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Background Amylases produced by fungi during solid-state fermentation are the most widely used commercial enzymes to meet the ever-increasing demands of the global enzyme market. The use of low-cost substrates to curtail the production cost and reuse solid wastes are seen as viable options for the commercial production of many enzymes. Applications of α-amylases in food, feed, and industrial sectors have increased over the years. Additionally, the demand for processed and ready-to-eat food has increased because of the rapid growth of food-processing industries in developing economies. These factors significantly contribute to the global enzyme market. It is estimated that by the end of 2024, the global α-amylase market would reach USD 320.1 million (Grand View Research Inc., 2016). We produced α-amylase using Aspergillus oryzae and low-cost substrates obtained from edible oil cake, such as groundnut oil cake (GOC), coconut oil cake (COC), sesame oil cake (SOC) by solid-state fermentation. We cultivated the fungus using these nutrient-rich substrates to produce the enzyme. The enzyme was extracted, partially purified, and tested for pH and temperature stability. The effect of pH, incubation period and temperature on α-amylase production using A. oryzae was optimized. Box–Behnken design (BBD) of response surface methodology (RSM) was used to optimize and determine the effects of all process parameters on α-amylase production. The overall cost economics of α-amylase production using a pilot-scale fermenter was also studied. Results The substrate optimization for α-amylase production by the Box–Behnken design of RSM showed GOC as the most suitable substrate for A. oryzae, as evident from its maximum α-amylase production of 9868.12 U/gds. Further optimization of process parameters showed that the initial moisture content of 64%, pH of 4.5, incubation period of 108 h, and temperature of 32.5 °C are optimum conditions for α-amylase production. The production increased by 11.4% (10,994.74 U/gds) by up-scaling and using optimized conditions in a pilot-scale fermenter. The partially purified α-amylase exhibited maximum stability at a pH of 6.0 and a temperature of 55 °C. The overall cost economic studies showed that the partially purified α-amylase could be produced at the rate of Rs. 622/L. Conclusions The process parameters for enhanced α-amylase secretion were analyzed using 3D contour plots by RSM, which showed that contour lines were more oriented toward incubation temperature and pH, having a significant effect (p < 0.05) on the α-amylase activity. The optimized parameters were subsequently employed in a 600 L-pilot-scale fermenter for the α-amylase production. The substrates were rich in nutrients, and supplementation of nutrients was not required. Thus, we have suggested an economically viable process of α-amylase production using a pilot-scale fermenter.

An infrared-assisted hot air dryer was designed and developed for turmeric slices. The dryer has been developed using an infrared heating source, heating coils, and blower.The total power required for the infrared drying and hot air drying was 2.25 kW and 36.35 kWh, respectively, with a blower capacity of 6.06 m 3 /min. An infrared drying (IRD), hot air drying (HAD), and infrared-assisted hot air drying (IRHAD) were used to dry turmeric slices (5 mm thickness) at different drying temperatures 50 C, 60 C, and 70 C with constant air velocity 2 m/s and bed thickness 25 mm. The maximum drying efficiency of 25.22% and the minimum specific energy consumption of 1.24 kWh/kg were observed in the IRHAD method at 70 C and considered as the best drying method for drying turmeric slices. The drying rates values were double in IRHAD than IRD and HAD. Seven drying models, namely, Newton, Page, Modified page, Diffusion approximation, Two-term exponential, Henderson-Pabis, and Logarithmic, were used to validate the experimental data obtained during drying. Based on the maximum R 2 value and lowest error values, the Page model was found to be the best fit for characterizing the drying kinetics of turmeric slices. At 60 C drying temperature, the logarithmic model and twoterm exponential model were found best fit for HAD and IRHAD, respectively. Practical ApplicationsRecently, turmeric gaining a lot of economic importance due to its antiviral properties and health benefits. Turmeric has many applications in the food industry, including natural coloring agents, flavor enhancers, and preservatives. Washing, boiling, drying, polishing, and size reduction are the unit operations involved during the processing of turmeric. The commercial value of turmeric can be decided based on the percentage of volatile compounds present. Many studies observed that the reduction in volatile compounds due to improper drying. The farmers following the sun drying techniques, which consume more time, non-homogenous drying, and lesser drying rate. Hence, an efficient alternate drying technique should be identified to overcome the problems faced by the farmers and turmeric processing industries. In this context, the present study was undertaken to design an infrared-assisted dryer for efficient, quick, and uniform heating of turmeric slices.

Naturally occurring phytochemicals with promising biological properties are quercetin and its derivatives. Quercetin has been thoroughly studied for its antidiabetic, antibacterial, anti-inflammatory, anti-Alzheimer's, anti-arthritic, antioxidant, cardiovascular, and wound-healing properties. Anticancer activity of quercetin against cancer cell lines has also recently been revealed. The majority of the Western diet contains quercetin and its derivatives, therefore consuming them as part of a meal or as a food supplement may be sufficient for people to take advantage of their preventive effects. Bioavailability-based drug-delivery systems of quercetin have been heavily studied. Fruits, seeds, vegetables, bracken fern, coffee, tea, and other plants all contain quercetin, as do natural colors. One naturally occurring antioxidant is quercetin, whose anticancer effects have been discussed in detail. It has several properties that could make it an effective anti-cancer agent. Numerous researches have shown that quercetin plays a substantial part in the suppression of cancer cells in the breast, colon, prostate, ovary, endometrial, and lung tumors. The current study includes a concise explanation of quercetin's action mechanism and potential health applications.