Cheddar cheese : Its texture, chemical composition and rheological properties.

Procedures associated with Quantitative Descriptive Analysis were used to identify and subsequently train a panel to quantify the perceived textural attributes of Cheddar cheese. Seventeen types of Cheddar were assessed by the panel for creaminess, crumbliness (fingers), crumbliness (chewing), firmness, graininess, hardness (first bite), hardness (cutting), and springiness. Cluster and Principal Component analyses of the sensory data revealed that the cheese samples could be subdivided into young, mature and extra mature Cheddars in terms of the textural attributes measured. The panel was also able to distinguish between the low fat and genuine Cheddars.The percentage fat, moisture and salt contents and the pH level of the seventeen Cheddar samples were established. An inverse correlation between fat and moisture content and a positive correlation between pH level and salt content were observed. The rheological properties were measured using three tests performed on an Instron Universal Testing Machine - a compression test, a cutting test and a stress relaxation test - and, where appropriate, were reported in terms of true stress and true (Hencky) strain curves. The viscoelastic properties of Cheddar observed during stress relaxation tests were modeled using a Generalised Maxwellian model consisting of two exponential elements and a residual term. Considerable variation in all the rheological properties was observed amongst the Cheddar samples. The rheological parameters did not distinguish between the samples to the same extent as the sensory assessment. However, Cluster Analysis of the rheological data did differentiate between the rheological profiles of the young (mild & medium) and the remaining mature/extra mature samples.The relationships between the textural attributes and the chemical and rheological parameters were investigated. No relationship between chemical composition and texture was identified, but correlations between the rheological parameters and the textural attributes were not uncommon. Multiple regression techniques were employed to construct mathematical models to predict the textural attributes from the rheological data. Successful models were constructed utilising parameters from the compression and cutting tests for all the attributes apart from creaminess. More precise models were constructed for firmness, springiness and crumbliness (fingers) where the action of the instrumental test from which the rheological parameters were obtained resembled the test method used by the panel.The chemical, textural and rheological properties of an English Cheddar were determined at various stages during its ripening period to investigate any changes that occurred. A slight increase in pH was the only chemical change recorded. Progressive changes in the majority of the textural attributes were observed. The most dramatic changes included a decrease in springiness and an increase in creaminess. A changing rheological profile was also observed during maturation, a decreasing strain at fracture being the most notable development. The sequence of changes in both the textural and rheological properties was divided into three fairly distinct phases, the initial stage reflecting the developments necessary before the cheese would be suitable for retail sale and the final stage including the development of the necessary textural attributes characteristic of a Mature English Cheddar. It was evident that the timing of the maturation period was pertinent to the development of textural attributes characteristic of particular maturities of Cheddar cheese. The textural attributes of the maturing Cheddar were also predicted at each stage of maturation using the mathematical models constructed in the initial study. Accurate predictions were made for all the attributes except crumbliness (chewing) and graininess

The impact of hop bitter acid and polyphenol profiles on the perceived bitterness of beer

Thirty-four commercial lager beers were analysed for their hop bitter acid, phenolic acid and polyphenol contents. Based on analytical data, it was evident that the beers had been produced using a range of different raw materials and hopping practices. Principal Components Analysis was used to select a sub-set of 10 beers that contained diverse concentrations of the analysed bitter compounds. These beers were appraised sensorially to determine the impacts of varying hop acid and polyphenolic profiles on perceived bitterness character. Beers high in polyphenol and hop acid contents were perceived as having ‘harsh’ and ‘progressive’ bitterness, whilst beers that had evidently been conventionally hopped were ‘sharp’ and ‘instant' in their bitterness. Beers containing light-stable hop products (tetrahydro-iso-α-acids) were perceived as ‘diminishing’, ‘rounded’ and ‘acidic’ in bitterness. The hopping strategy adopted by brewers impacts on the nature, temporal profile and intensity of bitterness perception in beer

The effect of consumption context on consumer hedonics, emotional response and beer choice

The context of a consumer test affects participant response. Data collected in a sensory laboratory is likely to have little predictive value of consumer experience in real-life situations. This study determined the effects of context on consumer response to two commercial beers. Regular beer consumers (n=100) rated liking and emotional response using ten beer-specific emotion categories for two beers (Lager and Ale) under three different conditions: (1) a sensory testing facility (Lab), (2) a natural consumption environment (Bar) and (3) using an evoked context (Evoked). Their choice of product to take home was also recorded. Overall results showed significant product differentiation for liking (F (99, 2, 1) = 8.46, p = 0.004) and product choice (Q (1, N = 100) = 4.85, p = 0.028) in the Bar but not in the Lab or Evoked context. Emotional variables highlighted significant product differentiation (p < 0.05) but more so in the Bar than in the Lab or Evoked context. However, clustering participants on liking revealed three distinct clusters differing in sensitivity to context. Two clusters showed opposing but consistent preference for one of the two products regardless of context. The third cluster was more influenced by context, showing a more discriminating response in the Bar. These findings showed that consumers differ in their degree of context-sensitivity and the extent to which evoking a context gives similar results to a real environment. They also highlighted the importance of segmentation and confirmed the added insights gained by measuring emotional response compared to liking

Perceived bitterness character of beer in relation to hop variety and the impact of hop aroma

The impact of hop variety and hop aroma on perceived beer bitterness intensity and character was investigated using analytical and sensory methods. Beers made from malt extract were hopped with 3 distinctive hop varieties (Hersbrucker, East Kent Goldings, Zeus) to achieve equi-bitter levels. A trained sensory panel determined the bitterness character profile of each singly-hopped beer using a novel lexicon. Results showed different bitterness character profiles for each beer, with hop aroma also found to change the hop variety-derived bitterness character profiles of the beer. Rank-rating evaluations further showed the significant effect of hop aroma on selected key bitterness character attributes, by increasing perceived harsh and lingering bitterness, astringency, and bitterness intensity via cross-modal flavour interactions. This study advances understanding of the complexity of beer bitterness perception by demonstrating that hop variety selection and hop aroma both impact significantly on the perceived intensity and character of this key sensory attribute

Measuring consumer emotional response and acceptance to sustainable food products

© 2020 Elsevier Ltd With current global challenges such as population growth, climate change and water scarcity, it is critical to develop sustainable strategies to achieve food security. One way to tackle this is by developing new products that use alternative and more sustainable ingredients. Bambara groundnut is a low-impact African legume as it can be grown on marginal soils and is resistant to high temperatures. The aim of this study was to investigate UK consumer acceptability and emotional response to snack products containing Bambara groundnut flour as an alternative sustainable ingredient. A key objective was to understand the contribution that measuring emotional response would reveal. Additionally the impact of extrinsic information on consumer acceptability and emotional response to snack products was investigated by sharing information concerning Bambara groundnut's sustainability and nutritional credentials. 100 UK participants were recruited to evaluate two biscotti and two cracker products. For each category a standard product made from standard ingredients sourced commercially, and one made replacing some of standard flour with Bambara flour were obtained. For each sample, participants were asked to rate their overall liking and emotional response based on sensory properties of the product (the blind condition). Participants were invited back for a second session, where they were informed about global resource challenges, and the sustainable features and nutritional value of Bambara, and which products contained this as an ingredient (informed condition). Under the blind condition, no significant differences in overall liking were observed between standard and Bambara products, indicating UK consumers accept the sensory properties of products that contain Bambara flour. Interestingly, the extrinsic information shifted consumer emotional response towards more positive emotions and less negative emotions when consuming products containing Bambara flour. It also made them felt less guilty when consuming the Bambara products, suggesting consumers engage with the idea of sustainable ingredients, and that this sustainable ingredient has potential for future new product development. It also highlighted the value of measuring emotional response for novel products to understand what may drive purchase behaviour when products are matched for liking. Food neophobia status did not impact product acceptability and emotional response between Bambara and standard products, however overall a lower emotional response was found for medium neophobic consumers in general who are more likely to evade novel products

The impact of PROP and thermal taster status on the emotional response to beer

With an increasingly competitive global market, understanding consumer emotional response to products can provide a different perspective to identify drivers of consumer food choice behaviour beyond traditional hedonic measurement. This study investigated how two taste phenotypes (Thermal taster status (TTS) and PROP taster status (PTS)) impacted liking and emotional response to beers varying in bitterness, carbonation and serving temperature. Volunteers (n = 60, balanced for TTS and PTS) were invited to express their liking and emotional response to 2 commercial beers of contrasting bitterness, presented at two different carbonation levels (commercial carbonation and low carbonation level) and served at two temperatures (cold and ambient). In general, when beers were served at their commercial carbonation level and at a cold temperature, they received higher liking scores and evoked more positive emotions and less negative emotions. Signficant temperature ∗ carbonation interactions were found for liking and some emotion categories. At commercial carbonation levels, cold beer was better liked and evoked more positive emotions than beer served at ambient temperature, but no such temperature effect was observed at the low carbonation level. Although the sample size was relatively small, significant effects for liking were observed for PTS but not TTS, suggesting PTS is a more influential factor regarding liking than TTS. However, thermal tasters (TT) rated 6 out of 10 emotion categories significantly higher for beer than thermal non-tasters (TnT), indicating emotional response may be more sensitive to capture the differences across taste phenotypes than liking, and that TT show increased negative emotions to beer in general. PROP supertasters (ST) rated some emotion categories significantly higher than non-tasters (NT) and, in contrast to TTS these were the more positive emotions, such as excited and content. This is the first study to report an impact of both TTS and PTS on emotional response. Furthermore, this study observed significant relative effects of TTS and PTS on emotional response, where the effect of PTS was more pronounced in TnT. This highlights the importance of investigating the combined effects of different phenotypes on consumer response representing the reality of different consumer segments

Impact of salt crystal size on in-mouth delivery of sodium and saltiness perception from snack foods

Fried, sliced potato crisps were flavored with sodium chloride of varying size fractions to investigate the impact of salt crystal size on the delivery rate of sodium to the tongue and resultant saltiness, measured over 65 s with a defined chew protocol (three chews, then holding the bolus in the mouth without swallowing). Salt crystal size impacted upon the delivery rate and perceived saltiness. The smallest crystal size fraction dissolved and diffused throughout the mouth to the tongue saliva faster than the medium and the largest ones; the smallest crystal size fraction also had the highest maximum concentration and greatest total sodium. These results correlated well with the sensory perceived saltiness, where the smallest crystal size fraction resulted in the fastest Tmax, highest maximum saltiness intensity and maximum total saltiness. The different delivery rates can be explained by differential dissolution kinetics and enhanced mass transfer of sodium across the saliva

Exploring the relationships between taste phenotypes, genotypes, ethnicity, gender and taste perception using Chi-square and regression tree analysis

© 2020 Elsevier Ltd It is well known that perceived taste intensity varies greatly among individuals, and that several factors including taste phenotypes (PROP Taster Status (PTS), Sweet Liking Status (SLS), Thermal Taster Status (TTS)), ethnicity and gender, contribute to variation in taste responsiveness, although such factors are usually investigated in isolation. This study aimed to investigate the association between different taste pheno/genotypes, explore whether these taste phenotypes associated with ethnicity (Caucasian vs Asian) and gender, and determine the relative effects of the different factors on perceived taste intensity. As analysis of this type of data with ANOVA can be difficult due to confounding factors, interactions, and small sample sizes in subcategories, the use of regression tree analysis as an alternative approach was investigated. To that end, two-hundred and twenty-three volunteers were phenotyped for their PTS, SLS and TTS and genotyped for TAS2R38 –rs713598 and gustin –rs2274333. They also rated their perceived intensity of five basic taste and metallic solutions on a gLMS scale. No significant association between the three taste phenotypes were found indicating PTS, SLS and TTS are independent taste phenotypes. However, the results indicated that Asians were not only more likely to be PROP supertasters, but also more likely to be thermal tasters or Low Sweet Likers, compared to Caucasians. Gender was also significantly associated with SLS, where males were more likely to be High Sweet Likers. For perceived taste intensity, traditional ANOVA analysis proved to be challenging. The alternative approach, using regression trees, was shown to be an effective tool to provide a visualised framework to demonstrate the multiple interactions in this dataset. For example, ethnicity was the most influencing factor for perceived sour and metallic taste intensity, where Asians had heightened response compared to Caucasians. The regression tree analysis also highlighted that the PTS effect was dependent on ethnicity for sour taste, and PTS and TTS effect was dependent on ethnicity for metallic taste. This study is the first study to use regression tree analysis to explore variation in taste intensity ratings, and demonstrated it can be an effective tool to handle and interpret complex sensory datasets

Effect of pulsed delivery and bouillon base on saltiness and bitterness perceptions of salt delivery profiles partially substituted with KCl

Reducing salt levels in processed food is an important target for a growing numbers of food manufacturers. The effects of pulsed delivery (Dynataste) and bouillon base on saltiness and bitterness perception of partially substituted solutions (KCl) were investigated. Pulsed delivery did not enhance salt perception and resulted in greater Overall Bitterness Scores for the same level of substitution with KCl. The presence of the bouillon base masked to a certain extent the loss of saltiness induced by the substitution and resulted in lower Overall Bitterness Scores of the substituted profiles