What Is Chalky? Investigating Consumer Language and Perception of Fine Particles in Beverages Containing Pea and Potato Starch.

Despite its importance as an undesirable food texture, the phenomenon of chalkiness remains understudied. Chalky sensations presumably arise from fine particulates found in foods, but semantic overlap with other common descriptors of small particles, like gritty or sandy, is unclear. Here, we compare the usage of Chalky with related descriptors, and determine the effect of particle size, concentration, and xanthan content on Chalky ratings in a model beverage. A 23 factorial design with starch particle size (D90 = 33.8 and 64.6 µm), starch concentrations (10 and 20% w/v), and xanthan content (0.075 and 0.15% w/v) was used. Participants' salivary flow rate was also assessed. A multi-sip taste test was performed where naïve consumers (n = 82; 39% men, 60% women; age range = 18-79 years) rated the intensity of Chalky, Powdery, Gritty, Sandy, Mouthdrying, and Residual mouthcoating at 0, 30, and 60 s after each of three consecutive sips. All attribute ratings were highly correlated, with Chalky, Powdery, and Residual Mouthcoating being more closely correlated with each other than Gritty or Sandy. Although Chalky was still reported 60 s after consumption, no evidence of build-up was found with repeated sips. A larger size and higher concentration increased Chalky ratings, with the low-salivary-flow group reporting greater ratings for Chalky relative to the high-flow group. Our results suggest consumer percepts of small particles are overlapping but not entirely redundant. This suggests researchers and product developers should carefully distinguish between these descriptors when trying to understand consumer perception of food products containing fine particles.

Sugar reduction in chocolate compound by replacement with flours containing small insoluble starch granules.

Consumer concern about intake of added sugars has increased commercial demand for sugar-reduced chocolates. However, substitution with high-potency sweeteners is not possible as sugar serves as an important bulking agent. Here, we investigated replacement of sucrose in chocolate compound with oat or rice flours, with starch granules smaller than 10 µm, focusing on texture, sweetness, and acceptability. In Study 1, six chocolates were made: a control with 54% sucrose, four sucrose-reduced versions (reductions of 25% or 50%, using either oat or sweet rice flour), and one 54% sucrose chocolate with reduced refining time. These chocolates were compared in a Difference from Control (DFC) test in a within-subject design, with and without nose clips. Particle size distribution, yield stress, and plastic viscosity were measured. Chocolates with 25% sucrose reduction by either sweet rice or oat flour (or reduced refining time) were not significantly different from the blind control (p > 0.05), regardless of nose clip use. In open-ended comments, participants reported differences in rice-flour-containing chocolates were due to a chalkier texture, while oat-flour-containing chocolates were described as smoother, softer, and creamier. DFC scores from the chocolates were positively correlated with plastic viscosity and negatively correlated with yield stress. In Study 2, 25% reduced sugar chocolates made with rice flour were liked significantly less than control, but the oat flour sample did not differ from control. Collectively, these results suggest up to 25% of sucrose in chocolate can be replaced with oat flour without negatively affecting texture or consumer acceptance.

Microscopic assessment of the degradation of millet starch granules by endogenous and exogenous enzymes during mashing.

The high gelatinization temperature (GT) of millet starch prevents the usage of infusion or step mashes as an effective means to generate fermentable sugars (FS) in brewing because the malt amylases lack thermostability at GT. Here, we investigate processing modifications to determine if millet starch can be efficiently degraded below GT. We determined that producing finer grists through milling did not introduce enough granule damage to markedly change gelatinization characteristics, though there was improved liberation of the endogenous enzymes. Alternatively, exogenous enzyme preparations were added to investigate their ability to degrade intact granules. At the recommended dosages (0.625 µL/g malt), significant FS concentrations were observed, although at lower concentrations and with a much-altered profile than possible with a typical wort. When exogenous enzymes were introduced at high (10×) addition rates, significant losses of granule birefringence and granule hollowing were observed well below GT, suggesting these exogenous enzymes can be utilized to digest millet malt starch below GT. The exogenous maltogenic α-amylase appears to drive the loss of birefringence, but more research is needed to understand the observed predominate glucose production.

Salivary α-amylase activity and flow rate explain differences in temporal flavor perception in a chewing gum matrix comprising starch-limonene inclusion complexes.

Starch-guest inclusion complexes (ICs) are a novel, clean-label flavor encapsulation system with the potential to improve stability of aroma volatiles. While amylase has been shown to modulate guest release in vitro, release by sensory perception has not been evaluated. Here, Temporal Check-All-That-Apply (TCATA) and CATA were used to compare flavor perception of starch-limonene ICs to uncomplexed limonene, and the differences in perception were explored as a function of participant salivary α-amylase activity (sAA) and salivary flow rate (sFR). High sFR levels decreased limonene perception while high sAA increased limonene perception, highlighting the potential influence of these physiological factors on flavor perception of foods. Temporal flavor perception of a chewing gum containing starch-limonene ICs and a second chewing gum containing uncomplexed limonene and corn starch (CTL) was evaluated by 99 untrained consumers who assessed taste, texture, and aroma attributes over 17 min by TCATA and CATA. In addition, participants were segmented into three clusters based on their sAA and sFR, and cluster TCATA curves for each sample and attribute were statistically compared. Overall, participants rated Citrus, Sour and Bitter (p < 0.05) significantly higher for the IC sample and rated Sweet higher for the CTL. For Citrus, Sour, and Bitter, significant differences were observed between the three clusters for the IC chewing gum, while the CTL gum showed no significant differences for these three attributes. We demonstrate that flavor perception of starch-guest ICs varies with participants' salivary α-amylase activity and flow rate. Additionally, TCATA and CATA were found to be well suited to characterize flavor release systems over a long period of time as multiple flavor percepts can be simultaneously tracked.

Design aspects of vaginal applicators that influence acceptance among target users.

Although sensory-guided product design is most traditionally used by food and beverage companies, the approach has widespread application for many other products, including pharmaceuticals and medical devices. Previously, our team used sensory methods to explore preclinical optimization of soft-gel vaginal microbicides. Past clinical trials suggest vaginal microbicides may be an effective means for women to protect themselves from HIV and other sexually transmitted infections, but these microbicides will not work if they are not used due to poor acceptability. Our prior work suggests properties like firmness, size, and shape all influence women's willingness to try soft-gel vaginal suppositories. As product insertion is part of the overall experience of using vaginal microbicides, understanding the features of vaginal applicators that appeal to women, and incorporating these insights into vaginal drug delivery systems, may also improve user adherence. Despite widespread use of vaginal applicators, there is minimal public data on women's perceptions of and preferences for physical applicator features. Other work suggests women want vaginal applicators that are single use, pre-filled, made of plastic, and easy to use, store, and discard. Applicator attributes that may be important to women, such as length, color, or visual appeal, have not been investigated previously. The objective of this research was to understand what physical applicator attributes are appealing to women. Here, 18 commercially available applicators were evaluated by a convenience sample of women (n = 102) for overall liking and perceptions of various attributes (perceived length and width, ease-of-grip, expected ease-of-use, expected comfort inside the body, visual appeal, color liking, and environmental friendliness). Preference mapping using both liking data and attribute data showed attributes such as color, visual appeal, ease of grip, expected ease of use, and expected comfort inside the body drove higher liking ratings for applicators, while perceived length negatively affected liking. In general, plastic tampon applicators contained more positive features and were better liked relative to a cardboard tampon applicator or applicators for insertion of medicated gels or suppositories. Incorporating more desirable features into applicators meant for insertion of vaginal microbicides or other vaginal medications may improve the user experience, and possibly user adherence.

Crystal and molecular structure of V-amylose complexed with ibuprofen.

Rectangular V-amylose single crystals were prepared by adding racemic ibuprofen to hot dilute aqueous solutions of native and enzymatically-synthesized amylose. The lamellar thickness increased with increasing degree of polymerization of amylose and reached a plateau at about 7 nm, consistent with a chain-folding mechanism. The CP/MAS NMR spectrum as well as base-plane electron and powder X-ray diffraction patterns recorded from hydrated specimens were similar to those of V-amylose complexed with propan-2-ol. Amylose was crystallized in an orthorhombic unit cell with parameters a = 2.824 ± 0.001 nm, b = 2.966 ± 0.001 nm, and c = 0.800 ± 0.001 nm. A molecular model was proposed based on structural analogies with the Vpropan-2-ol complex and on assumptions on the stoichiometry of ibuprofen. The unit cell would contain four antiparallel 7-fold amylose single helices with ibuprofen molecules distributed inside and between the helices.

Electrospinning of Octenylsuccinylated Starch-Pullulan Nanofibers from Aqueous Dispersions.

We aimed to develop a greener process for dry-electrospinning food-grade modified starch through the elimination of organic solvents. The rheological properties and electrospinnability of aqueous dispersions of commercial octenylsuccinylated (OS) starches with various molecular weight (Mw) were investigated, yet only nanofibers with beads or defects could be obtained from OS starch with the highest Mw, i.e., Purity Gum@ Ultra (PGU). Further improvement in the fiber morphology was achieved by adding pullulan (PUL) as a minor component in the spinning dope. Smooth, continuous, and bead-free nanofibers (147-250 nm) were obtained from the PGU-PUL dispersions. Shown on an electrospinnability map, the successful electrospinning of 12%, 15%, and 20% (w/v) aqueous PGU dispersions required a minimum addition of 6%, 5%, and 3% (w/v) of PUL, respectively. The addition of PUL contributed to establishing sufficient molecular entanglement for electrospinning. This study provides a promising green process to produce starch-based nanofibers for use in various applications, e.g., drug delivery, wound dressing, and tissue engineering.

Assessment of Midline Lingual Point-Pressure Somatosensation Using Von Frey Hair Monofilaments.

Detection and discrimination threshold estimates for oral point pressure are assessed using Von Frey Hair monofilaments. Consistent with previously published protocols, threshold estimates are determined using a two-interval forced choice (2-IFC) paradigm with a three down/one up approach. Detection threshold estimates determine the mean force in which a participant can identify the presence of pressure. During the detection threshold procedure, the participant is instructed to choose which of two sequentially presented observation intervals contained the tactile test stimulus. If the participant performs three correct detections in a row (i.e., 3 'hits'), the researcher decreases the stimulus to the next lower target force level. With one incorrect detection (a 'miss'), the researcher increases the force delivered to the next higher level. This threshold estimation approach is known as a 3-down/1-up adaptive staircase. Reponses are recorded on a paper ballot, and a participant's estimated threshold is defined as the geometric mean of five reversals. During the discrimination threshold procedure, the participant is asked to make a choice between two serially presented stimuli as to which is the "harder" or "stronger" pressure. The same scoring of 'hits', 'misses', and stopping points are used. Detection and discrimination testing for oral point pressure at tongue midline takes approximately 20 min to complete. Using these commercially-available clinical tools, individual touch sensation profiles for the midline tongue can be achieved in a relatively time and cost effective means.

Perseorangin: A natural pigment from avocado (Persea americana) seed.

High consumer demand has led global food color manufacturers and food companies to dramatically increase the development and use of natural colors. We have previously reported that avocado (Persea americana) seeds, when crushed in the presence of air, develop a red-orange color in a polyphenol oxidase-dependent reaction. The objective of this study was to identify the major colored compound in colored avocado seed extract (CASE). Column chromatography and high performance liquid chromatography were used to isolate the most abundant colored compound in CASE. This compound, henceforth referred to as perseorangin, was a yellow-orange solid. Structural analysis was performed using high-resolution mass spectrometry, and infrared and nuclear magnetic resonance spectroscopy. We determined that perseorangin is a glycosylated benzotropone-containing compound with a molecular formula of C29H30O14. Liquid chromatography with electrospray ionization mass spectrometry-based metabolomic analysis of CASE and uncolored avocado seed extract showed that perseorangin was unique to CASE.

In Vitro Antioxidant and Cancer Inhibitory Activity of a Colored Avocado Seed Extract.

Avocado (Persea americana) seeds have been used traditionally for a number of health-related indications. Because of its high polyphenol content, we investigated the potential antioxidant and anticancer effects of a colored avocado seed extract (CASE). CASE exhibited an oxygen radical acceptance capacity value of 2012 ± 300 trolox equivalents/mg. CASE reduced lipid hydroperoxide formation in an oil-in-water emulsion (33% reduction at 500 µg/mL). CASE dose-dependently reduced the viability of human breast (MCF7), lung (H1299), colon (HT29), and prostate (LNCaP) cancer cells in vitro. The half maximal inhibitory concentrations ranged from 19 to 132 µg/mL after treatment for 48 h. CASE treatment downregulated the expression of cyclin D1 and E2 in LNCaP cells. This was associated with cell G0/G1 phase cycle arrest. CASE also dose-dependently induced apoptosis in LNCaP cells. CASE reduced nuclear translocation of nuclear factor κB, a prosurvival signal. Further studies are needed to examine these effects in in vivo models.

Electrospun nanofiber mats from aqueous starch-pullulan dispersions: Optimizing dispersion properties for electrospinning.

A green method to fabricate starch-based nanofibers is provided. High-temperature (≈162 °C) was used to destructure high-amylose starch in water. Sodium palmitate was added to enhance the stability of high-amylose starch in water at room temperature and increase the conductivity of the electrospinning dope. Flow properties and zeta potential of starch-palmitate dispersions were characterized by rheometer and dynamic light scattering, respectively. Pullulan was mixed in as a minor component of the starch-palmitate complex (starch:pullulan at a ca. 2:1 ratio) and the mixture electrospun. Pullulan hindered starch association and modified the dispersion properties, promoting molecular entanglement without gelation. The presence of sodium palmitate-starch inclusion complexes in the fiber was confirmed by differential scanning calorimetry and X-ray diffraction. Tensile strength of the nanofiber composite was found to be weaker than that of micro-sized pure starch fiber mats. This method provides future industry with lower cost by eliminating the use of organic chemicals.

Oral somatosensatory acuity is related to particle size perception in chocolate.

Texture affects liking or rejection of many foods for clinically relevant populations and the general public. Phenotypic differences in chemosensation are well documented and influence food choices, but oral touch perception is less understood. Here, we used chocolate as a model food to explore texture perception, specifically grittiness perception. In Experiment 1, the Just Noticeable Difference (JND) for particle size in melted chocolate was ~5 µm in a particle size range commonly found in commercial chocolates; as expected, the JND increased with particle size, with a Weber Fraction of ~0.17. In Experiment 2, individual differences in touch perception were explored: detection and discrimination thresholds for oral point pressure were determined with Von Frey Hairs. Discrimination thresholds varied across individuals, allowing us to separate participants into high and low sensitivity groups. Across all participants, two solid commercial chocolates (with particle sizes of 19 and 26 µm; i.e., just above the JND) were successfully discriminated in a forced-choice task. However, this was driven entirely by individuals with better oral acuity: 17 of 20 of more acute individuals correctly identified the grittier chocolate versus 12 of 24 less acute individuals. This suggests phenotypic differences in oral somatosensation can influence texture perception of foods.

Qualitative exploration of intrinsic and extrinsic factors that influence acceptability of semisoft vaginal suppositories.

BACKGROUND: Vaginal microbicides are a promising means to prevent the transmission of HIV and other sexually transmitted infections, by empowering women to initiate use prophylactically when they perceive themselves to be at risk. However, in clinical trials, microbicides have shown mixed results, with the consistent finding that effectiveness varies substantially as a function of user adherence. METHODS: Based on the assumption that adherence is driven, at least in part, by product properties that influence acceptability, we used softgel technology to develop vaginal drug delivery systems in the intermediate texture space between solids and liquids to overcome potential shortcomings of current dosage forms. Here, we used focus groups and surveys to determine women's initial reactions (i.e., acceptance and willingness-to-try) for semisoft vaginal suppositories intended for HIV and STI prevention, with a specific focus on how perception of and preferences for vaginal suppositories may be influenced by product characteristics such as size, shape, and firmness. RESULTS: Via focus groups, we identified intrinsic and extrinsic factors relevant to acceptability of semisoft suppository prototypes. Willingness-to-try depended on factors like intended functionality, anticipated leakage, type of sex, recommended frequency of use, type of sexual partner, and perceived risk. When handled ex vivo, shape, size, and firmness of suppositories communicated information about ease of imagined insertion and handling, perceived effectiveness, anticipated awareness and comfort of the product in the body. These impressions were partly based on prior experience with vaginal products. CONCLUSIONS: Sensory attributes appear to play a substantial role in women's preferences and willingness to try the semisoft suppositories. Using these methods during preclinical development should help efficiently optimize a final product that is both biologically efficacious and preferred by women, toward a goal of enhancing adherence and effectiveness.

Inclusion complex formation between high amylose corn starch and alkylresorcinols from rye bran.

The formation of high amylose corn starch (HACS)-alkylresorcinol (AR) inclusion complexes was demonstrated using HACS and a crude AR extract from rye bran, and was confirmed by complementary characterization techniques. Inclusion complex was extracted using hot 2-propanol/water (3:1), and thirteen different AR homologs were identified in the 2-propanol/water extract. However, this extraction regime was insufficient to remove all guests from the inclusion complexes, but did result in annealing of the V-type crystallinity, yielding an endotherm with higher onset and peak temperatures and dissociation enthalpy. The remaining guest compounds were recovered by disruption of the inclusion complexes with DMSO followed by liquid-liquid extraction. A total of nine AR homologs were recovered and two saturated long alkyl chain AR homologs (C21:0 and C19:0) were obviously enriched in the complexes compared to the crude AR extract. The formation of HACS-AR inclusion complexes may have the potential to inhibit staling in baked goods.

Encapsulation and stabilization of ß-carotene by amylose inclusion complexes.

In the present study, we report a novel composition based on amylose (or starch) inclusion complex with an amphiphilic material as an effective encapsulation platform technology to incorporate guests of interest. Specifically, the encapsulation of ß-carotene in amylose-surfactant and amylose/starch-ascorbyl palmitate (AscP) inclusion complexes was investigated. Surfactants of different hydrophilicity/lipophilicity were selected to cover a broad range of HLB values. The formation of the inclusion complexes was characterized by X-ray diffraction and differential scanning calorimetry. The ability of amylose-surfactant system to encapsulate ß-carotene was dependent on the HLB value of the surfactants, instead of their ability to induce inclusion complexation. The incorporation of ß-carotene hindered amylose-surfactant inclusion complex formation, whereas no significant effect was observed on structural and thermal properties of starch-AscP inclusion complex in the presence of ß-carotene. The X-ray diffraction pattern of amylose-AscP-ß-carotene showed that ß-carotene molecules did not crystallize into a separated phase and thus were suggested to be homogeneously immobilized within the polycrystalline amylose-AscP inclusion complexes. During a storage period of six weeks at 20 and 30°C, the stability of ß-carotene was improved by encapsulation in starch-AscP inclusion complexes compared with that in physical mixtures of the three components.

Degree of free fatty acid saturation influences chocolate rejection in human assessors.

In foods, free fatty acids (FFAs) traditionally have been viewed as contributing an odor, yet evidence has accumulated that FFAs also contribute a unique taste ("oleogustus"). However, minimal work has been conducted using actual foods to test the contribution of FFA to taste preferences. Here, we investigate flavor, taste, and aroma contributions of added FFA in chocolate, as some commercial manufacturers already use lipolysis of triglycerides to generate unique profiles. We hypothesized that small added concentrations of FFAs would increase preferences for chocolate, whereas higher added concentrations would decrease preferences. We also hypothesized a saturated fatty acid (stearic C18) would have a lesser effect than a monounsaturated (oleic C18:1), which would have a lesser effect than a polyunsaturated (linoleic C18:2) fatty acid. For each, paired preference tests were conducted for 10 concentrations (0.04% to 2.25%) of added FFAs compared with the control chocolate without added FFAs. Stearic acid was tested for flavor (tasting and nares open), whereas the unsaturated fatty acids were tested for both aroma (orthonasal only and no tasting) and taste (tasting with nares blocked to eliminate retronasal odor). We found no preference for any added FFA chocolate; however, rejection was observed independently for both taste and aroma of unsaturated fatty acids, with linoleic acid reaching rejection at lower concentrations than oleic acid. These data indicate that degree of unsaturation influences rejection of both FFA aroma and taste in chocolate. Thus, alterations of FFA profiles in foods should be approached cautiously to avoid shifting concentrations of unsaturated fatty acids to hedonically unacceptable levels.

Innovative sensory methods to access acceptability of mixed polymer semisoft ovules for microbicide applications.

Vaginal microbicides are a promising means to prevent the transmission of HIV, empowering women by putting protection under their control. We have been using gel technology to develop microbicides in the intermediate texture space to overcome shortcomings of current solid and liquid forms. We recently formulated semisoft ovules from mixed polymer combinations of carrageenan and Carbopol 940P to overcome some of the flaws with our previous generation of formulations based solely on carrageenan. To determine the user acceptability of the reformulated gels, women first evaluated intact semisoft ovules before evaluating ovules that had been subjected to mechanical crushing to simulate samples that represent post-use discharge. Women then evaluated combinations of intact and discharge samples to understand how ovule textures correlated with texture of the resulting discharge samples. Carbopol concentration directly and inversely correlated with willingness to try for discharge samples and intact samples, respectively. When evaluating intact samples, women focused on the ease of inserting the product and preferred firmer samples; conversely, when evaluating discharge samples, softer samples that resulted in a smooth paste were preferred. Significant differences between samples were lost when evaluating pairs as women made varying trade-offs between their preference for ease of inserting intact ovules and acceptability of discharge appearance. Evaluating samples that represent different stages of the use cycle reveals a more holistic measure of product acceptability. Studying sensory acceptability in parallel with biophysical performance enables an iterative design process that considers what women prefer in terms of insertion as well as possibility of leakage.

Investigating Mixture Interactions of Astringent Stimuli Using the Isobole Approach.

Astringents (alum, malic acid, tannic acid) representing 3 broad classes (multivalent salts, organic acids, and polyphenols) were characterized alone, and as 2- and 3-component mixtures using isoboles. In experiment 1, participants rated 7 attributes ("astringency," the sub-qualities "drying," "roughing," and "puckering," and the side tastes "bitterness," "sourness," and "sweetness") using direct scaling. Quality specific power functions were calculated for each stimulus. In experiment 2, the same participants characterized 2- and 3-component mixtures. Multiple factor analysis (MFA) and hierarchical clustering on attribute ratings across stimuli indicate "astringency" is highly related to "bitterness" as well as "puckering," and the subqualities "drying" and "roughing" are somewhat redundant. Moreover, power functions were used to calculate indices of interaction (I) for each attribute/mixture combination. For "astringency," there was evidence of antagonism, regardless of the type of mixture. Conversely, for subqualities, the pattern of interaction depended on the mixture type. Alum/tannic acid and tannic acid/malic acid mixtures showed evidence of synergy for "drying" and "roughing"; alum/malic acid mixtures showed evidence of antagonism for "drying," "roughing," and "puckering." Collectively, these data clarify some semantic ambiguity regarding astringency and its subqualities, as well as the nature of interactions of among different types of astringents. Present data are not inconsistent with the idea that astringency arises from multiple mechanisms, although it remains to be determined whether the synergy observed here might reflect simultaneous activation of these multiple mechanisms.

Salivary protein levels as a predictor of perceived astringency in model systems and solid foods.

Salivary protein difference value (SP D-value) is a quantitative measure of salivary protein replenishment, which reportedly relates to individual differences in perceived astringency. This in vitro measure is calculated as the difference in total salivary protein before (S1) and after (S2) stimulation with tannic acid, with a greater absolute value (S2-S1) indicating less protein replenishment. Others report that this measure predicts perceived astringency and liking of liquid model systems and beverages containing added polyphenols. Whether this relationship generalizes to astringent compounds other than polyphenols, or to solid foods is unknown. Here, the associations between SP D-values and perceived astringency and overall liking/disliking for alum and tannic acid (experiment 1) as well as solid chocolate-flavored compound coating with added tannic acid or grape seed extract (GSE) (experiment 2) were examined. In both experiments, participants (n=84 and 81, respectively) indicated perceived intensity of astringency, bitterness, sweetness, and sourness, and degree of liking of either aqueous solutions, or solid chocolate-flavored compound coating with added astringents. Data were analyzed via linear regression, and as discrete groups for comparison to prior work. Three discrete groups were formed based on first and third quartile splits of the SP D-value distribution: low (LR), medium (MR), and high responding (HR) individuals. In experiment 1, significantly higher mean astringency ratings were observed for the HR as compared to the LR/MR groups for alum and tannic acid, confirming and extending prior work. In experiment 2, significantly higher mean astringency ratings were also observed for HR as compared to LR groups in solid chocolate-flavored compound containing added tannic acid or GSE. Significant differences in liking were found between HR and LR groups for alum and tannic acid in water, but no significant differences in liking were observed for chocolate-flavored compound samples. A significant linear relationship between SP D-values and perceived astringency was observed for both alum and tannic acid (p's<0.001), although the variance explained was relatively low (R(2)=0.33 and 0.29, respectively). In the solid chocolate-flavored compound spiked with either tannic acid or GSE, the relationship was not significant (p=0.17 and 0.30; R(2)=0.03 and 0.02, respectively). Due to the weak associations overall, and the lack of significant differences in perception of astringency between the MR and LR groups, we conclude that SP D-values are not a strong predictor of astringency, especially in solid, high-fat foods. Additional research investigating alternative methods for quantifying individual differences in astringency, as well as exploring the underlying complexities of this percept appears warranted.