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Sugar beet pulp (SBP) is a by-product of the sugar industry in which the dietary fiber content ranges from 73% to 80%. Compared to cereal fibers mainly used in biscuit production, sugar beet fibers are gluten free and have a perfect ratio of 2/3 insoluble fiber. In this work, sugar beet pulp was extruded with corn grits (ratios of corn grits to sugar beet pulp in extrudates were 85:15, 70:30, and 55:45), and the obtained sugar beet pulp extrudates (SBPEs) were used for improving the nutritional quality of cookies. The wheat flour in cookies was replaced with SBPEs in the amount of 5, 10, and 15%. The influence of three factors (the percentage of sugar beet pulp in the SBPEs, the size of the SBPE particles, and the percentage of wheat flour substituted with SBPEs) and their interactions on the nutritional quality of cookies, as well as their physical and sensory characteristics are examined using the Box–Behnken experimental design. The addition of extruded sugar beet pulp (SBPEs) significantly increased the amount of total dietary fiber and mineral matter of cookies. On the whole, the addition of SBPEs increased cookie hardness, but the hardness decreased with an increase in extrudate particle size. Sensory characteristics (except for the taste) were the most influenced by extrudate particle size.

Influence of the milling parameters on the reduction process of the wheat middlings by the smooth rolls was investigated. Three level and four variables Box–Behnken experimental design with response surface methodology was applied in order to evaluate effects of milling parameters and to optimize grinding conditions for various responses. As independent variables roll gap (0.04–0.1 mm), differential (1.1.–1.9), roll speed (300–500 rpm) and feed rate (0.2–0.4 kg/cm min) were employed. Responsive variables were flour yield, ash content and energy consumption. In order to optimize milling process adequate models were obtained by regression analysis. Possibilities of the optimization of the milling parameters in order to obtain different combination of the desired outputs are illustrated by four examples.

Sunflower meal, a by-product of oil extraction from sunflower seeds, is an important protein source in domestic as well as European feed industry. There is a common interest for the proper utilization of sunflower meal and for the development of an effective fractionation process in order to obtain a nutritionally improved sunflower meal. This paper proposes and compares two dry fractionation processes for the improvement of sunflower meal protein content on a laboratory scale. The first phase of both processes included two step milling using a hammer and roller mill. In the second phase, the ground sunflower meal was fractionated by sieving or by air classification. Results indicated that the implementation of any of the suggested processes improved protein content of the starting sunflower meal to a level sufficient to categorize it as "high-protein" according to current national regulation on animal feed quality, with the fraction yields over 50%. For the air classification process the most promising result was achieved for air flow of 7 m3 /h (12.8% relative protein enrichment, 56.42% fraction yield). For the fractionation process with sieving as a separation step, when fractions smaller than 350 µm were conjoined, relative protein enrichment of 28.5% and fraction yield of 51.17% were achieved. The high protein content (48.81% on dry basis) of the joined fraction enables enough space for optimizing the protein content - fraction yield ratio of obtained sunflower meal. By applying sieves with larger aperture, it is possible to obtain higher yields of sunflower meal categorized as high-protein on account of a slight decrease in protein content, which gives this process a certain flexibility and potential for application on a larger scale.

White chocolate does not contain fat-free cocoa solids and thus lacks bioactive components. In the present study, white chocolate was enriched with encapsulated blackberry juice in concentrations: 60 g kg−1, 80 g kg−1, and 100 g kg−1. The results showed an increase of volume weighted mean in enriched chocolates with increasing the concentration of encapsulate from 13.06 μm in white chocolate to 18.05 μm in chocolate with 100 g kg−1 of encapsulate. Casson viscosity of chocolate mass increased at the same time (from 0.63 Pa in white chocolate to 1.22 Pa in chocolate with a maximum concentration of encapsulate) due to an increase of specific surfaces of solid particles in chocolate. Internal structure and surface gloss in chocolate with 100 g kg−1 of encapsulate are also affected where the lack of free fat phase caused mat color on the surface. However, the addition of encapsulated blackberry juice to white chocolate led to the creation of new type of enriched chocolate with attractive color and blackberry taste. Total polyphenol content (mg GAE/100 g) of white chocolate is increased from 40.75 to 75.06, 145.86, and 153.95 in chocolates with 60 g kg−1, 80 g kg−1, and 100 g kg−1 of encapsulate, respectively.

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 (

Waffles, cookies, and crackers are considered to be one of the most often consumed confectionery products. Their complex composition in terms of raw materials used for their production often implies more than one source of heavy metals that end up in the final product. Therefore, the analysis of the heavy metals in these types of products is necessary. The present study deals with the determination of the correlations between the content of essential metals with potential toxic effects (copper, iron, zinc, manganese, and cobalt) determined by inductively coupled plasma‐atomic emission spectrometry in waffles, cookies, and crackers collected from the market in Autonomous Province of Vojvodina, Republic of Serbia. The concentrations determined were in the following ranges: Cu (0.299–0.5015 mg/kg d.w.), Fe (3.301–65.35 mg/kg d.w.), Zn (1.962–15.58 mg/kg d.w.), Mn (1.406–27.7 mg/kg d.w.), and Co (0.01–0.26 mg/kg d.w.). The mutual dependence of their concentrations was determined by chemometric linear and nonlinear regression methods which showed to be useful in the fast and easy determination of iron, manganese, zinc, and cobalt concentrations in the studied groups of confectionery products. PRACTICAL APPLICATIONS: The practical application of the established chemometric models is reflected in the possibility of predicting the concentration of one metal in waffles, cookies, and crackers based on the concentration of the other one. In this way, the additional experiments can be avoided and the concentration of particular metal can be precisely determined, which is confirmed by the internal and external statistical validation procedures of the established chemometric models.

The aim of this study was the optimization of supercritical fluid extraction (SFE) of wheat germ oil obtained as by‐product from industrial mill. Extraction kinetics modeling and response surface methodology (RSM) were used for that purpose. SFE was performed with broadening Box‐Behnken experimental design, where pressure (250–350 bar), temperature (40–60°C), and CO₂ flow rate (0.2–0.4 kg/hr) were used as independent variables. Five empirical kinetic equations were successfully utilized for modeling of SFE. Model IV (Kandiah and Spiro model) provided the best fit with experimental data, according to statistical parameters (R², sum of squared errors and average absolute relative deviation). Furthermore, initial slope calculated from this model was used as a response variable for RSM optimization. It could be concluded that SFE should be performed at elevated pressure (350 bar) and CO₂ flow rate (0.4 kg/hr), while temperature should be held at a lower level (40°C) in order to achieve a maximal initial slope. PRACTICAL APPLICATIONS: Optimization and modeling of industrial processes are crucial factors that will determine its efficiency and profitability. This research provided information about modeling of green and environmentally friendly extraction technique, that is, SFE, which could be successfully utilized for recovery of valuable oil from food industry by‐product, that is, wheat germ. Commonly used empirical models were successfully applied for modeling of extraction process and influence of SFE factors on model parameters was determined providing information about mass transfer phenomena during extraction. Further investigation provided determination of the highest initial extraction rate constant which could be applicable for optimization of industrial scale processes.

peer-reviewed, In this study, sunflower meal is ground by a hammer mill after which air zigzag gravitational air classifieris used for separating sunflower hulls from the kernels in order to obtain protein rich fractions. Three hammer mill sieves with sieve openings diameter of 3, 2 and 1 mm were used, while three air flows (5, 8.7 and 12.5 m3/h) and three feed rates (30%, 60% an 90% of bowl feeder oscillation maximum rate) were varied during air classification process. For describing the effects of the test variables on the observed responses Principal Component Analysis, Standard Score analysis and Response Surface Methodology were used. Beside experimental investigations, CFD model was used for numerical optimization of sunflower meal air classification process. Air classification of hammer milled sunflower meal resulted in coarse fractions enriched in protein content. The decrease in sieve openings diameter of the hammer mill sieve increased protein content incoarse fractions of sunflower meal obtained at same air flow, and at the same time decreased matchingfraction yield. Increase in air flow lead to the increase in protein content along the same hammer mill sieve. Standard score analysis showed that optimum values for protein content and ratio of coarse and fine fractions have been obtained by using a sieve with 1 mm opening diameter, air flow of 12.5 m3/hand 60% of the maximum feeder rate. Fraction ratio and protein content were mostly affected by the linear term of air flow and the sieve openings diameter of the hammer mill sieve in the Second Order Polynomial model. The main focus of CFD analysis was on the particle simulation and the evaluation of the separation efficiency of the zigzag classifier., This work is a part of Integrated and Interdisciplinary Research Project No III 46012, funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia.

Background Many studies have described cocoa polyphenols as being bioactive compounds with a potential positive effect on human health. Although dark chocolate is a most powerful source of antioxidants, their content is lower in milk chocolate; conversely, in white chocolate the fat-free cocoa solids are omitted. The aim of this study was to increase polyphenol content and antioxidant capacity of white chocolate by adding encapsulated green tea extract (GTE) in amounts of 60, 80 and 100 g kg-1 . Results GTE influenced the particle size parameters, increasing the volume weighted mean from 15.43 μm in white chocolate to 19.34 μm in chocolate with 100 g kg-1 GTE. At the same time, the viscosity of enriched chocolate also increased owing to the addition of new solid particles. The surface color of enriched chocolates changed in accordance with the amount of encapsulate, where all enriched chocolates had a slightly lighter color after 12 months of storage. Total polyphenol content (mg gallic acid equivalents (GAE) kg-1 ) increased from 0.41 in white chocolate to 2.73 in chocolate enriched with maximal GTE. This amount of GTE increased antioxidant capacity (mmol Trolox equivalents kg-1 ) from 1.22 in white chocolate to 16.12. After 12 months of storage, degradation of polyphenols was found to be a maximum of 37.27%, while antioxidant capacity decreased up to 44.14%. Conclusion In addition to the impact on chocolate viscosity, GTE added value through the polyphenol content and sensorial profile of the new product with an unusual green tea flavor and a shelf life of at least 12 months. © 2019 Society of Chemical Industry.

Wheat germ was firstly defatted using supercritical CO2 extraction and raffinate was further utilized for polyphenols isolation. For that purpose solid-liquid, ultrasound-assisted and microwave-assisted extraction (MAE) techniques were applied. MAEs were performed at different levels of ethanol concentrations, extraction time, liquid-solid ratio and irradiation power, while ethanol concentration was only variable for other extraction techniques. Obtained extracts were evaluated in terms of total extraction yield, total phenols yield and in vitro antioxidant activity, whereas under certain conditions MAE exhibited the highest response values. MAE was analyzed by response surface methodology (RSM) and artificial neural network (ANN) techniques which were compared in terms of fitting quality, influence analysis and optimization. Results indicated that RSM and ANN could be successfully used to describe experimental data. Both methods exhibited certain advantages, i.e. ANN showed minor advantage of fitting quality, while RSM provided further insight in influence analysis. Optimized MAE conditions determined by RSM were ethanol concentration of 58.03%, extraction time of 14.48 min, liquid-solid ratio of 25 mL/g and irradiation power of 800 W. MAE conditions optimized by ANN were different in terms of ethanol concentration (50%), extraction time (15 min) and irradiation power (400 W), and same in terms of liquid-solid ratio.

peer-reviewed, The aim of this study was to determine the effect of the main milling variables, i.e., agitator shaft speed (50, 75 and 100%, which is 25, 37.5 and 50 rpm) and milling time (30, 45 and 60 min) on physical and sensory properties of fat filling, as well as on energy consumption during the production in a laboratory ball mill. Within the response surface method, the face centered central composite design is used. A response surface regression analysis for responses was performed and a full quadratic model was fitted to the experimental data. It is shown that agitator shaft speed had the most significant influence on physical properties (particle size distribution, rheological and textural propertes) and sensory characteristics of fat filling, while the milling energy consumption is highly influenced by milling time with contribution 55.4%, followed by agitator shaft speed (40.04%). The model obtained by regression analyses was used to perform the optimization of processing parameters in order to provide the combination of agitator shaft speed and milling time that cost less energy while at the same time do not compromise the quality of the fat filling. Optimization of production of fat filling in a laboratory ball mill would imply the maximum agitator shaft speed and 30-min milling time.

Roller mills are one of the most frequently used grinding machines especially for cereal milling. Magnitude and type of the forces acting on particle depend on the set of roll parameters. Particle size distribution (PSD) resulting from milling a particular feed size critically depends on the ratio of roll-gap to input particle size. Box-Behnken experimental design was applied in order to optimize roll-gap adjustments and desired PSD of the milling output obtained by subsequent grinding of wheat on three pair of rollers. Adequate models, which allow the optimization of the milling process, were obtained by regression analysis. Values that define the PSD of the output, i.e. weight fractions of the milling output size fractions, were set to minimum, maximum or values within a certain interval. The examples of optimization which set the roll-gap values to ensure the desired PSD of the output, were obtained with a high level of desirability.

The work is concerned with the effects of applying the drum detachers as flake disrupters in industrial wheat flour mills. The stocks entering and leaving the drum detachers applied on the different reduction passages in two industrial mills were intercepted and employed in the experiments. The changes in the flour release and flour ash content were followed. The results show that the drum detachers are effective in disrupting the flakes formed in the smooth roller mills grinding zone. However, the contribution of the drum detachers to the overall milling efficiency is in close correlation with the nature of the formed flakes. If the flakes are primarily composed of endosperm particles, the employment of drum detacher results in a statistically significant increase of the flour yields without deterioration of flour quality. If flakes, formed on the end passages of the reduction system, contain large portion of branny particles, the increase of the flour ash content following the drum detacher is statistically significant. [Projekat Ministarstva nauke Republike Srbije, br. 031014]

One of the potential raw materials which could be used for production of food with added nutritional value is tomato pomace, a by-product from tomato processing. On the other hand, requirements of consumers for diverse food with potential for health benefits impose the need for creation of products made from different cereals. In this respect, the aim of this study was to evaluate the influence of addition of dried tomato pomace on the physical and sensory properties of whole grain rye flour cookies. The whole grain rye flour was substituted with tomato pomace powder in two levels (15% and 25%) in the standard formulation of short-dough cookie. The quality of final products was evaluated by instrumental and sensory methods. The results clearly demonstrated that redness (+a*) and yellowness (+b*) were highly influenced by level of tomato pomace in the cookie formulations due to its content of carotenoid pigments. The spread factor of the cookies made with addition of tomato pomace powder was higher than the control sample. Hardness of the cookie samples decreased for approximately 50% for the cookie sample with 25% tomato pomace level substitution when compared with control sample. According to the results of sensory analysis, substitution level of 15% caused decrease of surface roughness, fracturability, and granularity, as well as increase of caramel flavour intensity. Substitution level of 25% caused higher degree of cookie softening and more pronounced tomato flavour.

Introduction of the eight-roller mill into the wheat flour milling process significantly reduces the investment costs and overall energy requirements compared to the conventional milling system. However, the conditions for controlled milling are less favorable and could result in deterioration of flour yield and quality. Paper compares milling results obtained using a conventional process and process with an eight-roller mill employed on the tail-end passages of the reduction system. At the same roll gap and under the same sieving conditions, the flour release was lower in the process with the eight-roller mill compared to the conventional milling system. By decreasing the roll gap and increasing the upper size limit (granulation) of flour in the process with the eight-roller mill it is possible to increase flour yield and decrease milling energy consumption per unit mass of flour produced. This can be achieved without deterioration of flour quality as determined by ash content. [Projekat Ministarstva nauke Republike Srbije, br. 031014]