SENSORY PROPERTIES AND CONSUMER PERCEPTION OF 'HOME-MADE'AND COMMERCIAL DAIRY ICE CREAM

Sensory properties and consumer perception of 2 'home-made'and 4 commercial dairy ice creams were examined. Conventional profiling by a trained panel found that most samples differed significantly in all attributes, but distinction of 'home-made'from commercial products was limited to few attributes. Principal component analysis separated the 'home-made'products from the commercial ones mainly on the basis of differences in appearance, aroma, creamy flavors and textural attributes. A consumer group (n=105) recorded preconception of 'home-made'ice cream acceptance, then received the product samples, in unlabeled condition, for assessment of degree of liking (DOL) and for identification as 'home-made'or commercial. Internal preference mapping of the DOL ratings showed that consumers were more closely grouped around samples which had higher intensities of certain attributes. Higher 'denseness', 'vanilla'aroma and 'buttery'flavor, were associated with more liking for commercial products. The 'home-made'high fat sample, although liked, tended to be grouped with commercial products. More marked textural attributes of 'ice crystals'and 'breakage'aided identification of the low-fat 'home-made'formulation, which was less liked overall. Overall, differences between the 'home-made'and commercial samples were small but consumer perception of the term 'home-made'was viewed favorably for dairy ice cream.     

THE EFFECT OF INFORMATION RELATED TO FAT CONTENT AND TASTE ON CONSUMER RESPONSES TO A REDUCED-FAT FRANKFURTER AND A REDUCED-FAT CHOCOLATE BAR

The effects of product information on responses to frankfurter sausages and chocolate bars were studied by comparing sensory and hedonic ratings in two conditions: blind tasting and tasting with information present. Furthermore, the effect of information alone was investigated by having the subjects rate the expected sensory and hedonic intensities of the products on the basis of packages with different claims. Three groups of subjects were tested by giving them different information: The basic group (no added claims, n=31), the reduced-fat group (products claimed to have reduced-fat, n=29) and the flavorful group (products claimed to have full meat/chocolate flavor, n=31). Product information increased the rated pleasantness of the frankfurter in all three information groups compared to the blind ratings. The information did not affect the pleasantness of the chocolate bars. The expected attribute intensities of the frankfurters and chocolates were rated lower by the reduced-fat group than by the other groups. Overall, the effect of product information was more clearly seen in ratings of sensory attributes than in pleasantness ratings.     

NUTRITIONAL, PHYSICAL AND SENSORY CHARACTERISTICS OF VARIOUS CHOCOLATE-FLAVORED PEANUT–SOY BEVERAGE FORMULATIONS

Mixture design and pilot‐plant scale processing protocol were developed to obtain the best chocolate‐flavored peanut–soy beverage formulation. Twenty‐eight formulations were evaluated for nutritional (lysine content), physical (viscosity [η], visual stability index [VSI]) and nine sensory (consumer liking) attributes. Lysine contents (mg/g protein) (44.1–57.1) were close to the reference (51.0) and in the desirable range observed for other peanut‐based beverages. Higher viscosity indicated lower consumer liking, but lower viscosity resulted in lower VSI. Formulation ?8 having 43.9% peanut, 36.3% soy protein isolate (SPI) and 19.8% chocolate syrup had the highest consumer liking and the best balance of physical properties (η = 41.5 mPa·s; VSI = 0.99). As compared to commercial chocolate milk (6 = slightly like to 7 = moderately like), it was rated higher for appearance (7.0), color (6.8) and sweetness (6.4). Two SPI formulations (?6 and ?7) and a soy flour formulation (?14) were rated highest for aroma (6.2), color (7.0) and flavor (6.0), respectively.     

FLAVOR MODIFICATION OF MILK CHOCOLATE BY CONCHING IN A TWIN-SCREW, CO-ROTATING, CONTINUOUS MIXER

Short-time continuous conching of chocolate offers significant economic advantages over traditional long-time batch methods. High-shear continous mixers can affect conching in a matter of minutes as compared to hours for traditional systems. Milk chocolate conched in two twin-screw, co-rotating, continous mixers operating in series was compared by a variety of sensory methods to chocolate conched by a batch method. A significant difference (P < 0.05) in flavor was found between chocolates conched at 60C by the continuous and batch methods, yet there was no preference for either chocolate. Chocolate conched by the batch method (23 h at 60C) had stronger caramel flavor (P < .10) than chocolate conched continuously, but there were no significant differences (P < .10) in sweet, chocolate or milk flavor. In the continuous system, caramel flavor generally increased with conching temperature and residence time; although, at the highest temperature (95C) and the longest residence time (7.5 min) caramel flavor decreased. Increasing the temperature of continuous conching from 70 to 90C produced chocolate significantly (P < .10) more like chocolate conched in a batch system for 21.5 h at 60C.     

PERCEIVED EATING DIFFICULTIES AND PREFERENCES FOR VARIOUS TEXTURES OF RAW AND COOKED CARROTS IN YOUNG AND ELDERLY SUBJECTS

The aim of the study was to determine how those texture attributes that elderly people find difficult to eat are related to their preferences for different modifications of carrot textures. This study was conducted with same methods in Finland and in the United Kingdom (UK). Trained sensory panels in both countries described sensory profiles of a range of carrot samples with same glossary of texture terms. The texture of carrot samples was manipulated using different preparation and cooking methods. Based on the Principal Component Analysis (PCA), boiled and puréed samples were perceived as soft, wet, pulpy and smooth, whereas raw samples were dry, brittle, rough, crispy and crunchy. Two age groups were used for the consumer tests: a young adult group aged 23 to 40 years, mean 32 (Finland) and 33 (UK) and an elderly group aged over 60 years, mean 75 (Finland) and 76 (UK). Both the elderly and young adult respondents considered samples as difficult to eat if they needed a long chewing time, were crunchy, hard, brittle, dry, rough or sharp, such as raw slices and coarsely grated samples. On the other hand, slimy, wet, smooth, soft and pulpy samples, such as boiled carrots and purée, were considered as easy-to-eat. The young adults liked more difficult textures such as rough, crispy, crunchy and hard than did the elderly respondents, but the easiest textures were not liked by either age group. Subjects with dental deficiencies liked easier textures more than those fully dentate.     

COMPARISONS OF VOLATILE COMPOUNDS RELEASED DURING CONSUMPTION OF A COMPLEX FOOD BY DIFFERENT ASSESSORS WITH EXPRESSIONS OF PERCEIVED FLAVOR DETERMINED BY FREE CHOICE PROFILING

Comparisons of volatile compounds released during consumption by different assessors with individual differences in the assessors'chewing patterns, saliva production rates and ultimately their expressions of perceived flavor have received little research attention to date, although such comparisons are fundamental to the understanding of flavor. To address this, eight untrained assessors were chosen and each consumed six Cheddar cheeses during Buccal Headspace Analysis of the volatile compounds released, while in parallel measures of each assessor's mastication behavior using Electromyography, their stimulated saliva production during consumption and their sensory perceptions of the cheeses flavor during Free Choice Profiling were determined. Relationships between the volatile compounds released and the sensory and physiological measures were investigated using Principal Components Analysis, Generalised Procrustes Analysis and Partial Least Squares regression. It was found that although there were differences between assessors'mastication behavior and saliva production rates, the assessors'individual volatile profiles obtained by Buccal Headspace Analysis were similar for each cheese examined. Also, Partial Least Squares was successful in predicting the most important flavor differences between cheeses from the volatile compounds released during their consumption by different assessors.     

EFFECT OF PRICE ON PLEASANTNESS RATINGS AND USE INTENTIONS FOR A CHOCOLATE BAR IN THE PRESENCE AND ABSENCE OF A HEALTH CLAIM

The effect of price information on hedonic and use intention responses to a chocolate bar was investigated in the absence and presence of a health claim related to energy, satiety value and cholesterol content. First, Finnish students (n = 79) tasted and rated blind three chocolate bars (one regular, two containing functional ingredients). Second, one group (“Informed,” n = 40) evaluated the samples with the health claim and price information, the other group (“Control,” n = 39) as a regular bar with price information only. A separate focus group (n = 6) interview was conducted to obtain further views of the claim and samples. Neither the health claim nor the price affected pleasantness ratings, while the increasing price significantly reduced the likelihood of buying and preferred frequency of eating the chocolate bar in both groups. Price affected the likelihood of buying more strongly among females than among males, and involvement with chocolate bars affected the likelihood of buying in the control, but not in the informed group. The focus group interview indicated that healthfulness might be irrelevant for chocolate products. Overall, price heavily affected the likelihood of buying the target product, but price and the health claim were incapable of altering hedonic responses to it.     

NOTE ON COMPUTERIZED DATA COLLECTION IN CONSUMER SENSORY EVALUATION

Panelists with computer experience (n = 24) and without (n = 26) rated three foods representing liked, neutral and disliked categories using a 9-point hedonic scale on computer and paper ballots. In paired t-test results between computer and ballot ratings, no differences were found in overall acceptance, flavor and appearance attributes. Regression analysis indicated a significant (p<0.01) linear relationship between computer and paper ballot ratings. Computer ballot ratings for overall acceptance were comparable to paper ballot ratings in a consumer sensory evaluation test. Slight differences in overall acceptance were found between computer and paper ballot responses from panelists with and without computer experience. GLM indicated the group without computer experience rated overall acceptance and flavor attributes for cereal, and appearance and flavor attributes for potato chips significantly higher (p<0.05) than panelists with computer experience.     

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.     

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.     

Potential of alfalfa as an alternative molt induction diet for laying hens: egg quality and consumer acceptability

Dietary molt induction to initiate additional egg laying cycles in commercial laying hen flocks is a wide spread practice in the United States. Feed deprivation is the most commonly used method but this practice has generated several concerns which has lead to research for viable alternative approaches. From a management standpoint a single ingredient molting diet consisting of high fiber-low energy represents an easily adaptable diet for large laying hen production units. Alfalfa meal is readily available in most commercial locations and possesses many of the desirable properties of an ideal laying hen molt diet. In the current study hens at a commercial laying facility were molted by both alfalfa and feed deprivation. After the hens had reentered post-molt commercial egg production, eggs were examined for egg quality performance. Egg shell strength, albumen height, yolk height, weight, length, and yolk color were all tested using various mechanical techniques. The eggs were also sampled for testing by consumer sensory panels that assessed the desirability of the eggs' color and flavor/texture. Eggs laid by hens molted by alfalfa had a significantly lower (p<0.05) "a*" level of colorimetry. Eggs laid by hens molted with alfalfa also exhibited significantly higher (p<0.05) egg weights and length. In the consumer sensory test, there was no significant difference (p>0.05) in color or flavor/texture scores in eggs from either feed deprived or alfalfa molted hens. The consumer sensory and mechanical quality attributes indicates that alfalfa shows promise as an alternative molt induction diet by providing a single diet option for extending egg production into a second egg laying cycle.     

Food perception with age and its relationship to pleasantness

Differences between elderly subjects (n = 46, 61-86 years) and young subjects (n = 36, 18-25 years) in food perception and food liking were investigated. Intensity and liking ratings were assessed for custard dessert, in which flavor enrichment, textural change, and irritant addition were incorporated as strategies to compensate for sensory losses with increasing age. The sensory acuity (taste, olfaction, irritation, chewing efficiency) of both young and elderly subjects was measured with the help of different sensitivity tests. The elderly perceived the custards differently from the young, mainly as less intense in flavor (cherry/vanilla) and less intense in creaminess/swallowing effort. Several of the observed interaction effects were different for the elderly and the young. The majority of these differences manifested as lower intensity slopes for the elderly. Losses in sensitivity to taste and to olfactory and trigeminal stimuli as well as a reduced chewing efficiency were observed on average for the elderly compared with the young. Furthermore, subgroups of the elderly were observed in which the compensatory strategies flavor enrichment, textural change, and irritant addition led to an increase in food liking. However, these subgroups did not differ in their sensory acuity. The present study does not support the assumption that age-associated changes in food perception-caused by losses in sensory acuity-inevitably reduce the food liking of the elderly.