Amparo Tárrega

In-Mouth Mechanisms Leading to Flavor Release and Perception

During eating, foods are submitted to two main oral processes—chewing, including biting and crushing with teeth, and progressive impregnation by saliva resulting in the formation of a cohesive bolus and swallowing of the bolus. Texture influences the chewing behavior, including mastication and salivation, and in turn, these parameters influence texture perception and bolus formation. During this complex mouth process, flavor compounds are progressively released from the food matrix. This phenomenon is mainly dependent on the food texture, the composition and in-mouth breakdown, and on saliva impregnation and activity, but an individuals anatomical and physiological aspects characteristics should also be taken into account. This article reviews the knowledge and progresses on in-mouth processes leading to food breakdown and flavor release and affecting perception. Relationships between food texture and composition, food breakdown, oral physiology, and flavor release are developed and discussed. This review includes not only the mechanical aspects of oral physiology but also the biological aspects such as the influence of saliva composition, activity, and regulation on flavor perception. In vitro and in silico approaches are also described.

Influence of label information on dark chocolate acceptability

The aim of the present work was to study how the information on product labels influences consumer expectations and their acceptance and purchase intention of dark chocolate. Six samples of dark chocolate, varying in brand (premium and store brand) and in type of product (regular dark chocolate, single cocoa origin dark chocolate and high percentage of cocoa dark chocolate), were evaluated by 109 consumers who scored their liking and purchase intention under three conditions: blind (only tasting the products), expected (observing product label information) and informed (tasting the products together with provision of the label information). In the expected condition, consumer liking was mainly affected by the brand. In the blind condition, differences in liking were due to the type of product; the samples with a high percentage of cocoa were those less preferred by consumers. Under the informed condition, liking of dark chocolates varied depending on both brand and type of product. Premium brand chocolates generated high consumer expectations of chocolate acceptability, which were fulfilled by the sensory characteristics of the products. Store brand chocolates created lower expectations, but when they were tasted they were as acceptable as premium chocolates. Claims of a high percentage of cocoa and single cocoa origin on labels did not generate higher expectations than regular dark chocolates.

Inulin blend as prebiotic and fat replacer in dairy desserts: Optimization by response surface methodology

The purpose of this work was to optimize the formulation of a prebiotic dairy dessert with low fat content (<0.1g/100g) using a mixture of short- and long-chain inulin. Response surface methodology was applied to obtain the experimental design and data analysis. Nineteen formulations of dairy dessert were prepared, varying inulin concentration (3 to 9 g/100g), sucrose concentration (4 to 16 g/100g), and lemon flavor concentration (25 to 225 mg/kg). Sample acceptability evaluated by 100 consumers varied mainly in terms of inulin and sucrose concentrations and, to a lesser extent, of lemon flavor content. An interaction effect among inulin and sucrose concentration was also found. According to the model obtained, the formulation with 5.5 g/100g inulin, 10 g/100g sucrose and 60 mg/kg of lemon flavor was selected. Finally, this sample was compared sensorially with the regular fat content (2.8 g/100g) sample previously optimized in terms of lemon flavor (146 mg/kg) and sucrose (11.4 g/100g). No significant difference in acceptability was found between them but the low-fat sample with inulin possessed stronger lemon flavor and greater thickness and creaminess.

Dark chocolate acceptability: influence of cocoa origin and processing conditions.

BACKGROUND Chocolate properties can vary depending on cocoa origin, composition and manufacturing procedure, which affect consumer acceptability. The aim of this work was to study the effect of two cocoa origins (Ghana and Ecuador) and two processing conditions (roasting time and conching time) on dark chocolate acceptability. RESULTS Overall acceptability and acceptability for different attributes (colour, flavour, odour and texture) were evaluated by 95 consumers. Differences in acceptability among dark chocolates were mainly related to differences in flavour acceptability. The use of a long roasting time lowered chocolate acceptability in Ghanaian samples while it had no effect on acceptability of Ecuadorian chocolates. This response was observed for most consumers (two subgroups with different frequency consumption of dark chocolate). However, for a third group of consumers identified as distinguishers, the most acceptable dark chocolate samples were those produced with specific combinations of roasting time and conching time for each of the cocoa geographical origin considered. CONCLUSION To produce dark chocolates from a single origin it is important to know the target market preferences and to select the appropriate roasting and conching conditions.

Vane yield stress of native and cross-linked starch dispersions in skimmed milk : Effect of starch concentration and λ-carrageenan addition

The effects of starch concentration and -carrageenan addition on the yield stress values of native and cross-linked waxy maize starch-milk systems were studied. Static yield stress (0-S) and dynamic yield stress (0-D) of each dispersion were measured using the vane method before and after breaking down its structure by shearing, respectively. Increases in values of 0-S with concentration of starch and -carrageenan were higher for cross-linked starch than those of native starch. 0-D values of cross-linked starch also increased with the concentration of starch and -carrageenan. In contrast, for native starch samples, 0-D values were very low and did not vary much with concentration of either starch or -carrageenan indicating that the structures responsible for the yield stresses were highly sensitive to shearing.

Fat and salt contents affect the in-mouth temporal sodium release and saltiness perception of chicken sausages.

In cooked meats, sodium chloride is involved in taste, texture and flavour release. So a reduction in the salt content may have an impact on overall perception and acceptability. The aim of this study was to evaluate the influence of composition on sodium release and saltiness intensity in chicken sausages. The rheological properties of the sausages differed according to composition. Temporal sodium release and temporal saltiness intensity were evaluated by four selected subjects when eating sausages. At each time point, the effect of the salt level in sausages on sodium release was positive and highly significant. The effect of lipids on sodium release was negative. Concerning perception, the amount of salt used had a positive effect on saltiness intensity, and lipids seemed to exert a masking effect. Generally, clear relationships between salt levels, sodium release and saltiness intensity were found but the masking effect of lipids on saltiness intensity probably also involved texture or fat perception mechanisms.

Active compounds and distinctive sensory features provided by American ginseng (Panax quinquefolius L.) extract in a new functional milk beverage

American ginseng (Panax quinquefolius L.) has recognized neurocognitive effects, and a ginsenoside-rich extract of the root of the plant has been shown to improve cognitive functions in young adults. This study aimed at assessing the chemical and sensory profiles of a UHT-treated, low-lactose functional milk containing American ginseng. Individual ginsenosides in the milk were analyzed by HPLC. Descriptive sensory analysis was performed by a trained panel to quantitatively document sensory changes resulting from the addition of ginseng and the UHT process on flavored and unflavored milks. Consumer acceptance of the product was also investigated. Total ginsenoside content in the UHT-treated milk enriched with the ginseng extract after UHT process treatment was 7.52 mg/100 g of milk, corresponding to a recovery of 67.6% compared with the content in the unprocessed extract. The intake of 150 to 300 mL of this ginseng-enriched milk provides the amount of total ginsenosides (11.5 to 23 mg) necessary to improve cognitive function after its consumption. Both the presence of ginsenosides and their thermal treatment affected some sensory properties of the milk, most notably an increase in bitterness and metallic taste, the appearance of a brownish color, and a decrease in milky flavor. Levels of brown color, bitterness, and metallic taste were highest in the industrially processed ginseng-enriched milk. The bitterness attributable to ginseng extract was reduced by addition of vanilla flavor and sucralose. A consumer exploratory study revealed that a niche of consumers exists who are willing to consume this type of product.

Yogurt viscosity and fruit pieces affect satiating capacity expectations

The extent to which a food is expected to deliver satiation is called expected satiation. Many factors affect this expectation, including a number of sensory properties such as texture. The present study explores the relationships between two kinds of texture variations in a yogurt and its expected satiating capacity (ESC). One texture variation consisted in adding three types of pineapple particles: fresh pineapple purée (+PP samples), small cubes of fresh pineapple (+PF samples), and small cubes of lyophilized pineapple (+LP samples). The other texture variation was the viscosity of the yogurt base: yogurt thickened with starch (high viscosity yogurt, HVY-samples) and without starch (low viscosity yogurt, LVY-samples). A total of 8 samples were obtained: the two basic yogurts without added fruit (sample LVY and sample HVY), and each of these with one of the three kinds of pineapple particles (samples LVY+PP, LVY+FP, LVY+LP, HVY+PP, HVY+FP and HVY+LP). A total of 98 consumers described the sensory characteristics of the 8 yogurts on a CATA questionnaire and evaluated the expected satiating capacity (ESC) and acceptability that the yogurts elicited. In addition, the consumers were asked about the characteristics they had considered when evaluating the ESC of the samples. Correspondence Analysis was used to understand how the consumers perceived and described the differences in yogurt texture. Penalty Analysis and Partial Least Squares regression were conducted to explain the differences in ESC among the yogurt samples and to determine the attributes that had significant positive and negative effects. The results indicated that starch addition (a more viscous product base) increased the mean ESC values regardless of the pineapple particle added. This could be attributed to more extensive oral handling due to the creaminess and mouth coating contributed by these yogurts. Second in importance for higher ESC perception was the presence of lyophilized pineapple cubes, which required some chewing before swallowing since they are dry and crispy. The attributes that were related more to ESC were principally those associated with the yogurt base texture (creamy, mouth coating, consistent, dense, fatty, thick and homogeneous) and others related to the fruit added, such as integrated texture or pleasant fruit pieces.

Optimisation of octinyl succinic anhydride starch stablised w1/o/w2 emulsions for oral destablisation of encapsulated salt and enhanced saltiness

Sodium (salt) was encapsulated within the inner water phase of w1/o/w2 food emulsions externally stabilised by starch particles with the ultimate aim of enhancing saltiness perception. The physical properties of the starch particles were modified by octenyl succinic anhydride (OSA) treatment (0–3%) to vary the degree of hydrophobicity of the emulsifying starch. During oral processing native salivary amylase hydrolysed the starch and destabilised the o/w emulsion releasing the inner w/o phase and subsequently sodium into the oral cavity, resulting in a salty taste. Whilst increasing OSA treatment levels increased the stability of the emulsion, intermediate or low levels of starch modification resulted in enhanced saltiness. It is therefore proposed that 1.5% OSA modified starch is optimal for sodium delivery and 2% OSA modified starch is optimal for sodium delivery in systems that require greater process stability. It is also shown that sodium release was further enhanced by oral processing and was positively correlated with native amylase activity. The results demonstrate a promising new approach for the reduction of salt or sugar in emulsion based foods.

Investigating the oronasal contributions to metallic perception

Metallic taints elicited when consuming food can be unpleasant for the consumer, and are therefore problematic to food manufacturers. Although metallic has been proposed as a taste in the past, evidence remains inconclusive. This study investigates the oral and nasal contributions to metallic perception using sensory evaluation and headspace analysis using gas chromatography mass spectrometry (GC-MS). When sniffing the headspace over divalent salt solutions some were discriminated from water. GC-MS did not detect volatiles in the sample headspace, one hypothesis being that sample volatiles react with phospholipids in the nasal cavity and it is lipid oxidation products which are perceived. Copper sulphate was reported as metallic when tasted with the nose occluded to eliminate retronasal perception, suggesting a gustatory or trigeminal mechanism may be involved. This work indicates orthonasal stimulation is involved in metallic perception, and contributes to the ongoing debate over metallic being a taste, trigeminal or flavour response.