Use of healthier fats in biscuits (olive and sunflower oil): changing sensory features and their relation with consumers' liking

The aim of this study was to evaluate consumer acceptability of biscuits when saturated fat was replaced by olive or sunflower oil and to determine the sensory characteristics responsible for changes in acceptability. Ninety seven consumers evaluated the acceptability of six biscuit samples varying in the fat source (dairy shortening, olive oil and sunflower oil) and fat content (10.6% and 15.6%). Using a Check All That Apply question (CATA), consumers also evaluated sensory properties of biscuits. Results indicated that the replacement of saturated fat (dairy shortening) by vegetable oils had an effect on biscuit acceptability which depended on biscuit fat content. According to biscuits' acceptability data, three different clusters of consumers were identified. By using a multiple factor analysis, the relationship among sensory CATA data and acceptability of each cluster explained the different acceptability patterns of consumers. For most of consumers acceptability was related to attributes “crispy”, “easy to chew” and “biscuit flavour” which, for one group were perceived in shortening biscuits and, for another in both olive and shortening biscuits. However, for the third group of consumers, acceptability was only related to flavour attributes like “roasted flavour” or “biscuit flavour” that were perceived in vegetable oil biscuits which were the preferred biscuits while, shortening biscuits were disliked and perceived as having an “off flavour”.     

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.     

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.     

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).     

Effects of Fat and Sugar on Dough and Biscuit Behaviours and their Relationship to Proton Mobility Characterized by TD-NMR

This study aimed to analyse the effect of large variations in fat and sucrose contents of biscuit formulation on dough rheology, biscuit quality and proton mobility. Control dough (full fat and sucrose) and 25 and 50% fat and sucrose-reduced doughs were elaborated. Rheological properties of dough were determined. Dough cooking behaviour and biscuit quality were evaluated. Fat reduction produced an increase in the consistency and elastic properties of the dough. The decrease in sucrose content affected to a lesser extent the rheological properties at room temperature, although it produced significant changes during dough baking. The biscuit quality decreased with fat and sucrose reductions. The reduction of fat or sucrose produced gluten hydration and extra interactions and subsequent cross-linking during baking, and a reduction of sucrose led to the swelling and partial gelatinization of starch during baking. A dipolar reversed eco NMR sequence was applied to determine changes in the amount and mobility of solid and mobile components both in dough and biscuits. TD-NMR results allowed corroborating the proposed hypotheses about the effects on dough and biscuit characteristics as a consequence of reduction of main ingredients, as fat and sucrose. The redistribution of water after baking can be correlated with biscuit factor and breaking force.     

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.     

Understanding the Effect of Sugar and Sugar Replacement in Short Dough Biscuits

Sucrose is the main sugar used in short dough biscuit formula, and it plays an important role in the biscuit manufacturing as well as in the biscuits final quality. However, for health reasons, high levels of sucrose are undesirable, making sucrose replacement an important issue to study. The present study focused on sucrose reduction and its replacement by polyols (erythritol and maltitol) in short dough biscuits. The effects were investigated in a model system composed of gluten and different sugars (sucrose, maltitol, and erythritol), in biscuit dough, and in baked biscuits. Modulated thermal analysis showed that sucrose decreases the glass transition temperature; however, for both polyols studied, no transition was found due to a plasticization effect. The gelatinization of starch in the biscuits was not affected by the sugar or quantity of sugar used. Temperature sweeps of short dough revealed that the presence of sugar delays the transitions. Furthermore, G* increased with sucrose replacement, with the smallest changes for the maltitol-containing biscuits compared to the control. Finally, texture and dimension analyses were carried out. Sugar-free and erythritol-containing biscuits were compact, elastic, and resistant to the breaking force compared to the control biscuits and the maltitol-containing biscuits.     

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.     

Textural attributes of commercial biscuits. Effect of relative humidity on their quality

Two commercial biscuits of semi‐sweet type, ‘Marie’ and ‘Petit Beurre’ were used for investigating: (i) their texture variability as a function of the location and the side of puncturing and (ii) the influence of storage under different relative humidity on their texture, porosity and colour. Significant texture differences were found as a function of the location of puncturing (centre or periphery of biscuit area), as well as between the upper and the opposite side of a biscuit. At small relative humidity changes (11–32%) a distinct relationship between texture and moisture content was not noticed. In ‘Petit Beurre’ at a_w 0.32 a peak was observed in the puncture force values. In both biscuits porosity increased with their moisture content, accompanied by an area expansion. Significant differences in colour were mainly noticed between the upper and opposite side of the biscuits. Colour was less influenced by relative humidity changes.     

Effect of Fat Replacement by Inulin on Textural and Structural Properties of Short Dough Biscuits

The aim of this study was to evaluate the effects of inulin as fat replacer on short dough biscuits and their corresponding doughs. A control formulation, with no replacement, and four formulations in which 10, 20, 30, and 40 % of shortening was replaced by inulin were studied. In the dough, shortening was observed surrounding flour components. At higher fat replacement levels, flour was more available for hydration leading to significant (P?<?0.05) harder doughs: from 2.76 (0.12)?N in 10 % fat-replaced biscuits to 5.81 (1.56)?N in 30 % fat-replaced ones. Biscuit structure was more continuous than dough structure. A continuous fat layer coated the matrix surface, where starch granules were embedded. In general, weight loss during baking and water activity decreased significantly (P?<?0.05) as fat replacement increased. Biscuit dimensions and aeration decreased when fat replacement increased, e.g., width gain was +1.20 mm in 10 % fat-replaced biscuits and only +0.32 mm in 40 % fat-replaced ones. Panelist found biscuits with 20 % of fat replacement slightly harder than control biscuits. It can be concluded that shortening may be partially replaced, up to 20 %, with inulin. These low fat biscuits are similar than the control biscuits, and they can have additional health benefits derived from inulin presence.     

青稞全谷及麸皮对饼干品质的影响

饼干是颇受消费者喜欢的休闲食品,提高其品质对人们的生活有着重要的影响。本文通过在饼干的制作过程中添加0%、5%、10%、15%不同比例的青稞全谷物和青稞麸皮,测定了其蛋白质含量、质构、颜色变化并对饼干进行感官评价,结合对CML含量的抑制效果来确认最优添加量。结果表明:青稞全谷物及青稞麸皮添加量均为15%时,此时蛋白质含量最高,分别为6.83%±0.03%和6.78%±0.14%;且质构指标硬度、内聚性、弹性、咀嚼性均在消费者可以接受的范围;饼干呈现棕褐色,深受消费者喜爱;感官得分分别为15.8分和15.1分;对晚期糖基化终产物CML的抑制率分别为27.46%和22.54%,抑制效果最佳。因此在杂粮饼干的加工中,选择青稞全谷物和麸皮添加量均为15%,既能保证饼干具有较好的感官,又能最大限度的抑制CML的生成。     

木耳酥性饼干配方、质构和保质期

以低筋粉、木耳粉为原料,添加适量油脂、白糖、食盐、泡打粉等研制木耳酥性饼干,并测定产品理化性质、硬度和保质期。结果表明:以低筋粉100 g,木耳粉12.5 g,白糖25 g,泡打粉2.5 g,食盐1.7 g,油脂含量40 g(其中黄油8 g,棕榈油32 g),抗氧化剂TBHQ 180 mg/kg(以油脂计)为最佳配方所制成的木耳酥性饼干产品外形饱满、内质结构细密均匀、酥松、细腻、色泽均匀、香味浓厚,感官评分达(94±1)分。木耳酥性饼干成品含水分2.8 g/100 g,灰分2.56 g/100 g,脂肪33.2 g/100 g,酸价(以油脂计)0.45 mg/g,过氧化值(以油脂计)0.0012 g/100 g,硬度27.30 N,符合酥性饼干的标准。通过保质期加速实验预测产品保质期为1年。本研究获得了兼具功能特性、组织结构好、口感酥脆、口味独特的木耳酥性饼干。     

Evaluation of Starch Degradation and Textural Characteristics of Dietary Fiber Enriched Biscuits

Abstract

The effects of dietary fiber inclusion on biscuit texture, cooking properties, and sugar release after in vitro degradation were investigated. Inulin, β-glucan enriched fraction (BGEF), potato fiber, and a resistant starch were used. Effects of the dietary fibers on the pasting properties of flour based mixtures were investigated using a rapid visco analyzer. Results showed a reduction in visco-pasting properties (peak viscosity and final viscosity) of the flour–dietary fiber systems with increasing fiber content. Addition of dietary fiber into the biscuits affected biscuit shrinkage and height development during cooking, as well as generally reducing the resistance of biscuits to snapping during texture analysis tests. Sugar release during in vitro degradation studies showed a highly significant decline when comparing dietary fiber enriched biscuits to the control samples. This would have a beneficial effect in potentially reducing the glycaemic index and subsequent glycaemic loading of such foods.     

Phenolic extracts of carrot,grape leaf and turmeric powder: antioxidant potential and application in biscuits

Natural antioxidants have gained interest for their role in preventing lipids oxidation. The goals of this investigation were to study the antioxidant potential of carrot (Daucus carota), grape (Vitis vinifera) leaf and turmeric (Curcuma longa) powder extracts and to evaluate their addition as natural antioxidants in biscuits. Physical and chemical properties of biscuit were evaluated during processing and storage. Electrophoretic properties of biscuit dough were carried out to understand the impact of different extracts on the processing of biscuits. Biscuits prepared with 1 % (w/w) grape leaves ethanol (70 %) extract (GLE), carrot aqueous extract (CE), and tumeric aqueous extract (TE) were acceptable. Among extracts, TE was found to retain only 11.2 % activity, wherein GLE had retained 51.0 % activity after baking, which was comparable to butylated hydroxyanisole and better than tert-butylhydroquinone (TBHQ). TBHQ was found to possess the highest activity, followed by GLE, TE and CE, respectively. The ash content of biscuits enriched with TE and GLE was near to that of the control sample. Addition of CE, GLE and TBHQ reduced the force required for breakage. After 15 days of storage, PV was increased in all samples, but in the case of GLE-enriched sample there was a sudden increase in PV from 0.034 to 0.374. Supportive electrophoresis study indicated that there was no change in the protein subunits of biscuit dough fro different samples. It could be concluded that GLE, CE and TE might be used in biscuit baking as natural antioxidants.     

Studies on the Optimization and Stability of Low-Fat Biscuit Using Carbohydrate-Based Fat Replacers

The objective of this study was to optimize and develop low-fat soft dough biscuits using carbohydrate-based fat replacers (combinations of polydextrose and guar gum). Central composite rotatable design was utilized to optimize the levels of sugar, composite fat (fat, polydextrose, and guar gum), ammonium bicarbonate, and water. The parameters measured were spread ratio, hardness, stress-strain ratio, and sensory properties. Composite fat and sugar were found to be important determinants of biscuit hardness. The principal effect of fat substitutes on biscuits’ attributes was crisper texture but with higher brittleness. The level of water had a significant effect on spread ratio (p < 0.1), hardness (p < 0.1), and stress-strain ratio (p < 0.05). It was also observed that by varying the level of ammonium bicarbonate in the formulation from 0.5 to 2.5 g/100 g flour, the dimensions and texture of the biscuits were affected. The optimum ingredient levels on 100 g flour basis were found to be sugar 24 g, fat 10.5 g, polydextrose 24.2 g, guar gum 0.3 g, ammonium bicarbonate 2 g, and water 24 mL. It was found from the storage study that low-fat biscuit with 70% fat replacement was more oxidative stable than the control sample.     

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.     

Effect of native and germinated finger millet flour on rheological and sensory characteristics of biscuits

Wheat flour was replaced with native finger millet flour (NFMF) and germinated finger millet flour (GFMF) at 30–50% levels to make soft dough biscuits. Dough rheological properties and baking characteristics of the blends were evaluated. Farinograph data of wheat flour replaced with NFMF and GFMF showed a decrease in water absorption, dough stability and an increase in mixing tolerance index as the level of replacement increased. Extensibility of dough decreased for both NFMF and GFMF as the levels increased. The hardness of biscuit dough measured by texture profile analysis increased from 125 to 234 N for NFMF and 118 to 126 N for GFMF. Scanning electron microscopic studies on the biscuit dough showed polygonal finger millet starch granules adhering to wheat starch granules and protein matrix. The results of the study indicated that the replacement level of 40% with either NFMF or GFMF produced biscuits with acceptable sensory attributes. Addition of sodium stearoyl‐2‐lactylate (SSL) showed further improvement in terms of spread ratio, surface characteristics and texture.     

挤压薏米粉饼干研制及品质分析

以低筋面粉和挤压混合米为原料,对饼干的配方进行优化,并对其理化性质、质构、扫描电镜结果等进行分析。以感官品质为指标,进行单因素试验优化饼干配方,在单因素试验基础上进行四因素三水平正交优化,确定挤压混合米饼干的最佳配方为:低筋面粉与挤压混合米研磨粉共100 g,配比70︰30,绵白糖30 g,黄油20 g,植物油30g,蛋清35 g,泡打粉1.5 g;通过理化指标检验,饼干与对照相比,膳食纤维含量得到提高;通过质构分析,饼干脆度适中,硬度较大;通过扫描电镜发现,饼干酥松性好,内部孔隙结构均匀。产品色泽金黄,口感酥脆、细腻,具有独特的薏米香味。     

Characterisation of flour, starch and fibre obtained from sweet potato (kumara) tubers, and their utilisation in biscuit production

Sweet potato (kumara) tubers of differing colours (orange, red and white) were used to produce tuber flour, a purified starch fraction and an isolated fibre extract. The fractions from each tuber colour were added into a biscuit mixture, and the effects of tuber source and fraction composition were observed in relation to the physico-chemical characteristics of biscuits. Addition of sweet potato flour and fibre fractions to white wheat flour significantly reduced the pasting properties (peak and final viscosity) of the resulting gels by up to seven-fold compared with the control wheat flour gel (as determined by the Rapid Visco Analyser). The addition of sweet potato starch affected the pasting properties of wheat flour–sweet potato starch mixes to a lesser extent. Biscuit texture (force required to cause a biscuit to fracture) was significantly reduced with the incorporation of sweet potato fibre into the biscuit dough preparation, this was linked to a reduction in biscuit thickness and spread ratio. However, the addition of sweet potato flour and starch resulted in biscuits of similar firmness as the control biscuits.