Consumers' hedonic expectations and perception of the healthiness of biscuits made with olive oil or sunflower oil

Vegetable oils can be used as an alternative to solid fats to produce biscuits with a healthier fatty acid profile. The aim of this work was to study how consumers perceived the information about fat on biscuit labels when olive oil or sunflower oil was used instead of a saturated fat and how much the replacement affected acceptability. Six samples of biscuits were prepared, varying in fat source (dairy shortening, olive oil and sunflower oil) and in fat content (10.6 and 15.6%). Biscuit labels were designed to include the claims “with olive oil”, “with sunflower oil” or “low in saturated fat” and nutritional facts tables with the respective values that corresponded in each case. Consumers (n = 100) evaluated their liking for the samples and perception of their healthiness under three conditions: blind (the biscuit was provided), expected (the label was provided) and informed (both biscuit and label were provided). In general, consumers expected that they would like the olive and sunflower oil biscuits with low fat contents the most, although when they tasted the biscuits these samples obtained the lowest liking scores. Thus, they did not associate a low-fat vegetable-oil biscuit with a decrease in sensory properties compared to its high fat counterpart. Furthermore, when information on the fat source was provided the consumers seemed to attach less importance than they should have to the total fat level. Although the fat source claim (“with olive oil” or “with sunflower oil”) and the nutritional claim (“low saturated fat content”) included on the labels increased the consumers' liking scores, eventually both the sensory quality of the samples and the information provided affected the actual liking for the samples. However, the perception of the biscuits' healthiness was based on the label information alone and the hedonic characteristics of the samples did not affect it.     

Effect of Fat on Mechanical and Acoustical Properties of Biscuits Related to Texture Properties Perceived by Consumers

This study aims to measure the changes in the mechanical and acoustic properties of biscuits when solid fat was replaced by vegetable oils and to relate these properties to the texture sensations perceived by consumers. Twelve biscuit formulations containing different types of fat (two shortenings and four oil/hydrocolloid systems) and different fat contents (10.6 and 15.6 %) were studied. The mechanical and acoustic properties of the biscuits were measured instrumentally by a three-point bending test and two penetration tests using cylindrical and spherical probes. The values of parameters, such as the maximum peak, distances, slopes and number of events were obtained from the force-distance and sound-distance curves. Results showed that both fat type and content affected instrumental texture of biscuits. When reducing fat content, biscuits presented high force at breaking and at penetration and more fractures during cylinder penetration. When the saturated fat was replaced by the oil/xanthan gum system, the biscuit proved more elastic, resistant to breaking and noisy during penetration. Moreover, when the fat content was decreased or the shortening was replaced with the oil/gel systems, the number of force events (>0.1 N) during sphere penetration was lower. Free-choice profiling was used to determine the differences in texture characteristics perceived by consumers (n?=?28), and relationships between the consumers’ perception and instrumental parameters was performed by partial least squares regression analysis. Results show that higher force at breaking values and at penetration and a large amount of fractures during the cylinder penetration were related with hard and crunchy perception in biscuits. Moreover, high values of the resistance to breaking parameter and large amount of sound events were also related with an increased sensation of the hardness. Finally, a high number of microfractures (0.1 N) during the penetration with sphere were found to be related with the perception of mealy, crumbly and brittle sensations. The olive oil/HPMC system at the high fat content conferred similar mechanical and acoustical properties to those provided by the shortening fats, leading to biscuits with similar texture properties in the mouth.     

Sunflower Oil–Water–Cellulose Ether Emulsions as Trans-Fatty Acid-Free Fat Replacers in Biscuits: Texture and Acceptability Study

A new vegetable, and trans-fatty acid-free, fat replacer consisting of a sunflower oil–water–cellulose ether emulsion was employed to replace 100 % of the shortening in a short dough biscuit recipe, and the dough and biscuit texture properties were evaluated. In comparison to the shortening dough, the cellulose emulsion dough was significantly (p?<?0.05) softer and more elastic. However, the cellulose emulsion biscuits had higher spreadability, implying that the increase in dough elasticity was not affecting this property, probably because of the decrease in dough hardness. Although the cellulose emulsion biscuits contained 33 % total less fat than the shortening biscuits, their instrumental texture properties were very similar, implying that the cellulose emulsion avoids the increase in hardness associated with fat reduction. This was associated with the thermal gelation ability of the cellulose ethers, which develops during baking. The overall consumer acceptance was significantly (p?<?0.05) higher in the shortening biscuits, but their scores were very similar to those of the cellulose emulsion biscuits (maximum difference 1.1/9 points).     

Influence of gluten-free flour mixes and fat powders on the quality of gluten-free biscuits

Studies were conducted to develop gluten-free biscuits comparable in quality to wheat (W) biscuits and superior to those made from commercial gluten-free flour (Gf), suitable for coeliac sufferers. Three mixes of brown rice flour (R), corn starch (C), potato starch (P), soya flour (S), buckwheat flour (B) and millet flakes (M) were studied: RCPS in the percentage 70, 10, 10, 10, RPBM (50, 30, 10, 10) and RCPM (25, 25, 25, 25). Biscuits were tested for water activity, moisture, texture (snap test), diameter, thickness and colour (L* value), biscuit dough for hardness and stickiness. Various correlations >0.8 indicated for the three mixes, W and Gf that firm, non-sticky doughs yielded firm, thin, non-oval biscuits. Cluster analysis revealed that RCPS was most similar to W with regards to all parameters measured, and RCPS also showed best overall acceptability in sensory testing. Three fat powders were studied for use instead of palm oil: high and low fat dairy powder (HFP, LFP) and microencapsulated high fat powder based on vegetable fat (ME). HFP and ME yielded biscuits of comparable texture to palm oil, LFP resulted in much firmer biscuits, attributed to lower fat and higher protein and total sugar content.     

Performance and fatty acid profiling of interesterified trans free bakery shortening in short dough biscuits

Short dough biscuits were prepared using interesterified trans free bakery shortening (IETFS). Hydrogenated shortening (HS) based biscuits were prepared as a control. The diameter, height and spread ratio were determined. Biscuits were analysed up to 8 months for hardness, moisture and acidity of the extracted fat. IETFS biscuits were significantly (P < 0.05) less hard, had a higher spread ratio and were rated higher on all sensory attributes. Their overall acceptability score on a nine point hedonic scale was 8.2 ± 0.8 as compared to 7.3 ± 0.7 for control biscuits. The fatty acid fraction of control biscuits was: saturated fat, 51.6%; trans fat, 14.5%; monounsaturated fat, 28.0%; and polyunsaturated fat, 5.9% and that of IE trans free biscuits was: saturated fat, 54.8%; trans fat, 0.6%; monounsaturated fat, 38.1%; and polyunsaturated fat, 6.5%. The IETFS was found to be appropriate as an alternate to hydrogenated shortening, providing both functionality and nutritive advantage in biscuits.     

HPMC and inulin as fat replacers in biscuits: Sensory and instrumental evaluation

Because a high fat content in foods is associated with health disorders, consumers demand low fat products, but without any loss of their texture quality. The instrumental texture and sensory properties of biscuits in which 15 and 30 g/100 g of the fat has been replaced by two different carbohydrate-based fat replacers (inulin and hydroxypropyl methylcellulose) were studied. The instrumental texture measurements showed that inulin and hydroxypropyl methylcellulose (HPMC) biscuits were harder and the sound emissions were higher than for the control biscuits. The trained sensory panel rated the biscuit with 15 percent fat replacement by inulin as crisper than the control. The consumer study revealed that fat replacement up to 15 g/100 g with inulin or HPMC provided acceptable biscuits, but higher replacement decreased the overall acceptability.     

Effect of mustard flour incorporation on nutritional, textural and organoleptic characteristics of biscuits

Nutritional, sensory and textural characteristics of defatted mustard flour fortified biscuits were studied to optimize the mustard flour supplement in the blend for making biscuits. The wheat flour was replaced by defatted mustard flour at 5, 10, 15 and 20% incorporation levels in biscuit preparation. The protein content of mustard flour biscuit increased nearly 2.5 times as a result of mustard flour incorporation, coupled with reduction in fat and an increase in fiber content. Sensory evaluation results revealed that the sample containing 15% defatted mustard flour scored highest in most of the attributes including overall acceptability. Textural characteristics of all dough and biscuit upto 15% supplement of defatted mustard flour were similar while at 20% level, the values were significantly different. The study reveals that incorporation of 15% defatted mustard flour gave desirable results in terms of nutritional, sensory and textural attributes of mustard fortified biscuits.     

Physical, chemical and sensory characteristics of cooked meat emulsion style products containing vegetable oils

Beef frankfurters and cooked salamis (containing 19.5% pork back fat) were compared with samples containing vegetable oils. The pork back fat was replaced with Soya-seed oil (19.5%), sunflower oil (19.5%, 24%, 27.5%), cotton-seed oil (19.5%), corn-seed oil (19.5%) or palmine (19.5%). The emulsion stability of the products containing vegetable oil was good, even if the temperature of the batters reached 20°C. However, firmness, lightness of internal colour and flavour intensity were reduced in the vegetable oil specimens. In terms of flavour, panellists scored the acceptability of the experimental products as follows: control best; sunflower, corn-seed and palmine next and soya- and cotton-seed worst.     

Comparison of check-all-that-apply and forced-choice Yes/No question formats for sensory characterisation

The application of check-all-that-apply (CATA) questions for sensory product characterisation is gaining acceptance and popularity. This question format has been reported to be a quick and reliable means of gathering sensory profiles from consumers, concurrently with hedonic assessment. However, a limitation of CATA questions is that they do not encourage deep processing by respondents. Forced-choice questions, where respondents answer “yes” or “no” for each term, may encourage systematic processing and be useful when consumers undertake sensory profiling tasks. This research compared sensory profiles elicited by consumers using CATA questions or forced-choice Yes/No questions and contribute to ongoing investigations of CATA questions and related question formats with a view to developing guidelines for best practise. Across seven consumer studies with 600+ consumers and multiple product categories, consistent evidence was obtained that forced-choice Yes/No questions are associated with higher term citation frequencies. However, this did not consistently translate into greater product discrimination. Conclusions regarding similarities and differences amongst samples and the stability of sample and term configurations were generally independent of question format (i.e., whether the sensory data were elicited by CATA or forced-choice Yes/No questions). Overall, the comparison of CATA and forced-choice Yes/No questions for sensory characterisation suggested parity of the two question formats. This extended to consumers’ perceived difficulty and tediousness for completing the test. Regardless of question format, consumers, on average, perceived the tests as easy and not tedious.     

Sensory and physicochemical changes occurring during storage of Galician chorizo in oil

 Changes in the physicochemical and sensory properties of Galician chorizos stored in olive oil, sunflower oil or pork fat were monitored over a 19-week period. The results of analysis of variance showed that the storage medium had a significant effect on some variables. Specifically, moisture content, water activity, acid value and cohesiveness were lowest in chorizos stored in sunflower oil; acid value and pH were highest in chorizos stored in olive oil; external smoky and paprika odours were lowest, and after-taste intensity highest, in chorizos stored in pork fat. Acid value, peroxide index, hardness, colour, external odour intensity, perceived hardness and acid flavour all increased significantly during storage, while pH and water activity declined. In all three storage media, external rancid odour and rancid after-taste were first detected at week 17, when the peroxide index peaked. The overall rating was best for chorizos stored in sunflower oil. Received: 9 September 1997 / Revised version: 24 November 1997     

Sensory and physicochemical changes occurring during storage of Galician chorizo in oil

 Changes in the physicochemical and sensory properties of Galician chorizos stored in olive oil, sunflower oil or pork fat were monitored over a 19-week period. The results of analysis of variance showed that the storage medium had a significant effect on some variables. Specifically, moisture content, water activity, acid value and cohesiveness were lowest in chorizos stored in sunflower oil; acid value and pH were highest in chorizos stored in olive oil; external smoky and paprika odours were lowest, and after-taste intensity highest, in chorizos stored in pork fat. Acid value, peroxide index, hardness, colour, external odour intensity, perceived hardness and acid flavour all increased significantly during storage, while pH and water activity declined. In all three storage media, external rancid odour and rancid after-taste were first detected at week 17, when the peroxide index peaked. The overall rating was best for chorizos stored in sunflower oil. Received: 9 September 1997 / Revised version: 24 November 1997     

Olive stone powder: A potential source of fiber and antioxidant and its effect on the rheological characteristics of biscuit dough and quality

Being waste products of olive fruits, olive stones could be used as a healthy functional food ingredient thanks to their rich antioxidant properties, nutrients and dietary fibers. In this study, wheat flour was substituted by olive stone powder at levels of 0, 5, 10 and 15%. The rheological properties of biscuit dough and proximate composition, color values, total phenolic content, antioxidant activity, textural characteristics and sensorial properties of biscuit samples were investigated. Wheat flour replacement by olive stone powder increased antioxidant activity, fat and fiber content of biscuit samples (p < 0.05). The biscuits prepared with addition of 15% olive stone powder had 30.44 ± 0.03% DPPH radical scavenging activity, 11.22 ± 0.09% crude fiber, and 26.32 ± 0.22% fat. According to results of sensory analysis, wheat flour could be substituted up to 15% by olive stone powder to prepare biscuits without causing unacceptable product in terms of sensory properties.     

What does it mean to check-all-that-apply? Four case studies with beverages

The use of check-all-that-apply (CATA) questions in product-focused consumer research on foods and beverages is now common, and the method is known to provide valid sensory product characterisations. Extensive methodological research has been conducted and has supported uptake, but understanding of how consumers complete CATA questions is incomplete, particularly with regard to their decision to select or not a term to describe the sensory properties of products. The present research was situated within this gap, and using open-ended questions participants (n = 636) were asked to describe how they perceived a pair of samples with regard to an attribute and link this to CATA term selection. The results, obtained for taste (‘sweet’ and ‘sour/acidic’) and flavour (‘cinnamon’ and ‘smoky’) confirmed consumers’ ability to accurately perform sensory characterisation tasks. In particular, it was found that: i) the great majority of the consumers accurately used the CATA terms for describing the sensory characteristics they perceived in a sample, ii) when a term was not selected for describing samples, the majority of the consumers indicated that the corresponding sensory attribute was not perceived, iii) when a term was selected for describing only one of the samples in a pair, consumers reported to have perceived a difference in attribute intensity between the samples. Thus, CATA questions remain a desirable option for sensory product characterisation tasks with consumers, but should be selected with thought as they may not always be able to achieve desired sample discrimination due to the binary nature of the responses.     

Application of near (NIR) infrared and mid (MIR) infrared spectroscopy as a rapid tool to classify extra virgin olive oil on the basis of fruity attribute intensity

A sensory analysis of 112 virgin olive oils was performed by a fully trained taste panel. The samples were divided in “defective” and “not defective” on the basis of their olfactory attributes. Then, the “not defective” samples were classified into “low”, “medium” and “high” according to the fruity aroma intensity perceived by assessors. All samples were also analysed by FT-NIR and FT-IR spectroscopy and processed by classification methods (LDA and SIMCA). The results showed that NIR and MIR spectroscopy coupled with statistical methods are an interesting technique compared with traditional sensory assessment in classifying olive oil samples on the basis of the fruity attribute. The prediction rate varied between 71.6% and 100%, as average value. The spectroscopic methods, combined with chemometric strategies, could represent a reliable, cheap and fast classification tool, able to draw a complete fingerprint of a food product, describing its intrinsic quality attributes, that include its sensory attributes.     

A new sensory tool to analyse the oral trajectory of biscuits with different fat and fibre contents

Reformulating traditional products such as biscuits can be a useful tool for providing the population with healthier snacks. However, it involves changes in the eating characteristics of the final product. This study focuses on the oral perception of these biscuits, using the Temporal Dominance of Sensation (TDS) technique with two different amounts of fat (60 g and 30 g fat/100 g flour) and fibre (4 g and 8 g fibre/100 g flour). The TDS data obtained with a trained panel showed that hardness was the first dominant attribute in all the formulations during the mastication process. The dominance of the other parameters appeared to depend more on the fat and fibre contents, as crispness appeared with high-fat biscuits and crunchiness with low-fat, high-fibre ones, whilst both attributes were perceived in intermediate formulations. In the high-fibre formulations, grittiness and dry mouthfeel appeared during chewing and dry mouthfeel was dominant. At the end of the mastication all the biscuits were perceived as pasty. A fat mouthfeel was also perceived with both high-fat and low-fat biscuits, with or without the addition of a low level of fibre. Penalty analysis based on JAR scales, showed that excessive hardness and excessive dry mouthfeel were the most penalizing sensory characteristics causing significant drop in biscuit acceptability.     

Replacement of beef fat in Frankfurters by interesterified palm,cottonseed and olive oils

Three interesterified vegetable oils (IVOs) prepared from palm, cottonseed, and olive oil, respectively, have been studied for application to Frankfurters. Beef fat (10%) was replaced by one of the IVOs at 20, 60 or 100%. Fatty acid composition of the lipid fraction in the Frankfurters and saturated/unsaturated ratios were established for all batches. We found that total or partial replacement of beef fat by IVOs did not lead to significant changes in appearance, colour, texture, flavour or sensory score. We conclude that IVOs may be successfully applied as beef fat substitutes in Frankfurters.     

SENSORY TEXTURE OF COMMERCIAL BISCUITS AS A FUNCTION OF WATER ACTIVITY

The variation in sensory texture of four types of commercial biscuits as a function of water activity, using both a trained sensory panel and a consumer panel, was studied. The biscuits were: (a) like toasted bread, aerated and sweet; (b) cracker from whole-wheat flour; (c) cracker from normal flour; (d) sweet biscuit, vanilla flavored. Texture changes were discriminated better when tested in the mouth than manually. The transition from crisp to noncrisp was gradual and continuous, and could be adequately modeled using Fermi's equation. The sensory perception of crispiness loss depended on how it was measured: for 'crisp with molars' the loss occurred at a lower water activity than for 'noise'. The water activities at which consumers found the crispiness ideal were different for each type of biscuit, showing that the moisture content of a biscuit should be adjusted at particular values for each product to satisfy consumer preferences. The correlation of sensory acceptability versus 'crispiness with molars' showed one of the biscuit types to be an outlier, while the rest were well correlated. Differences between biscuits in relation to their textural changes with a_w can be explained by differences in their microstructure, degree of starch gelatinization and gluten development.