Quantitative Descriptive Analysis (quantitative + descriptive_analysis)

Distribution by Scientific Domains


Selected Abstracts


IMPACT OF DRYING AND STORAGE TIME ON SENSORY CHARACTERISTICS OF ROSEMARY (ROSMARINUS OFFICINALIS L.)

JOURNAL OF SENSORY STUDIES, Issue 1 2007
M.C. DÍAZ-MAROTO
ABSTRACT The effect of drying treatment on the aroma characteristics of rosemary (Rosmarinus Officinalis L.) was studied using the Quantitative Descriptive Analysis (QDA) with a trained panel and by Free Choice Profiling (FCP) analysis with a consumer group. Differences between samples were observed after applying Principal Component Analysis to the QDA data and Generalized Procrustes Analysis to the FCP data. The highest differences were found between fresh rosemary samples and dried samples. However, dried samples (obtained by oven-drying at 45C and commercial samples purchased at the markets and stored for 6 months) showed significant differences in their sensory characteristics. Odor detection thresholds of the fresh rosemary leaves were calculated in water and in potato sauce, and significant differences were found. [source]


STORAGE TIME STUDY OF SUGAR-FREE AND REDUCED CALORIE MILK CHOCOLATES

JOURNAL OF FOOD QUALITY, Issue 5 2009
LAURO LUÍS MARTINS MEDEIROS DE MELO
ABSTRACT In order to study storage time, sensory properties and acceptability among consumers, regular, free-sugar (sucralose [Sucra] or stevioside [Ste]) and free-sugar/reduced calorie (Sucra or Ste], with whey protein concentrate as fat replacer) milk chocolates were evaluated over storage (0, 3, 6 and 9 months). Quantitative descriptive analysis showed that sensory properties do not change throughout the studied storage period. These results were confirmed by acceptability data. No significant changes (P , 0.05) were observed on acceptability means for appearance, aroma, flavor, texture and overall liking. These results show that sugar-free and reduced calorie milk chocolates prepared with high-intensity sweeteners, Sucra and Ste, with partial fat replacement with whey protein concentrate had a similar storage time behavior as compared with regular chocolates. PRACTICAL APPLICATIONS This research aims to study sensory storage time of regular, sugar-free and sugar-free/reduced calorie milk chocolates. It can help food industries to understand storage time of these products as sensory properties for highly stable food products, such as chocolate, usually define shelf life. [source]


QUANTITATIVE DESCRIPTIVE SENSORY ANALYSIS OF FIVE DIFFERENT CULTIVARS OF SWEET POTATO TO DETERMINE SENSORY AND TEXTURAL PROFILES

JOURNAL OF SENSORY STUDIES, Issue 1 2010
C.S. LEIGHTON
ABSTRACT A trained sensory panel was used to establish terminology for describing the sensory attributes of different cultivars orange-fleshed sweet potato (OFSP) and white-fleshed sweet potato (WFSP). Quantitative descriptive analysis was applied to evaluate the samples in terms of the aroma, texture, flavor and aftertaste attributes. Thirteen attributes were identified. Principal component analysis (PCA) was applied to identify any factors differentiating between the sweet potato cultivars. The findings indicated that the main differences were, in PC1, the flavor and density and adhesive textural characteristics, and, in PC2, the grainy and firm textural characteristics of the different cultivars. OFSP displayed a more dense and pasty texture, which was most intense in the Resisto cultivar. W119 had a more grainy texture when compared with the other cultivars tested. WFSP was more moist and fibrous. Therefore, OFSP differed in color, was sweeter and displayed flavor characteristics of yellow vegetables (such as butternut and pumpkin) when compared with WFSP. PRACTICAL APPLICATIONS Although standard sensory evaluation techniques were used in this project, the materials used were sweet potatoes, which are of interest. Sweet potato is a root vegetable, and in this project, a lexicon for the textural properties, as well as a flavor profile of sweet potato, was developed. Such information can be used for sensory evaluation of other root vegetables. The shear force of the sweet potatoes was measured, and the methodology to determine shear forces and its contribution to the overall evaluation of the texture of sweet potatoes is included in the article. Furthermore, white-fleshed sweet potatoes are commonly known, and the flavor of WFSP is compared with that of orange-fleshed sweet potatoes. [source]


Multi-way models for sensory profiling data

JOURNAL OF CHEMOMETRICS, Issue 1 2008
Rasmus Bro
Abstract One of the problems in analyzing sensory profiling data is to handle the systematic individual differences in the assessments from different panelists. It is unavoidable that different persons have, at least to a certain degree, different perceptions of the samples as well as a different understanding of the attributes or of the scales used for quantifying the assessments. Hence, any model attempting to describe sensory profiling data needs to deal with individual differences; either implicitly or explicitly. In this paper, a unifying family of models is proposed based on (i) the assumption that latent variables are appropriate for sensory data, and (ii) that individual differences occur. Based on how individual differences occur, various mathematical models can be constructed, all aiming at modeling simultaneously the sample-specific variation and the panelist-specific variation. The model family includes Principal Component Analysis (PCA) and PARAllel FACtor analysis (PARAFAC). The paper can be viewed as extending the latent variable approach commonly based on PCA to multi-way models that specifically take certain panelist-variations into account. The proposed model family is focused on analyzing data from quantitative descriptive analysis with fixed vocabulary, but it also provides a foundation upon which comparisons, extensions and further developments can be made. An example is given which shows that even for well-working data, models handling individual differences can shed important light on differences between the quality of the data from individual panelists. Copyright © 2007 John Wiley & Sons, Ltd. [source]


THE EFFECT OF REFRIGERATED STORAGE ON SENSORY PROFILE AND PHYSICAL-CHEMICAL CHARACTERISTICS OF MINIMALLY PASTEURIZED ORANGE JUICE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2009
TATIANA BEATRIS TRIBESS
ABSTRACT Minimal pasteurization of orange juice (OJ) consists of using minimum holding time and temperature to ensure partial inactivation of pectin methylesterase (PME). This process produces juice with preserved sensory attributes and has a better acceptance by consumers when compared with commercially pasteurized OJ. Sensory profile and physical-chemical characteristics of minimally processed OJ was determined, during refrigerated storage, for two OJ blends with different pH values and the same level of PME thermal inactivation. A selected and trained sensorial panel (n = 16) performed sensory analysis, based on a quantitative descriptive analysis, twice a week for 30 days, evaluating the attributes of appearance (suspended particles and color intensity), odor (natural orange and fermented orange) and flavor (orange characteristic, fermented orange, acid and bitter taste). Storage presented great effect on OJ sensory profile; however, it was not noticeable on physical-chemical characteristics. PRACTICAL APPLICATIONS Minimal pasteurization of orange juice (OJ) consists of using minimum holding time and temperature to ensure partial inactivation of pectin methylesterase. This process produces juice with longer shelf life than fresh squeezed orange juice, preserved sensory attributes and better acceptance by consumers when compared with commercially pasteurized OJ. This study can contribute for quality evaluation of minimally pasteurized OJ under refrigeration. [source]


SENSORY PROFILING AND POSITIONING OF JILEBI SAMPLES BY MULTIVARIATE ANALYSIS

JOURNAL OF FOOD QUALITY, Issue 6 2004
MAYA PRAKASH
ABSTRACT Sensory profilograms based on the quantitative descriptive analysis (QDA) of jilebi using 12 attributes were drawn for nine market samples. The instrumental texture measurement of shear values and CIE color measurement for L*, a* and b* were determined for all the samples. Further, canonical discriminant analysis was run to position the samples. The results indicated that samples 9, 4 and 5 were grouped together in the same quadrant, which represented desirable attributes of jilebi viz, crispness, sweetness, glossy appearance and overall quality (OQ). Samples 6, 8 and 2 have taken a different quadrant with attributes like juicy and porous; while sample 3 was away in a separate quadrant with undesirable attribute namely heated oil. Crispness of jilebi had high positive correlation with OQ and texture (shear value). [source]


SENSORY FLAVOR PROFILING AND MAPPING OF MARKET SAMPLES OF CUMIN (CUMINUM CYMINUM L.)

JOURNAL OF FOOD QUALITY, Issue 4 2004
ANUPAMA DATTATREYA
ABSTRACT Eight market samples of cumin (R1, R2, R3, R4, R5, R6, R7 and R8) from different regions of India were examined for sensory quality by conducting threshold tests, time-intensity (TI) profiling and flavor profiling. Principal component analysis (PCA) was carried out to group the samples. Threshold values ranged from 0.006 to 0.017% with R7 and R8 lots showing lower values for their thresholds (0.006%). Higher intensity of aroma of R7 and R8 was further confirmed by more of a lingering aroma as shown by the TI study. Flavor profiling by quantitative descriptive analysis showed that the market samples of cumin did not differ significantly (P , 0.05). Mapping of samples using PCA technique showed, based on intensity of attributes, four distinct groups comprising a) R1 and R3, b) R7, c) R2 and R5 and d) R4 and R8. R6 occupied a position in between a and b. [source]


Culture-Specific Variation in the Flavor Profile of Soymilks

JOURNAL OF FOOD SCIENCE, Issue 8 2006
R.S.J. Keast
ABSTRACT:, A modified quantitative descriptive analysis (QDA) method was used to determine sensory profiles of 8 soymilk products: 3 manufactured in Australia, 3 manufactured in Singapore, 1 manufactured in Malaysia, and 1 manufactured in Hong Kong. A panel (n= 7) was selected, trained in descriptive profiling of soymilk, and developed a soymilk language that was used to evaluate the flavor attributes of the soymilk products. A repeated-measure ANOVA showed highly reproducible panel performance, and significant differences in soymilk attributes among all soymilks. A principal component analysis (PCA) revealed 2 main groupings among the soymilks that corresponded to cultural origin: Australia and Asia (Singapore and Hong Kong/Malaysia). Products from Australia were significantly stronger in milky, astringent, salty notes and pale in color, while products from Asia were significantly stronger in beany, cooked beans, sweet, and pandan notes (P < 0.05). In addition, the Asian soymilks could be separated into 2 subgroups, with Singaporean soymilks having deeper color, greater viscosity, and less green flavor than Hong Kong/Malaysia soymilks. Australian produced soymilk is bovine-milk-like compared with Asian soymilk, presumably due to bovine milk being the primary source of milk in Australia. We conclude that culture-specific flavor preferences are a determining factor in flavor profiles of soymilks from geographically distinct regions. [source]


EVALUATION OF REPLICATED PROJECTIVE MAPPING OF GRANOLA BARS

JOURNAL OF SENSORY STUDIES, Issue 5 2010
JESSICA KENNEDY
ABSTRACT The application of projective mapping to quickly gather information on overall product differences provides a unique way to probe consumer perceptions and gather product information. A group of 15 consumers performed a projective mapping exercise three times on a set of eight "berry flavored" granola bars, including descriptors of the products. The projective mapping task was performed in replicates to evaluate the consistency of results obtained via this technique. Analysis of the replications by multifactor analysis indicated for the majority of consumers, that the three individual maps did not show a high degree of similarity (80% of RV coefficients < 0.5). However, consensus maps from the three replications indicated a similar group perception of the products over the replications, as depicted by hierarchical multifactor analysis. Terms collected from the maps were summarized and regressed into the product space for interpretation, both in terms of consumer criteria used to differentiate among products and identification of key product attributes. PRACTICAL APPLICATIONS The findings from this study add to the growing knowledge on projective mapping. The results presented here aimed to substantiate the value and reliability of projective mapping when used with consumers. Although projective mapping is not a replacement for quantitative descriptive analysis, it is an efficient tool for consumer research; as well as product or category exploration which can be utilized early in the product development process. The addition of descriptors directly onto the maps by panelists makes it possible to use projective mapping as a stand-alone method by increasing the amount and interpretability of data provided by panelists. When used with consumers, projective mapping links the consumer perception of the product space with a consumer-driven lexicon. [source]


SENSORY AND INSTRUMENTAL TEXTURE MEASUREMENT OF THERMALLY PROCESSED RICE

JOURNAL OF SENSORY STUDIES, Issue 5 2005
M. PRAKASH
ABSTRACT Rice is the staple food of many countries and its sensory quality is of great concern to the consumers. Its preservation through thermal processing in retort pouches for ready-to-eat purposes was carried out by different time,temperature schedules with and without oil to achieve a minimum Foof 3 min. The sensory analysis of the cooked rice carried out using quantitative descriptive analysis showed that a process schedule of 118C, 8 min was optimum to have the optimal sensory characteristics. The same rice samples were subjected to instrumental texture measurements by texture analyzer using a crosshead speed of 0.5 mm/s with 90% compression for hardness and stickiness parameters. The instrumental hardness showed high correlation with sensory hardness, chewiness and overall quality (r = 0.72; r = 0.73; r = 0.79) and a negative correlation with sensory stickiness (r = ,0.75). Applying principal component analysis, thermally processed rice samples were further classified based on the sensory and instrumental texture attributes. [source]


RELATIONSHIP BETWEEN SENSORY AND TEXTURE MEASUREMENT OF JAMUN AND POSITIONING OF JAMUN SAMPLES

JOURNAL OF SENSORY STUDIES, Issue 1 2002
R. RAVI
ABSTRACT Profilograms based on the quantitative descriptive analysis (QDA) of jamun using nine attributes were drawn for four market samples and ten samples prepared using various instant mixes available in the local market. The instrumental texture measurement of shear values were determined for all the samples. Correlations between sensory and instrumental texture measurement (shear force) were studied. The shear values were found to be correlated positively with softness, juiciness and milkiness. Further canonical discriminant analysis was run to position the samples in relation to others. The results indicated that samples M1, M2, M4, S3, S4, S6 and S10 group together in the same quadrant which represents desirable attributes of jamun viz, color, softness, juiciness, milkiness and overall quality. The jamuns from the instant mixes (S) can replace the control samples, traditionally prepared market samples (M) as they match the product profile very closely. [source]