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.     

Extrusion-based 3D printing of food pastes: Correlating rheological properties with printing behaviour

Development of 3D food printing applications requires in-depth knowledge on printing behaviour of food materials. In extrusion-based 3D printing, rheological properties of a recipe are critical to achieve successful printing. The objective of this research is to investigate potential correlations between printability of formulations and simple rheological properties. We used tomato paste as a model system to investigate the correlation between printing stability, dispensability and rheological properties. The results show a linear correlation between ingredient's flow stress, zero shear viscosity and corresponding printing stability. The extrusion pressure necessary to extrude tomato paste increased linearly with increasing flow stress. More experiments with other aqueous-based food formulations indicated that their printability aligned reasonably well with the correlation of tomato paste; however, for fat-based products different printing behaviour was observed. Finally, we propose a rational guideline for developing aqueous food recipes with desired printability based on flow stress measured by shear rheology.     

Parameters affecting the printability of 3D-printed processed cheese

In considering three-dimensional (3D) printing of food materials, fundamental understanding of the “printability” characteristics of different food materials is of vital importance to successfully meet user needs. In this study, a processed cheese formulation was 3D-printed with a modified 3D printer. Both intrinsic factors (i.e., pH and intact casein content) and measureable attributes (i.e., texture, printing accuracy, rheology and microstructure) were analysed. Using rheological methods, the optimal viscosity range (7.55–10.94 Pa.s) at which processed cheese will print successfully (i.e., simultaneously flow from the extrusion head uninhibited and build a layered structure) was identified. Processed cheese with a higher pH (5.8) was found to give a printed product that was significantly (P < 0.05) softer, gummier and more resilient in texture than the same recipe with a lower pH (5.4 and 5.6). Printed cheese containing exclusively fresh curd was significantly (P < 0.05) harder than that containing mild or mature Cheddar cheese. 3D printing at higher temperatures (60 °C) led to harder and more resilient cheese than printing at lower temperatures (40 °C). Overall, formulation and printing parameters for processed cheese significantly affect properties relating to “printability”.     

Impact of processing parameters and post-treatment on the shape accuracy of 3D-printed baking dough

Apart from the material compositions, processing parameters of a 3D printer also affect the modelling effect of printed samples. This paper presents the influence of processing parameters including filament diameter (2.10, 2.30, 2.50 mm), nozzle movement speed (20, 25, 30 mm/s), nozzle diameter (0.8, 1.5, 2.0 mm) and nozzle height (2.10, 2.40, 2.60 mm), as well as that of post-process fast-cooling (−65 °C; 0, 5, 10 min), on the rheological properties and geometric accuracy of a 3D-printed food construct made of baking dough (BD). Results showed that the printed object whose shape best matched the target geometry could be obtained with the following processing parameters: filament diameter of 2.30 mm, nozzle movement speed of 25 mm/s, nozzle diameter of 2.0 mm and nozzle height of 2.40 mm during 3D printing, combined with fast-cooling at −65 °C for more than 10 min after printing and before baking.     

小米曲奇预拌粉配方的优化

以预糊化小米粉为主要原材料,研制小米曲奇预拌粉。通过单因素试验,研究小米粉添加量、吉士粉添加量、奶粉添加量、泡打粉添加量、糖粉添加量对小米曲奇感官评分和硬度的影响。采用Box–Behnken法设计试验方案,运用响应面分析法建立二阶多项式非线性回归方程和数值模型,以感官评分和硬度为评判指标,优化小米曲奇预拌粉配方。优化后配方为:小米粉60.00g、低筋面粉40.00 g、吉士粉6.50 g、泡打粉1.00 g、糖粉45.00 g、奶粉8.00 g。在此条件下小米曲奇的理论感官评分为95.04分、硬度为510.11 g。在此配方下制作的小米曲奇呈棕黄色,与市售黄油曲奇相比,具有独特的小米香气和风味。预拌粉降低了小米曲奇制作的专业性、技术性,提高生产效率,利于生产品质稳定、健康味美的小米曲奇产品。     

Shear-induced structuring of phase-separated sodium caseinate - sodium alginate blends using extrusion-based 3D printing: Creation of anisotropic aligned micron-size fibrous structures and macroscale filament bundles

3D food printing is considered a promising method to prepare personalized foods having unique macroscopic design and composition. It is still challenging to create 3D printed foods with tailored microstructure, e.g. fibrous microstructures, to print meat-like foods. In this study we investigated the preparation of 3D printed model food gels that have macro- and microscale aligned fibrous structures using sodium caseinate - sodium alginate (SC/SA) blends with extrusion-based printing. A bath containing an agar fluid gel was used to allow precise deposition and solidification of the SC/SA blend after the printing process. Besides, the influences of nozzle type and printing speeds on texture were assessed. We succesfully created aligned micron-size fibrous structures and macroscale aligned filament bundles. Filaments extruded using tapered nozzles had finer fibrous structures compared to those extruded using straight nozzles. Both printing speed and nozzle type significantly influenced Young's moduli of 3D printed model food gels. A higher printing speed resulted in smaller Young's moduli of individual printed filaments. This study shows that anisotropic structures can be created by extrusion-based 3D printing of phase-separated sodium caseinate - sodium alginate blends. The results of this study might become relevant when striving for meat analogues made by 3D-printing.     

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.     

An exploratory consumer study of 3D printed food perception in a real-life military setting

3D printing has the potential to produce on-demand food tailored to individuals’ needs and preferences. The present study explored 3D printed food acceptance in a real-life military setting. Over a period of 4 weeks, soldiers consumed and evaluated multiple recovery snack bars. In week 1, participants received a benchmark bar that was created with conventional manufacturing processes. In week 2 to 4 participants received a 3D printed snack bar with increasing customisation options: choice of texture (soft or crunchy) in week 2; choice of texture and taste (sweet or savoury) in week 3; and choice of texture, taste and ingredients (4 types of dough, 13 types of filling) in week 4. Attitudes towards 3D food printing and potential drivers of 3D printed food acceptance were assessed in weeks 1 and 4 before and after repeated consumption of the snack bars.After repeated consumption participants judged 3D printed food to be significantly better as compared to before consumption (t = 2.86, p = 0.015). Food neophobia, food technology neophobia and food choice motives did not change during the experiment (all p > 0.05). The benchmark bar was liked better than the 3D printed bars. However, among the 3D printed bars, mean scores on overall liking, and liking of taste and texture were highest for the version that was customized most (week 4). Our findings illustrate that consumer empowerment, desired degree of personalisation, state of development and appropriateness of 3D food printing technology all play a role in 3D printed food acceptance.     

小麦面粉的3D打印特性

本实验以8种不同蛋白质量分数小麦面粉为研究对象,通过测定其理化特性、糊化特性、混合特性、流变特性及3D打印特性,研究小麦面粉不同品质特性与3D打印特性的关系。结果显示,蛋白质量分数对小麦面粉的3D打印特性有显著影响,蛋白质量分数在9%～10%时（ZY原味小麦粉、BN 4199小麦粉和XL中式面点粉）打印效果较好,制品整体形状规则、表面平整、纹路清晰,与模型的符合程度较高。面团的损耗模量（G’’）影响其挤出行为,而储能模量（G’）影响其支撑三维结构的能力,ZY原味小麦粉面团的损耗角正切值（tan δ）较大,有利于面团挤出成型;XL中式面点粉G’较大,有利于面团打印后保持自身的形状。在选用的8种小麦面粉中,XL中式面点粉的蛋白质量分数为9.33%,与设计的30 mm×30 mm×10 mm模型相比,其打印体积误差仅为0.26%。打印制品蒸制熟化后在X轴和Y轴方向上长度略有增加,但Z轴方向上长度略有减小,且发生一定程度的褐变。综上,小麦面粉作为3D打印材料是可行的,这有利于拓展3D打印技术在食品领域的应用。     

Optimization of chocolate 3D printing by correlating thermal and flow properties with 3D structure modeling

3D printing is a new promising technology capable of creating intricate food shapes. To stabilize the mechanical properties of the complex printed food it may require support structures. The 3D shape of chocolate was designed with different support structures (cross support, parallel support and no support) and its effect on the snapping properties was investigated. This study also determined the relationship between the physical properties of chocolate used for printing and the quality of the printed 3D constructs. The dimensions (wall thickness, height, and diameter), weight as well as physical properties (melting properties, flow behaviour, snap ability) of the 3D printed chocolate were evaluated. The nozzle temperature before deposition was maintained at 32 °C in order to extrude the melted state of the sample as the flow behaviour curves indicated that the melting of chocolate started between 28 °C to 30 °C. Incorporation of Magnesium Stearate (MgST) in the chocolate formulation aid in material lubrication and increase flow efficiency during deposition. Results showed that there was a minor difference between the predetermined diameter and the actual output diameter for each sample suggesting similarity between the printed 3D structure and the pre-designed 3D model. Wall thickness of printed item varied along the height due to uneven deposition of chocolate as the layer height increased. The breaking strength of the sample was strongly related to the additional support structure, with 3D chocolate with cross support structure requiring the highest force (N) to break the sample.Industrial relevanceThe development and production of food with 3-Dimensional printing (3DP) technology has potential to create and produce food in a more advanced format that will be a new paradigm shift in the food industry. Through 3D printing, personalised food can be created in terms of shape and nutritional composition. To firmly establish this promising technology as a powerful tool for engineering food it is required a thorough understanding of the supply ingredients and strategies to enhance printability. This study demonstrates the use of flow enhancer and inclusion of support structure in the designed shape were key factors influencing printability capacity of chocolate (edible ink chosen as a model).     

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.     

红枣桃酥的加工工艺研究

以糕点专用粉、红枣粉为原料,起酥油、白砂糖、碳酸氢钠、碳酸氢铵、鸡蛋等为辅料,通过单因素试验和正交试验确定出加工红枣桃酥的最佳配方为：糕点专用粉100g、红枣粉6g、起酥油55g、白砂糖30g、膨松剂（碳酸氢钠0.8g、碳酸氢铵1.2g）2.0g。在此工艺条件下,制成的桃酥在保持了传统桃酥口感和风味不变的同时,降低桃酥中糖的用量,并赋予了桃酥新的营养价值。     

Synergistic effect of microwave 3D print and transglutaminase on the self-gelation of surimi during printing

To improve the molding quality of 3D printed surimi products under the disturbance of self-gravity and post-processing, the synergistic effect of a microwave 3D print (MW3DP) and transglutaminase (TGase) on the self-gelation process of surimi from fluid to solid gel state during 3D printing is investigated. Simulation and 3D printing results show that microwave power affected the extrudability by changing the temperature distribution of surimi in the nozzle. Rheological properties of the squeezed-out surimi were monitored while the gel properties, microstructure and self-gelation mechanism of products after printing were analyzed. Surimi exhibited shear-thinning behavior when microwave power was less than 60 W/g. After printing, the solid gels with better shape fidelity and large protein aggregates appeared at 40 and 50 W/g when TGase was added. Results indicate that hydrogen bonds and ɛ-(γ-Glu)-Lys are main forces to maintain molding quality, and TGase is activated by microwaves to promote the self-gelation process.Industrial relevance3D food printing, as an emerging technology in food industry, has great potential in meeting the individual needs of consumers for shapes and nutrition. One of the challenges that restricts the large-scale industrialization and commercialization of 3D food printing is that deformation will occur during printing and subsequent processing because most food materials are still flowing after printing. This study provided a synergistic method of MW3DP with a focused heating mode and TGase, realizing self-gelation of surimi during printing. A solid product with high resistance to deformation was obtained in this condition. Valuable guidance is provided to obtain heat-induced solid products with better shape fidelity. In addition, a more complex hollow shape can be printed to improve the personalization of food manufacturing, thus promoting further applications of 3D printing in food industry.     

Comparison of nutritional quality,phenolic compounds,and antioxidant activity of conventional and 3D printed biscuits from wholegrain and multigrain flours

Complementing traditional food processing techniques with emerging ones like three-dimensional (3D) food printing can re-innovate the derived products as more consumer-centric with known human wellness values. This study investigated the nutritional quality, polyphenol composition, and antioxidant activity of conventional and 3D printed biscuits from the same wholegrain and multigrain flours. Fermented cowpea and germinated quinoa were bioprocessed at 28 °C for 48 h and freeze-dried to obtain cowpea sourdough and malted quinoa flours, and the flours subsequently used to prepare kneaded and shaped dough or 3D printed dough baked as biscuits. Some chemical compositions of the biscuits revealed minute differences in ash, fiber, protein, threonine, serine, as well as potassium content and significant differences (p ≤ 0.05) in total flavonoid contents and phenolic compounds. The 3D printed biscuits from biomodified flours had improved concentrations of methionine, aspartic, glutamic, higher iron and phosphorus contents, slightly varied antioxidant activities, and better appearances than the corresponding conventional biscuits. The comparable and improved chemical compositions of the 3D printed biscuits indicate the possible use of value-added intermediate products from traditional processing techniques with emerging technology to manufacture in-demand novel foods with wellness-promoting properties beyond basic nutrients.     

3D printed meat and the fundamental aspects affecting printability

Three-dimensional (3D) printing, one of the forms of additive manufacturing, has become a popular trend worldwide with a wide range of applications including food. The technology is adaptable and meets foods nutritional and sensory needs allowing meat processing to reach a sustainable level, technology addressing the food requirement of the ever-increasing population and the fast-paced lifestyle by reducing food preparation time. By minimizing food waste and the strain on animal resources, technology can help to create a more sustainable economy and environment. This review article discusses the 3D printing process and various 3D printing techniques used for food printing, such as laser powder bed fusion, inkjet food printing, and binder jetting, a suitable 3D technique used for meat printing, such as extrusion-based bioprinting. Moreover, we discuss properties that affect the printability of meat and its products with their applications in the meat industry, 3D printing market potential challenges, and future trends.     

Reducing freeze-thaw drip loss of mixed vegetable gel by 3D printing porosity

This research aimed to reduce freeze-thaw drip loss of the vegetable gel composite mixture of Chinese cabbage puree, carrot powder and xanthan gum by 3D printing porosity. Infill percentage (%) was set as printing parameter to change porosity of 3D printed samples. Infill percentage (%) of 20, 40, 60, 80, and 100 yielded porosities (%) of 54.97 ± 0.16, 38.25 ± 0.53, 21.82 ± 0.54, 1.06 ± 0.02 and 0 ± 0 respectively. The freeze-thaw drip loss of printed samples with different porosities varied significantly (p < 0.05). The drip loss (%) increased with increasing porosity, which were 5.06 ± 0.10, 5.49 ± 0.11, 7.17 ± 0.14, 7.92 ± 0.17, and 9.02 ± 0.16 respectively. The results of water distribution measured by Low field-nuclear magnetic resonance (LF-NMR) confirmed that the greater the porosity, the more the freeze-thaw drip loss. In addition, the printability, fidelity and textural properties of 3D printed mixed vegetable gel with different infill levels before and after freeze-thawing, as well as color of native mixed gel and freeze-thaw printed samples were also investigated.Industrial relevanceThis study provides ideas to reduce freeze-thaw drip loss of 3D printed mixed vegetable gel with high moisture content; the reduction of porosity during printing can be achieved by increasing the infill percentage appropriately without the need for other equipment for post-processing. This saves equipment costs and energy consumption in the industry. This procedure would allow the creation of foods with attractive appearances for consumption at either a restaurant or at home, as well as reducing drip loss after freeze-thawing.     

Effect of butter content and baking condition on characteristics of the gluten‐free dough and bread

This study aimed to investigate effect of butter content (0–30 g/100 g flour) and baking conditions hot air baking (HA), microwave baking (MW) and hot air‐microwave baking (HA‐MW) on quality of the rice flour dough and bread. The increased butter (up to 15 g butter/100 g flour) enhanced elastic modulus (G′) and viscous modulus (G″) of dough and specific volume of bread. Additionally, the increased butter improved crust colour and reduced hardness of the bread. The HA‐MW and MW conditions were useful for the gluten‐free bread by reducing baking time and predicted glycemic index (GI), regardless of butter content. However, enthalpy of retrogradation and crystallinity in the HA‐MW and MW bread stored at 4 °C for 7 days were increased and higher than those of the HA bread, indicating a faster staling. The predicted GI of both MW and HA‐MW bread remained at a medium level during storage.     

Microscopic structure,viscoelastic behaviour and 3D printing potential of milk protein concentrate-hydrocolloid complex coacervates

To prepare a milk protein-enriched ink for extrusion-based 3D food printing, this study investigated the effects of a wide range of hydrocolloids on the microstructures, viscoelastic characteristics and 3D printing performance of milk protein concentrate (MPC). The distributions of hydrocolloids and milk protein in mixed coacervates were characterised by fluorescent covalent labelling and confocal laser scanning microscope (CLSM), and the microstructure of the coacervates was observed by scanning electron microscopy (SEM). In addition, the rheological properties of prepared protein coacervates, including steady shear test, dynamic oscillatory test, thixotropy and creep recovery were investigated. Meanwhile, Burger’s model was fitted to the creep behaviour to further study their viscoelastic properties. The results showed that κ-carrageenan, pectin, guar gum and sodium alginate significantly increased the zero-shear viscosity, thixotropy and solid-like behaviour while xanthan showed an opposite phenomenon. Results showed that the presence of hydrocolloids improved the 3D printability of MPC by forming a complex network between protein particles and hydrocolloids, and guar gum, pectin and κ-carrageenan better help maintain the deposited 3D structures of MPC ink than xanthan.     

Effects of wheat sourdough process on the quality of mixed oat-wheat bread

The aim of this work was to study the effects of sourdough fermentation of wheat flour with Lactobacillus plantarum, on the quality attributes of mixed oat-wheat bread (51 g whole grain oat flour and 49 g/100 g white wheat flour). Emphasis was laid both on β-glucan stability as well as bread structure and sensory quality. The variables of the sourdough process were: dough yield (DY), fermentation time, fermentation temperature, and amount of sourdough added to the bread dough. The sourdough process was shown to be a feasible method for mixed oat-wheat bread, and, when optimized, provided bread quality equal to straight dough baking. A small amount (10g/100 g dough) of slack sourdough fermented at high temperature for a long time resulted in the most optimal sourdough bread with the highest specific volume (3.5 cm³/g), the lowest firmness after 3 days storage (0.31 kg), and low sensory sourness with high intensity of the crumb flavour. Wheat sourdough parameters did not affect the content of oat β-glucan in the bread. Additionally, both straight dough and sourdough bread contained 1.4-1.6 g β-glucan/100 g fresh bread. The average molecular weight of β-glucan was 5.5 × 10⁵ in both types of bread, while that of oat flour was 10 × 10⁵. This indicates that a slight degradation of β-glucan occurred during proofing and baking, and it was not affected by variation in the acidity of the bread between pH 4.9-5.8.