Feasibility of a small-scale production system approach for palm sugar sweetened dark chocolate

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.

Structural Characteristics, Rheological Properties, and Antioxidant Activity of Novel Polysaccharides from “Deer Tripe Mushroom”

The polysaccharide was extracted by water extraction and alcohol precipitation method from “deer tripe mushroom,” which was domesticated and bred from wild Auricularia delicata in Zambia. The structure of the deer tripe mushroom polysaccharide (DTMP) was characterized by gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), scanning electron microscope (SEM), and other analytical techniques. And the rheological and gel properties and antioxidant capacities of the polysaccharide were studied. The results showed that DTMP was mainly composed of mannose, fructose, glucose, and galacturonic acid, of which the galacturonic acid was the main component. By calculation, the molar ratio of mannose : fructose : glucose : galactoacid in DTMP is 0.8 : 14.8 : 1.0 : 26.32. The polysaccharide was mainly composed by α-1,4-glycosidic bond. DTMP solution showed a shear-thinning (pseudoplastic) behaviour, and its pseudoplasticity was more obvious at a concentration of 2%. The power law model was used to evaluate the viscosity curves of DTMP, and its viscosity and consistency indices both increased as the concentration increased, whereas both indices decreased as the concentration decreased. The viscosity of the polysaccharide solution changed as the pH changed: the polysaccharide solutions had a higher viscosity at pH = 10. DTMP showed gel-like behaviour (G′ ＞ G″), and the gel strength enhanced with the increase of concentration (2%–10%). In addition, the antioxidant experiment of DTMP showed that it had good antioxidant activity, and there was a significant dose-effect relationship between its activity and concentration in the low concentration range.

Optimization of prebiotic sucrose-free milk chocolate formulation by mixture design

The purpose of the current research was to determine optimal situation by applying Simplex lattice mixture design for the formulation of prebiotic sucrose-free milk chocolate. Chocolate samples were prepared using two different sugar alcohols containing xylitol and maltitol along with galactooligosaccharide as prebiotic substance. The effects of sugar alcohols and prebiotic blends on rheological attributes and some physical characteristics were assessed. The outcomes represented the high coefficient of determination (≥ 90%) of fitted models. The optimization of the variables indicated that using 20.857 g maltitol, 7.131 g xylitol and 5.012 g galactooligosaccharide generated the optimized chocolate with the highest desirability (1.00) without undesirable changes in the rheological and physical properties. Furthermore, the optimum formulation was prepared to validate the optimum model. The sensory evaluation of the optimized formulation of chocolate pleased the consumer needs.

Effects of polyols on the quality characteristics of sucrose-free milk chocolate produced in a ball mill

Sucrose-free milk chocolates containing different types of bulk (isomalt, xylitol and maltitol) and high intensity (Stevia) sweeteners were produced by using a ball mill. The main quality characteristics of the formulated chocolates were evaluated and compared with those of the conventional sample containing sucrose. The Casson model was the best fitting model for the rheological data. Casson viscosity and Casson yield stress were significantly affected by the type of bulking agent in chocolates formulated with xylitol (p < 0.05). However xylitol notably improved the overall acceptability according to the sensory analysis results. Chocolates containing the sucrose replacers demonstrated lower T_onset values and higher enthalpy than the control sample. Sucrose-free chocolates illustrated a higher degree of particle agglomeration. Bulk sweeteners meanwhile seem to have high potential for milk chocolate production with low calorie values by using the ball mill technique. Industrial applications: the production of sucrose-free chocolates with conventional methods requires a lot of time and energy. Recently, using alternative methods for chocolate production has been raising interest in many small industries. This study proposed a ball mill method for the preparation of sucrose-free milk chocolates with physiochemical properties almost ranging in the standard limit defined for chocolate. Although using the ball mill method presents a more cost-effective technique for chocolate production and provides shorter processing times for small chocolate industries, it seems to be less efficient in evaporating moisture than the conventional processing. Challenges are still ahead for upgrading this alternative technique to be efficient in evaporating more moisture during operation ending in a high quality product.

Sucrose-free milk chocolates containing different types of bulk (isomalt, xylitol and maltitol) and high intensity (Stevia) sweeteners were produced by using a ball mill.