Comparison of the effects of sucrose and hexose on furfural formation and browning in cookies baked at different temperatures

The influence of the type of sugar and baking temperature on sugar degradation, hydroxymethylfurfural (HMF) formation and browning was studied in model cookies. The baking process was characterised by the temperature in the cookie and the water content and activity. A reference browning was selected to compare the differently processed cookies. The accumulation of HMF was modelled at three temperatures for three formulas (sucrose (S-CK), glucose (G-CK) or fructose (F-CK)). HMF started to accumulate at a_w between 0.5 and 0.7 depending on the temperature and followed a first order kinetic, highly dependent on the baking temperature and type of sugar. Cookies baked at 200 °C accumulated 10–100 times less HMF than those baked at higher temperatures. Below 250 °C, S-CK produced less HMF than G- or F-CK, but the inverse was observed at 300 °C.     

Effect of leavening agents and sugars on the formation of hydroxymethylfurfural in cookies during baking

The effects of recipe compositions in terms of leavening agent (ammonium and sodium bicarbonates) and sugars (sucrose and glucose), and baking conditions (temperature and time) on HMF formation in cookies were studied. Five recipes were prepared by varying the types of leavening agent and sugar. The cookies were baked at different temperatures (180, 200, 210 and 220 °C) for different time (10, 15, 20 and 25 min) to monitor physical and chemical changes in cookie composition in terms of water activity, pH, surface browning, sugar decomposition, and hydroxymethylfurfural (HMF) formation. Decreasing moisture to a level under a water activity of 0.4 appeared as the critical point in baking where the rate of HMF formation drastically increased after this point. After this stage, sucrose decomposed very rapidly if ammonium bicarbonate was used as the leavening agent at temperatures greater than 200 °C. Replacing ammonium bicarbonate with sodium bicarbonate maintained pH of cookies ranging between 9.0 and 10.0 during baking, which limited the decomposition of sucrose.     

Mitigation of acrylamide formation in cookies by using Maillard reaction products as recipe modifier in a combined partial conventional baking and radio frequency post-baking process

This study aimed to mitigate acrylamide formation in cookies by lowering thermal energy input along with certain recipe modifications. Lowering temperature required longer cooking times as expected in order to achieve desired final moisture content. To shorten cooking time, conventional baking was combined with radio frequency post-baking process. Lack of development of surface browning in cookies during lower-temperature baking could be overcome by adding the Maillard reaction products (MRP) into dough. The MRP used to modify dough was prepared by heating a binary mixture of arginine and glucose at 100?°C for 6?h or by overbaking thin dough-layered disks. In comparison with control cookie baked at 205?°C for 11?min, combined conventional baking (205?°C for 8?min) and radio frequency post-drying process (45?s) decreased acrylamide formation in biscuits by up to 50?%. The use of Maillard reaction products to improve the visual acceptability of cookies to the consumer may have applications in food industry.     

Cookie- Versus Cracker-Baking—What's the Difference? Flour Functionality Requirements Explored by SRC and Alveography

The many differences between cookie- and cracker-baking are discussed and described in terms of the functionality, and functional requirements, of the major biscuit ingredients—flour and sugar. Both types of products are similar in their major ingredients, but different in their formulas and processes. One of the most important and consequential differences between traditional cracker and cookie formulas is sugar (i.e., sucrose) concentration: usually lower than 30% in a typical cracker formula and higher than 30% in a typical cookie formula. Gluten development is facilitated in lower-sugar cracker doughs during mixing and sheeting; this is a critical factor linked to baked-cracker quality. Therefore, soft wheat flours with greater gluten quality and strength are typically preferred for cracker production. In contrast, the concentrated aqueous sugar solutions existing in high-sugar cookie doughs generally act as an antiplasticizer, compared with water alone, so gluten development during dough mixing and starch gelatinization/pasting during baking are delayed or prevented in most cookie systems. Traditional cookies and crackers are low-moisture baked goods, which are desirably made from flours with low water absorption [low water-holding capacity (WHC)], and low levels of damaged starch and water-soluble pentosans (i.e., water-accessible arabinoxylans). Rheological (e.g., alveography) and baking tests are often used to evaluate flour quality for baked-goods applications, but the solvent retention capacity (SRC) method (AACC 56-11) is a better diagnostic tool for predicting the functional contribution of each individual flour functional component, as well as the overall functionality of flours for cookie- and/or cracker-baking.     

Role of precursors on the kinetics of acrylamide formation and elimination under low moisture conditions using a multiresponse approach – Part I: Effect of the type of sugar

The effect of type of sugar on the kinetics of acrylamide formation and elimination reactions was investigated under low moisture conditions using equimolar asparagine–sugar model systems, heated at temperatures between 120 and 200 °C. The monosaccharides glucose and fructose and the disaccharide sucrose were selected to study this effect. A mechanistic model was used as a basis for multiresponse modelling of the different responses measured (acrylamide, glucose, fructose, sucrose, asparagine, aspartic acid and melanoidins). In spite of the higher acrylamide yield per mol initial asparagine for sucrose over fructose to glucose, the kinetic parameters estimated for acrylamide formation revealed that the type of sugar, monosaccharide or disaccharide, had only a limited effect on this reaction. The corresponding activation energy, however, was significantly lower in case the disaccharide sucrose was added. An opposite trend was observed for the acrylamide elimination rate constant, being significantly higher for the system with sucrose, whereas the temperature dependence of this rate constant remained unaffected by the type of sugar available under the reaction conditions considered.     

The role of wheat flour constituents, sugar, and fat in low moisture cereal based products: a review on sugar-snap cookies

Much research has been done to understand the contribution of different flour constituents to the cookie quality. Most authors agree on the role of starch in cookies, which, although it is the main flour constituent, has a relatively small influence on cookie quality. Flour proteins, which are quantitatively less important than starch, seem to have a more pronounced role in cookie baking. However, in literature, there is no consensus about their role and influence on the product quality. As for starch, there is much more agreement about the role of non-starch polysaccharides and flour lipids. Not only flour, but also other ingredients of the cookie (dough) formula, such as shortening (fat), sugar, and water are important for the quality of the end product. We here provide the different points of view in this area and speculate on the functionality and quality determining properties of flour constituents, sugar, fat, and water and their role and influence during the different stages of cookie baking and on the end quality of sugar-snap cookies.     

A new approach to evaluate the risk arising from acrylamide formation in cookies during baking: Total risk calculation

From a food engineering point of view, a viable approach in evaluating the risk related to acrylamide formation in heated foods is still lacking. In this study, thermal process calculation procedure used to evaluate safe levels of microbial inactivation by means of time-temperature history of the product during processing was adapted to evaluate the risk associated with acrylamide formation in cookies during baking. The rate constants were determined in model cookies during baking at different temperatures. For a risk threshold value of 200 ppb of acrylamide, thermal formation times were calculated as 6.29, 0.20 and 0.03 min for 150, 200 and 250 °C, respectively. The F and z values were determined as 0.20 min and 30 °C, respectively, for acrylamide formation in cookies during baking. Calculated total risk values compared well with experimentally measured acrylamide concentrations of cookies baked under different conditions confirming the success of risk evaluation procedure.     

Antioxidant activity of cookies and its relationship with heat-processing contaminants: a risk/benefit approach

Formation of both health promoting and potential harmful substances (acrylamide and hydroxymethylfurfural) has been associated to the extent of the Maillard reaction. The effects of recipe compositions in terms of leavening agent (ammonium and sodium bicarbonates) and sugars (sucrose and glucose), and baking conditions (temperature and time) on the antioxidant activity (AOA) in cookies were studied. The cookies were baked at different temperatures (180–220 °C) for different times (10–25 min). AOA was measured by the ferric reducing power (FRAP), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2,-diphenyl-1-picrylhydrazyl (DPPH) coloured radicals, and oxygen radical absorbance capacity (ORAC-fluorescein) in automated plate-reader assays. Net AOA varied regarding the assay applied, whereas higher AOA was always obtained for the ABTS assay and lower for DPPH assay, and ranging from 2 to 200 μmol Trolox/g sample. At higher temperature and baking times, higher AOA in cookies regardless of the formulation was recorded. Glucose enhances formation of compounds with higher AOA compounds as compared with sucrose recipes. Ammonium bicarbonate clearly promotes the formation of AOA for sucrose recipes but this effect is not observed in glucose recipes and varied with the AOA procedure applied. A risk/benefit index, based on the concomitant formation of neo-formed contaminants and substances with AOA (potentially health-promoting substances) is presented, and its application for recipe comparison is discussed. Risk/benefit index rapidly increased with increased temperature and time of baking.     

Factors affecting 3D printing and post-processing capacity of cookie dough

This study aimed to investigate the factors affecting the printability and post-processing capacity of cookie dough in extrusion-based three-dimensional (3D) printing by modifying the recipe without the addition of gums or stabilizers. Cookie dough formulations with different types of fat (butter and shortening), flour (wheat, rice, and tapioca), the amount of non-fat milk (32.5 or 65 g/100 g flour), and the sugar level (37.5 or 55 g/100 g flour) were investigated for their printability and post-processing capacity. Rheological properties, microstructure, and printability of printing inks were monitored while the moisture loss and dimensional stability after baking were analyzed in printed and baked structures, respectively. Results indicated that cookie dough formulations with reduced sugar content were more printable. The best sample to build a shape that could withstand the baking process was the recipe of 37.5 g sugar, 62.5 g shortening, 100 g tapioca flour, and 32.5 g milk, which yielded printed cookie samples with the ease of printing, better visual printing outcomes, and no structural deformation after baking.Industrial relevance3D food printing is an emerging technology with many potential applications in the food industry. It is important to understand the effects of key components of food materials on the printing, which enable a wider range of structures just using a single nozzle, and provide tailored nutrition and personalization in extrusion-based 3D printing. Understanding the effects of food processing on 3D printed food items is critical to broadening its applications. This study selected cookie dough as a model system to investigate the 3D food printing since it is mainly composed of fat, sugar, flour, and milk that are the most common ingredients in many food products. Establishing knowledge of the interactions between different food components and contribution of each individual ingredient may help develop a guideline for extrusion-based 3D food printing. In addition, the results acquired from this study can fill knowledge gaps regarding the role of cookie dough component in 3D printing and their effects on post-processing of 3D printed foods.     

Effect of crust temperature and water content on acrylamide formation during baking of white bread: Steam and falling temperature baking

The effect of crust temperature and water content on acrylamide formation was studied during the baking of white bread. To assess the effect of over-baking, we used a full factorial experimental design in which the baking time was increased by 5 and 10 min at each baking temperature. Additional experiments were performed with steam baking and falling temperature baking. Immediately after baking, the crust was divided into the outer and inner crust fractions, and the water content and acrylamide concentration of each fraction was measured. The outer crust had a significantly lower water content and higher acrylamide concentration than the inner crust did. Crust temperature in combination with water content had a significant effect on acrylamide formation, higher temperatures resulting in higher acrylamide concentrations. However, at very high temperatures and lower water contents, acrylamide concentration was observed to decrease, though the bread colour was then unacceptable for consumption. Steam and falling temperature baking, on the other hand, decreased the acrylamide content while producing bread crust with an acceptable colour. The lowest acrylamide values and an acceptable crust colour were produced by steam baking.     

Baking kinetics of muffins in convection and steam assisted hybrid ovens (baking kinetics of muffin…)

Effects of oven type and baking temperature on acrylamide concentration, surface browning, temperature profiles and drying rates of muffins were investigated. Muffins were baked in convection and steam assisted hybrid ovens at 145, 160 and 175 °C for different baking times. For all oven types, the acrylamide concentration of muffins increased with increasing baking time and temperature (p < 0.05). The formation was considered as the first order reaction kinetics except for the lowest baking temperature at natural convection and steam assisted hybrid ovens. The reaction rate constant, k was found to be in the range of 0.027–0.078 (min⁻¹). For the forced convection oven, the effect of baking temperature on acrylamide concentration followed the Arrhenius type of equation; with activation energy of 36.35 kJ/mol. The minimum drying rate was observed by the steam assisted hybrid oven, at all conditions. Steam assisted baking resulted in lower acrylamide concentration at all baking temperatures, while providing the average moisture content not significantly different.     

Effects of baking on protein digestibility of organic spelt products determined by two in vitro digestion methods

Consumption of organic foods is steadily increasing because it is believed to be healthier than conventional foods. This study was designed to investigate protein digestibility of organic spelt bread, biscuit, cookie and muffin in comparison to their corresponding normal wheat products. Three types of fermented bread products namely, yeast leavened, sour and yeast/sour dough were evaluated. Protein digestibility was assessed based on two methods, three-enzyme one-step and two-enzyme two-step digestion in vitro. The one-step digestion method produced results that were comparable with in vivo (rat) methods whereas the two-step digestion method was more reliable in determining differences among the examined wheat products. Organic spelt used in the present study was comparable to common wheat in protein content averaging 15.4 g/100 g dry matter. Slight differences were observed between organic spelt and common wheat products in protein digestibility determined by the two digestion methods. However, significant differences were found among each wheat products. In general, after baking protein digestion was significantly increased. Spelt and common wheat bread products had similar protein digestibility within each type of bread with sour dough breads had the highest protein digestibility. Biscuit, cookie and muffin products possessed lower protein digestibility than breads. In general, variations in protein digestibility due to baking were more noticeable than that found between the two wheats.     

Effect of pre-dehydration treatment on the in vitro digestibility of starch in cookie

In order to understand the effect of pre-dehydration on the in vitro digestibility of cookie starch, cookie dough samples were dehydrated by vacuum treatment, and melting temperature (T(m)) of the crystalline amylopectin in the dough, internal temperature and water content of the dough during baking, and non-hydrolysed starch content of the obtained cookies were investigated. The T(m) of crystalline amylopectin increased with decreased water content of the dough, and the result was described as a T(m)-curve. The internal temperature of non-dehydrated dough surpassed the T(m)-curve during baking. Pre-dehydrated dough, on the other hand, always indicated a lower internal temperature than the T(m)-curve. The non-hydrolysed starch content obtained under a given condition increased significantly with a decrease in the initial water content of cookies. This will be because the melting of crystalline amylopectin was prevented, at least partially, during baking.     

Study on formation of acrylamide in asparagine–sugar microwave heating systems using UPLC-MS/MS analytical method

Microwave heating can be regarded as a possible way to produce a considerable amount of acrylamide. The present study investigated the formation of acrylamide in asparagine–glucose, asparagine–fructose and asparagine–sucrose microwave heating systems by the response surface methodology (RSM) and the orthogonal array methodology (OAM). The acrylamide content was rapidly quantified by a validated ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. Results of RSM study indicated that in the asparagine–glucose system, the acrylamide content increased in the combined condition of high temperature accompanying with short heating time (>190 °C, <20 min) or low temperature accompanying with long heating time (<180 °C, >30 min). In the asparagine–fructose system, the similar conclusion was made in the combined condition of high temperature accompanying with short heating time (>175 °C, <20 min) or low temperature accompanying with long heating time (<170 °C, >25 min). In the asparagine–sucrose system, the amount of acrylamide enhanced with the increase of both heating temperature and heating time. The fitted mathematic models were successfully applied to the quantification of acrylamide formation when the heating temperature and heating time fell into the ranges of 120–240 °C and 5–35 min simultaneously. OAM study showed that acrylamide is readily formed via heating binary precursors 5 min at 180 °C in the asparagine–glucose and asparagine–fructose systems. However, acrylamide is readily generated when the binary precursors are heated 15 min at 180 °C in the asparagine–sucrose system.     

Dynamics of γ-aminobutyric acid in wheat flour bread making

The dynamics of the health-improving non-protein amino acid γ-aminobutyric acid (GABA) during bread making were studied. Wheat flour contains trace levels of GABA (<15 ppm) and ca. 160–175 ppm of its precursor, glutamic acid (GA). During dough mixing, the levels of both GA and GABA largely increased. While wheat flour endogenous glutamic acid decarboxylase (GAD) performs some minor conversion of GA into GABA, yeast is the main contributor to GABA formation. Comparison of amino acid levels of dough samples, without or with yeast, indicated that yeast favours both GA and GABA formation already during mixing. Fermentation decreased both GA and GABA contents, due to amino acid consumption by the yeast, which used more GA than GABA. Proofing and baking resulted in large GABA losses, the latter probably in Maillard browning reactions during baking. Thermal loss of GA was less pronounced than that of GABA. Breads contained only trace levels of GABA and ca. 90–130 ppm of its precursor. Exogenous supplementation of recombinantly produced GAD of Yersinia intermedia decreased GA levels in mixed and fermented dough and increased GABA levels. The highest GAD dosage used resulted in fermented doughs with ca. 300 ppm of GABA, i.e. three times higher than the level present in the reference sample (no GAD added). After baking, a significant GABA level was left in the bread samples (ca. 115 ppm) and GABA-enriched breads were obtained. Addition of sodium glutamate (100–380 ppm) to a bread recipe containing no added GAD clearly indicated that its precursor was not the limiting factor for GABA conversion during bread making since the resulting breads contained no GABA, or only trace levels (ca. 20 ppm).     

Interaction effects of fermentation time and added asparagine and glycine on acrylamide content in yeast-leavened bread

The interaction effects of fermentation time and added asparagine and glycine on acrylamide precursors (asparagine and reducing sugars) in dough and content of acrylamide in yeast-leavened wheat bread were studied. Two experiments, with low and high levels of added asparagine (0–0.044 and 0.071–0.476 g/100 g flour, respectively), were performed. Glycine was added (0.042–0.380 g/100 g flour) only in the high asparagine addition experiment. The fermentation time, which was varied between 13 and 164 min, showed a reducing effect on acrylamide precursors in the dough in both experiments (p < 0.001). These effects of fermentation were more pronounced in the experiment with low asparagine levels, which resembled levels in ingredients. In contrast, fermentation time did not affect the content of glycine in the dough. Added asparagine increased the levels of asparagine in dough and of acrylamide in bread (p < 0.001). A strong correlation was found between the contents of asparagine in the fermented dough and acrylamide in breads at all levels of asparagine. Glycine significantly increased the colour intensity and reduced the acrylamide in bread (p < 0.001) with the latter effect being dependent on the level of asparagine.     

A stability study of green tea catechins during the biscuit making process

A green tea extract (GTE) was incorporated into biscuit as a source of tea catechins. The stability of tea catechins in the biscuit making process was studied. A method was developed for the separation and quantification of tea catechins in GTE, dough, and biscuit samples using a RP-HPLC system. GTEs at 150, 200, and 300 mg per 100 g of flour were formulated. The results obtained showed that green tea catechins were relatively stable in dough. The stability of (−)-EGCG and (−)-ECG was determined at an interval of every 2 min during baking. Their stability decreased as the baking progressed and increased as the concentration of GTE was increased in the biscuit dough. The stability of (−)-EGCG also increased as pH of the dough was reduced and made less alkaline.     

Effect of high pressure processing on sugar‐snap cookie dough preservation and cookie quality

In this study, cookie dough was subjected to high pressure processing (HPP) to evaluate the effect of this technology on the microbiological features and on the quality characteristics of both the dough and the cookies. HPP reduced the microbial counts of mesophilic bacteria and yeast/molds. Microbiological inactivation in the cookie dough was maintained for 7 days of storage at ambient temperature suggesting extended shelf‐life of the cookie dough. Cookie dough treated with HPP had higher density. Upon baking the spread rate of HPP treated dough was higher resulting in less baking time. The HPP cookie dough and the corresponding cookies made from them had darker tones compared to the untreated dough. Digital images of cookie surfaces showed that HPP cookies had smoother surface and tiny cracks which were evenly distributed.

Practical applications

The utilization of high pressure for processing represents an opportunity to aid in the preservation and extension of self‐life of cereal products. Cookie dough, traditionally not preserved a room temperature, can be processed by high pressure and stored at ambient temperature. Cookies prepared with high pressured cookie dough spread faster during baking reducing total cooking time significantly, reducing, thus, processing time. Cookie quality characteristics are not significantly affected by high pressure processing.     

Rheological and physical evaluation of jet‐cooked oat bran in low calorie cookies†

Different levels of shortening in cookies (10%, 20% and 30% by weight) were replaced with 20% jet‐cooked oat bran, also called Nutrim oat bran (OB), to prepare cookies with fewer calories. The cookies containing Nutrim OB were investigated in terms of rheological and physical properties and compared with a control. As more shortening was replaced with Nutrim OB, a decrease in the diameter and an increase in the height of cookies were observed. The increased moisture content from Nutrim OB caused a decrease in the dynamic viscoelastic properties of cookie dough. Squeezing flow method showed shear thinning behaviours in all cookie doughs. Also, the elongational viscosity of cookie dough decreased significantly with more replacement of shortening with Nutrim OB. The rheological properties of cookie dough during baking indicated that all of the samples had similar types of viscoelastic characteristics during baking. However, the cookies containing more Nutrim OB exhibited more elastic properties which resulted in a decreased cookie diameter. There was no significant difference in cookie hardness among samples with up to 20% shortening replacement but the cookies became lighter in colour as the Nutrim OB content was increased.     

Impact of mixing time and sodium stearoyl lactylate on gluten polymerization during baking of wheat flour dough

The impact of differences in dough transient gluten network on gluten cross-linking during baking is insufficiently understood. We varied dough mixing times and/or added sodium stearoyl lactylate (SSL; 1.0% on flour dry matter basis) to the recipe and studied the effect on subsequent gluten polymerization during heating. The level of proteins extractable in sodium dodecyl sulfate containing media was fitted using first order kinetics. The extent and rate of gluten polymerization were lower when mixing for 8 min than when mixing for 2 min. This effect was even more outspoken in the presence of SSL. The present observations were explained as resulting from less gliadin incorporation in the polymer gluten network and from interaction of SSL with the gluten proteins. Finally, a higher degree of gluten polymerization during baking increased the firmness of the baked products.