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Pumpkin seeds were dried in a vibro-fluidized bed dryer (VFBD) at different temperatures at optimized vibration intensity of 4.26 and 4 m/s air velocity. The drying characteristics were mapped employing semiempirical models and Artificial Neural Network (ANN). Prediction of drying behavior of pumpkin seeds was done using semiempirical models, of which, one was preferred as it indicated the best statistical indicators. Two-term model showed the best fit of data with R2 − 0.999, and lowest χ2 − 1.03 × 10−4 and MSE 7.55 × 10−5. A feedforward backpropagation ANN model was trained by the Levenberg–Marquardt training algorithm using a TANSIGMOID activation function with 2-10-2 topology. Performance assessment of ANN showed better prediction of drying behavior with R2 = 0.9967 and MSE = 5.21 × 10−5 for moisture content, and R2 = 0.9963 and MSE = 2.42 × 10−5 for moisture ratio than mathematical models. In general, the prediction of drying kinetics and other drying parameters was more precise in the ANN technique as compared to semiempirical models. The diffusion coefficient, Biot number, and hm increased from 1.12 × 10−9 ± 3.62 × 10−10 to 1.98 × 10−9 ± 4.61 × 10−10 m2/s, 0.51 ± 0.01 to 0.60 ± 0.01, and 1.49 × 10−7 ± 4.89 × 10−8 to 3.10 × 10−7 ± 7.13 × 10−8 m/s, respectively, as temperature elevated from 40 to 60°C. Arrhenius’s equation was used to the obtain the activation energy of 32.71 ± 1.05 kJ/mol.

Natural colorants/pigments are nowadays gaining popularity due to increased consumer awareness and severe health problems caused by the use of synthetic pigments. The efficient extraction of natural pigments from different plant sources leads to their effective application as substitutes for synthetic pigments in the food processing sector. In the present review, authors discussed the mechanistic approach of a novel ultrasonication technique in the extraction of natural color pigments having potential bio-functional characteristics leading to numerous health benefits. The recent advancements in the ultrasound-assisted extraction (UAE) of plant pigments including anthocyanins, betalains, carotenoids, and chlorophyll were explored. The most significant observations were that the extraction efficiency improved due to the phenomenon of cavitation, low installation and maintenance costs, and reduced energy requirement. Further, the optimum extraction conditions, stability, and bioaccessibility of the pigment compound significantly impact the process parameters.Moreover, recent progress in enhancing the performance of the UAE technique was addressed. Practical applicationsUltrasound-assisted extraction (UAE) is an effective way to improve the recovery of natural pigments from plants. Ultrasound treatment is a novel green extraction technology that offers a wide range of benefits. The present review conveys a better understanding of UAE mechanisms and optimum conditions of extracted pigments from different plant sources for their effective use as a natural colorant in food applications on an industrial scale.

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Muskmelon seeds hold tremendous potential to be utilized as a source of bioactive compounds as these seeds are discarded as waste during melon processing. Hence, the present study aims to optimize the process parameters of a vibro-fluidized bed drying i.e., temperature (40-60°C), vibration strength (0.55-1.23), and air velocity (7-11 m/s) on bioactive compound of muskmelon seeds. Maximum retention total phenolic content (977.56 mg GAE/100 g), total antioxidant activity (47.84% DPPH reduction), oil yield (50.40%), and linoleic acid content (39.54%) were obtained at optimal conditions of 54.20°C drying temperature, 10.98 m/s air velocity, and 1.23 vibration intensity with the desirability of 0.917. The effect of temperature in comparison to air velocity and vibration strength is predominant on bioactive compounds retention. Practical applicationsMuskmelon seeds have been recognized as the proficient source of essential oils and bioactive compounds such as polyphenols and antioxidants, due to which they hold an immense potential to be utilized as a nutritional source in the food and pharmaceutical industries. From optimization of vibro-fluidized bed drying process of muskmelon seeds, it has been confirmed that intervention of vibration in fluidization could produce high-quality dried seeds. Vibro-fluidized bed dryer can be implemented as an alternative drying method to reduce drying time, processing costs, and provide a better quality of the product.