Metoda Pengeringan Zat Warna Bubuk Ekstraksi Kulit Bawang Merah menggunakan Convection Oven-drying dan Spray-drying

Pigmen warna dalam kulit bawang merah hasil ekstraksi mengandung senyawa yang dapat memberi warna pada kain. Ekstrak dalam bentuk cair tidak tahan lama dalam penyimpanan sehingga dibuat dalam bentuk bubuk agar lebih tahan lama. Tujuan dalam penelitian ini adalah untuk mendapatkan zat warna lebih tahan lama dalam penyimpanan dengan cara pengeringan. Proses pengeringan zat warna yang dilakukan pada penelitian ini menggunakan oven dan spray dryer. Karakterisasi yang digunakan untuk mengevaluasi hasil pencelupan menggunakan spektrofotometri, Laundry-O- meter untuk ketahanan terhadap pencucian dan crockmeter untuk ketahanan terhadap gosokan. Hasil yang didapat dari penelitian ini adalah berat kering zat warna bubuk Hasil pengeringan menggunakan oven dan spray dryer masing-masing sebesar 4,97 gram dan 2,68 gram dari 1 Liter larutan ekstraksi. Kandungan air yang terdapat dalam zat warna bubuk dengan pengeringan menggunakan oven sebesar 35% sedangkan menggunakan spray dryer sebesar 3% setelah didiamkan selama 2 bulan. Evaluasi terhadap hasil pencelupan menggunakan zat warna bubuk hasil pengeringan menggunakan oven dan spray dryer masing-masing memiliki ketuaan warna (K/S) sebesar 3,46 ; kerataan warna (standar deviasi) sebesar 0,105; kecerahan dan arah warna L* 74, 28 ; a* 0,68 dan b* 25,55 ; dan ketuaan warna (K/S) sebesar 3,05 ; kerataan warna (standar deviasi) sebesar 0,08 ; kecerahan dan arah warna L* 77,19 ; a* - 2,03 dan b* 27,32. Untuk ketahanan luntur warna terhadap pencucian dan ketahanan warna terhadap gosokan basah serta kering keduanya memiliki hasil yang sama yaitu 4-5 dan 5. Kandungan air zat warna bubuk dan kerataan warna yang lebih baik dihasilkan dengan pengeringan menggunakan spray dryer.

Isothermal Air Flow Investigation in Industrial Baking Oven of Different Impeller Locations using Computational Fluid Dynamics (CFD) Approach

Computational fluid dynamics (CFD) modelling was performed on a forced convection oven to investigate the isothermal airflow. Three oven design configurations based on their impeller location (back, side, and top wall) were compared with respect to their Turbulence Kinetic Energy (TKE) profile to determine the optimal configuration design for quick uniform baking. The air velocity was estimated from both experimental and modelling approaches at specific points in an oven with the back walled impeller. The CFD model was validated resulting in a calculation error of 30.34% of actual velocity which was mainly due to limitation in grid density and the turbulence modelling. The other two oven configurations were simulated and their average TKE data were extracted and compared. The third configuration (impeller at the top wall) was found to have the highest average TKE of 3.55 m2/s2 followed by the first configuration (impeller at the back wall) with 3.30 m2/s2 which provides a relatively uniform TKE distribution across the cavity. The findings show the significance of impeller placement in oven performance.

Structural properties of cellulose nanofibril foam depending on wet foaming conditions in Pickering stabilization

Porous cellulose nanofibril (CNF) foam was prepared by stabilizing bubbles with CNF and a surfactant and then drying the stabilized wet foam in a convection oven. The consistency of carboxymethylated CNF (CMCNF) and the addition amount of the surfactant were controlled and the effects of these factors on the CNF wet foam and dry foam properties were investigated. An adequate amount of the surfactant (0.02–0.04 wt%) with CMCNF consistency higher than 0.5 wt% yielded wet foams with excellent stability. When the wet foam was dried at 60 °C in an oven, dry CNF foam with over 97% porosity was generated. The stable wet foams resulted in dry CNF foam with a sphere-like pore structure and low levels of shrinkage during drying. In contrast, unstable wet foams generated dry foam with severe shrinkage and large cavities. The pore size and the porosity of the dried foam were determined by the shape of bubbles in the wet foam and the degree of shrinkage during drying, which, in turn, affected the mechanical strength. In addition, the compressive strength of the oven-dried foam was 83% higher than that of the freeze-dried foam. Therefore, the preparation of a stable wet porous CMCNF foam by controlling the CMCNF consistency and the amount of surfactant was essential for obtaining a porous CMCNF foam with a uniform pore structure and good mechanical strength by oven drying. Graphic abstract

Effect of the Addition of Chia Seed Gel as Egg Replacer and Storage Time on the Quality of Pork Patties

Two types of patties were prepared: control and with chia seeds gel instead of beaten egg. The patties were cooked in the steam-convection oven, vacuum packed and stored at 4 °C. The pork patties with chia addition were characterized by similar water activity and pH values to the control samples. They showed lower values of the b* colour parameter as well as colour saturation (C*) and hue angle values (h°) on the cross-section and lower values of colour parameters L*, a* and b* and C* on the surface than the controls. The addition of chia seeds improved the texture parameters of the tested products. Pork patties with chia seeds were softer and showed better chewiness than the control samples. Chia slowed down oxidative changes in pork patties during storage. The use of 8.0% addition of chia seeds was only slightly noticeable in taste of the pork patties and these samples received similar overall quality scores as control samples.

METHOD OF EXPRESS DIAGNOSTICS OF FISHSEMI-FINISHED PRODUCTS

Background. The main aspects of quality assessment of fish raw materials and combi ovens for its heat treatment are considered. The results of connection researches of structural and mechanical properties of raw materials with its thermophysical charac­teristics and parameters of necessary culinary processing are presented. The expediency of using physical methods for assessing the quality of raw materials to predict the mode of heat treatment is determined. The aim of the study is to develop a system of rapid diagnostics of structural-mecha­nical and thermophysical properties of fish semi-finished products for the insti­tutions of the HoReCa industry. Materials and methods. The object of research is the structural-mechanical and thermophysical properties of grass carp and their changes during storage. The subject of research – culinary semi-finished products, specifically – grass carp steaks. Determination of structural and mechanical properties of steaks was carried out by a measuring sensor of original design, developed on the basis of components of ITM LLC. The heating kinetics of grass carp semi-finished products were performed in a PolEco cabinet at a temperature of 180 ºC and forced convection. The temperature in the samples was recorded by standard thermal sensors of the UMCD with a measure­ment period of 20 seconds. The amount of active electricity, consumed for the preparation of steaks, was determined excluding the reactive component, by using current measuring clamp. Culinary processing of steaks was in the steam convection oven Convotherm OEB 6.10. Results. A set of structural and mechanical properties of grass carp steaks with different shelf life was determined with a sensor of the original design of UMCD. The correlation of changes in the indicators of adhesion, penetration and relaxation force after compression with the shelf life of steaks was established. A correlation between the shelf life and the heating speed of the samples was established with a standard thermo sensors of UMCD. The heating speed of the samples after 24 h of storage increases by 10–11 %. By recording the current in the power cable of the combi steamer, the electricity consumption for cooking 12 portions of steaks (2400 g) was determined. The possibility of saving electricity from 4.6 % for cooking freshly asleep fish and up to 16.5 % for chilled fish stored for 24 hours was established. Conclusion. The measuring sensor was tested. It allows determining the rela­xation, strength and adhesion of fish raw materials in the express mode. It was found that the structural-mechanical and thermophysical properties of grass carp change with storage time. It is experimentally confirmed that the change of information parameters of heat treatment in the steam convection oven is a criterion of quality of culinary products from freshwater fish. The developed method of express diagnostics allows determining the rheological properties of raw materials from freshwater fish and optimizing the heat treatment of culinary products in restaurants in terms of differential quality of raw materials. Due to the selection of individual processing modes for fish raw materials of different consistency and shelf life, it is possible to reduce electricity consumption by the steam convection oven by 4.6–22.4 %.

Structural and parametric synthesis of the control system of the unobserved output for the object with distributed parameters

Method of synthesis of a control system for the object with the distributed parametres, providing compensation of dynamic properties of the object and giving to it of properties of standard model of a set. The system possesses the property of an adaptability to parametrical interference of the object. Control along the unobservable coordinate of the object is implemented by synthesizing a chain structure that implements a transfer function close to the inverse transfer function of the object. Weak sensitivity to parametric instability is provided by solving the inverse problem of dynamics. As an example, the heating of a massive billet in a convection oven is considered.

GROUND TRUTH SOIL MOISTURE ESTIMATION ALONG WITH MINIMAL DRIZZLING TIME

The aim of this study was to determine the soil moisture along with minimal drizzling time using two methods using hot air convection oven (HA-CO) and microwave oven (MO) to find out the best method for estimation the soil moisture. The convection oven method was considered as the most accurate method to determine the soil moisture; hence, we utilized this method as source for assessing the results. The experiment was conducted in lab which was completely based on random 110 dry soil samples weight of approximately 100 gram from the bare land. In convection oven method we used 105 °C for 24 hours and in microwave oven method we used different thermal power (180, 360, 540, 720 and 900 watt) for different time duration. The result based on the RMSE between soil moisture retrieval from hot air convection oven method and soil moisture retrieval from microwave oven method. 720 watt takes 15 minutes to dry the soil while 900 watt takes 8 minutes; both are gives approximately same results as convection oven method, which takes 24 Hours. Therefore for retrieval of soil moisture we can utilize the microwave oven method at 900 watt power. The low RMSE for 900 watt is 0.51% shows that the microwave oven method is most convenient, time saving and safe method for retrieval of soil moisture.

Effects of drying methods on the physicochemical properties and antioxidant capacity of Kuini powder

Kuini powders were obtained through spray-drying, freeze-drying, vacuum oven drying and convection oven drying. Colour, water activity (Aw), moisture content, hygroscopicity, wettability, flowability, degree of caking, water solubility index (WSI), total colour change, total phenolic content and total carotenoid content of Kuini powders were determined and compared. Convection oven drying resulted in the highest yield (46.97%), moisture content (4.91%), Aw (0.55) and WSI (74.33%) among all the drying methods. However, convection oven-dried Kuini powder had the lowest hygroscopicity and wettability, which were 18.66% and 12.04 s, respectively. Spray drying resulted in poor hygroscopicity (22.41%), degree of caking (22.16%), wettability (275s), WSI (45.67%) and higher colour change (59.81). Least total colour change (19.05) and higher yellowness (57.31) were observed in freeze-drying. In addition, freeze-dried Kuini powder had the highest total phenolic content (24.76 mg/100 g) and total carotenoid content (1.61 mg/100 g). Drying temperature had a negative and significant correlation with the retention of color pigments and antioxidant content. The physicochemical properties and antioxidant content of freeze-dried Kuini powder were preferred over spray-dried, vacuum oven-dried and convection oven-dried powders. Hence, freeze-drying offers potential application in the food products.

Effects of Rapid Microwave-Curing on Mechanical and Piezoresistive Sensing Properties of Elastomeric Nanocomposites

Carbon nanotubes (CNTs) have the unique ability to absorb microwave radiation and efficiently transfer the energy into substantial heat. When adequately dispersed in a thermoset polymer, such as polydimethylsiloxane (PDMS), the nanocomposite can be fully cured in seconds in a microwave oven rather than in hours in a convection oven. In this paper, cylindrical PDMS nanocomposites containing well-dispersed CNTs are fabricated by either microwave-curing or conventional thermal-curing. The mechanical, electrical, and piezoresistive properties of the fabricated samples are compared to understand the effects of different curing methods. Microwave-cured nanocomposites exhibit a significantly reduced compressive modulus for different CNT loadings. In addition, the electrical conductivity of microwave-cured nanocomposites is significantly enhanced over the thermally-cured counterparts. Experimental results demonstrate that the one-step microwave-curing procedure can improve the electrical conductivity of 1 wt% nanocomposites by almost 150 % over thermal-curing. However, their piezoresistive sensitivity remains remarkably similar, showing the potential for microwave-curing to replace thermal-curing for the manufacturing of highly flexible CNT-based nanocomposites.