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Ernst J Woltering - One of the best experts on this subject based on the ideXlab platform.
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pre storage application of 1 methylcyclopropene does not affect the flavour of conference pears ripened after 8 months of commercial standard controlled atmosphere storage
Postharvest Biology and Technology, 2021Co-Authors: Bastiaan Brouwer, Manon Mensink, Esther Hogeveenvan Echtelt, Ernst J WolteringAbstract:Postharvest 1-methylcyclopropene (1-MCP) applications are commercially used on ‘Conference’ pears to obtain an improved fruit quality after storage for up to 11 months. Treatment with 1-MCP may result in firmer and greener fruit at the end of storage. During subsequent shelf life, 1-MCP treated pears may show slower ripening, including a reduced rate of softening and a reduced production of aroma volatiles. The lower levels of aroma volatiles and consumer complaints of reduced flavour suggest that flavour is negatively affected by 1-MCP treatments, which has raised concern within in the Dutch fruit industry. In the present study, the effect of pre-storage 1-MCP treatment on post-storage ripening and flavour perception was studied. Untreated and 1-MCP-treated pears (325 nL L−1) were stored for 8 months at -0.8 °C under controlled atmosphere conditions of 3 kPa O2 and 0.6 kPa CO2 according to commercially used protocols. At day 7 and 9 of the subsequent shelf life at 10 °C, 1-MCP-treated fruit showed decreased yellowing and ethylene production, whereas firmness was similar to that of untreated fruit. The production of aroma volatiles was significantly reduced in 1-MCP-treated fruit; this was especially observed for different acetate esters, ethanol and butanol. Despite the reduction in aroma volatiles, a consumer panel could not distinguish (in a Tetrad Test) between samples from untreated and 1-MCP-treated fruit with similar firmness. This indicates that the important aroma volatiles, although reduced in abundance, were still above threshold levels and did not affect overall flavour perception. We conclude that 1-MCP does not affect flavour when pears within equal firmness classes are compared.
Hye Seong Lee - One of the best experts on this subject based on the ideXlab platform.
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sensory discrimination by consumers of multiple stimuli from a reference stimulus configuration in a not ar and constant ref duo trio superior to triangle and unspecified Tetrad
Food Quality and Preference, 2016Co-Authors: Yuna Jeong, Bia Kang, Minju Jeong, Minjeong Song, Michael J Hautus, Hye Seong LeeAbstract:In the food industry, overall discrimination Tests are used with untrained/naive consumer subjects to compare multiple Test stimuli against a fixed reference, such as a company’s gold standard or a stimulus familiar to the consumer. Such Tests are used for various objectives, including reformulation and cost reduction. Yet, studies on relative discrimination power and efficiency have been limited to experimental designs with a fixed pair of stimuli and method comparisons based on the same numbers of Tests. In the present study, two reminder methods, A-Not A with Reminder (A-Not AR) and 2-AFC with Reminder (2-AFCR), were investigated as potentially better methods for experimental designs including comparisons of multiple pairs of stimuli for consumer discrimination. 2-AFCR is procedurally equivalent to a constant-reference duo-trio Test with the reference presented first (DTF) and thus this Test is referred to as the constant-ref. DTF/2-AFCR Test in this paper. The practical efficiency of these two reminder methods, attributed to their effective stimulus configurations in replicated Tests (i.e. using a fixed reference and lower number of different stimuli required in a Test), was Tested in comparison with the two most commonly used balanced reference classification methods, the triangle Test and the unspecified Tetrad Test, by equalizing the number of stimuli required for the different methods. Namely the relative operational discrimination power was studied based on the same number of stimuli rather than the same number of Tests. 180 naive consumers performed a set of 12 replicated triangle Tests and, based on the results, were divided into one of three equally-performing groups. A related-samples design was implemented for comparison between the triangle and the other three methods. An independent-samples design was implemented across the three groups to compare the A-Not AR, constant-ref. DTF/2-AFCR, and unspecified Tetrad methods. Statistical ratio comparisons of d′ estimates obtained from different methods revealed that discrimination performance in the reminder methods was better than in both the Tetrad and triangle methods. No discrimination difference was found between the triangle and Tetrad Tests having all possible Test sequences, although the triangle Test considering only the optimal Test sequences, which were the same as those in the constant-ref. DTF/2-AFCR, resulted in superior discrimination than the Tetrad Test. Collectively, these results suggest that when assessing the discriminability of multiple stimuli from a fixed reference, the reminder scheme is the superior research design.
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optimal difference Test sequence and power for discriminating soups of varying sodium content dtfm version of dual reference duo trio with unspecified Tetrad Tests
Food Research International, 2015Co-Authors: In Ah Kim, Hye Lim Kim, Ha Yeon Cho, Hye Seong LeeAbstract:As sodium reduction has become very important in the food industry, various types of unspecified duo-trio Tests have been studied to improve its efficiency for studying samples with high sodium content, and a constant-saltier-reference duo-trio Test with dual reference, one reference in the first position and the second reference in the middle between the two Test stimuli (DTFM), has been recommended. For the duo-trio Test, a 'comparison of distance' (COD) strategy has been generally assumed. Yet, theoretically for DTFM, the 2-AFC reminder (2-AFCR) τ-strategy is also possible, which would make DTFM more efficient than the unspecified Tetrad Test. In this study, the hypothesis was that when subjects are pre-exposed to two types of samples, the 2-AFCR τ-strategy can be adopted in a constant-reference DTFM using a fixed design experiment. In order to Test this hypothesis, unspecified Tetrad Tests involving categorization tasks were used as a means of pre-exposure to the two types of samples for DTFM, and a performance comparison was conducted. Two groups of 39 untrained/naive subjects performed both the unspecified Tetrad and DTFM Tests in varying orders for the purpose of discriminating two different soup samples of varying sodium content. A comparison of the d' estimate across different methods supported the hypothesis that the more efficient 2-AFCR τ-strategy was appropriate when the Tetrad Test preceded DTFM, while when DTFM was performed first without pre-categorization of samples, the conventional duo-trio COD strategy was appropriate for the constant-reference DTFM.
Michael Omahony - One of the best experts on this subject based on the ideXlab platform.
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the Tetrad Test looking back looking forward
Journal of Sensory Studies, 2013Co-Authors: Michael OmahonyAbstract:Until recently, the Tetrad Test was considered an interesting idea but was seldom used. It was not until Ennis and Jesionka revisited the topic of power for discrimination Tests, that it was observed that the Tetrad Test had, theoretically, considerably more power than the triangle Test. This made it a suitable candidate as a replacement for the low powered, yet commonly used, triangle method. This has sparked a lot of activity concerning the Tetrad and there will be more to come. Yet, the Tetrad had been explored beforehand, for the purposes of Testing Thurstonian models. Had the authors had the right tools, could they have produced any evidence to support Ennis and Jesionka's observation? Practical Applications The use of difference Tests where the attribute change is not described to the judge, is especially useful for Testing consumers in normal conditions of consumption. In such normal conditions, unlike those for a two-alternative forced choice (paired comparison), there is no person nearby specifying the nature of the attribute that should be attended to while consuming food samples. The nature of the difference between such food samples has to be discovered by the consumer. Available Tests like the triangle or duo-trio are not statistically powerful and therefore require large samples of data, which can incur greater expense. Yet, the Tetrad is more theoretically powerful than these Tests and is thus worthy of, and is indeed receiving, further investigation.
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variance of d for the Tetrad Test and comparisons with other forced choice methods
Journal of Sensory Studies, 2013Co-Authors: Michael OmahonyAbstract:Tetrad Tests are forced-choice discrimination methods that have received comparatively little attention in the past. However, recently, their relatively large statistical power has stimulated interest in these methods. In this paper, some historical notes for the Tetrads are presented along with some recent developments in the use of the Tetrads. Tables of B are presented for the specified and unspecified Tetrad Tests. R/S-Plus codes are provided for calculating d′s and variances of d′s for the Tetrads. The paper notices that the psychometric function for the unspecified Tetrad given by Ennis et al. can be expressed as closed forms. The influential psychometric function for the triangle method can also be expressed as closed forms, which are similar to those of the unspecified Tetrad. The latter part of the paper pulls together tables of d′ and B scattered throughout the literature into single tables for ease of comparison with those values for the Tetrad Test. In the same spirit, power curves scattered across the literature are also pulled together in a single figure for ease of comparison. Practical Applications Thurstonian discriminal distance d′ is a first appropriation, method-independent measure of sensory differences and treatment effects. Estimations of d′ and variance of d′ for the Tetrads can be used to compare treatment effects evaluated using the Tetrads and other discrimination methods.
Bastiaan Brouwer - One of the best experts on this subject based on the ideXlab platform.
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pre storage application of 1 methylcyclopropene does not affect the flavour of conference pears ripened after 8 months of commercial standard controlled atmosphere storage
Postharvest Biology and Technology, 2021Co-Authors: Bastiaan Brouwer, Manon Mensink, Esther Hogeveenvan Echtelt, Ernst J WolteringAbstract:Postharvest 1-methylcyclopropene (1-MCP) applications are commercially used on ‘Conference’ pears to obtain an improved fruit quality after storage for up to 11 months. Treatment with 1-MCP may result in firmer and greener fruit at the end of storage. During subsequent shelf life, 1-MCP treated pears may show slower ripening, including a reduced rate of softening and a reduced production of aroma volatiles. The lower levels of aroma volatiles and consumer complaints of reduced flavour suggest that flavour is negatively affected by 1-MCP treatments, which has raised concern within in the Dutch fruit industry. In the present study, the effect of pre-storage 1-MCP treatment on post-storage ripening and flavour perception was studied. Untreated and 1-MCP-treated pears (325 nL L−1) were stored for 8 months at -0.8 °C under controlled atmosphere conditions of 3 kPa O2 and 0.6 kPa CO2 according to commercially used protocols. At day 7 and 9 of the subsequent shelf life at 10 °C, 1-MCP-treated fruit showed decreased yellowing and ethylene production, whereas firmness was similar to that of untreated fruit. The production of aroma volatiles was significantly reduced in 1-MCP-treated fruit; this was especially observed for different acetate esters, ethanol and butanol. Despite the reduction in aroma volatiles, a consumer panel could not distinguish (in a Tetrad Test) between samples from untreated and 1-MCP-treated fruit with similar firmness. This indicates that the important aroma volatiles, although reduced in abundance, were still above threshold levels and did not affect overall flavour perception. We conclude that 1-MCP does not affect flavour when pears within equal firmness classes are compared.
Linciano P. - One of the best experts on this subject based on the ideXlab platform.
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Isolation of a High-Affinity Cannabinoid for the Human CB1 Receptor from a Medicinal Cannabis sativa Variety: Δ9-Tetrahydrocannabutol, the Butyl Homologue of Δ9-Tetrahydrocannabinol
'American Chemical Society (ACS)', 2020Co-Authors: Linciano P., Citti C., Luongo L., Belardo C., Maione S., Vandelli M. A., Forni F., Gigli G., Lagana A., Montone C. M.Abstract:The butyl homologues of \u3949-tetrahydrocannabinol, \u3949-tetrahydrocannabutol (\u3949-THCB), and cannabidiol, cannabidibutol (CBDB), were isolated from a medicinal Cannabis sativa variety (FM2) inflorescence. Appropriate spectroscopic and spectrometric characterization, including NMR, UV, IR, ECD, and HRMS, was carried out on both cannabinoids. The chemical structures and absolute configurations of the isolated cannabinoids were confirmed by comparison with the spectroscopic data of the respective compounds obtained by stereoselective synthesis. The butyl homologue of \u3949-THC, \u3949-THCB, showed an affinity for the human CB1 (Ki = 15 nM) and CB2 receptors (Ki = 51 nM) comparable to that of (-)-trans-\u3949-THC. Docking studies suggested the key bonds responsible for THC-like binding affinity for the CB1 receptor. The formalin Test in vivo was performed on \u3949-THCB in order to reveal possible analgesic and anti-inflammatory properties. The Tetrad Test in mice showed a partial agonistic activity of \u3949-THCB toward the CB1 receptor
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Isolation of a High-Affinity Cannabinoid for the Human CB1 Receptor from a Medicinal Cannabis sativa Variety: Δ9-Tetrahydrocannabutol, the Butyl Homologue of Δ9-Tetrahydrocannabinol
'American Chemical Society (ACS)', 2020Co-Authors: Linciano P., Citti C., Luongo L., Belardo C., Maione S., Vandelli M. A., Forni F., Gigli G., Lagana A., Montone, Carmela MariaAbstract:The butyl homologues of Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabutol (Δ9-THCB), and cannabidiol, cannabidibutol (CBDB), were isolated from a medicinal Cannabis sativa variety (FM2) inflorescence. Appropriate spectroscopic and spectrometric characterization, including NMR, UV, IR, ECD, and HRMS, was carried out on both cannabinoids. The chemical structures and absolute configurations of the isolated cannabinoids were confirmed by comparison with the spectroscopic data of the respective compounds obtained by stereoselective synthesis. The butyl homologue of Δ9-THC, Δ9-THCB, showed an affinity for the human CB1 (Ki = 15 nM) and CB2 receptors (Ki = 51 nM) comparable to that of (-)-trans-Δ9-THC. Docking studies suggested the key bonds responsible for THC-like binding affinity for the CB1 receptor. The formalin Test in vivo was performed on Δ9-THCB in order to reveal possible analgesic and anti-inflammatory properties. The Tetrad Test in mice showed a partial agonistic activity of Δ9-THCB toward the CB1 receptor
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Isolation of a High-Affinity Cannabinoid for the Human CB1 Receptor from a Medicinal Cannabis sativa Variety: \u3949-Tetrahydrocannabutol, the Butyl Homologue of \u3949-Tetrahydrocannabinol
'American Chemical Society (ACS)', 2020Co-Authors: Linciano P., Citti C., Luongo L., Belardo C., Maione S., Vandelli M. A., Forni F., Gigli G., Lagana A., Montone C. M.Abstract:The butyl homologues of \u3949-tetrahydrocannabinol, \u3949-tetrahydrocannabutol (\u3949-THCB), and cannabidiol, cannabidibutol (CBDB), were isolated from a medicinal Cannabis sativa variety (FM2) inflorescence. Appropriate spectroscopic and spectrometric characterization, including NMR, UV, IR, ECD, and HRMS, was carried out on both cannabinoids. The chemical structures and absolute configurations of the isolated cannabinoids were confirmed by comparison with the spectroscopic data of the respective compounds obtained by stereoselective synthesis. The butyl homologue of \u3949-THC, \u3949-THCB, showed an affinity for the human CB1 (Ki = 15 nM) and CB2 receptors (Ki = 51 nM) comparable to that of (-)-trans-\u3949-THC. Docking studies suggested the key bonds responsible for THC-like binding affinity for the CB1 receptor. The formalin Test in vivo was performed on \u3949-THCB in order to reveal possible analgesic and anti-inflammatory properties. The Tetrad Test in mice showed a partial agonistic activity of \u3949-THCB toward the CB1 receptor
