Effect of Defatted Wheat Germ Content and Its Particle Size on the Rheological and Textural Properties of the Cookie Dough

Overview of the Sustainable Valorization of Using Waste and By-Products in Grain Processing

In an increasingly resource-constrained era, using waste and by-products from grain processing has a wide appeal. This is due to the nutritive value and economic aspects of this process and due to its compatibility with the trend towards more sustainable food systems. Following the fundamentals of circular economy, a current need is the effective utilization of grain waste and by-products for conversion into value-added products in the food industry. The aim of this study is twofold: (1) using bibliometrics and the literature found in various databases, we aim to understand the progress of valorizing grain waste and by-products in human nutrition. The literature within various databases, namely, Google Scholar, Web of Science, and Elsevier Scopus, has been evaluated for its merits and values. (2) We aim to explore knowledge-based strategies by reviewing the literature concerning the possible use of grain waste and by-products for the food processing industry, reducing the burden on virgin raw materials. The review allowed us to unlock the latest advances in upcycling side streams and waste from the grain processing industry.

Optimization of rheological characteristics of bread dough supplemented with defatted wheat germ

Optimization of bread dough formulation with defatted wheat germ (DWG) in terms of dough rheological properties was the objective of this study. Fractional factorial design 2 V 5 - 1 was applied in order to investigate influence of DWG granulation (<150 µm and 150-1000 µm), DWG content (10 and 20%), addition of gluten (0 and 5%), ascorbic acid (0.004 and 0.008%) and combined improver (0.1 and 0.3%) on farinograph and extensograph parameters. Responsive variables were water absorption and the degree of softening, obtained by farinograph, and resistance to extension and extensibility as well as their ratio, obtained by extensograph analysis. Gluten addition expressed dominant positive effect on water absorption and the degree of softening. The most pronounced negative effect on dough resistance exhibited DWG content (contribution of 57%). The combination of DWG with smaller particle size and 5% of gluten addition increased both resistance and extensibility, but R/E ratio was not affected. The optimal values for DWG granulation, DWG content, gluten content, ascorbic acid content and combined improver content were: < 150 µm, 14.24%, 4.83%, 0.004% and 0.1%, respectively, while predicted values for desired responsible variables were: water absorption 65.90%, degree of softening 84.05 FU, resistance 301.30 EU, extensibility 108.55 mm and R/E 2.5.

Investigating release kinetics of phenolics from defatted wheat germ incorporated chewing gums

BACKGROUND

Wheat germ (WG) is a valuable by-product of the commercial milling industry and is used as a functional ingredient in various foods. Therefore, in this study, it is aimed to utilize defatted wheat germ (DWG) (1%, 3%, 5%, 10%) in chewing gum formulation, which is a different food matrix besides the conventional structures, and investigate the release kinetics of phenolics from DWG incorporated chewing gums with a new centrifugation method.

RESULTS

According to the results, it was observed that DWG was a good source of total phenolics (2254.15 mg GAE kg^-1 ). Based on the results obtained from texture profile and sensory analyses, DWG addition did not cause any reverse effect on the chewing gum texture. Centrifugation method was used to indirectly simulate the physical effects of the chewing process. In particular, after 5 min of chewing and centrifugation, phenolic release levels were 59.07% and 59.41%, respectively. The model used in the previous studies showed a better correlation than Korsmeyer-Peppas model for ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid), CUPRAC (cupric ion reducing antioxidant capacity), and DPPH (2,2-diphenyl-1-picrylhydrazyl) assay results.

CONCLUSION

The results showed that phenolics release from gum base polymer matrix might be dominated by erosion of matrix due to chewing action. Similar phenolic release kinetics were obtained by centrifugation and chewing methods. Therefore, centrifuge equipment can be used to simulate the chewing forces acting on the gum when optimization is performed. © 2019 Society of Chemical Industry.

Hydrocolloid clustering based on their rheological properties

In this study, we proposed an objective classification of seven commercial hydrocolloids and four novel hydrocolloids. Total of 74 rheological parameters was generated by steady (flow behavior, hysteresis loop, single shear decay, in-shear structural recovery experiments), dynamic (strain sweep and frequency sweep tests), and transient (creep/recovery and stress relaxation) shear measurements. Subsequently, the parameters were classified into seven categories with more than 60% similarity indexes in each group using agglomerative hierarchical clustering based on those properties related to the number of linkage, strength of linkage, distance of linkage, rupture and flow, rate of destruction, the extent of destruction, and the state of destructured samples in the absence of flow field. Fuzzy c-means classifier used to extract patterns for each class. Our results correspond to four different classes; κ-carrageenan and agar gum were categorized in the first class, high methoxyl pectin, xanthan, sage seed gum and basil seed gum in the second class, alginate gum and Balangu-Shirazi seed gum in the third class, and guar gum, cress seed gum and carboxymethyl cellulose in the fourth class. Using this classification technique, complete rheological patterns can be extracted for each class. This classification provides a map for other researchers to rationally design the best test type which could describe adequately different properties of materials and avoid experiments with a similar type of parameters. The main reason for the frequent use of hydrocolloids in various industries is their ability to modify the rheology. A lot of works have been done to study the rheological behavior of many hydrocolloids in model and food systems. As there is still demand for new sources of hydrocolloids with more specific functionality in foods, probing the similarities among commercial and emerging hydrocolloids could help us to rationally design structural features in different formulations, besides gives insight into the structure-function relationship between them. This object could be attained by clustering, a part of the pattern recognition theory. Contrary to the traditional clustering methods, in which the membership of a product is exclusive for only a class, in constraint clustering by fuzzy logic methods, a partial membership can be shared by two or more classes. In this way, using the fuzzy logic clustering method, we clustered a number of commercial and novel hydrocolloids based on the steady, transient, and dynamic shear rheological properties and found a specific pattern among them. PRACTICAL APPLICATIONS: The main reason for the frequent use of hydrocolloids in various industries is their ability to modify the rheology. A lot of works have been done to study the rheological behavior of many hydrocolloids in model and food systems. As there is still demand for new sources of hydrocolloids with more specific functionality in foods, probing the similarities among commercial and emerging hydrocolloids could help us to rationally design structural features in different formulations, besides gives insight into the structure-function relationship between them. This object could be attained by clustering, a part of the pattern recognition theory. Contrary to the traditional clustering methods, in which the membership of a product is exclusive for only a class, in constraint clustering by fuzzy logic methods, a partial membership can be shared by two or more classes. In this way, using the fuzzy logic clustering method, we clustered a number of commercial and novel hydrocolloids based on the steady, transient, and dynamic shear rheological properties and found a specific pattern among them.

Encapsulated sour cherry pomace extract: Effect on the colour and rheology of cookie dough

In this study, the effect of encapsulated sour cherry pomace extract on the physical characteristics of the cookie dough (colour, textural and rheological properties) was investigated. Sour cherry pomace extract encapsulated in whey (WE) and soy proteins (SE) was incorporated in cookie dough, replacing 10% (WE10 and SE10) and 15% (WE15 and SE15) of wheat flour. The dough samples containing encapsulates had the grey-blue colour ( b* values significantly decreased compared to control sample). Due to the presence of anthocyanins, a* values of the dough colour increased significantly with the addition of encapsulates. The addition of soy protein encapsulate increased hardness, resistance to extension and viscosity of cookie dough and decreased deformation compliance ( J), while the addition of whey encapsulate caused dough softness, higher deformation compliance and lower values of viscosity compared to control sample. Values of storage and loss modulus, G' and G″, significantly decreased when wheat flour was replaced with WE and increased when the flour was replaced with soy protein encapsulate. The addition of soy protein encapsulate resulted in higher cookie hardness.

Defatted wheat germ application: Influence on cookies’ properties with regard to its particle size and dough moisture content

The introduction of agro-food industry by-products rich in bioactive compounds represents major challenge in food industry sector. The influence of wheat germ particle size (<150 µm, 150–1000 µm, and 800–2000 µm), wheat germ content (5, 10, and 15%), and dough moisture content (20, 22, and 24%) on chemical, textural, and sensory characteristics of cookies was investigated using the Box–Behnken experimental design. The substitution of wheat flour with wheat germ increased the protein, fat, mineral, and fiber content of the cookies. The particle size of wheat germ affected the textural properties of cookies. As the particle size of wheat germ increased, the hardness of cookies decreased. The color of the cookie was most influenced by the interaction of dough moisture content and wheat germ particle size. Wheat germ level up to 15% had no significant effect on the sensory characteristics of cookies. A suitable combination of defatted wheat germ level, its particle size, and dough moisture content can improve the nutritional value of cookies, without causing a negative effect on the cookies’ sensory characteristics.