The effect of agitator shaft speed on energy consumption of a ball mill

A laboratory ball mill refiner for chocolatc and confectionery fat fillings consisting of vertical cylinder, equipped with a rotating shaft with arms, and filled with steel balls as a grinding medium has been used in the experiments. In this type of size reducing equipment, the feed material is comminuted between the moving media, the stirrer and the grinding chamber wall by compression and shear. The aim of the study was to examine the effect of agitator shaft speed on energy consumption of a laboratory ball mill. With constant mass of the steel balls (30 kg), the agitator shaft speed was increased from 10% to 100% of the maximum speed which coresponds to a speed of 50 rpm. The power consumption [W] was recorded upon which milling energy consumption [J/kg] has been calculated. The results were statistically analyzed using ANOVA. The increase of the agitator shaft speed, in steps of 10% to the maximum speed of 50 rpm, led to a statistical significant increase in milling energy consumption

Study on the possibilities of the rationalization of wheat flour milling processusing the eight-roller mill

U radu je proučavana mogućnost racionalizacije tehnološkog postupka mlevenja pšenice primenom osmovaljne stolice u fazi mlevenja griza i osevaka. Na svim ispitivanim prolazištima mlevenja griza i osevaka, pri istom razmaku između valjaka i istoj veličini otvora sejnog tkiva za odsejavanje brašna, ukupan prinos brašna u postupku sa osmovaljnom stolicom manji je nego u klasičnom postupku. Pomenuta razlika varira u zavisnosti od uzorka i prolazišta mlevenja, ali je uvek statistički značajna. Nižim vođenjem valjaka u postupku sa osmovaljnom stolicom, u poređenju sa razmacima između valjaka u klasičnom postupku, u zavisnosti od uzorka i prolazišta mlevenja se smanjuje razlika, dostiže ili prevazilazi prinos brašna u odnosu na klasični postupak. Povećanjem veličine otvora sejnog tkiva za odsejavanje brašna značajno se povećava prinos brašna u postupku sa osmovaljnom stolicom, pri čemu se pri odabiru sejnog tkiva u obzir mora uzeti i veličina svetlog otvora. Odabirom odgovarajuće veličine otvora sejnog tkiva može se i prevazići prinos brašna u klasičnom postupku. Niže vođenje valjaka i/ili povećanje veličine otvora sejnog tkiva za odsejavanje brašna, pri primeni osmovaljne stolice, nema za posledicu pogoršanje kvaliteta brašna (po pitanju sadržaja pepela) u odnosu na klasični postupak. Specifični utrošak energije za usitnjavanje po jedinici mase brašna, pri istom vođenju valjaka i istoj veličini otvora sejnog tkiva za odsejavanje brašna, veći je u postupku sa osmovaljnom stolicom nego u klasičnom postupku. Povećanjem izvoda brašna u postupku sa osmovaljnom stolicom, značajno se smanjuje specifični utrošak energije za usitnjavanje. Mogućnost ostvarenja bliskih efekata usitnjavanja u fazi mlevenja griza i osevaka, u klasičnom i postupku sa osmovaljnom stolicom, ukazuje da je za dalju racionalizaciju savremenog tehnološkog postupka mlevenja pšenice neophodno uključivanje osmovaljne stolice.Rationalization of the wheat flour milling process using the eight-roller mill in the reduction system has been investigated. At the same roll gaps and same sieving conditions, a lower flour yield has been obtained using an eight-roller mill compared to a conventional one. The difference is statistically significant regardless the passage. By decreasing the roll gap in the process with the eight-roller mill, compared to the roll gap in the conventional process, it is possible to decrease the difference, obtain a similar or even exceed the flour release in the conventional system. Increasing the size of the screen aperture for sifting flour, while percent open area of the screen also needs to be observed, results in significant increase of flour yield (in some cases exceeding the flour yield in the conventional system). Adjustments of the roll gap and sieving conditions in the process with the eight-roller mill are not followed by deterioration of flour quality. At the same roll gaps and same sieving conditions, energy requirements for grinding are higher in the process with the eight-roller mill compared to a conventional system. With the increase of the flour release in process using the eight-roller mill, these energy requirements can be significantly reduced. The possibility of achieving similar milling results to those obtained in the conventional system, while the investment costs and overall energy requirements are significantly lower, justifies the use of the eight-roller mill in the reduction system of the wheat flour milling process

The effect of using the drum detachers in the industrial wheat flour mills

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

Estimating the relative efficiency of separation between endosperm and bran in the wheat flour milling process

The aim of the w heat flour milling process, along with the size reduction, is to obtain the best possible dissociation of the starchy endosperm from the other parts of the kernel. Milling tends to concentrate various section of the kernel into different flour mill streams but the complete separation of the anatomic parts can not be achieved. The gradinets of ash. protein and cellulose content increase while the starch content decreases from the center portion to the outer portion of the kernel. Considering the significant dilTerencies between the chemical composition of the kernel layers, distribution of chemical compounds in intermediate, final and subproducts of the milling process come as a result of the level of dissociation achieved during the milling process. These differences serve as a basis for the mill process control. Ash determination is probably the most widely used tool while even greater differencies exist in cellulose and especialy stach content. In this work mathematical model has been defined and used to evaluate the relative efficiency of the separation of endosperm from the outer pericarp leyers of the kernel. The model is based on quantity rates (flour extraction and subproducts yield) and qulitative analyses (starch and cellulose content in the wheat, flour and subproducts)

Physical properties of dough for cookies with chestnut flour

A challenge for food producers is certainly to find suitable flour that can replace wheat flour in the production of flour–based products. Chestnut flour can be adequate substitute for wheat flour in the production of gluten–free flour confectionary products, due to high starch and sugar content. The objective of this work was to characterize physical changes, rheological and textural properties of dough for cookies with chestnut flour. The control dough was only with wheat flour. The substitution of wheat flour with chestnut flour for examined dough samples was at three different levels (20, 40 and 60%). Moisture of the dough was 22%.Dynamic oscillatory measurements describe all dough samples as typical viscoelastic systems with dominant elastic modulus G' over viscous modulus G". The modulus ratio (tan δ=G"/G') decreased with increase in amount of chestnut flour. Also, the dough compliance (J) determined by creep and recovery curves decreased, thus more chestnut flour resulted in more brittle consistency of the dough. Texture determination confirmed the rheological results. Resistance to extension of the control dough sample was the highest, as well as dough extensibility. Application of chestnut flour and increase in its amount reduced these texture parameters for dough samples. Optimal physical properties of dough were achieved with low amounts of chestnut flour of 20%

The effect of soy flour on cookie quality

Cookies are a popular confectionery product with a unique texture and taste, long shelf life and a relatively cheap price; therefore, it is a widespread snack among people of all generations. Nevertheless, cookies are usually made of wheat flour and most formulations are highly caloric and have a low fiber content. Soy flour is an excellent source of proteins, fibers, vitamins and minerals and it is being considered as a great supplement to wheat flour because it increases nutritive characteristics of the final product. By their digestibility and amino acid content, soy proteins are very similar to proteins derived from animals. They also contain many essential amino acids, which are deficient in most of the cereals. The purpose of this work was to determine the effect of soy flour on quality of cookies. Wheat flour was supplemented with 35% of soy flour (full-fat toasted, low-fat toasted, defatted lightly toasted, toasted and soy protein concentrate). The supplementation of wheat flour with soy flour had affected nutritive value and sensory characteristics of cookies

Physical properties of dough for cookies with chestnut flour

A challenge for food producers is certainly to find suitable flour that can replace wheat flour in the production of flour–based products. Chestnut flour can be adequate substitute for wheat flour in the production of gluten–free flour confectionary products, due to high starch and sugar content. The objective of this work was to characterize physical changes, rheological and textural properties of dough for cookies with chestnut flour. The control dough was only with wheat flour. The substitution of wheat flour with chestnut flour for examined dough samples was at three different levels (20, 40 and 60%). Moisture of the dough was 22%. Dynamic oscillatory measurements describe all dough samples as typical viscoelastic systems with dominant elastic modulus G' over viscous modulus G". The modulus ratio (tan δ=G"/G') decreased with increase in amount of chestnut flour. Also, the dough compliance (J) determined by creep and recovery curves decreased, thus more chestnut flour resulted in more brittle consistency of the dough. Texture determination confirmed the rheological results. Resistance to extension of the control dough sample was the highest, as well as dough extensibility. Application of chestnut flour and increase in its amount reduced these texture parameters for dough samples. Optimal physical properties of dough were achieved with low amounts of chestnut flour of 20%

The Effect of Soy Flour on Cookie Quality

Cookies are a popular confectionery product with a unique texture and taste, long shelf life and a relatively cheap price; therefore, it is a widespread snack among people of all generations. Nevertheless, cookies are usually made of wheat flour and most formulations are highly caloric and have a low fiber content. Soy flour is an excellent source of proteins, fibers, vitamins and minerals and it is being considered as a great supplement to wheat flour because it increases nutritive characteristics of the final product. By their digestibility and amino acid content, soy proteins are very similar to proteins derived from animals. They also contain many essential amino acids, which are deficient in most of the cereals. The purpose of this work was to determine the effect of soy flour on quality of cookies. Wheat flour was supplemented with 35% of soy flour (full-fat toasted, low-fat toasted, defatted lightly toasted, toasted and soy protein concentrate). The supplementation of wheat flour with soy flour had affected nutritive value and sensory characteristics of cookies

THE PHYSICAL PROPERTIES, POLYPHENOL CONTENT AND SENSORY CHARACTERISTICS OF WHITE CHOCOLATE ENRICHED WITH BLACK TEA EXTRACT

Chocolate contains a variety of different compounds such as fats, carbohydrates, proteins, vitamins, and minerals. Fat-free cocoa particles are also extremely rich in polyphenols. While dark chocolate is a most powerful source of antioxidants, the content of these components decreases with the reduction in the content of dark cocoa particles in chocolate. White chocolate differs from milk and dark through the absence of fat-free cocoa particles containing antioxidants. Today\u27s investigations are focused on finding new methods of creating functional confectionery products. Accordingly, in this study white chocolate was enriched with100 g kg-1 of encapsulated black tea extract in order to increase its polyphenol content. The addition of encapsulated black tea extract to white chocolate increased the viscosity of enriched chocolate mass to the extent that is acceptable for the production of this kind of product. Total polyphenol content in enriched chocolate was increased over 6 times compared to white chocolate. However, black tea encapsulate contributed to foreign taste of medications in enriched chocolate, making it unacceptable by consumers

CHOCOLATE, SNACKING AND SELECTED DIETARY HABITS IN PUPILS: BMI-FOR AGE APPROACH

Besides pleasant taste, the potential health benefits of cocoa and chocolate products have been known for many years. Formerly accepted as a medicine, chocolate nowadays among consumers represents everyday delicacy primarily associated with caries, obesity, high blood pressure, and diabetes. However, recent studies indicate the potential role of chocolate in cardiovascular diseases prevention and benefits linked to lower body mass index (BMI). The presented study aims to examine adolescents’ habits regarding chocolate, sweets, salty snacks and fast food consumption as well as corresponding products intake frequency and relate them with BMI. The study population encompassed 525 participants attending elementary and high schools in the province of Vojvodina, Serbia, from which 42.5% were boys and 57.5% girls. The risk for overweight and participants’ nutritional status were determined through BMI assessment. The majority of participants had normal range nutritional status (70.5%) followed by overweight (19.8%) and obese (7.6%). Increased number of overweight and obese nutritional statuses was recorded among boys compared to girls. Results revealed that fruits as a snack are most frequently consumed between meals, followed by salty snacks and sweets, regardless of the participants’ nutritional status. The highest share of sweets consumption between meals was noticed among participants with obese nutritional status (15%). Furthermore, more than 40% of participants with overweight and normal range nutritional status do not consume chocolate at all, while 2.5% of participants with obese nutritional status stated that they consume chocolate on a daily basis