The effect of frequency of consumption of artificial sweeteners on sweetness liking by women

ABSTRACT:  Research into sweetness perception and preference thus far has demonstrated that sweetness preference is related not to the total sugar consumed by an individual but the amount of refined sugar ingested. Research has yet to be conducted, however, to determine whether a diet high in artificial sweeteners contributes to sweetness liking and preference with the same result as a diet high in sugar. The purpose of this research was to determine if such a relationship exists with regard to diets high in artificially sweetened beverages. Seventy-one female participants were recruited and screened for sweetener consumption in beverages. Sixty-four of these individuals were selected for sensory testing. All participants evaluated orange juice samples (ranging from 0% added sucrose to 20% added sucrose) for liking of sweetness using a 9-point hedonic scale. Based on screening survey data, participants were categorized according to sweetener consumption group (artificial sweetener consumers and natural sweetener consumers) and by overall sweetened beverage intake (low or high, regardless of sweetener type normally consumed). Sensory data were analyzed to compare sweetness liking in each of these groups. Significant differences in liking were observed, with individuals in the high sweetened beverage intake group preferring sweeter orange juice than those in the low-intake group. Categorization by sweetener type resulted in no significant differences between the groups, indicating that regardless of the type of sweetener consumed in a beverage, liking of sweetness will be influenced in the same manner.     

Discriminability and appropriateness of category scaling versus ranking methods to study sensory preferences in elderly

Two methods: the nine-point hedonic scale and hedonic ranking, have been compared for their discrimination power and appropriateness when studying hedonic responses in elderly. A group of 35 elderly subjects (aged 60–88) and a control group of 35 young adults (aged 20–25) participated in the comparison. Five samples of each of two commercial fruit juices (apple and orange) differing in sensory profiles served as test material. Generally hedonic discriminability in elderly was lower than in young subjects for both methods. Ranking appeared to be more discriminating for apple juice samples, where hedonic differences among samples were smaller (F sample_apple=8.80); for orange juice samples, of more pronounced hedonic differences (F sample_orange=17.24) both methods revealed equal discriminability. From simplicity of the task and “user friendliness” of the tasting procedure, hedonic ranking seems to have some advantages over nine-point hedonic scaling. Results obtained by both methods for both juices were significantly correlated for elderly as well as for young subjects. However, the strength of correlation (Spearman R value) in elderly was much lower (R_apple=0.2217; R_orange=0.2213) than in young (R_apple=0.4766; R_orange=0.4844). Repeatability of hedonic assessment of orange juice samples performed by elderly (n=27) 2 weeks after first evaluation for both methods was very good and did not show any advantage of one method over another.     

Sugar reduction in probiotic chocolate-flavored milk: Impact on dynamic sensory profile and liking

Reducing the sugar content of processed products has been claimed to be one of the most efficient strategies for decreasing sugar intake. The present work aimed at studying the influence of sugar reduction on the dynamic sensory profile and consumers' liking of probiotic chocolate-flavored milks using a novel temporal methodology, and to evaluate two alternatives (vanilla flavor and thaumatin) to attenuate the sensory changes caused by sugar reduction. Probiotic chocolate-flavored milks were formulated with different reductions in added sugar (0, 20, 40 and 60%). Vanilla flavor and thaumatin were added to the sugar-reduced samples at two concentrations. Samples were evaluated by trained assessors using Temporal check-all-that-apply (TCATA). Additionally, consumers evaluated the dynamic sensory profile of a subset of the samples using TCATA and indicated their overall liking using a 9-point hedonic scale. Results from the present work showed that the main effect of sugar reduction on the dynamic sensory profile of the probiotic chocolate-flavored milks was related to changes in sweetness, bitterness and thickness. A reduction in added sugar of 20% led to changes in sweetness intensity, which were perceived by both trained assessors and consumers. However, consumers' liking was not significantly affected by sugar reduction up to 40%. The addition of vanilla flavor at suprathreshold concentrations was not efficient in increasing sweetness perception in chocolate-flavored milks with the lowest sugar reduction percentage, suggesting that it may not be a feasible alternative for reducing sugar in this product category. These results suggest that in many situations sugar content of food products could be decreased without a relevant impact on consumers' sensory and hedonic perception.     

Patulin in domestic and imported apple-based drinks in Belgium: occurrence and exposure assessment

Apple-based beverages are regularly consumed by adults and children in Belgium. They are locally produced or imported from other countries. The apples used as starting material for these productions are frequently contaminated by mycotoxin-producing moulds and damaged during transport and handling. The current study was undertaken to investigate whether patulin (PAT) is present in the industrial or handicraft-made apple juices and ciders consumed by the Belgian population and to assess the population's exposure to this mycotoxin through apple-based drinks. Belgian (n = 29) and imported (14) apple juices as well as ciders (7) were assayed for PAT by high-performance liquid chromatography with ultraviolet light detection. PAT was detected respectively in 79, 86 and 43% of these tested samples. However, no contaminated sample exceeded the safe level of 50 µg PAT l^-1. Levels of PAT contamination were comparable in Belgian and imported juice samples. The overall mean PAT concentrations were 9.0 and 3.4 µg l^-1 for contaminated apple juices and ciders, respectively. This study also indicates that there was no statistically significant difference in the mean PAT contamination between clear (7.8 µg l^-1) and cloudy (10.7 µg l^-1) apple juices, as well as between handicraft-made apple juices (14.6 µg l^-1) and industrial ones (7.0 µg l^-1). On the basis of the mean results, a consumer exposure assessment indicates that a daily intake of 0.2 litres apple juice contributes to 45% of the provisional maximum tolerable daily intake for a child of 10 kg body weight.     

Dietary habits and the perception and liking of sweetness among Australian and Malaysian students: A cross-cultural study

This study examined whether the perception of, and preference for, varying levels of sucrose in water, orange juice, custard and biscuit were related to dietary intakes of sugar and sweet foods in 69 Caucasian Australian and 63 Malaysian university students living in Australia. The two ethnic groups were equally able to discriminate the relative differences in sucrose concentration among the test samples, and a similar percentage of each group were sweetness likers or dislikers. Some significant differences between the ethnic groups' sweetness intensity and preference ratings were observed, but the differences were food-specific and were not always apparent for the same sucrose level in the different test foods. Within each ethnic group, more subjects had greater difficulty discriminating different sucrose levels in a solid, high fat biscuit. The Australian group had higher mean liking ratings than the Malaysian group for the orange juice and biscuit samples. However, both groups preferred similar levels of sucrose in the juice, custard and biscuit, which were similar to the amounts of sucrose present in current commercial products. The hedonic response pattern to the sucrose solution was not a good predictor of the hedonic responses to the other test stimuli, which indicates that preferred levels of sweetness are food-specific. Sweetness intensity ratings were not significantly associated with any of the dietary intake variables or bitterness ratings to 6-n-propylthiouracil. However, subjects who preferred higher levels of sucrose in the test stimuli tended to have higher dietary intakes of sugar and sweet foods.     

Application of a written scenario to evoke a consumption context in a laboratory setting: Effects on hedonic ratings

Consumer hedonic testing of products is typically conducted under controlled sensory laboratory conditions. This setting does not accurately represent how food and drink are consumed. Literature demonstrates that consumer hedonic ratings elicited in the natural consumption context differ to those elicited under controlled conditions. This suggests that when removing a product from its natural consumption context, accurate hedonic ratings may not be obtained. The interest of this research was to develop an approach that evokes a consumption context in the sensory laboratory and study its impact on hedonic ratings. A written scenario was developed that was effective at making participants imagine an occasion when they desired a refreshing beverage. Consumer hedonic ratings of four apple juice samples elicited using the evoked consumption context (context condition) were compared to those elicited in a control condition (i.e., no evoked context). Differences in mean hedonic ratings of the samples were observed between the two conditions with greater sample discrimination observed for the evoked context condition. Consumers using the evoked context found it easy to indicate their product liking/disliking, and felt that the liking information they provided was accurate, more so than consumers in the control setting. Sensory practitioners need to be aware of the potential use of an evoked context in a control setting for eliciting product hedonic ratings, and understand its impact on mean hedonic ratings.     

Modeling the combined effects of pH, temperature and ascorbic acid concentration on the heat resistance of Alicyclobacillus acidoterrestis

In this study, thermal inactivation parameters (D- and z-values) of Alicyclobacillus acidoterrestris spores in McIlvaine buffers at different pH, apple juice and apple nectar produced with and without ascorbic acid addition were determined. The effects of pH, temperature and ascorbic acid concentration on D-values of A. acidoterrestris spores were also investigated using response surface methodology. A second order polynomial equation was used to describe the relationship between pH, temperature, ascorbic acid concentration and the D-values of A. acidoterrestris spores. Temperature was the most important factor on D-values, and its effect was three times higher than those of pH. Although the statistically significant, heat resistance of A. acidoterrestris spores was not so influenced from the ascorbic acid within the concentration studied. D-values in apple juice and apple nectars were higher than those in buffers as heating medium at similar pH. The D-values ranged from 11.1 (90 °C) to 0.7 min (100 °C) in apple juice, 14.1 (90 °C) to 1.0 min (100 °C) in apple nectar produced with ascorbic acid addition, and 14.4 (90 °C) to 1.2 min (100 °C) in apple nectar produced without ascorbic acid addition. However, no significant difference in z-values was observed among spores in the juices and buffers at different pH, and it was between 8.2 and 9.2 °C. The results indicated that the spores of A. acidoterrestris may survive in fruit juices and nectars after pasteurization treatment commonly applied in the food industry.     

Effects of an evoked refreshing consumption context on hedonic responses to apple juice measured using best–worst scaling and the 9-pt hedonic category scale

Awareness of the need to consider a product’s consumption context when measuring consumer hedonic response of a product is increasing among consumer sensory researchers. This study investigated the effects of evoking a consumption context using a written scenario on hedonic response measured using best–worst scaling and the 9-pt hedonic category scale. Hedonic responses for four apple juices with relatively large sensory differences were compared when measured in the evoked context ‘when having something refreshing to drink’ using best–worst hedonic scaling (n = 65) and the 9-pt hedonic scale (n = 48). Best–worst scaling discriminated between the four apple juices when a refreshing context was evoked (p < 0.01), while the juices were equally liked using the 9-point scale (p = 0.41) when the same context was evoked. Consumers perceived best–worst scaling to be more difficult than the 9-pt scale, however there was no difference between the two methods for consumers perceived accuracy of their liking information. The present study highlights that the effect of an evoked context on hedonic response may not be universal for hedonic methods. Further research is needed to understand the effect of evoking context on the liking of products, and to determine whether this measure reflects product liking in an actual consumption context.     

Acceptance of sugar reduction in flavored yogurt

To investigate what level of sugar reduction is accepted in flavored yogurt, we conducted a hedonic test focusing on the degree of liking of the products and on optimal sweetness and aroma levels. For both flavorings (strawberry and coffee), consumers preferred yogurt containing 10% added sugar. However, yogurt containing 7% added sugar was also acceptable. On the just-about-right scale, yogurt containing 10% sugar was more often described as too sweet compared with yogurt containing 7% sugar. On the other hand, the sweetness and aroma intensity for yogurt containing 5% sugar was judged as too low. A second test was conducted to determine the effect of flavoring concentration on the acceptance of yogurt containing 7% sugar. Yogurts containing the highest concentrations of flavoring (11% strawberry, 0.75% coffee) were less appreciated. Additionally, the largest percentage of consumers perceived these yogurts as “not sweet enough.” These results indicate that consumers would accept flavored yogurts with 7% added sugar instead of 10%, but 5% sugar would be too low. Additionally, an increase in flavor concentration is undesirable for yogurt containing 7% added sugar.     

Chemical-Sensory Characteristics and Consumer Responses of Blackcurrant Juices Produced by Different Industrial Processes

Four blackcurrant juices were produced in industrial scale to study the impact of different processes on the sensory-chemical characteristics and hedonic responses of consumers. Two juices were produced without enzymatic treatment of berries with or without further clarification and filtration. The residue was re-pressed using an enzyme-aided processing method to yield the third juice. The forth juice was obtained by conventional enzymatic processing of berries. The enzyme-aided juices were more astringent and bitter than the non-enzymatic juices, mostly due to higher contents of phenolic compounds, lower contents of sugars, and lower pH and sugar/acid ratio. Higher degree of polymerisation and lower procyanidin/prodelphinidin ratio in proanthocyanidins also contributed to higher intensities of astringencies of the enzyme-aided juices. Overall, the non-enzyme-aided juices received higher ranking in flavour, the enzyme-aided juices in odour. Sweetness, roundness, berryness, and high-sugar content were positive drivers for liking, whereas astringency, bitterness and high content of phenolic compounds were negative drivers. High-pectin content masked the astringency and bitterness of the juices. Higher liking ratings correlated with the previous consumption of blackcurrants and higher age of consumers. Gender showed clear impact on consumer rating of the juices. Males liked more enzyme-aided juices than females and vice versa with the juices produced without the use of enzymes. The processes investigated by this study maybe optimised for commercial production of juices targeted for different consumer groups.     

Comparison of two sugar reduction strategies with children: Case study with grape nectars

Excessive sugar consumption has been identified as the main dietary determinants of obesity among children and adolescents. Sugar sweetened beverages are one of the main sources of added sugar in the diet. Therefore, gradual sugar reduction in these products can contribute to decreasing sugar intake and encourage children to slowly develop preference for products with lower sugar concentration. However, specific recommendations on how to implement gradual sugar reduction programs are still lacking. The aim of the present study was to compare two sugar reduction strategies (stepwise vs. gradual) on children’s sensory and hedonic perception of grape nectar. One hundred and seventeen 6–12 years old children participated in a two-part study: a 9-week study and a final liking test at the end of 11 weeks. In the 9-week study, children were divided in two sugar reduction strategies: stepwise and gradual. Children’s sensory and hedonic perception was evaluated using 9-point hedonic scales and check-all-that-apply questions. There were no major differences between the gradual and stepwise reduction groups in children’s sensory and hedonic perception. However, results showed that the gradual reduction strategy led to smaller changes in children’s sensory and hedonic perception than the stepwise strategy. In the final test, children in the stepwise group gave significantly higher liking scores to the samples than those in the gradual sugar reduction strategy. Comparing the overall liking between the first time the children tasted the grape nectars and the final test, a significant difference was observed for the sample with lower sugar content only for the stepwise group, which was higher in the 11th week. Although differences between the sugar reduction strategies were small, the gradual reduction strategy seems to be recommended over the step-wise strategy.     

PSYCHOPHYSICAL AND PSYCHOMETRIC EVALUATION OF COMMERCIAL APPLE JUICES

Psychophysical and psychometric relationships of five commercial apple juices were evaluated. Sugar content of apple juices ranged from 9.6 to 10.6%, acid content from 0.40 to 0.51% and phenolic content from 0.12 to 0.23%. Sweetness intensity (log) correlated with sugar content (r = 0.92), sourness intensity (log) with acid content (r = 0.93) and sugar-acid ratio (r = 0.92), and bitter/astringent taste (log) with phenolic content (r = 0.95) and the acid content (r = 0.91). The expected correlation between sweetness intensity and sugar acid ratio was absent. Preference (like/dislike) scores for thefive brands of apple juices were significantly different at p < 0.05 and ranged from 5.70 to 7.90. Preference did not correlate with any chemical contents, ratios or sensory intensities. Preference for apple juice was adequately described by multivariate equations combining aroma intensity either with sugar content (r²= 0.91) or sweetness intensity (r²= 0.99).     

Preference for salt in a food may be alterable without a low sodium diet

In response to current efforts to reduce population-wide dietary salt intake, the objective of this study was to determine whether liking for reduced sodium and low sodium tomato juice could increase following repeated exposure over an extended period. Eighty-three adult subjects participated in a three-part study: an initial taste test, a 16-week longitudinal study, and a final taste test. Subjects gave liking ratings of four tomato juice samples ranging in sodium from 640 mg (a concentration comparable to a commercially available product) to 136 mg per 237 ml serving (a low sodium concentration) at both taste tests. For the longitudinal study, subjects were divided into two balanced groups based on PROP sensitivity, hedonic sensitivity to salt, and motivation to reduce dietary salt intake; the abrupt group received tomato juice reduced in sodium to reach a low sodium target at week four, and the gradual group received juice reduced in sodium via difference thresholds to reach the same target at week 14. Though liking for the juice with the highest salt content was unchanged between taste tests, liking for all reduced salt juices increased at the final taste test relative to the initial taste test among subjects in both salt reduction groups. In addition, subjects in both groups experienced a downward shift in preference for salt in tomato juice, indicating that repeated exposure may be sufficient to alter preference for salt in a food in the absence of a low sodium diet. That salt preference may be altered by exposure alone within the context of a high salt diet is promising for both the food industry and individual consumers.     

Effects of pulsed electric field treatment of apple mash on juice yield and quality attributes of apple juices

The influence of apple mash treatment with pulsed electric fields (PEF) on yield and quality attributes of the resulting cloudy juices were investigated. Apple juice was produced at laboratory scale (400 g apples per lot) by mash treatment with pulsed electric fields at three different field intensities (1, 3, 5 kV/cm, n = 30 pulses) and manual pressing at room temperature. The juices were compared with untreated control juices of the same mash and with a juice after pectolytic mash treatment. Relative to the control samples, juice yield increased with increasing field intensities. The overall composition as described by pH, total soluble solids, total acidity, density, contents of sugar, malic acid and pectin, respectively, as well as the nutritive value with respect to polyphenol contents and antioxidant capacities (TEAC, FRAP, DPPH) of the PEF-treated apple juices did not significantly differ from the controls.Industrial relevanceThis paper addresses the composition of apple juice after mash treatment applying pulsed electric fields and maceration enzymes, respectively. Since substantial equivalence of products derived from novel technologies, such as PEF, relative to their conventionally produced counterparts is required according to European food law, this aspect is of great relevance, especially for commercialisation of fruit juices based on PEF technology. Furthermore, the nutritional value of juices produced at different pulsed electric field activities is of relevance for their marketing.     

Sensory quality and compositional characteristics of blackcurrant juices produced by different processes

Effects of enzymatic and non-enzymatic juice pressing on key orosensory and chemical quality factors of blackcurrant juices were studied in laboratory scale using berries of five different cultivars (Mortti, Mikael, Marski, Ola and Breed15). Enzymatic processing increased the juice yield by 10–22% and the content of various phenolic compounds in juice by 4–10-fold as compared to the non-enzymatic process. Higher intensity of the mouth-drying astringency of the enzyme-aided juice was the most significant orosensory difference between the processes. Juices of different blackcurrant cultivars varied in sweetness, sourness and bitterness. The most intensive sensory attributes of the juices were sourness and puckering astringency regardless of processing method. They correlated positively with each other and were contributed by acid content and pH. In enzyme-aided juices, the contents of flavonol glycosides and hydroxycinnamic acids were associated with mouth-drying astringency, and sugar/acid ratio correlated with sweetness. These correlations were less clear in non-enzyme juices possibly due to lower content of phenolic compounds and the high content of pectin.     

N-methyl carbamate concentrations and dietary intake estimates for apple and grape juices available on the retail market in Canada.

Infants and young children consume fruit juices and drinks at rates exceeding those of older children and adults. Carbamate pesticides are known to be used on a broad spectrum of crops, including orchard and vine crops such as apples and grapes. Concern over potential exposure to these acutely toxic pesticides by infants and young children has increased in the last decade. Liquid chromatography with fluorescence detection was used to determine the concentrations of seven N-methyl carbamates and three transformation products in domestic and imported apple and grape juices collected across Canada. Carbaryl was the most frequently (58.6%) detected N-methyl carbamate in juice samples studied. It was observed more frequently in grape juices than in apple or mixed juices. Oxamyl and methomyl were detected in apple juice samples, although they were below detection limits in all grape and mixed juice samples analysed. Maximum levels of carbaryl, methomyl and oxamyl were 93, 6.7 and 4.6 ng ml(-1), respectively. All other analytes were not present in any juice sample at concentrations above the method detection limit (0.3 ng ml(-1)). In all cases, N-methyl carbamate residues were well below the maximum residue limit established for apples and grapes in the Canadian Food and Drug Regulations. No estimated dietary intakes were above the acceptable daily intakes in any age-sex category, where an acceptable daily intake has been proposed. Carbaryl short-term intake estimates were calculated and all were below the proposed acute reference doses.     

Consumer responses to an off-flavor in juice in the presence of specific health claims

Adult US subjects (n=78) tasted and rated three juice samples containing 0, 0.3, and 0.6% KCl blind and informed. Three subgroups were informed that the juices contained functional ingredients to improve either (1) physical endurance and energy (2) mental alertness and memory, or (3) mood and emotional well-being. A control group received no information. Degree of liking and likelihood of consuming the juice once, twice or four times a day, for a total of four or 16 times, were rated. Adulteration with KCl decreased all ratings of liking, while information about health benefits increased ratings of liking in subgroups 1 and 2. Likelihood of consumption decreased with increasing KCl, with the increasing number of times per day, and with total dose regimen. The data suggest that the consumption of a functional food will be inversely related to the severity of off-flavor and to the required frequency and duration of consumption. No support was found for the notion that a slight off-flavor is a positive marker of health benefits to consumers.     

A longitudinal comparison of two salt reduction strategies: Acceptability of a low sodium food depends on the consumer

In their 2010 publication, Strategies to Reduce Sodium Intake in the United States, the Institute of Medicine suggested the FDA mandate salt reduction at the food industry level via a strategy of gradual, step-wise decline. The objective of this study was to compare the acceptability trajectories of a gradual to an abrupt salt reduction strategy of a high sodium food, and to determine if these trajectories were impacted by an individual’s hedonic sensitivity to salt and/or motivation to reduce dietary salt intake. Eighty-three subjects participated in a three-part study: an initial taste test, a 16-week longitudinal study, and a final taste test. At the initial and final taste tests, subjects indicated liking of tomato juice at four salt concentrations ranging from 136 mg sodium/serving (low sodium) to 640 mg sodium/serving (comparable to a commercially available product). To create two groups for the 16-week study, subjects were balanced for 6-n-propylthiouracil sensitivity, motivation to reduce dietary salt intake, and hedonic sensitivity to salt (the difference in liking between the highest and lowest salt concentrations in tomato juice served at the initial taste test). One group received juice abruptly reduced in salt at week 4 to a target low sodium level; the second group received juice gradually reduced in salt via difference threshold steps determined in a preliminary study (cumulating reductions of 12% each), to reach the target at week 14. We observed no overall difference in liking for low sodium juice at the end of the study as a result of salt reduction strategy; however, the trajectory of liking ratings over time differed between groups. Gradual salt reduction was more effective than the abrupt salt reduction because the abrupt reduction was accompanied by a large immediate drop in liking whereas the gradual reduction better maintained acceptability throughout the process. Subjects with low hedonic sensitivity responded favorably to both salt reduction strategies and would likely have no difficulty in adjusting to the taste of reduced salt foods. However, subjects with high hedonic sensitivity disliked reduced salt juice at some point during the study, regardless of strategy, and would likely have difficulty in adjusting to the taste of reduced salt foods.     

Effects of tangential microfiltration and pasteurisation on the rheological,microbiological, physico‐chemical and sensory characteristics of sugar cane juice

The aim of this study was to determine the physico‐chemical, microbiological, rheological and sensory characteristics of sugar cane juice with passion fruit pulp (5% w/w) added and which had been submitted to microfiltration and pasteurisation (90 °C/30 s; 95 °C/30 s) processes. The results showed that the juices obtained after the microfiltration and pasteurisation processes had low microbial counts. The microfiltered juice showed a reduction in the soluble solids, acidity and vitamin C content (P = 0.05), while the pasteurised juice showed no change in these parameters (P > 0.05) in relation to the natural sugar cane juice, with the exception of vitamin C, which was not detected after the thermal treatment. In relation to the rheological properties, Newtonian behaviour was observed for both microfiltered and pasteurised juices. The sensory tests on a hedonic scale showed good acceptance of both juices (microfiltered and pasteurised).