Significance of furosine as heat-induced marker in cookies

The effects of recipe formulation in terms of leavening agents (ammonium and sodium bicarbonates), sugars (sucrose and glucose), initial moisture content, and baking conditions (temperature and time) on furosine formation in cookies were studied. The cookies were baked at different temperatures for different times to monitor the progress of the early stage of the Maillard reaction. Change in furosine levels as an indicator of the Amadori products showed a typical kinetic behavior with a rapid increase to an apparent maximum followed by exponential decrease during baking. Initial water activity of cookie dough had no remarkable effect on the apparent maximum, but lowering the water activity decreased the time required to attain it. In addition, levels of furosine in the final product are highly correlated to the initial water content of dough at the same baking conditions. The levels of furosine attained were significantly lower in cookies composed of sucrose than in cookies composed of glucose. Early stage of the MR is rapidly overcome during baking as the Amadori product degraded in the advanced stage. Among the leavening agents, ammonium bicarbonate was the most effective for the progress of the Maillard reaction in cookies during baking.     

Effects of extrusion cooking conditions and chemical leavening agents on lysine loss as determined by furosine content in corn based extrudates

The aim of this study was to investigate the effects of different variables on lysine loss as determined by furosine content in corn-based extrudates. Three formulations were prepared to study the effects of different chemical leavening agents, processing conditions (feed moisture content: 22, 24 or 26%; exit die temperature: 110 or 150 °C), and extrusion cooking methods (with/without CO₂ injection) on furosine formation. Furosine levels of extrudates from both extrusion methods decreased around 20% when feed moisture content was increased from 22% to 26%. Amadori compounds (precursor of furosine) are formed in the early stages of the Maillard reaction, and later they are converted to further products. Consequently, furosine contents of extrudates significantly decreased as exit die temperature increased from 110 to 150 °C. Furosine contents of extrudates produced with sodium- and ammonium-bicarbonate at 150 °C exit die temperature significantly decreased, while the ones produced at 110 °C significantly increased. This may be due to accelerated formation of fructosyllysine at higher pH values followed by early degradation at 150 °C. The CO₂ injection method did not have a significantly different effect on furosine content of extrudates than that produced by the conventional extrusion method, but had a positive effect on the physical properties of extrudates.     

Properties of sugar-snap cookies as influenced by lauric-based shortenings

The objective of this work was to assess the effect of different lauric-based shortenings with varying solid fat content (SFC) on sugar-snap cookie dough properties and cookie quality. Shortenings were produced by blending high oleic sunflower oil, palm kernel oil and palm stearin in different ratios, obtaining shortenings with different SFCs. It was observed that the SFC of the shortening largely influences the rheological properties of the cookie dough. At small deformations, fat crystals add elasticity to the dough; while at large deformations, fat-structure is disrupted, and it does not contribute to dough hardness. Fats with intermediate SFCs decrease dough resistance due to an enhanced shortening ability. Nevertheless, this effect is only obtained when shortening is homogeneously distributed in the dough. The SFC of the shortening influences dough and cookie structure by preventing gluten polymerization which was observed by a decrease in cookie break strength. A prerequisite for this effect is that shortening is finely dispersed in the dough. Good quality cookies were obtained using lauric-based shortenings, and best results were obtained with SFC between 20 and 25%. Higher SFC (around 45–50%) led to the production of unacceptable sugar-snap cookies.     

Effect of bread making on formation of Maillard reaction products contributing to the overall antioxidant activity of rye bread

This paper reports the effects of flour extraction rate on antioxidant activity, early, fluorescent and coloured Maillard reaction products in rye flour, crumb, crust and bread. Extent of the reaction was determined by analyses of furosine, fluorescence compounds and browning while antioxidant properties were measured by Folin reaction, Trolox Equivalent Antioxidant Capacity (TEAC) and Oxygen Radical Antioxidant Capacity (ORAC_FL) assays. Antioxidants present in rye flours and breads scavenged peroxyl and ABTS radicals and reduced Folin-Ciocalteu reagent. Data indicated that baking favoured the formation of antioxidant compounds. In controversy, milling to obtain white rye flour negatively affected bread quality.     

Enrichment of cookies with glutathione by inactive yeast cells (Saccharomyces cerevisiae): Physicochemical and functional properties

Cookie is one of the favorite cereal products which could be formulated by using various ingredients for enrichment. The aim of this study was to determine the effects of the inactivate yeast cells addition to cookie formulation in terms of glutathione (GSH) content, antioxidant activities, physicochemical and sensorial properties. Also, the cookies were produced with GSH (pure, 98%) addition to compare the effects of inactive yeast GSH with pure GSH on revealed properties. According to results, The GSH contents and the antioxidant activities increased in dough and cookie samples with inactive yeast addition compared to control and pure GSH added dough and cookie samples. The increases in GSH contents and antioxidant activities were observed after baking in all samples. The pure GSH addition increased the moisture content, spread ratio and L* value while decreased the hardness and b* values of the cookies. The contrary results were obtained by inactive yeast addition in terms of the physicochemical properties where the protein content of the cookies increased with inactive yeast addition by approximately 25%. The loss of GSH content decreased while the antioxidant activities and nutritional value increased in cookies by inactivate yeast addition.     

Physicochemical characteristics as the markers in predicting the self-life of gluten-free cookies

The objective of this study was to investigate the effect of different storage conditions on physicochemical stability assessment of gluten-free rice-buckwheat cookies. Second order polynomial (SOP) models were developed to explore the effects of storage time (0–6 months), at ambient (23 ± 1 °C) and elevated (40 ± 1 °C) temperature, packaging condition (packed and unpacked samples), and cookie surface position on the level of water activity (a_w), hydroxymethylfurfural content, peak force, and colour parameters (L*, a*, b*, h*, C*, ΔE*). The chemical characteristics of cookies were influenced by temperature, while the colour properties were mostly influenced by the position of the sample surface. The firmness was affected upon the synergy effect of temperature and packaging condition. The performance of the developed SOP models was to investigate the effect of storage conditions on the observed parameters, which showed a good fit to the experimental (r² > 0.8). The obtained results demonstrated that the developed empirical models gave an appropriate fit to experimental data and predicted the physicochemical properties at a satisfactory level, and that they could be successfully implemented to cookie stability assessment.     

A comparative study of physicochemical tests for quality prediction of Argentine wheat flours used as corrector flours and for cookie production

Several physicochemical tests are employed in quality evaluation of wheat. Most of the exported Argentinean wheat flour is used as corrector flour in breadmaking. A small percentage is actually used in cookie production. No study has determined which predictive tests are most suitable for the quality prediction of bread (using flour as corrector) and cookies made from Argentinean wheat. The objectives of this study were to compare the suitability of predictive tests in the assessment of wheat flour attributes in the production of bread and cookies and to establish the relationship between the tests and flour components. Several expected associations were found between the SRC test and the composition parameters. Moreover, various flour components influencing the SDS sedimentation index (SDS-SI), the Zeleny index and the alkaline water retention capacity (AWRC) were established. The cookie factor (CF) was negatively correlated with sucrose, carbonate and water SRC and with AWRC. In addition, the bread loaf specific volume (LV) was correlated with the SDS-SI, the Zeleny index and the lactic acid SRC. In conclusion, several components of Argentine wheat affecting predictive tests were found. The SRC test allowed straight assessment of the bread and cookie quality of Argentinean wheat.     

Dough mixing characteristics measured by Mixsmart software as possible predictors of bread making quality in three production regions of South Africa

South Africa has three wheat production regions, the winter rainfall region where spring wheat is planted; the summer rainfall where winter and intermediate wheat is cultivated; and the irrigation region where spring wheat is grown. The aim of this study was to determine dough mixing characteristics as measured by Mixsmart^® software in these three regions over seasons and locations, and to relate this to important quality characteristics. In the winter rainfall area Mixsmart characteristics were very poor predictors of baking quality, especially of loaf volume, flour protein content and wet gluten content. The best predictors of loaf volume in this region were flour protein content and wet gluten content, which were highly interrelated. In the irrigation area, midline peak value and midline right value were very good predictors of flour protein content, gluten content and loaf volume. Midline peak value was highly correlated with protein content in both the irrigation and summer rainfall areas and was a better predictor than peak time of baking quality. The ideal would be to select several parameters from the mixograph and use them in a multivariate statistical analysis to obtain a more accurate prediction of loaf volume in the irrigation and summer rainfall areas.     

响应曲面法优化美拉德反应以制备蘑菇酪氨酸酶活性抑制组分

MRPs作为天然抗褐变剂,可抑制引起果蔬酶促褐变的酪氨酸酶的酶活。为进一步优化美拉德反应以制备酪氨酸酶活性抑制组分,本研究采用响应面法对MRPs制备工艺进行研究。在单因素实验基础上,确定美拉德反应初始pH、反应温度、反应时间、底物浓度比(糖∶氨基酸)4个因素,设计4因素5水平的二次回归中心组合试验。经响应面法分析,为方便实际操作,确定最佳工艺条件为:初始pH为2.94,反应时间为1.9 h,反应温度为110.09℃,底物浓度比(糖∶氨基酸)为0.57。经实验验证,得出结果与理论值相对误差较小,故采用二次回归中心组合设计得到的最优MRPs制备条件参数准确可靠。     

Effects of formulation and extrusion cooking conditions on furfural and hydroxymethylfurfural content

The objective of this research was to investigate the effects of different ingredients (reducing sugars, leavening agents, citric acid), processing conditions (feed moisture content, exit die temperature), and extrusion cooking methods (with/without CO₂ injection) on furfural and 5-hydroxymethylfurfural (HMF) formation in corn-based extrudates. The decrease in furfural levels was 16% upon addition of sodium-bicarbonate, while the increase was 12% upon addition of ammonium-bicarbonate for extrudates produced at 150 °C and feed moisture content of 22%. The furfural concentration of extrudates produced at 150 °C and feed moisture content of 22% without leavening agents was 810 μg/100 g and increased to 11,901 μg/100 g upon citric acid addition (about a 15-fold increase). Furthermore, both low feed moisture and high exit die temperature had promoting effects on furfural and HMF contents. The CO₂ injection method did not have considerable effect on furfural and HMF levels of the extrudates; however, it positively affected the physical properties of extrudates.     

Physico-chemical properties of low-fat cookies containing wheat and oat bran gels as fat replacers

Wheat and oat bran-based fat replacers in the form of gels were used for partial replacement of fat (30–50%) in a cookie formulation. Dough rheological properties, physical (cookie dimension, weight loss, moisture content and water activity), textural (hardness and fracturability), colour and sensory parameters were evaluated to characterize full-fat and fat-reduced cookies. Based on the obtained results it was concluded that the fat reduction in cookie formulation at the level of 30% maintained sensory properties of the full-fat cookies. Therefore, this level of fat replacement was chosen for further analysis: 30% WBG (wheat bran gel-containing cookies) and 30% OBG (oat bran gel-containing cookies) were examined in terms of nutritional and functional properties. It was revealed that fat replacement using bran gels at the level of 30% resulted in the fat-reduced added-value cookies in terms of dietary fibre, minerals and phenolics. 30% WBG cookies possessed higher dietary fibre, mineral and phenolic content in comparison to 30% OBG and the full-fat cookies.     

Effect of different carbohydrates on the functional properties of black rice glutelin (BRG) modified by the maillard reaction

The objective of this study was to investigate the effects of the glycosylation of BRG on its structures and functional properties. The glycosylation of BRG was achieved via Maillard reactions with four carbohydrates, including arabinose (AN), sodium alginate (SA), maltodextrin (MD), and lactose (LT), and the corresponding conjugates were named BRG-AN, BRG-SA, BRG-MD, and BRG-LT, respectively. The formation of the BRG conjugates was confirmed by changes in the BRG amino groups, conjugation degree, as well as molecular weight. BRG-AN and BRG-MD presented a significantly higher conjugation degree and lower amino group levels compared to the other two conjugates. Circular dichroism (CD) analysis indicated that all the conjugated BRG displayed markedly decreased levels of β-sheets and increased levels of α-helixes. However, only BRG-AN increased significantly in irregular loops. Results from the Fourier Transform Infrared Spectroscopy (FTIR) analysis indicated that the most apparent changes in the structures of BRG conjugates were evident as absorption peaks at 3389 cm⁻¹, 1528 cm⁻¹, 1230 cm⁻¹, and 953–1180 cm⁻¹. After glycosylation, the solubility, emulsion activity index (EAI), and emulsion stability index (ESI) of BRG were significantly improved. After glycosylation of the BRG, induced by Maillard reactions with four carbohydrates, the denaturation temperature (T_d) and enthalpy (ΔH) change values increased substantially from 90.16 °C to 124.28 °C and 11.01 J/g to 18.43 J/g, respectively. The results indicated that BRG-AN exhibited better solubility, EAI, and ESI than the other BRG conjugates.     

Strain hardening as an indicator of bread-making performance: A review with discussion

Since strain hardening has been proposed as an important quality indicator of dough with respect to bread-making performance, a large body of experimental support for this concept has been published. Nevertheless, some questions remain with respect to the use of the concept of strain hardening. This is the subject of this review. Discussion points will include the most relevant indicator of strain hardening in relation to bread-making performance, methods to determine strain hardening and the benefits and limitations of using strain hardening as a parameter that characterises the bread-making performance of bread dough.     

葡萄糖-赖氨酸美拉德产物分级组分对香蕉酶促褐变的抑制

酶促褐变是香蕉加工中拟解决的关键问题,非硫安全高效抑制剂的筛选是目前的研究热点。美拉德产物（Maillard reaction products,简称MRPs）展示了其良好的抑制酶促褐变的能力,然而美拉德产物分级组分的相关研究尚未见报道。通过透析处理得到大于和小于3 500 u的分级组分,比较其抑制香蕉酶促褐变的相关能力,并对抑制机理进行研究。结果显示：3种MRPs中,MW>3 500 u的MRPs具有较好的还原力,MW<3 500 u的MRPs具有较好的DPPH·清除率、螯合铜离子能力以及抑制多酚氧化酶酶活的能力。MW<3 500 u的MRPs对游离酶抑制常数（KI）和对酶-底物络合物的抑制常数（KIS）分别为0.198 mmol/L和1.508 mmol/L,抑制类型属于混合型抑制。     

小麦脂类研究进展

小麦脂类是影响小麦品质的重要因素之一,与面包、糕点、南方馒头等食品的加工品质有密切关系。本文综述了小麦脂类的种类与分布,脂类分析方法,脂类、蛋白质互作和脂类、碳水化合物互作与烘烤品质的关系,脂类的遗传与品质改良等,旨在阐明小麦面粉中脂类的数量及组分、脂类与烘烤加工品质的关系及其作用机制,为从事相关研究及食品加工工作的人员提供参考。     

Effects of infrared heating on phenolic compounds and Maillard reaction products in maize flour

Maize grains were heated by infrared radiation for 50–100 s, than flaked and milled. The output was set to 110, 115, 120 and 140 °C to determine the effect of temperature on the formation of acrylamide, 5-hydroxymethylfurfural (HMF) and furosine, as well as the level of phenolic compounds in maize flour and its total antioxidant capacity (TAC). Acrylamide and HMF levels were increased as the load of the heat treatment was increased in grains, while furosine concentration was rapidly increased to an apparent maximum (34.96 μg/g) followed by decrease during heating. Acrylamide, as well as HMF variables correlated very well with TAC of heat-treated flour (r² = 0.98 and 0.86). The process of infrared heating had a great influence on the reduction of phenolic compound contents. However, new antioxidants that were formed as a result of the Maillard reaction increased the total antioxidant capacity of heat-treated maize flour.     

Applications of Green Tea Extract in Bakery Products

Green tea extract （GTE） is a rich source of tea catechins with antioxidative,anticarcinogenic and antiarteriosclerotic activities and it has been applied in food such as bakery products to provide health benefits and extend the shelf life.This review outlines the stability of green tea catechins during baking process of bakery products supplemented with GTE and the effects of GTE on the functional properties,sensory properties,physical characteristics and Maillard reaction of bakery products.     

Effect of germination on total phenolic compounds,total antioxidant capacity,Maillard reaction products and oxidative stress markers in canihua (Chenopodium pallidicaule)

Germination of cereals/pseudo-cereals has been suggested as an effective method to increase antioxidant compounds. However, this process could also lead to high reducing sugar levels and subsequent Maillard reaction products. The aim of this work was to determine the time course effect of canihua (Chenopodium pallidicaule) germination on: 1) antioxidant capacity, 2) extractable and non-extractable phenolic compounds content, 3) Maillard reaction products and 4) oxidative stress markers. Germination increased antioxidant capacity, phenolic compounds and Maillard reaction products, including advanced glycated end products while it decreased oxidative stress markers. All parameters exhibited a similar time course pattern with a maximum at 72 h. In addition to the increase in phenolic compounds and antioxidant capacity, canihua germination produced advanced glycated end products. The impact on human health of these compounds in germinated seeds deserves future attention.     

烟叶烘烤研究进展

综述了品种、成熟度、烤房类型、装烟方式和密度、工艺技术等影响烟叶烘烤质量的因素,讨论了培育易烤性好的品种、改良密集烤房、推广烟草机械化生产、开发利用新能源等提高烟叶烘烤质量的措施,并就下一步研究重点进行了展望。     

壳聚糖降低蔗汁氨基酸的试验

通过壳聚糖降低混合汁和滤清汁氨基酸含量的试验研究,认为壳聚糖对除去蔗汁氨基酸有一定效果,并提出了在制糖生产中减少美拉德反应的措施。