with Jerseys than with Holsteins. After 56 d of feeding, increased dietary fat and lasalocid had little influence on digestibility of feed nutrients. Adaptation to lasalocid feeding appeared to be gradual and prolonged, extending beyond 35 d. Results suggest no economically important beneficial synergistic effects from feeding added fat plus lasalocid to lactating dairy cows.     

Reduced calorie emulsion-based foods: Protein microparticles and dietary fiber as fat replacers

The potential of using microparticulated whey protein (MWP) in combination with either modified starch or locust bean gum (LBG) as fat mimetics to fabricate reduced calorie emulsion-based sauces and dressings was studied. The influence of food matrix composition (protein, polysaccharide, and fat content), ionic strength, and pH on the properties of thermally processed model emulsions (90 °C/10 min) was investigated. Increasing protein concentration (2.5–7.5%) increased the mean (d_3,2) particle diameter due to the formation of large protein aggregates. All MWP-containing systems had a creamy white appearance with high lightness (L* > 75). Addition of fat droplets (5%) further increased their lightness (L* > 90) due to enhanced light scattering. Addition of starch, LBG, or MWP increased emulsion viscosity due to the increased effective volume fraction of the dispersed phase. Addition of calcium chloride (10 mM) and pH adjustment (2–8) caused little change in the physicochemical properties of the mixed systems. Overall, the appearance and rheological properties of the mixed systems were similar to commercial sauces and dressings. This study demonstrates that reduced calorie food emulsions with appearance and consistency similar to those of full-fat versions can be formulated using protein microparticles and polysaccharides.     

Fat contributes to the buffering capacity of chicken skin and meat but enhances the vulnerability of attached Salmonella cells to acetic acid treatment

Chicken skin and chicken meat display different buffering effects which may impact the survival of Salmonella attached to them when treated with acids. This study investigated the role that differences in fat composition of chicken skin and meat play in their buffering capacity. The survival of Salmonella attached to chicken skin and meat in the presence of fat, and treated with acetic acid was also investigated. Fat was extracted from chicken skin and meat and the buffering capacities of chicken skin, meat, extracted fat and their respective remnants were determined. Two strains of Salmonella Typhimurium and two strains of S. Enteritidis were attached independently to each of the chicken component listed above and enumerated before and after treatment with 0.3 M acetic acid. Chicken skin has a higher fat content as compared to chicken meat. Skin (13 mmol H⁺/(pH1 kg)) had a stronger buffering capacity (p < 0.05) than the extracted fat alone and skin remnants alone (7.0 mmol H⁺/(pH 1 kg) and 6.9 mmol H⁺/(pH 1 kg) respectively). From an initial inoculum (~ 9 log CFU/g), Salmonella cells attached better (p < 0.05) to chicken meat (~ 8 log CFU/g) and chicken skin (~ 7 log CFU/g) than extracted fat (~ 1.5 log CFU/g). Skin remnants without fat were better (p < 0.05) at protecting attached Salmonella than other chicken components. For example S. Typhimurium ATCC 33062 decreased ~ 1 log CFU/g (p < 0.05) on skin remnants after acetic acid treatment while its viable counts on other components decreased from ~ 1.5 to 7 log CFU/g (p < 0.05). We suggest that the fat content present in the skin may enhance the vulnerability of attached cells to acetic acid.     

Effects of packaging systems and fat concentrations on microbiology,sensory and physical properties of ground beef stored at 4 ± 1 °C for 25 days

This study evaluated effects of modified atmosphere (MAP, 0.4% carbon monoxide [CO], 30% carbon dioxide, and 69.6% nitrogen), vacuum (VP) and polyvinyl chloride (PVC) packaging systems and fat levels (10, 20 and 30% fat) on ground beef stored at 4 ± 1 °C for 25 days for microbiology, sensory, pH, thiobarbituric acid reactive substances (TBARS), objective color, headspace and residual CO. As storage time increased, pH decreased (P < 0.05) for MAP and VP and increased (P < 0.05) for PVC. TBARS varied (P < 0.05) among MAP and VP treatments. Except for day 1, CO headspace concentrations were similar among fat concentrations, and residual CO absorption in meat increased (P < 0.05) for all MAP treatments. In all treatments, degree of lightness was similar, redness decreased and brown discoloration increased during storage. As psychrotrophic bacteria counts increased, panelists detected color and off-odor deterioration in all systems. The CO treatment had no effect on maintaining the carboxymyoglobin “cherry red” fresh meat color during meat spoilage.     

Effects of catechin-enriched green tea beverage on visceral fat loss in adults with a high proportion of visceral fat: A double-blind,placebo-controlled,randomized trial

The effects of catechin-enriched green tea on Chinese adults with a high proportion of abdominal visceral fat were evaluated. Subjects (118) were randomly assigned to consume daily a beverage containing 609.3 mg catechins and 68.7 mg caffeine or a control beverage for 12 weeks. Abdominal fat area, body weight and composition were measured at week 0, week 8, and week 12. One hundred and four subjects completed the trial. Average visceral fat area, body weight, and body fat were reduced significantly by catechin-enriched green tea treatment but these effects were not seen in the control group with per-protocol sets analysis. The decrease at week 12 in the visceral fat area in the catechin group was greater than that in the control group (P = 0.04). Thus, consumption of the catechin-enriched green tea beverage for 12 weeks induced visceral fat loss in Chinese adults with a high proportion of abdominal visceral fat.     

Amelioration of hyperglycemia,hyperlipidemia, oxidative stress and inflammation in steptozotocin-induced diabetic rats fed a high fat diet by riceberry supplement

Dark purple riceberry bran contains a higher dietary fiber and antioxidant compounds than unpigmented rice bran. Riceberry supplement (RB) was used to evaluate the effects on biochemical parameters, skeletal muscle glucose transporter 4 (GLUT4), oxidative stress and inflammation in a streptozotocin (STZ)-induced diabetes rat. To elucidate the effects were due to dietary fiber supplementation and/or bioactive components, equivalent amounts of dietary fiber present in RB were also fed to STZ-induced diabetic rats. Diabetes Sprague–Dawley rats (non-FBG ? 16.65 mM) were randomly divided into five groups: DM fed a high fat (HF) diet, DM-RB1 fed 5% RB, DM-RB2 fed 41% RB, DM-F1 fed 0.6% fiber and DM-F2 fed 5% fiber. After 12 weeks, significant improvement of BG, insulin, HbA1_C, IPGTT and GLUT4 levels were observed in DM-RB1 and DM-RB2 groups. Hyperlipidemia was significantly improved in DM-RB2 and DM-F2 groups. Oxidative stress (TBARS), antioxidant enzymes (SOD, CAT, and GPx), antioxidant capacity (ORAC), pro-inflammation cytokine (TNF-α and IL-6) were improved in DM-RB1 and DM-RB2 groups. Improvement of pancreas and spleen histology was found in DM-RB1 and DM-RB2 groups. These indicate the potential of RB to improve hyperglycemia and hyperlipidemia conditions as well as alleviate oxidative stress and inflammation.     

A new sensory tool to analyse the oral trajectory of biscuits with different fat and fibre contents

Reformulating traditional products such as biscuits can be a useful tool for providing the population with healthier snacks. However, it involves changes in the eating characteristics of the final product. This study focuses on the oral perception of these biscuits, using the Temporal Dominance of Sensation (TDS) technique with two different amounts of fat (60 g and 30 g fat/100 g flour) and fibre (4 g and 8 g fibre/100 g flour). The TDS data obtained with a trained panel showed that hardness was the first dominant attribute in all the formulations during the mastication process. The dominance of the other parameters appeared to depend more on the fat and fibre contents, as crispness appeared with high-fat biscuits and crunchiness with low-fat, high-fibre ones, whilst both attributes were perceived in intermediate formulations. In the high-fibre formulations, grittiness and dry mouthfeel appeared during chewing and dry mouthfeel was dominant. At the end of the mastication all the biscuits were perceived as pasty. A fat mouthfeel was also perceived with both high-fat and low-fat biscuits, with or without the addition of a low level of fibre. Penalty analysis based on JAR scales, showed that excessive hardness and excessive dry mouthfeel were the most penalizing sensory characteristics causing significant drop in biscuit acceptability.     

Enrichment of the conjugated linoleic acid content of bovine milk fat by dry fractionation

This study investigated the effect of fat fractionation on the conjugated linoleic acid (cis-9, trans-11-C_18 : 2) content of bovine milk fat. Anhydrous milk fat was fractionated into hard and soft fractions using controlled cooling and agitation. Fractionation of milk fat pre-melted at 60°C using a temperature programme of 33–10°C and a cooling rate of 0.58°C h⁻¹ yielded a soft fraction containing 63.2% more conjugated linoleic acid (2.22 g 100 g⁻¹ FAME), which was also enriched in polyunsaturated fatty acids and vaccenic acid (trans-11-C_18 : 1) compared with the parent fat. Agitation following fractionation was found to have a negative effect on the conjugated linoleic acid content of the soft fraction. Refractionation of the soft fraction did not increase the yield of conjugated linoleic acid. The conjugated linoleic acid and trans fatty acid content of 26 selected food products ranging in milk fat content from 0 to 100% is reported. Conjugated linoleic acid concentrations ranged from 0 to 16.2 mg g⁻¹ fat and were generally lower than the trans fatty acid content which ranged from 0 to 155.7 mg g⁻¹ fat. Spreads containing vegetable oils contained higher trans fatty acid and lower conjugated linoleic acid contents than milk fat-containing products. This study highlights that a milk fat fraction enriched in conjugated linoleic acid may be achieved by dry fractionation.     

The use of sedimentation field-flow fractionation in the size characterization of bovine milk fat globules as affected by heat treatment

Size distribution of fat globules affects the appearance, taste and stability of milk and milk-based products. Full-fat, semi-fat and chocolate bovine milk were subjected to heat treatment within a temperature range of 50–125 °C for 1 h. Sedimentation field-flow fractionation was employed to determine the changes in mean particle diameter of milk fat globules as affected by heat treatment. The mean particle diameter of fat droplets increased with increasing heating temperature for most samples. The particle size of fat globules increased on average 40 nm (4.65%) for full-fat and 72 nm (8.52%) for semi-fat milk following the heat treatment (50–125 °C). Chocolate milk exhibited considerable increase in particle size (104 nm, 12.53%) within a certain temperature range (50–110 °C), followed by a decrease in particle size when heated at 125 °C for 1 h. Heat-induced flocculation due to attractive interactions between hydrophobic sites on denatured protein molecules on different droplets was assumed to be mainly responsible for the increases in particle size observed in this study. Extensive heat-induced denaturation of milk proteins was also indicated by Native PAGE. Sedimentation field-flow fractionation proved to be a useful technique for adequately monitoring heat-induced changes in particle size distributions in milk.     

Effect of varying salt and fat levels on the sensory and physiochemical quality of frankfurters

The sensory and physiochemical properties of frankfurters with varying fat and salt levels were investigated. Twenty frankfurter formulations were produced with varying concentrations of fat (10%, 15%, 20%, 25% w/w) and salt (1%, 1.5%, 2%, 2.5%, 3% w/w). Frankfurters were assessed instrumentally for colour, moisture, fat, cooking loss and texture profile analysis. Consumers (n = 25) evaluated each product in duplicate for colour, coarseness, tenderness, juiciness, salt taste, meat flavour, off-flavour and overall acceptability using a hedonic scale. Salt levels below 1.5% were shown to have a negative effect on consumer acceptability, with 2.5% salt concentration being the most accepted (P < 0.001) by consumers. However, frankfurters containing the lower fat levels 10% and 15% fat with higher salt levels (2.5–3%) were significantly the most acceptable variants to consumers. Samples containing less fat and salt were found to be tougher, less juicy and had greater cooking losses. Thus salt perception is very important for consumer acceptability, but fat levels can be potentially reduced without significantly affecting overall acceptability.     

Effects of a high fat diet on long-chain fatty acids composition in rats serum and liver

A reliable and sensitive technique had presented to monitor the content of long-chain fatty acids (LCFAs) in biological materials. The purpose of this study was to report a method for separation and quantification of LCFAs by capillary gas chromatography (GC) with better recovery. With this method, we detected some changes of LCFAs in the serum and liver of rat fed with high fat diet. The result showed that the levels of C22:0, C22:6, C26:0 of serum of the high fat group were higher than that of the control group (P < 0.01); and the levels of C22:6, C26:0 of liver of the high fat group were higher than that of the control group (P < 0.01), but the levels of C22:0 and C24:0 of liver of the high fat group were lower than that of the control group (P < 0.01). It indicated that a high fat diet had an adverse effect upon normal metabolism.     

Milk enhances intestinal absorption of green tea catechins in in vitro digestion/Caco-2 cells model

The effect of milk on the absorption of polyphenols is still controversial so far. In order to determine the impact of milk addition on green tea catechins bioaccessibility and intestinal absorption an in vitro digestion/Caco-2 cell model was applied. Green tea extract (GTE) was solubilized in distilled water at 23 °C and 100 °C, combined with skimmed milk (GTE + 10% milk and GTE + 25% milk) and subjected to simulated gastric and intestinal digestion, followed by transepithelial absorption in Caco-2 cells monolayers. In the mixture with milk, gallated catechins: ECG and EGCG showed binding to milk proteins while EC and EGC seemed to have weaker affinity. Catechins were stable during gastric incubation and very sensitive to intestinal digestion. Bioaccessibility of green tea catechins brewed at 100 °C was higher than brewed at 23 °C. Catechins from digested GTE with 10% and 25% milk exhibited enhanced intestinal permeability in Caco-2 model in comparison to non-digested GTE and digested GTE without milk. Apparent permeability coefficients (P_app) of EGCG and ECG in digested GTE with 25% milk were significantly higher compared to those in GTE with 10% milk, and amounted to 2.41 × 10^− 6 cm/s and 1.39 × 10^− 6 cm/s. The recoveries of all catechins in GTE with milk in Caco-2 cells after 2 h incubation were significantly higher than that without milk. To summarize, these data suggest that milk addition may increase catechin bioavailability by enhancing their transepithelial absorption and uptake from green tea extract.     

Mate tea-mediated reduction in catecholamine synthesis improves cutaneous wound healing of chronically stressed mice

Chronic stress stimulates oxidant production and oxidative damage which compromise cutaneous wound healing. Mate tea rich is in antioxidant compounds and may be a good alternative for treatment of oxidative diseases. Therefore, the aim of this study was to investigate the effects of supplementation with mate tea on cutaneous healing in stressed mice. Mice were submitted to rotational stress (ST) and treated with mate tea (MT) daily until euthanasia. An excisional lesion was created on each mouse and 4 or 10 days later, the lesions were analyzed. In addition, murine skin fibroblasts were exposed to elevated epinephrine (E) levels plus mate tea, and fibroblast activity was evaluated. In in vivo assays, the supplementation with mate tea inhibited the stress-induced increase in: catecholamine synthesis (ST: 23.3 ± 2.5; ST + MT: 18.0 ± 0.9 ng/μl, p < 0.05), carbonyl protein content (ST: 962.0 ± 35.6; ST + MT: 35.7 ± 8.9 nmol/μg protein, p < 0.05), lipid peroxide levels (ST: 18.5 ± 2.3; ST + MT: 11.8 ± 1.2 nmol/mg protein, p < 0.05), wound contraction (ST: 44 ± 4; ST + MT: 17 ± 2%, p < 0.05), re-epithelialization (ST: 908 ± 35; ST + MT: 2081 ± 138 μm, p < 0.05), transforming growth factor-β (ST: 5.0 ± 0.02; ST + MT: 1.3 ± 0.06 u.a., p < 0.05), and myofibroblast density (ST: 19 ± 2; ST + MT: 9 ± 1%, p < 0.05). Stress-induced reduction in the amount of macrophages (ST: 133 ± 19; ST + MT: 392 ± 33 cells, p < 0.05) and neutrophils (ST: 1161 ± 62; ST + MT: 1313 ± 103 cells, p < 0.05) and hydroxyproline levels (ST: 1.3 ± 0.2; ST + MT: 4.6 ± 0.9 ng/mg tissue, p < 0.05), and this was reversed by mate tea. In in vitro assays, the treatment with mate tea reversed the reduction in collagen deposition (E: 1.7 ± 0.3; E + MT: 3.7 ± 0.01 pixels, p < 0.05) and the increase in cell proliferation (E: 331 ± 2; E + MT: 203 ± 3% of control, p < 0.05), accumulation of lipid peroxides (E: 0.66 ± 0.009; E + MT: 0.55 ± 0.01 nmol/mg protein, p < 0.05), and increase of tenascin-C protein expression (E: 3.8 ± 0.004; E + MT: 3.4 ± 0.004 a.u., p < 0.05) induced by epinephrine. In conclusion, the supplementation with mate tea improves the cutaneous wound healing of chronically stressed mice.     

The effect of fat content on the rheology,microstructure and heat-induced functional characteristics of Cheddar cheese

Cheddar cheeses with the different fat contents were made in triplicate and ripened at 4°C for 30 d and at 7°C for the remainder of the 180-d investigation period. The cheeses were designated: full-fat (FFC), 300 g kg⁻¹; reduced-fat (RFC), 219 g kg⁻¹; half-fat (HFC), 172 g kg⁻¹; and low-fat (LFC), 71.5 g kg⁻¹. A decrease in the fat content from 300 to ≤172 g kg⁻¹ resulted in significant (P<0.05) decreases in contents of moisture in non-fat substance and pH 4.6 soluble N (expressed as % total N), and increases in the contents of moisture, protein, intact casein and free amino acids. Reduction in fat content resulted in an increase in the volume fraction of the casein matrix and a decrease in the extent of fat globule clumping and coalescence. The mean values of fracture stress and firmness for the FFC were significantly lower than those of the RFC and HFC, which had similar values; the values for the LFC exceeded the limits of the test and were markedly higher than those of the other cheeses at all times. On baking the cheese, reduction in fat content resulted in significant increases in the mean melt time (time required for shred fusion) and apparent viscosity and a decrease in the mean flowability of the melted cheese. The stretchability of the FFC increased most rapidly and, at ∼15 and 30 d, attaining mean values which were significantly higher than those of the other cheeses. Thereafter the stretchability of the FFC decreased progressively to values that were significantly (i.e. at 150 d) or numerically (i.e., at 180 d) lower than those of the RFC and HFC. At ripening times ≥15 and ≤90 d, the stretchability of the LFC was significantly lower than that of the RFC, and significantly or numerically lower than the HFC.     

Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT + S), with ascorbic acid (GT + AA) and with sucrose and ascorbic acid (GT + S + AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P < 0.05) enhanced in GT + S + AA formulations (AUC_0–6 h = 3237.0 and 181.8 pmol h/L plasma respectively) relative to GT control (AUC_0–6 h = 1304.1 and 61.0 pmol h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (～51–53%) relative to EGCG and epicatechin gallate (ECG) (<20%) and was modestly enhanced in GT + S and GT + S + AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P < 0.05) higher from GT + S + AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea.     

Effect of milk fat concentration and gel firmness on syneresis during curd stirring in cheese-making

An experiment was undertaken to investigate the effect of milk fat level (0%, 2.5% and 5.0% w/w) and gel firmness level at cutting (5, 35 and 65 Pa) on indices of syneresis, while curd was undergoing stirring. The curd moisture content, yield of whey, fat in whey and casein fines in whey were measured at fixed intervals between 5 and 75 min after cutting the gel. The casein level in milk and clotting conditions was kept constant in all trials. The trials were carried out using recombined whole milk in an 11 L cheese vat. The fat level in milk had a large negative effect on the yield of whey. A clear effect of gel firmness on casein fines was observed. The best overall prediction, in terms of coefficient of determination, was for curd moisture content using milk fat concentration, time after gel cutting and set-to-cut time (R² = 0.95).     

Influence of enzymatic cross-linking on milk fat globules and emulsifying properties of milk proteins

The enzyme transglutaminase (TGase) can modify dairy protein functionality through cross-linking of proteins. This study examined the effects of TGase treatment on milk fat globules and the emulsifying properties of milk proteins. The extent of TGase-induced cross-linking of caseins increased with incubation time, with no differences between whole and skim milk. Extensive clustering of fat globules in extensively cross-linked raw whole milk occurred on homogenisation at 400 or 800 bar. Considerably less clustering of fat globules was observed when recombined milk (90 g fat L^–1) was prepared from TGase-treated skim milk and homogenised at 400 or 800 bar. TGase treatment did not affect fat globule size in cream, but prevented coalescence of fat globules therein, possibly through cross-linking of milk fat globule membrane components. TGase-induced cross-linking of milk proteins affected their emulsifying properties and may increase the stability of natural milk fat globules against coalescence.     

Sensory interaction of umami substances with model food matrices and its hedonic effect

Palatability changes in seven model foods (soups and mashed potato) evoked by various combinations of monosodium glutamate (MSG) and disodium inosinate and guanylate (I + G) were studied. Flavour enhancers were added to each food matrix according to the same factorial design. The magnitude, direction and regularity of hedonic responses were highly product-dependent. Contribution of MSG and I + G to palatability-enhancement also varied for different model product: in chicken broth and vegetable soup MSG played the leading role; in mushroom, red beets and asparagus soups contribution of I + G was considerable. In green peas cream soup the supplementation by MSG/I + G evoked mostly negative hedonic effect. Analysis of naturally present free amino acids revealed considerable differences in their amount and composition. The interaction of naturally present glutamates and added umami substances (and probably other sensory-active compounds) might be at least partially responsible for observed diversity of hedonic responses.