TEXTURE-FLAVOR INTERACTIONS IN LOW FAT STIRRED YOGURT: HOW MECHANICAL TREATMENT, THICKENER CONCENTRATION AND AROMA CONCENTRATION AFFECT PERCEIVED TEXTURE AND FLAVOR

The influence of thickening agent (0 and 7g/L), mechanical treatment (low and high) and flavoring agent concentration (2.2 to 63.2 μL/kg) on texture, taste and aroma of low fat stirred yogurts was investigated through sensory profiling by a panel of ten subjects trained on 13 attributes. Two assessment conditions were used: either in the presence or in the absence of olfactory perception (nostrils closed with nose clips). Sensory differences were greater for texture than for the other perception modalities. Olfactory perception enhanced yogurt astringency. If both thickener addition and mechanical treatment influenced texture attributes and rheology, the second factor had the strongest effect. Texture attributes were highly correlated with rheological parameters. Increasing flavoring agent concentration tended to decrease thickness and the addition of thickening agent depressed green apple notes and sweet taste, suggesting texture/flavor interactions.     

COMPARISON OF ATTRIBUTE LIKING AND JAR SCALES TO EVALUATE THE ADEQUACY OF SENSORY ATTRIBUTES OF MILK DESSERTS

Just-about-right (JAR) scales and attribute liking questions are usually used to study consumer perception of the sensory characteristics of food products. The aim of the present work was to compare the performance of attribute liking and JAR scales to evaluate consumers' perceived adequacy of flavor and texture of milk puddings. Two groups of consumers were asked to evaluate eight milk desserts using (1) overall liking followed by attribute liking for texture and flavor and (2) overall liking followed by JAR scales for thickness, creaminess, sweetness and vanilla flavor. Overall liking scores were significantly different when JAR scales or attribute liking questions were considered. Texture, flavor and overall liking scores were highly correlated to each other, providing the same information. JAR scales correlated better with the intensity of sensory attributes evaluated by a trained sensory panel, being JAR percentages a reliable tool to study the adequacy of sensory attributes.

PRACTICAL APPLICATIONS

Results from the present work showed that consumers might not be able to independently evaluate their liking of different sensory attributes of a product. For this reason, the use of attribute liking questions for studying the adequacy of sensory attributes in complex products would not be recommended. JAR scales were better indicators of the adequacy of sensory attributes. Consumers were able to independently evaluate texture and flavor attributes using JAR scales. However, the influence of JAR scales on overall liking scores should be taken into account when including these scales on consumer studies.     

SENSORY EVALUATION OF VANILLA-DAIRY DESSERTS BY REPERTORY GRID METHOD AND FREE CHOICE PROFILE

“Natillas” are semisolid dairy desserts widely consumed in Spain, with notable differences existing between commercial brands in their composition and sensory and physical properties. The repertory grid method, in conjunction with the free choice profile (FCP), was used to provide data on how consumers perceived eight commercial “natillas” samples. The most frequent terms used were: vanilla flavor, sweetness, consistency and liquid texture as described by 77, 67, 57 and 53% of the consumers, respectively. A three‐dimensional solution was chosen. Dimension 1 accounted for 27.23% of variance and separated the samples largely by yellow‐color intensity and consistency. Dimension 2 (15.88%) was mainly related to the visual attributes of texture, creaminess and different notes of flavor. The third dimension (11.34%) was related to structural‐texture attributes, orange‐yellow color and acid and artificial flavors. The assessors plot showed two clusters. Analysis of each group data revealed differences in their perception of sample variation, mainly regarding texture and color.     

THE USE OF FOURIER ANALYSIS TO COMPARE THE SENSORY PROFILES OF PRODUCTS

A consumer panel comprising 60 females evaluated three coffee whiteners and fresh milk for a number of sensory attributes including liking of flavor and appearance, overall liking, natural flavor and odor, creaminess and watery flavor. Fourier analysis was used to produce a plot which readily identified the whiteners with sensory profiles most similar to fresh milk. More importantly, the whitener whose sensory profile was significantly different from that of fresh milk was identified from the Fourier plot, something which could not be done by traditional univariate methods or even by an overall discriminant analysis.     

SENSORY PROFILES OF THE MOST COMMON SALMON PRODUCTS ON THE DANISH MARKET

The sensory profiles of the most common chilled and frozen salmon products available to consumers on the Danish market were studied. A sensory profiling was made on 12 salmon products varying in salmon species, origin, storage method and time. Samples stored in ice between 7 and 16 days, frozen for 1 month or stored in modified atmosphere for 5 days all had sensory profiles dominated by sea/seaweed odor, juicy and oily texture, fresh fish oil, and sweet and mushroom flavor. Marked differences in the sensory profiles of the frozen samples were found to correlate to differences in storage time. Frozen storage for 6 months resulted in firm texture, discolored appearance and rancid flavor. The samples stored in modified atmosphere for 7 days had a sensory profile with marked rancid and sour odor.     

COMPARISON OF THE SENSORY PROPERTIES OF ULTRA-HIGH-TEMPERATURE (UHT) MILK FROM DIFFERENT COUNTRIES

Shelf-stable milk, also known as ultra-high-temperature (UHT) milk is the most common form of milk in many parts of the world. This study compared the differences in flavor and texture of 37 commercially available UHT and sterilized milk samples including whole, 2% reduced-fat and low-fat milk obtained from markets in seven countries: France ( n =  2), Italy ( n =  11), Japan ( n =  1), Korea ( n =  2), Peru ( n =  3), Thailand ( n =  13) and the U.S.A. ( n =  5). Five highly trained panelists used flavor and texture profiling to describe the sensory properties of each milk sample. Data were analyzed by principal component analysis and hierarchical cluster analysis. Higher levels of processed, chalky, brown and cooked flavor notes generally corresponded to lower levels of fresh dairy flavor characteristics. In general, samples did not vary consistently within a country. Fat content did not correlate with dairy fat flavor or with viscosity. This research suggests that companies' manufacturing processes for UHT milk may have more impact than country or fat content in determining sensory properties of UHT milk.

PRACTICAL APPLICATIONS

Sensory properties of UHT milk from different countries developed in this study could be used by the dairy industry to understand the similarities and differences of UHT milk characteristics from different regions and to modify UHT milk characteristics to meet consumers' criteria or expectation. The study suggests that manufacturers who want to improve quality of UHT milk by modify flavor and texture properties should focus on improvements to the manufacturing processes.