Pulse beetle ( Callosobruchus maculatus) is a common weevil that is responsible for up to 24% of stored pulse losses. Using black gram grain storage, the efficiency of carbon dioxide gas against all life stages of Callosobruchus maculatus insects was tested at various concentrations and exposure times. The trials were carried out in pilot bins with a capacity of 25 kg. At a CO2 concentration of 50%, complete mortality of the egg stage of Callosobruchus maculatus was attained after 72 h of continuous exposure. At a CO2 concentration of 60% for 48 h, 100% larva mortality was achieved. At the most tolerant stage of pupa, recorded complete mortality is at a CO2 concentration of 70% for 96 hours of the exposure period. Adult insects are especially vulnerable to the high CO2 concentration. Adult mortality was achieved at a concentration of 20% with an exposure period of 48 h. The CO2-treated black grams were then stored for three months with the optimized CO2 concentration and exposure period, while physiochemical parameters such as water retention capacity and physiological loss in weight were determined. Grain stored in the silo showing significant 100% mortality of egg was measured after 20-25 days of observation. The use of a controlled atmosphere storage bin increased the mortality of the insect C. maculatus at all developmental stages, by means of increasing CO2 concentration and exposure time. Grain stored in a controlled atmosphere silo showed minimum losses of grain (4.10%) compared to the gunny bag storage (22.56%).
Enzymatic hydrolysis of soybean milk proteins with cysteine protease papain was performed in an advanced bioreactor, operated with batch mode. In soybean milk protein hydrolysis reaction, enzyme and substrate ratio and reaction temperature were varied, ranging from 0.029:100–0.457:100 and 30–60 °C, respectively. The degree of hydrolysis of soybean milk proteins was increased with increase of enzyme and substrate (soybean milk protein) ratio. However, the degree of hydrolysis was increased due to change of reaction temperature from 30 °C to 60 °C with enzyme and substrate ratio 0.229:100 and was reduced when hydrolysis reaction was performed with enzyme and substrate ratio 0.11:100 at hydrolysis temperature 60 °C. Antioxidant capacity of enzyme-treated milk had a similar trend with degree of hydrolysis. In a later exercise, a membrane bioreactor was adopted for continuous production of antioxidant and antibacterial peptides from soybean milk. The membrane bioreactor was operated for 12 h with constant feeding. Ceramic-made tubular membrane with a pore size 20 nm was used. Application of static turbulence promoter in a membrane separation process was investigated and its positive effects, with respect to higher permeate flux and lower energy consumption in filtration process, were proven. Antioxidant capacity and antibacterial activity against Bacillus cereus of enzyme-hydrolyzed milk and permeate from membrane were confirmed.
The use of renewable energy is crucial to the global growth of sustainability. Milk business amongst many other food industry divisions requires a significant amount of energy, making the meal processing business one of the most energy-intensive industries. As of right now, more than 30 percent of the dairy produced in India is processed. In distant parts of India, milk spoiling is more common due to the delay among milking and storing; as a result, facilities for quick pasteurization and storage are needed. Heated is necessary for pasteurization. Since for a long time, the Indian milk industry has relied on nonrenewable energy sources, that are not only becoming much more costly but are also to blame for significant environmental issues including greenhouse gases and health issues. Consequently, scientific communities, environmental and social organizations, and the governments have all pushed the use of green energy. Solar energy has been shown to be the most viable among various sustainable and renewable energies given the geographical position of India. Solar energy can be used to pasteurize milk because of the energy intensity and range of temperature requirements. Adsorbent refrigerator is recommended here since it is powered by waste/solar heat and can store (200 liters of milk) at low temperatures until it is distributed after the pasteurization process (easily available from farm waste). The solar collector of evacuated tube is used for minimizing heat loss and pasteurizing milk. The outcome demonstrates that milk can be simply pasteurized at 73°C for 25minutes at a flow rate of 5 liter per minutes. A solar energy adsorbent refrigeration system has been constructed and described for keeping 200 liters of milk at 10-15°C for 9–11 hours. Investigation findings indicate that the specific cooling power of the system is sufficient to store 200 liters of milk at 5.8 kW/kg and 5.5 kW/kg for 500 liter per hours hot water supplied at 92°C, 32°C condenser temperatures, and 5°C evaporator temperatures. The heat loss of evacuated tube collector is compared to solar concentrator. The study results provide evacuated tube collector is better for pasteurizing milk since to its highly efficient, longevity, and compactness.
27 November 2023 in Analecta Technica Szegedinensia
The 3D printing technology involves a digital manufacturing machine that produces three-dimensional objects according to designs created by the user via 3D modelling or computer-aided design/manufacturing (CAD/CAM) software. This work analyzes the processing timeline of the filament (material for 3D printing) from unboxing to the extrusion trough the nozzle. It is an important task to analyze the growth of bacteria on 3D printed surface and in gaps between the layers. By default, 3D printed object is not food safe after longer usage and direct contact with food (even though the food safe filaments were used), but there are solutions for this problem. We tested several methods to prevent or reduce the emerging microbial contamination. These methods are coating with epoxy resin, using antimicrobial and high temperature-resistant filaments. The best results were obtained by epoxy resin coating, where the object was cleanable like any other injection molded plastic object with smooth surface. Very good results have also been obtained by boiling the objects, and it is good to see that nowadays more and more special filaments have food safe certificate and can withstand boiling temperatures too. Using antibacterial filaments reduced bacterial colonies by 80%, which is not a perfect solution.
This study investigates the drying behavior of three polyamide-based 3D printing filaments (PA6-GF, PA6-CF, and PPA-CF) under varying temperature conditions. A comparative approach was applied using both segment-based and spool-based drying experiments. Moisture loss was recorded at 70 °C, 95 °C, and 120 °C, and the drying kinetics were modeled using a four-parameter logistic (4PL) function. Results revealed temperature-dependent differences in the drying rates and equilibrium moisture levels, with PPA-CF exhibiting the highest thermal resistance. The segment-based measurements enabled a precise kinetic evaluation, while the spool-based tests provided insights into real-world drying performance using hobbyist equipment. This study highlights that, while all three filaments benefit from pre-drying, optimal conditions vary significantly depending on the polymer matrix and reinforcement. The proposed 4PL-based modeling approach proved effective for characterizing the moisture removal process and can support improved drying protocols prior to fused filament fabrication. These findings contribute to a better understanding and optimization of filament conditioning practices in additive manufacturing.