Quantitative Sensory Analysis Research Articles

Effects of post-fermentation addition of green tea extract for sulfur dioxide replacement on Sauvignon Blanc wine phenolic composition, antioxidant capacity, colour, and mouthfeel attributes

This study examines the feasibility of replacing SO2 in a New Zealand Sauvignon Blanc wine with a green tea extract. The treatments included the control with no preservatives (C), the addition of green tea extract at 0.1 and 0.2 g/L (T1 and T2), and an SO2 treatment at 50 mg/L (T3). Five monomeric phenolic compounds were detected in the green tea extract used for the experiment, and their concentrations ranged in the order (−)-epigallocatechin gallate > (−)-epigallocatechin > (−)-epicatechin > (−)-epicatechin gallate > gallic acid. At the studied addition rates, these green tea-derived phenolic compounds contributed to ∼70% of the antioxidant capacity (ABTS), ∼71% of the total phenolic index (TPI), and ∼ 84% of tannin concentration (MCPT) of the extract dissolved in a model wine solution. Among wine treatments, T1 and T2 significantly increased the wine's colour absorbance at 420 nm, MCPT, gallic acid and total monomeric phenolic content. TPI and ABTS were significantly higher in wines with preservatives (i.e., T2 > T1 ≅ T3 > C, p < 0.05). These variations were observed both two weeks after the treatments and again after five months of wine aging. Additionally, an accelerated browning test and a quantitative sensory analysis of wine colour and mouthfeel attributes were performed after 5 months of wine aging. When exposed to excessive oxygen and high temperature (50 °C), T1 and T2 exhibited ∼29% and 24% higher browning capacity than the control, whereas T3 reduced the wine's browning capacity by ∼20%. Nonetheless, the results from sensory analysis did not show significant variations between the treatments. Thus, using green tea extract to replace SO2 at wine bottling appears to be a viable option, without inducing a negative impact on the perceptible colour and mouthfeel attributes of Sauvignon Blanc wine.

Enhanced aroma and flavour profile of fermented Tetragonula pagdeni Schwarz honey by a novel yeast T. delbrueckii GT-ROSE1 with superior fermentability

Beside a source of bioactive compounds, honey represents untapped-reservoir of beneficial microbes. Next generation sequencing technology was applied to aid the discovery of newly-isolated flavour yeast Torulaspora delbrueckii strain GT-ROSE1 from honey samples. Owing to the presence of natural duplicate regulatory sites in aromatic genes, it was used to create value-added fermented honey with unique aroma-flavour profile. This osmophilic strain could assimilate different carbons and tolerated to low pHs, high ethanol and sugars, exhibiting useful traits for food and alcoholic fermentation of sugar-based industries. Global analysis of aroma-flavour profile revealed higher total concentrations of key compounds after fermentation by GT-ROSE1, compared to commercial wine yeasts. Twenty-four volatile compounds were identified using a nontargeted HS-SPME-GC-MS method. High odour activity values and quantitative sensory analysis indicated fruity and rose flowery aroma of key compounds nonanol and 2-phenylethanol, respectively. Importantly, fermented Tetragonula pagdeni Schwarz honey with observed excellent antioxidant property displayed appealing characteristic of enhanced 2-phenylethanol of rose-like flavour with odour threshold of 16.08. Thus, flavour yeast could be used to improve chemical content and enhance sensory value of local food products.

Effect of the dietary supplementation based on essential oils on the quality of gilthead seabream

The effectiveness of using essential oils against fish parasites and pathogenic bacteria as environmentally friendly phytotherapeutic agents in the aquaculture industry is demonstrated. A commercial additive composed of garlic essential oil, thymol and carvacrol (AROTEC-G®) was added to a diet for gilthead seabream (Sparus aurata) as a protection strategy against Sparicotyle chrysophrii. The intense aromatic properties of these essential oils might lead to the need of a suppression time to reverse possible changes in the organoleptic quality of the fish. Two experimental groups were set up: an experimental group fed a commercial feed supplemented with AROTEC-G® (diet A) during the first 4 weeks of the nutritional assay, and after which the treatment was suspended for 14, 21 and 28 days after a first sampling performed (day 0); and a control group, fed the same basal diet without AROTEC-G® supplementation (diet C). A physicochemical evaluation measured the pH, colour and texture, and a descriptive quantitative sensory analysis (QDA) was carried out using a trained panel for gilthead seabream fillets. Overall, the findings showed that the use of dietary essential oils did not result in significant sensory differences after day 0 of the study, although slight differences were observed in some of the physicochemical parameters analysed.

Development of a new sensory analysis methodology for predicting wine aging potential. Application to champagne reserve wines

A new analysis method was developed to evaluate a sensory concept for food products. The concept “wine aging potential” is used by experts and professionals to describe the inherent capacity of great red or whites to develop qualitatively during aging. Previous authors who studied wine aging potential proposed a method of evaluation using a one-dimensional scale. However, during the concept description task, wine aging potential was linked to three dimensions: time; wine quality, and potential. The methods available in quantitative sensory analysis, such as Profile, Free Choice Profile and Flash Profile, do not allow for quantifying more than two dimensions simultaneously. A new, 3-dimensional scale and sensory analysis method was developed, based on cognitive definitions from professional tasters concerning the aging potential of champagne reserve wines.This method, called “projective categorization,” introduces several dependent variables, offering tasters a visual tool to evaluate the projected development of a wine’s quality over time on different dynamics.A specific, statistical analysis was developed for significant evaluation of wines and judges. This new tool was tested on 33 champagne reserve wines aged from 1 to 29 years. It demonstrated its capability in distinguishing accurately wines with different aging aptitudes. Indications concerning panel consensus and judges’ performance were also provided.This is the first time that a sensory methodology has been developed on the basis of a sensory concept in order to classify products. This method enabled obtaining a precision for categorizing champagne reserve wines linked to the judges’ consensus. The quality and reliability of the results seemed, in agreement with all sensory analysis methods, to be dependent on the number of judges.

Influence of the application of alternating impulses of pressure on the quantitative sensory analysis of pure water, associated liquid aqueous systems and solutions

Influence of the application of alternating impulses of pressure on the quantitative sensory analysis of pure water, associated liquid aqueous systems and solutions

The state of water and fat during the maturation of Cheddar cheese

Cheddar cheese predicted to develop into different quality classes has been evaluated by time domain Nuclear Magnetic Resonance, Thermogravimetric analysis and quantitative sensory analysis. The water and fat proton signals in the transverse relaxation decay curves have been deconvoluted. Proton transverse relaxation values for both the water and fat fractions decrease and the relative %age of the proton peak area, predominantly from the fat increases over a 450-day ripening period. The thermodynamic free water percentage increases during maturation. Water and fat attributes can distinguish between Cheddar cheese batches after 56 days. Cheese batches which have lower transverse relaxation values for the water and fat proton fractions and a higher relative %age of the proton peak area predominantly from fat at 56 days, mature after 270 days to be more yellow, rubbery and smooth, have a less sour and lingering aftertaste and are also harder to form into a cheese ball.

Thalamic pain: anatomical and physiological indices of prediction.

Thalamic pain is a severe and treatment-resistant type of central pain that may develop after thalamic stroke. Lesions within the ventrocaudal regions of the thalamus carry the highest risk to develop pain, but its emergence in individual patients remains impossible to predict. Because damage to the spino-thalamo-cortical system is a crucial factor in the development of central pain, in this study we combined detailed anatomical atlas-based mapping of thalamic lesions and assessment of spinothalamic integrity using quantitative sensory analysis and laser-evoked potentials in 42 thalamic stroke patients, of whom 31 had developed thalamic pain. More than 97% of lesions involved an area between 2 and 7 mm above the anterior-posterior commissural plane. Although most thalamic lesions affected several nuclei, patients with central pain showed maximal lesion convergence on the anterior pulvinar nucleus (a major spinothalamic target) while the convergence area lay within the ventral posterior lateral nucleus in pain-free patients. Both involvement of the anterior pulvinar nucleus and spinothalamic dysfunction (nociceptive thresholds, laser-evoked potentials) were significantly associated with the development of thalamic pain, whereas involvement of ventral posterior lateral nucleus and lemniscal dysfunction (position sense, graphaesthesia, pallaesthesia, stereognosis, standard somatosensory potentials) were similarly distributed in patients with or without pain. A logistic regression model combining spinothalamic dysfunction and anterior pulvinar nucleus involvement as regressors had 93% sensitivity and 87% positive predictive value for thalamic pain. Lesion of spinothalamic afferents to the posterior thalamus appears therefore determinant to the development of central pain after thalamic stroke. Sorting out of patients at different risks of developing thalamic pain may be achievable at the individual level by combining lesion localization and functional investigation of the spinothalamic system. As the methods proposed here do not need complex manipulations, they can be added to routine patients' work up, and the results replicated by other investigators in the field.

Contribution of Bacillus Isolates to the Flavor Profiles of Vanilla Beans Assessed through Aroma Analysis and Chemometrics.

Colonizing Bacillus in vanilla (Vanilla planifolia Andrews) beans is involved in glucovanillin hydrolysis and vanillin formation during conventional curing. The flavor profiles of vanilla beans under Bacillus-assisted curing were analyzed through gas chromatography-mass spectrometry, electronic nose, and quantitative sensory analysis. The flavor profiles were analytically compared among the vanilla beans under Bacillus-assisted curing, conventional curing, and non-microorganism-assisted curing. Vanilla beans added with Bacillus vanillea XY18 and Bacillus subtilis XY20 contained higher vanillin (3.58% ± 0.05% and 3.48% ± 0.10%, respectively) than vanilla beans that underwent non-microorganism-assisted curing and conventional curing (3.09% ± 0.14% and 3.21% ± 0.15%, respectively). Forty-two volatiles were identified from endogenous vanilla metabolism. Five other compounds were identified from exogenous Bacillus metabolism. Electronic nose data confirmed that vanilla flavors produced through the different curing processes were easily distinguished. Quantitative sensory analysis confirmed that Bacillus-assisted curing increased vanillin production without generating any unpleasant sensory attribute. Partial least squares regression further provided a correlation model of different measurements. Overall, we comparatively analyzed the flavor profiles of vanilla beans under Bacillus-assisted curing, indirectly demonstrated the mechanism of vanilla flavor formation by microbes.

A sensory study of the ageing bouquet of red Bordeaux wines: A three-step approach for exploring a complex olfactory concept

The ageing bouquet, which defines the overall quality of fine wines, counts among the most fascinating but least known phenomena in oenology. Its complexity and subtlety are highly-valued attributes, together with the perfume and flavour of a fine wine.The aim of this work was firstly to explore whether wine professionals shared a common representation of the ageing bouquet of red Bordeaux wines and then to move on how they perceive and translate its main sensory characteristics. In a first step, a large panel of wine professionals including winemakers, wine-science researchers, oenologists, wine consultants, and graduate students in oenology were invited to answer a questionnaire about their personal definition of the wine ageing bouquet concept. The lexical field generated through a free association task revealed that conceptualisation of the ageing bouquet involves a wide variety of quality dimensions, where intrinsic attributes, such as sensory clues, complexity, balance, and positive ageing evolution, play an important role. Importantly, this step showed the occurrence of a confusion of the ageing bouquet with a reductive fault of wine among the panel and emphasised the need for a careful selection of assessors before moving on to the next wine tasting steps.In a second step, 30 red Bordeaux wines were assessed by 13 wine professionals from the Bordeaux area who were selected among the best skilled ones thanks to the initial step of our study. They were initially required to score to which extend each tasted wine represented a qualitative ageing bouquet. Then, they were invited to freely express their individual sensory descriptions for those with the highest scores. A profile of aromatic attributes of the ageing bouquet typicality of these wines was then compiled on the basis of the frequency citation method. Although all wine professionals were not consensual in their assessment of the typicality of individual wines during tasting, they were able to express a collective representation of the main odour characteristics of a wine’s ageing bouquet. Their olfactory representations tended to highlight a pool of seven main aromatic notes: undergrowth, truffle, toasted, spicy, liquorice, mint, and fresh red- and black-berry fruits. As a third step, a validation of these seven more frequently elicited aromatic descriptors was addressed through a profiling of their sensory intensity by the panel. Three out seven (undergrowth, truffle, and spicy notes) were turned out significant for wines discrimination among the assessors. Overall, this study provides new insights into the ageing bouquet concept in red Bordeaux wines and offers an interesting framework for carrying out subsequent conventional quantitative sensory analysis as well as initiating qualitative and quantitative chemical work.

A quantitative sensory analysis of peripheral neuropathy in colorectal cancer and its exacerbation by oxaliplatin chemotherapy.

Peripheral neuropathy caused by cytotoxic chemotherapy, especially platins and taxanes, is a widespread problem among cancer survivors that is likely to continue to expand in the future. However, little work to date has focused on understanding this challenge. The goal in this study was to determine the impact of colorectal cancer and cumulative chemotherapeutic dose on sensory function to gain mechanistic insight into the subtypes of primary afferent fibers damaged by chemotherapy. Patients with colorectal cancer underwent quantitative sensory testing before and then prior to each cycle of oxaliplatin. These data were compared with those from 47 age- and sex-matched healthy volunteers. Patients showed significant subclinical deficits in sensory function before any therapy compared with healthy volunteers, and they became more pronounced in patients who received chemotherapy. Sensory modalities that involved large Aβ myelinated fibers and unmyelinated C fibers were most affected by chemotherapy, whereas sensory modalities conveyed by thinly myelinated Aδ fibers were less sensitive to chemotherapy. Patients with baseline sensory deficits went on to develop more symptom complaints during chemotherapy than those who had no baseline deficit. Patients who were tested again 6 to 12 months after chemotherapy presented with the most numbness and pain and also the most pronounced sensory deficits. Our results illuminate a mechanistic connection between the pattern of effects on sensory function and the nerve fiber types that appear to be most vulnerable to chemotherapy-induced toxicity, with implications for how to focus future work to ameloirate risks of peripheral neuropathy.

Actividad espontánea de nociceptores cutáneos en pacientes con neuropatía de fibras delgadas

Painful polyneuropathy may result from selective impairment of small diameter nerve fibers, while tactile and motor functions are preserved. In these patients clinical and electrophysiological assessment is usually unrevealing. We report three patients with a pure painful polyneuropathy. One of them had neurogenic pruritus additionally. Quantitative sensory analysis disclosed a slight warm hypoesthesia (3/3) and paradoxical hot sensation (2/3) in the feet. Intraneural recordings from the peroneal nerve demonstrated abnormal spontaneous activity in 8 of 17 nociceptive afferents. One of them displayed double firing reflecting impulse multiplication. These results support the notion that patients with pain or pruritus with a distal distribution similar to a polyneuropathy, could have small diameter afferent fiber damage, despite normal function of large diameter fibers.

Chemical references in sensory analysis of smoke flavourings

A new descriptive language and the corresponding set of chemical standard references for the evaluation of smoke flavourings is proposed. Analysis of variance (ANOVA) and linear discriminant analysis (LDA) were applied to validate this lexicon as well as to analyse reproducibility, discriminatory ability and homogeneity of the panel. Results confirmed that the developed methology was adequate to describe and discriminate commercial smoke flavourings. The number of low correlations demonstrates the need to maintain the majority of the descriptors for carrying out descriptive quantitative sensory analysis of smoke flavourings.

Factors contributing to taste and quality of commercially processed strained carrots

Commercially processed strained carrots were obtained from three different processing locations over a 1-year span. Selected carrot lots exhibited both desirable and undesirable sensory attributes based on informal evaluations, while additional carrots were chosen based on postharvest storage factors that may have influenced overall quality. Physicochemical analysis was conducted to determine factors influencing carrot taste and color attributes that could be utilized for retail quality assessment. Quantitative sensory analysis was performed on a subset of the production lots representing a diverse range in chemical composition. Basic taste attributes indicated that concentrations of 6-methoxymellein (6-MM), soluble phenolics and organic acids in relation to high moisture content were critical factors for strained carrot taste. Strained carrot color could not be attributed to processing location or chemical composition and was likely due to raw product variation between cultivars. Variation between each processing location was greater than variation within each location, and overall differences between lots was attributed to 6-MM and soluble phenolic acid concentrations. By screening raw carrots for indications of stress induced chemical constituents, an understanding of those factors contributing to commercially processed strained carrot taste can be obtained.