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.     

Effects of dough formula and baking conditions on acrylamide and hydroxymethylfurfural formation in cookies

The effects of dough formula and baking conditions on the formations of acrylamide and hydroxymethylfurfural (HMF) were studied in a cookie model system. Increasing the sugar concentration in the dough formula increased acrylamide formation during baking at 205 °C for 11 min. The effect of sugar on acrylamide formation was more pronounced for glucose than for sucrose, expectedly. Addition of citric acid into dough formula comprising sucrose increased the susceptibility of acrylamide formation, while it decreased acrylamide formation in the dough formula comprising glucose. Decreasing the pH of dough formula increased the tendency to surface browning and the formation of hydroxymethylfurfural in cookies during baking. The results suggest that a cookie with acceptable texture and colour, but having less than 150 ng/g of acrylamide, can be manufactured by lowering the baking temperature and avoiding reducing sugars in the recipe.     

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.     

On-line dynamic HS-SPME for monitoring endogenous aroma compounds released during the baking of a model cake

This work shows that using a dynamic SPME device combined with an instrumented oven, it is possible to monitor the release of a large amount of volatile compounds generated during the baking process of a real cereal product (sponge cake model) by directly sampling its baking vapours. The steam assisted dynamic SPME device made it possible to extract volatile compounds with very different volatility and hydrophobicity, such as 5-hydroxymethylfurfural and 2-methyl-propanal. Time dependent analyses of baking vapours made it possible to simultaneously follow the release of several odour compounds and thermal reaction markers at different stages of their generation in the sponge cake model. The release of newly formed aroma compounds during baking significantly affected the odour quality of baking extracts as shown by odour profiles and sensory preferences evaluated by Direct-GC–Olfactometry. GC–Olfactometry analysis was carried out on the final baking fractions to gain an understanding of the compounds which could contribute to overall odour quality.     

Starch Functionality in Cookie Systems

To study the function of starch in cookie baking, starch was isolated from a cookie flour and from cookies baked with the flour. Viscograms of starches indicated no detectable changes caused by cookie processing. Swelling power, solubility, gelatinization temperature range and enzyme susceptibility were unchanged by cookie preparation. X-ray diffraction patterns of starch isolated from cookies showed a strong “A” pattern. The starch was not affected by the baking process. Differential scanning calorimetry showed no apparent differences in phase transition peaks. Starch-gluten breads produced were of similar volume and quality characteristics. It was concluded that a) starch granules remain in their native condition during cookie baking, b) starch does not form a continuous structure in cookies and c) retrogradation cannot occur during cookie storage.     

Study of hydroxymethylfurfural and furfural formation in cakes during baking in different ovens,using a validated multiple-stage extraction-based analytical method

A procedure for extraction of hydroxymethylfurfural (HMF) and furfural from cakes was validated. Higher yield was achieved by multiple step extraction with water/methanol (70/30) and clarification with Carrez I and II reagents. Oven type and baking time strongly influenced HMF, moisture and volatile profile of model cakes, whereas furfural content was not significantly affected. No correlation was found between these parameters. Baking time influenced moisture and HMF formation in cakes from traditional and microwave ovens but not in steam oven cakes. Significant moisture decrease and HMF increase (3.63, 9.32, and 41.9 mg kg⁻¹ dw at 20, 40 and 60 min, respectively) were observed during traditional baking. Cakes baked by microwave also presented a significant increase of HMF (up to 16.84 mg kg⁻¹ dw at 2.5 min). Steam oven cakes possessed the highest moisture content and no significant differences in HMF and furfural. This oven is likely to form low HMF and furfural, maintaining cake moisture and aroma compounds.     

Accumulation of 5-hydroxymethyl-2-furfural in cookies during the backing process: Validation of an extraction method

During baking, complex chemical reactions take place in the cookies, such as the Maillard reaction (MR) and caramelisation (CR). Both reactions involve glucose and fructose, generated from starch and sucrose hydrolysis during baking. Among the many products formed, HMF a possible mutagen, seems particularly interesting because of a rapid accumulation during the process.     

天然抗氧化剂抑制曲奇中丙烯酰胺含量的研究

采用天然抗氧化剂荞麦、孜然和黑种草籽抑制曲奇中丙烯酰胺的生成。研究这3种配料对面粉中丙烯酰胺前体的含量、面粉和曲奇抗氧化的特性、曲奇烘焙特性和丙烯酰胺含量的影响,结果表明：这3种配料组合都可以增加面粉中还原糖和天门冬酰胺的含量,也可以增加面粉和曲奇的抗氧化特性(包括总酚类物质、DPPH自由基清除能力和ABTS+·的抑制能力)。当所添加的天然抗氧化剂含量增加时,曲奇颜色变深,表现为更低的L*,a*和b*值;荞麦和孜然的引入会增加曲奇中的水分含量,而黑种草籽则相反。所有天然抗氧化剂组合都可以增加曲奇的延展率。未添加天然抗氧化剂的曲奇中丙烯酰胺的含量为361.2μg/kg,而单独添加15%荞麦、15%孜然和15%黑种草籽使得曲奇中丙烯酰胺的含量分别降低了20.2%、67.6%和75.9%。感官分析结果表明：富含天然抗氧化剂的曲奇都可以被人们所喜欢。     

Acrylamide and 5-hydroxymethylfurfural formation during baking of biscuits: NaCl and temperature–time profile effects and kinetics

The present study aimed to investigate the effect of recipe and temperature–time on the formation of acrylamide and 5-hydroxymethylfurfural (HMF) during biscuit baking. Baking experiments were performed with biscuits of two different recipes, with and without NaCl, at 180 °C, 190 °C and 200 °C. Acrylamide and HMF reached highest concentrations at 200 °C for both recipes. The presence of NaCl in the biscuit formulation lowered acrylamide concentrations at 180 °C and 190 °C but not at 200 °C, and led to higher concentrations of HMF at all the tested temperatures. Sucrose hydrolysis was a key step in acrylamide and HMF formation during biscuit baking, even though a significant amount of acrylamide already had formed before the onset of sucrose hydrolysis. A lag phase was observed before sucrose hydrolysis occurred, which might depend on the melting of crystalline sucrose occurring at approximately 180 °C.A mathematical model based on the chemical reaction pathways was developed for the recipe with NaCl baked at 200 °C. The model described the chemical evolution during the last part of biscuit baking, and accurately predicted acrylamide and HMF content at the end of baking. The model showed the significant contribution of the reducing sugars to the formation of both acrylamide and HMF. The model could not be extended to the entire baking period because it was not possible to incorporate the lag phase observed before sucrose hydrolysis. The results reported in this study confirm that the kinetics of acrylamide and HMF formation in real food and dry systems may depend on the physical state of their precursors.     

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 flavour solvent (propylene glycol or triacetin) on vanillin, 5-(hydroxymethyl)furfural, 2,4-decadienal, 2,4-heptadienal,structural parameters and sensory perception of shortcake biscuits over accelerated shelf life testing

The influence of choice of flavour solvent, propylene glycol (PG) or triacetin (TA), was investigated during accelerated shelf life (ASL) testing of shortcake biscuits. Specifically, the differential effect on the stability of added vanillin, the natural baked marker compound 5-(hydroxymethyl)furfural (HMF), specific markers of oxidative rancidity (2,4-decadienal, 2,4-heptadienal), and the structural parameters of hardness and fracturability. Significantly more HMF was formed during baking of biscuits prepared with TA; these biscuits were also more stable to oxidative degradation and loss of vanillin during ageing than biscuits prepared with PG. Fresh TA biscuits were significantly more brittle than fresh PG biscuits. There was no impact of solvent choice on hardness. Sensory evaluation of hardness, vanilla flavour and oily off-note was tested during ASL testing. There was no significant impact of storage on sensory ratings for either the PG or TA biscuits.     

EFFECT OF SODIUM METABISULFITE ADDITION AND BAKING TEMPERATURE ON MAILLARD REACTION IN BREAD

ABSTRACT

In this study, the effect of sodium metabisulfite (SMBS) doses (0, 25, 50, 100 mg/kg dough) and baking temperatures (200, 230 and 250C) on the physical, chemical and sensory properties of bread were researched to reduce 5‐hydroxymethyl‐2‐furfural (HMF) and acrylamide contents. HMF and acrylamide contents of bread crust were decreased significantly by increasing SMBS dose and decreasing baking temperature. The HMF (137.29 mg/kg) and acrylamide (671.44 µg/kg) contents of bread crust were decreased by 33 and 67%, respectively by addition of 100 mg/kg SMBS. The maltol content of bread crusts were significantly affected by baking temperature, and were 7.19, 10.23 and 22.69 mg/kg in breads baked at 200, 230 and 250C, respectively. No HMF, acrylamide and maltol were detected in the bread crumb. The sulfur dioxide content of the crust and crumb of control bread was 6.99 and 10.69 mg/kg, and increased by 49 and 59%, respectively at 100 mg/kg SMBS dose. All breads were evaluated as acceptable by a sensory panel.

PRACTICAL APPLICATIONS

Since Maillard reaction products such as acrylamide and 5‐hydroxymethyl‐2‐furfural (HMF) are known as toxic compounds, mitigation of these compounds is important subject for health and nutrition. There is not an efficient method to prevent the formation of acrylamide and HMF in bread crusts comparison with potato crisps. The purpose of this research is to slow down Maillard reaction by addition of sodium metabisulfite in bread‐making process. As a result of this research, acrylamide and HMF content of bread crusts decreased by 33 and 67%, respectively with acceptable sensory evaluation.     

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.     

谷氨酸—木糖美拉德中间体的水相制备及其在桃酥中的应用

以谷氨酸和木糖为原料,研究反应时间、反应物配比、初始反应pH及真空脱水对谷氨酸—木糖美拉德反应中间体转化率的影响。结果表明,脱水过程可显著提高谷氨酸—木糖美拉德中间体的转化率至75.11%。为研究中间体在烘焙食品中的应用,将中间体以不同比例添加到桃酥中,通过GC/MS及感官评定等方法分析其对桃酥的风味影响,研究发现,中间体的添加可显著提高桃酥中吡嗪、吡咯的含量,丰富焙烤香气。随着中间体添加量的增大,桃酥中挥发性风味物质的总量提高,结合感官评定的结果,最终确定添加0.3%谷氨酸—木糖美拉德中间体时,整体增香效果最好。     

Inhibition of polyphenoloxidase activity by mixtures of heated cysteine derivatives with carbonyl compounds

It had previously been shown that soluble Maillard reaction products (MRP) made from thiol compounds and glucose or fructose contained powerful inhibitors of various fruit and vegetable polyphenoloxidase (PPO) activity. In MRP from cysteine and glucose, the amount of hydroxymethylfurfural (HMF) formed increased with the increase in glucose concentration (0-1 M), particularly under acidic (pH 2) conditions. Using model mixtures containing a preheated cysteine-derived compound and a carbonyl component, especially HMF, furfural and benzaldehyde, we showed that the neoformed compounds produced exhibited a stronger inhibitory potency toward PPO activity of eggplant, apple, and mushroom than former MRP. Optimal reaction conditions for the formation of inhibitory compounds when HMF reacted with preheated cysteine were investigated. It was found that a reactants molar ratio of 1:1 and a reaction time exceeding 1 h were the most efficient reaction conditions to generate inhibitory compounds. The stability of the newly formed products, evaluated during storage, showed that their inhibitory potency was globally kept at 4, 21, and 37 degrees C for 72 h but was unstable when stored at -20 degrees C and lost when exposed to UV radiations for 24 h.     

Acrylamide formation in a cookie system as influenced by the oil phenol profile and degree of oxidation

The purpose of this study was to investigate the effect of the olive oil phenolic compounds as well as of thermoxidised oil on the formation of acrylamide in a cookies system. Three virgin olive oils having different phenolic profile and a thermoxidised sunflower oil were selected. Cookies were baked at 190 °C for different times (8–16 min) following a basic recipe where type of oil was the variable. Additionally to acrylamide (AA), other parameters such as colour, moisture, antioxidant activity (AOA), and hydroxymethylfurfural (HMF) were measured. Results showed that concentration and composition of phenolic moiety of virgin olive oil significantly affect the acrylamide formation, particularly at prolonged baking time. Virgin olive oil with a higher dihydroxy/monohydroxy ratio was more efficient in the AA mitigation and AA was reduced up to 20%. Colour and AOA were not significantly different among the three types of oils. However, AA is dramatically increased when thermoxidised oil is used with a parallel increase of browning and HMF. It was concluded that lipid oxidation products should be considered as an important factor in acrylamide formation during baking of fat-rich products.     

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.     

Anthocyanin Degradation in the Presence of Furfural and 5-Hydroxymethylfurfural

The influence of furfural (F) and 5-hydroxymethylfurfural (HMF) on degradation of cyanidin-3-glucoside (CG) was investigated in blackberry juice and in a citrate buffer model solution (pH 3,45) at 24°, 50° and 70°C. Presence of 0.012 M F or HMF accelerated pigment degradation. The acceleration was directly temperature-dependent, more pronounced in fruit juice, and considerably decreased in nitrogen. CG and HMF disappearance – but not the interaction between these compounds – followed the first-order reaction kinetics. The influence of formaldehyde (Fa) acetaldehyde (Aa) and benzaldehyde (Ba) on the stability of CG was investigated in blackberry juice. CG degradation effect of non-furane aldehydes (0.012 M) was Fa < Aa < Ba. CG and cyanidine (C) reactivities were studied by condensation with F and examination of molecular electrone properties (cyanidine, keto-pseudobase, anhydrobase, chalcone). Furfural did not react with CG but it did react with C. Electron charge distribution points to anhydrobase as the tautomeric form of C most reactive to F. Possible mechanisms of C decomposition in presence of F are proposed and discussed.     

Effect of temperature and some added compounds on the stability of blood orange marmalade

Jams and marmalades are often wrongly believed to be stable products, as the degradation of pigments such as anthocyanins, browning reactions, and the formation of sugar degradation products may occur during storage. The paper aims at studying some of the degradation reactions occurring in blood orange marmalade stored at 20 °C and 35 °C. The addition of natural (tea extract) and naturally occurring (ascorbic acid, cysteine, gallic acid) compounds to marmalade was addressed at investigating the possible effect on retarding such phenomena. Results highlight the dependence of anthocyans and 5-hydroxymethyl-2-furaldehyde (HMF) levels on the storage temperature. Marmalades added with cysteine, unlike the samples added with phenol compounds, showed higher anthocyans and lower HMF levels just after processing, together with a reduced anthocyan loss kinetics and a slowdown of HMF formation during storage at both temperatures. PRACTICAL APPLICATION: Transformation of blood oranges into marmalade represents an alternative to fresh market in periods when the high availability of the citrus causes the collapse of prices. Blood orange marmalade is characterized by a high nutritional value, however, it is not widely distributed yet. Its storability is limited by color and organoleptic changes that influence consumers' acceptance. The optimization of blood orange marmalade preparation could help producers improve storability and widen distribution.     

Changes in Bioactive Compounds, Antioxidant Activity and HMF Formation in Rosehip Nectars During Storage

In this study, reaction kinetics of ascorbic acid degradation and hydroxymethylfurfural (HMF) formation in glass-bottled and cardboard-packaged rosehip nectars stored at 25, 35 and 45 °C were evaluated. Variations of total phenolics, total carotenoids, and antioxidant activity of samples were also evaluated. HMF formation followed a zero-order reaction, while a first-order reaction model was fitted to ascorbic acid degradation. The activation energies for ascorbic acid degradation and HMF formation were found as 56–63.9 and 42.9–53.0 kJ mol^?1, respectively. During storage, total phenolics content of rosehip nectars were decreased significantly. However, changes in the total carotenoids of rosehip nectars during storage were not statistically significant. Decreases in the antioxidant activity of glass-bottled rosehip nectars during storage at all applied temperatures were found statistically significant, whereas no significant variations were observed in the antioxidant activities of cardboard-packaged rosehip nectars.