Determination of the process effect on cocoa butter crystallization by rheometer: Kinetic modeling by Gompertz equation.

In this study, the effects of temperature (22, 24, 26, 28, and 30°C) and strain (0.1%, 1%, and 5%) on cocoa butter (CB) crystallization were investigated by oscillatory test, and the four-parameter Gompertz model was used to interpret the effect of parameters on pre-crystallization, nucleation, and crystal growth stages of CB. Lag time and growth rate were calculated using the Gompertz model using time-dependent storage modulus (G') data. According to the results, CB crystallization at 26°C with a 1% strain value had the highest growth rate value, the shortest lag time, and the formation of ßv polymorph type. Followingly, polymorphic types of the CB crystals were determined based on the melting points of polymorphs via the temperature ramp step, and the results obtained were correlated with a polarized light microscope. In conclusion, using a rheometer in both the observation of the pre-crystallization process and the determination of polymorph types is very important for research and development studies in the chocolate industry for process and formulation optimization. PRACTICAL APPLICATION: This study demonstrates the feasibility of a novel approach for investigating crystallization and oscillatory shear of CB using a rheometer, both for observing crystallization kinetics and determining polymorph type, accompanied by the Gompertz equation to model the crystallization kinetics. According to the results, the effect of process parameters (temperature and shear) on the crystallization behavior of CB can be observed by rheometer, which can provide a detailed perspective for chocolate manufacturers and researchers in research and development studies.

Influence of process conditions of alkalization on quality of cocoa powder.

In this study, the effects of independent variables such as alkaline (NaOH) salt concentration (3.0-6.0 g/100 mL), alkalization temperature (60-90 °C), and time (20-40 min) on cocoa powder (low-fat) properties were investigated by using Central Composite Design. The physicochemical and color properties of samples, powder characteristics, volatile component profile, total polyphenol content (TPC), as well as antioxidant activity potentials using different methods (DPPH and ABTS) were determined. Significant models were identified for the effects on major alkalization indicators (L*, a*/b*, pH), as well as TPC and antioxidant activity potential (DPPH), which are the main motivators for the preference and consumption of cocoa products (p < 0.05). The established model was validated, and their predicted values were found to be very close to real results. It was determined that the alkali concentration had a more significant effect on dependent variables, especially on alkalization indicators, compared to the other independent variables. Furthermore, strong correlations were determined between TPC and antioxidant activity potential and color properties (L*, a*, b*, and a*/b*). Optimum concentration, temperature and time were found to be 5.3 %, 84 °C and 35.7 min for maximizing a*/b* value. The establishment of such models lead to optimizing process conditions of alkalization with minimum effort and labor force for obtaining cocoa powder with desired quality depending on the usage purpose.

Investigating the effect of gum base components on chewing gum quality and aroma release mechanism: In-vitro kinetic modeling.

In this study, the effects of main gum base components, namely butyl rubber, polyvinyl acetate and natural resin, on the aroma (menthol) release mechanism and quality of sugar-free chewing gums were investigated. According to the results, the sensory evaluation of aroma release was closely similar to the analysis performed with the GC-MS equipment. The Korsmeyer-Peppas model was the best model explaining the menthol release from chewing gum, and it was found that the release was mostly in the form of Fickian diffusion. The polyvinyl acetate had the greatest effect on the aroma release, and the aroma intensity increased in parallel with the ratio in the formulations. According to the optimization results, softening temperatures and instrumental hardness of the sample, which showed the highest aroma durability were found to be 80.00 °C and 22.45 N.

Cocoa polyphenols and milk proteins: covalent and non-covalent interactions, chocolate process and effects on potential polyphenol bioaccesibility.

In this study, we discussed covalent and non-covalent reactions between cocoa polyphenols and proteins (milk and cocoa) and the possible effects of these reactions on their bioaccessibility, considering environmental and processing conditions. Better insight into these interactions is crucial for understanding the biological effects of polyphenols, developing nutritional strategies, and improving food processing and storage. Protein-polyphenol reactions affect the properties of the final product and can lead to the formation of various precursors at various stages in the manufacturing process, such as fermentation, roasting, alkalization, and conching. Due to the complex composition of the chocolate and the various technological processes, comprehensive food profiling strategies should be applied to analyze protein-polyphenol covalent reactions covering a wide range of potential reaction products. This will help to identify potential effects on the bioaccessibility of bioactive compounds such as low-molecular-weight peptides and polyphenols. To achieve this, databases of potential reaction products and their binding sites can be generated, and the effects of various process conditions on related parameters can be investigated. This would then allow to a deeper insight into mechanisms behind protein-polyphenol interactions in chocolate, and develop strategies to optimize chocolate production for improved nutritional and sensory properties.

Effect of Cold Atmospheric Pressure Argon Plasma Jet Treatment on the Freeze-Dried Mucilage of Chia Seeds (Salvia hispanica L.).

In the present study, the effects of the treatment of chia seeds with a cold atmospheric pressure plasma jet (CP) using argon as a working gas for different times (30, 60, and 120 s) on the rheological, structural, and microstructural properties of the freeze-dried mucilages at -54 °C were investigated. All mucilage gels showed pseudoplastic flow behavior, and CP treatment of chia seeds increased the viscosity of mucilages, probably due to the cross-linking between polymer molecules. The dynamic rheological analysis revealed that all mucilages were elastic gels and that CP treatment improved the elastic properties in a treatment time-dependent manner. Large amplitude oscillatory shear (LAOS) results showed that freeze-dried mucilages showed Type I strain-thinning behavior. Similar to small amplitude oscillatory shear (SAOS) results, CP treatment has affected and improved the large deformation behavior of mucilages depending on treatment time. Meanwhile, Fourier transform infrared spectroscopy (FTIR) revealed the incorporation of hydroxyl groups onto the surface and the formation of C-O-C glycosidic bonds during plasma treatment. Scanning electron microscope (SEM) micrographs showed the formation of denser structures with CP treatment time. Regarding color properties, CP treatment decreased the lightness values of mucilages. Overall, this study showed that CP is an effective way to modify both the SAOS and LAOS properties of freeze-dried chia mucilage and improve viscosity.

Chocolate flow behavior: Composition and process effects.

Chocolate is a non-Newtonian substance, and such substance has different viscosities at different shear rates. Rheological evaluations have become indispensable instruments for characterizing final chocolate, forecasting product efficiency and consumer acceptance. During production, the different steps depend on a well-defined viscosity and yield stress. Furthermore, the characteristics of the final chocolate (the surface and mouth-feel) are directly related to the chocolate's viscous behavior. There is a demand for better understanding the variables affecting chocolates flow behavior. Current research realized great insight into the chocolate flow behavior in different processes such as refining, conching, and tempering. Also, the influence of formulation and particle characteristics on flow behavior of the intermediate product and the final product were discussed. Each stage of the production process: mixing, refining, conching and tempering involves modifications of macroscopic characteristics of the chocolate ingredients thus affecting the rheological attributes of the final product. Particle size distribution and ingredient composition play substantial roles in shaping its flow behavior and sensory perception. The rheological properties of chocolate provide substantial information for food scientists to improve and optimize their products and manufacturing processes. Nowadays, a thorough understanding of chocolate flow behavior is a necessity for food scientists and industry.

Formulating and studying compound chocolate with adding dried grape pomace as a bulking agent.

The use of dried grape pomace (DGP) as a bulking agent for partly substitution of sugar, milk powder and whey powder in compound chocolate (CC) was investigated. D-optimal mixture design was used to determine the effect of composition on the particle size, flow behaviour (Casson yield value and plastic viscosity), as well as total phenolic and resveratrol contents before and after in vitro digestion. The various models (linear, quadratic and cubic) which were identified as significant (P < 0.05) were used in this study. As a result, DGP was found suitable to be used in CC as a bulking agent to partially substitute sucrose, milk powder and whey powder to increase functional properties and decrease the cost of the CC. For CC with the most acceptable rheological properties and a satisfactory level of TPC and resveratrol, optimum usage levels of DGP were identified as 7.1% to 10.0%. Further studies will require to modify flow behaviours by optimizing the particle size of pomace.

Development of a novel rheological method for determining melting properties of gelatin-based gummies.

In this study, a novel rheometer-based method was explored to determine the melting point of gummy, which is one of the most consumed confectionery products. The new method is based on the vertical deformation of a solid sample since melting points of the products were determined by performing onset analysis on the graph of gap values against temperature. Peltier system heating rate and sample thickness parameters were used to develop the method. To verify the obtained melting points, time sweep tests in the rheometer at constant temperature, conventional oven and water bath analysis, thermograms of the samples obtained from differential scanning calorimetry (DSC) and their microstructures at various temperatures with polarized light microscopy (PLM) were examined. Herein, it can be realized that the developed method detects the melting point of a gummy with a sensitivity of 1 °C when temperature increase rate and thickness values were 1 °C/min and 4000 µm, respectively. As a result of the application of the novel method for the commercial samples, the melting points of C1 and C2 gummy samples were determined as 45 °C and verified by other experiments with one unit of precision. Therefore, the method has brought a different perspective to the melting temperature analysis with ease of use and short-term detection by sensitive and reproducible results. Besides, it has come to the forefront as it allows the studied materials to be used in solid form in the rheometer.

Soft confectionery products: Quality parameters, interactions with processing and ingredients.

The motivation in the preference of confectionery products consists of the perception formed during the purchase and consumption. This perception is a direct determining factor in the repeated purchasing behavior of the consumer. Also, the products must meet consumer demands. For this reason, it is very important to understand the confectionery quality characteristics, the factors affecting them, and their interaction with each other. In this context, the effects of major and minor components used in innovative soft confectionery products on quality should be considered first. As with all other foods, new ingredient(s) incorporated into the formulation and processing changes have significant effects on the quality characteristics of soft confectionery products. Therefore, in this review study, after giving information about soft confectionery products and their quality characteristics, the interactions of especially innovative components and processes that have important effects on these foods were discussed in detail.

The fermentation-based production of gellan from rice bran and the evaluation of various qualitative properties of gum.

The potential for the use of rice bran, an agricultural waste, as a substrate in the manufacture of gellan gum was examined. Using a standard strain of Sphingomonas paucimobilis (ATCC 31461) and rice bran substrate, gellan gum was produced under optimized conditions. The optimal yield of gellan gum using rice bran substrate was found to be 11.96 g L-1 with 5% glucose, 10% inoculum, and a mixing speed of 300 rpm. Native gum was found to have a consistency index of 2.00 Pa.sn. The viscosity of the gum was found to be extremely stable when exposed to thermal stress. Concerning the rheological characteristics, the Herschel-Bulkley model offered a more realistic representation of the flow characteristics of gum solutions. The synthesized gums were mostly composed of glucose, rhamnose, and glucuronic acid. The acetic acid content of gellan gums was 2.95%, while the molecular weight was 2.88 × 105 Da. Characterization of native gellan gums by UV-Vis spectroscopy, SEM, TEM and FTIR spectroscopy is also presented.

Cold plasma modification of food macromolecules and effects on related products.

The food industry is in search of innovative processing technologies that are capable of providing food safety and improving quality with low processing costs and fast operations. As a new technique, cold plasma (CP) fulfills these requirements and thus gained significant attraction from researchers. Apart from general microbial inactivation purposes, CP can effectively modify the food macromolecules through reactions with reactive plasma species. In this context, this review focuses on the interactions between reactive plasma species and proteins, lipids, and polysaccharides. It also covers the changes in interfacial and mechanical properties of proteins and polysaccharides, effects on oleogels and xerogels, modifications in the allergenicity of proteins, and trans-free hydrogenation of oils. On the other hand, the concepts underlying the interactions between reactive plasma species and these macromolecules and the effects of processing parameters should be better understood, thus further studies should focus on these aspects.

Pre-crystallization process in chocolate: Mechanism, importance and novel aspects.

Pre-crystallization is an important step in the production of chocolate, which is defined as tempering of cocoa butter through primary and secondary nucleation. The goal of tempering is to obtain a sufficient amount of ßV polymorph of the right size. The pre-crystallization process has a great impact on the quality and production cost of final product. Development of chocolate technology requires the use of the most appropriate techniques and ingredients without negatively affecting the quality characteristics. Applications of novel technologies within the confectionery industry have allowed production of chocolate in sufficient quantities to meet the public needs. In order to provide and investigate the potential and usage of novel technologies, the present review focused on different pre-crystallization methods and factors affecting the processing conditions. Seeding and ultrasound-assisted pre-crystallization can be used as alternatives to conventional tempering process. However, in both methods, optimization of experimental conditions is required.

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.

Formulation of dark chocolate as a carrier to deliver eicosapentaenoic and docosahexaenoic acids: Effects on product quality.

In this study, dark chocolate enriched with EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) was developed using various forms and origins. Quality characteristics such as physical, thermo-gravimetric, rheological, textural and sensory properties of chocolates were investigated. The highest EPA/DHA stability was determined in samples prepared by free-flowing powder and microencapsulated forms of omega-3 fatty acids (FA). The L∗ and C∗ values varied from 32.16-33.37 and 7.45-8.09, respectively for the all samples. Hardness values ranged between 6422 and 8367 N and the use of EPA/DHA in the triglyceride form caused softer chocolate whereas control sample was the hardest sample. Melting and rheological properties were not significantly affected by the studied EPA/DHA sources (P < 0.05). Microencapsulated EPA/DHA added chocolate was the most preferred source whereas sample with algae oil showed the lowest acceptability. According to the results, dark chocolate can be used for delivering omega-3 FA by considering their origin and physical form.

Yield and rheological properties of exopolysaccharide from a local isolate: Xanthomonas axonopodis pv. vesicatoria

Background: The aim of the present study was to evaluate gum productivity of a local strain, Xanthomonas axonopodis pv. vesicatoria, isolated from pepper plant, and its rheological behavior for the first time compared to the standard strain, Xanthomonas campestris DSM 19000 (NRRL B-1459). The influence of operational conditions (agitation rate and inoculum volume) on gum production and rheological properties of gums from the Xanthomonas strains were investigated. Results: The isolated strain of Xanthomonas showed similar xanthan yield compared to the standard strain. Furthermore, this study clearly confirmed that gum yield depended on bacterial strain, agitation rate, and inoculum size. The most suitable conditions for the gum production in an orbital shaker in terms of agitation rate and inoculum size were 180 rpm and 5%, respectively, resulting in an average production of 10.96 and 11.19 g/L for X. axonopodis pv.vesicatoria and X. campestris DSM 19000, respectively. Regarding the rheological properties, Ostwald-de-Waele and power law models were used to describe flow and oscillatory behavior of the gum solutions, respectively. Consistency of the novel gum solution remarkably was much higher than the commercial xanthan gum solution. Flow and oscillatory behavior and their temperature ramps showed that weak gel-like structure could be obtained with less gum concentrations when the novel gum was used. Conclusion: Therefore, yield and technological properties of the aqueous solutions of the exopolysaccharide synthesized by X. axonopodis pv. vesicatoria were observed to be more suitable for industrial production.