INFLUENCE OF TEMPERATURE AND LIGHT EXPOSURE ON SENSORY SHELF-LIFE OF A COMMERCIAL SUNFLOWER OIL

The objectives of the present work were to: (1) correlate consumer acceptability measured with a consumer panel versus oxidized flavor measured with a trained sensory panel to thus define the sensory failure of a commercial sunflower oil; and (2) study the effect of storage temperature and light exposure on the sensory shelf‐life of sunflower oil bottled in polyethylene tetraphtalate (PET) with nitrogen in the headspace. Of the consumers, 15% unexpectedly preferred the more oxidized oil samples than the fresh ones. Their data were not considered in sensory failure calculations. By correlating the consumer data with the trained sensory panel data, a sensory failure point of 3.6 on a 0 to 10 oxidation flavor scale was obtained. Both storage temperature and exposure to light had a significant effect on shelf‐life. Estimated shelf‐lives at an ambient temperature of 20C were 281 days for light exposed oil, and greater than 2 years for oil kept in the dark.     

Determination of consumer acceptance limits to sensory defects using survival analysis

Survival analysis concepts and calculations were applied to consumers' acceptance/rejection data of samples with different levels of sensory defects. The following defects in UHT milk were studied: acid, caramel, cooked, dark color, lipolytic and oxidized. For each defect a series of nine concentrations were prepared and tested by 50 member consumer panels. The lognormal parametric model was found adequate for most defects and allowed prediction of concentration values corresponding to 10% probability of consumer rejection. For cooked flavor the model was not adequate due to a large number of right censored data, consumers did not find this defect objectionable. For oxidized flavor there were also many right censored values, but this was due to an inadequate concentration range.     

Urban consumer preferences and sensory evaluation of locally produced and imported rice in West Africa

Parboiled rice produced in Ghana is of poor quality and is being overtaken by imported rice. This study sought to investigate consumer preference and relate sensory attributes with consumer acceptability of rice. The majority of consumers preferred imported raw and parboiled rice to that produced locally. Acceptability was influenced by location and gender. Individual preferences of consumers varied and four different segments of consumers with similar liking of the rice samples were identified. The largest three segments (86% of consumers) preferred the imported rice but differed in their preferences for the local rice. A niche segment (14%) mostly preferred traditional local rice. Regression models to predict consumer preference from the sensory panel scores were based on either brown colour of the cooked rice or unshelled paddy in the uncooked form. The models were suitable for three of the consumer segments representing 86% of the consumers. This suggests that while a sensory panel could be used to rapidly monitor consumer acceptability in product development, it was not valid for all consumers. The implications of these findings are discussed.     

IRON CONTENT, SENSORY EVALUATION, AND CONSUMER ACCEPTANCE OF FOOD COOKED IN IRON UTENSILS

The purpose of this study was to determine the effect of cooking food in iron utensils on the iron content, sensory quality, and consumer acceptance/ preference of the food. Hamburger patties and applesauce were cooked in iron and in glass utensils and were analyzed for iron content by atomic absorption spectrophotometry and evaluated by a trained sensory panel, by consumers, and for chroma, pH, and refractometer changes. Cooking hamburger patties and applesauce in iron utensils increased iron in the food, did not affect sensory quality or consumer acceptance/preference of hamburger patties, but affected the color and flavor and decreased consumer acceptance/preference for applesauce.     

Development of soy-based bread with acceptable sensory properties

Consumption of soy protein has been associated with benefits related to numerous areas of health. Due to the widespread consumption of bread, one means of contributing to the health of individuals is through the incorporation of soy protein into bread. To this end, soy flour (SF) or soy protein isolates (SPIs) in 20% and 12% substitution levels, respectively, were added to flour during bread manufacture. The developed breads were tested using a consumer panel for acceptability, using a refined white bread as a control. These data were compared to attribute intensity data collected by the trained panel to identify specific flavor and texture characteristics affecting liking. The sensory profile of the 20% SF bread was acceptable and comparable to the control bread, despite a significantly stronger beany flavor. No significant differences in sensory properties of the SF and control breads were detected by the trained panel for many sensory attributes. The SPI bread, however, had a sensory profile that was significantly more firm, dense, sour, beany, bitter, and astringent with a strong aftertaste in comparison to the wheat control bread. Consumer liking scores for the SPI bread was significantly lower than the liking of the control and the SF added bread. PRACTICAL APPLICATION: Many soy-enriched foods, while contributing positively to health, are considered unacceptable by consumers. This is due to negative sensory properties, such as beany, painty, and astringent notes, often perceived by consumers. This study provides information on the level of SF that can be included in bread in an amount that does not detract from consumer acceptability. This level also allows for a Food and Drug Administration (FDA) health claim to be made.     

Consumer Acceptability Compared with Sensory and Instrumental Measures of White Pan Bread: Sensory Shelf-life Estimation by Survival Analysis

ABSTRACT: Two studies, one in Uruguay using Uruguayan white pan bread (WPB) and another in Spain using Spanish WPB, were carried out with trained judges and consumers from the country in question. The objectives were to correlate the consumer panel acceptability, trained sensory panel scores, and instrumental measurements of defects likely to appear during WPB storage, to compare the acceptability prediction models obtained in each country, and to apply survival analysis methodology to estimate the shelf life of the product. Logistic regression was used to predict the acceptance percentage and multiple regression was used to predict acceptability. Sensory variables (strange odor) showed a greater prediction capacity for Uruguayan WPB acceptability and acceptance percentage. For the Spanish WPB, instrumental cohesiveness and moisture content variables showed a greater prediction capacity for the acceptance percentage, whereas sensory (cohesiveness and color) and moisture content variables showed a greater prediction capacity for acceptability. Uruguayan WPB shelf life was 15 d for a 50% probability of consumer rejection and 13 d for a 25% probability of consumer rejection, whereas for Spanish WPB it was 23 d for a 50% probability of consumer rejection and 16 d for a 25% probability of consumer rejection.     

Influence of intramuscular fat content on lipid composition,sensory qualities and consumer acceptability of cured cooked ham

The present study is part of a project which aims to examine the influence of intramuscular fat (IMF) content on the sensory attributes and consumer acceptability of pork. An experiment was conducted to evaluate the influence of IMF level in muscle semimembranosus (SM) on the composition of its lipid fraction and on the sensory qualities and consumer acceptability of cured cooked hams. Thirty‐two carcasses were selected 24 h after slaughter from 125 Duroc × Landrace castrated male pigs showing large variability in SM muscle IMF content and were assigned to four IMF groups: ≤2%, 2–3%, 3–4% and >4%. Cured cooked ham slices were evaluated by a trained expert panel of 12 members and by a group of 56 consumers. Results from lipid analyses indicate that (i) an increase in IMF content was almost entirely reflected by an increase in the triglyceride content of the muscle and (ii) higher IMF levels were associated with higher free fatty acid and monoglyceride and lower cholesterol levels. The sensory evaluation of marbling significantly increased with IMF level, whereas other sensory qualities were unaffected. High IMF levels significantly depreciated the consumer perception of fat, aspect, taste and smell of ham slices. Overall, slices with the highest IMF levels got the least favourable rating by consumers. The present study indicates that increased IMF levels in muscle semimembranosus do not have significant effects on the sensory attributes of cured cooked hams, apart from the perception of marbling. However, high IMF levels have detrimental effects on the acceptability by consumers. © 2000 Society of Chemical Industry     

Modeling preference of commercial toasted white corn tortilla chips using proportional odds models

Eleven commercial toasted white corn tortilla chip products from the United States were evaluated by a group of 80 consumers of age 18–35 and by a trained sensory panel. Proportional odds models in conjunction with principal components were used for internal and external preference modeling of tortilla chip consumer overall acceptance. The internal preference modeling showed that flavor was the most important attribute to consumer overall acceptance followed by the interaction of appearance by flavor and texture. The external preference modeling showed that one flavor attribute (salt aftertaste) and one texture attribute (crispness) contributed significantly to increase consumer overall acceptance, whereas one appearance attribute (instrumental color a¹) significantly lowered consumer overall acceptance. The information reported in this study is important to the tortilla chip industry to produce tortilla chips with greater consumer acceptability. This study implies that proportional odds model using principal components is an alternative tool for consumer preference modeling.     

Consumer acceptance of new strawberry vinegars by preference mapping

Consumers’ acceptance of new strawberry vinegars was evaluated, and trained panellists described their sensory profiles. Four strawberry vinegars, three produced from puree and one from cooked must, were evaluated jointly. Due to obtaining the highest percentage of consumer acceptance, cooked strawberry must vinegar was considered to be the best. This vinegar stood out in general impression, raisin, and liqueur attributes. Internal preference maps confirmed a higher acceptance level for the strawberry vinegars over commercial vinegar. External preference mapping, obtained by PLS2 analysis, revealed that the main sensory attributes driving consumers’ preferences are raisin, toasted caramel, spicy, and liqueur aroma.     

SENSORY ANALYSIS OF SOY YOGURT AND FROZEN SOY YOGURT PRODUCED FROM RAPID HYDRATION HYDROTHERMAL COOKED SOY MILK

Sensory studies have been conducted on flavored soy yogurt (FLAVSYO) and frozen flavored soy yogurt (FROZSYO) made from rapid hydration hydrothermal cooked soy milk. Trained panel testing was conducted with a panel of 5. Consumer acceptance tests were carried out with 195 consumers using standard nine-point hedonic scales. The frequencies of the consumers who liked FROZSYO were high at like slightly to like extremely, the FLAVSYO and FROZSYO had less beany flavor than the soy milk. The data from the trained panel indicate that processing, fermentation, and flavoring significantly changed the major attributes. Relative to unflavored soy yogurt, the beany flavors, chalkiness, aftertaste, sweetness, uniformity, and mouth coating scores of the FLAVSYO and FROZSYO were closer to the corresponding sensory scores for the commercial yogurt.