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Pigeon pea is the most prominently used protein source for human consumption. This is one of the leading pulse utilized in various applications in food processing. Soaking is one of the mandatory unit operation required to convert it from raw to a consumable form. Insights into its mass transfer dynamics enable the design and optimization of processing conditions with due consideration of retention of its quality and nutrition. In the present investigation, the mass transfer dynamics of simultaneous water gain and solid loss taking place during soaking was studied. The experimental samples were soaked at 35, 50, 75, 85, and 100°C to represent the lower and upper gelatinization temperatures. The water diffusivities varied from 5.492 × 10 −10 to 13.84 × 10 −10 m 2 /s when soaking temperature was increased from 35 to 100°C. Similarly, solid diffusivities vary between 6.27 × 10 −10 at 35°C and 9.48 × 10 −10 m 2 /s at 100°C. The activation energies of both the phenomenon were estimated using the Arrhenius equation. The mass transfer process has been identified with three distinct stages. The first stage was characterized by void filling, expansion, and solid hydration. The second stage was marked at 5% of solid loss and characterized by solid loss, while the third stage contributed to the starch gelatinization process. Simultaneous water gain and solid loss in the grain was observed throughout the process at varying rates. The insights into mass transfers from this study can help in further modeling of pigeon pea soaking behavior.

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Apricot (Prunus armeniaca. L) is an important stone fruit grown abundantly in the temperate climate. Traditionally, the fruit stone (pit), leftover part of fruit after utilizing apricot flesh, contains the apricot kernel. These kernels are currently being explored for the oil extraction purpose. Therefore, postharvest management and processing of the apricot pit are imperative along with its process mechanization. Manual decortication of apricot pit is tedious and laborious task. Hence, a small‐scale apricot pit decorticator machine was developed to mitigate all these issues. The machine works on the principle of breaking the pit by impact and compression forces produced by reciprocating piston. Performance of the decorticator was evaluated using dry wild apricot pits. The independent variables, namely, crankshaft speed (60–100 rpm), moisture content (8.5–16.5% wb), feed per stroke (10–18 g/stroke), and impact clearance (0–2 mm) were selected for testing of the decorticator. Decortication efficiency and broken kernel percentage were obtained in the range of 67.25–77.49% and 8.97–30.17%, respectively. The best performance of the decorticator for maximum decortication efficiency with minimum percentage of broken kernels were found to be at 85 rpm crankshaft speed, 15% (wb) moisture content, 18 g/stroke feed per stroke, and 0.8 mm impact clearance. Pay‐back period of the decorticator was found to be 0.48 years. Practical applications Apricot kernel present in pit is very fragile because of its softness and friability. Hence, it is very difficult to remove the outside husk mechanically without crushing or breaking the inside kernel. There is very high value of whole and quality kernels in dry fruits, confectioneries, medicine, and cosmetics. Various traditional methods are very tedious, laborious and uneconomical to the farmers and result in low quality unhygienic products. Therefore, a mechanized apricot pit decorticator working on the principle of impact and compression forces has been developed to solve the problem. The machine can decorticate pits easily with maximum decortication efficiency, minimum brokens, and reduced drudgery. The developed decorticator has potential for commercial production of kernels. It will increase the commercial application of kernels in dry fruits, confectionery, medicines, cosmetics, and further value additions.

The knowledge of airflow resistance and distribution pattern in a highly porous-bed commodity like an onion is an important consideration in designing an appropriate ventilation system and for proper selection of fans. The resistance to airflow through bulk onions was determined at the airflow rates range of 0.04-1.0 m 3 /s.m 2 , bed depth of 0-100 cm, and scaled and descaled condition of onion at vertical and horizontal position of the onion stock. Three models (Shedd, Hukill and Ives, and Ergun) were investigated to describe pressure drop data of onion bulbs. The pressure drop through bulk onion was increased with an increase in airflow rate and bed depth.Also, pressure drop was 43.5 and 33.3% higher in scaled condition over the descaled condition of bulbs at the vertical and horizontal position of the column, respectively.Shedd model was found to more reliable among three models to describe airflow resistance in bulk of onion bulbs. Practical ApplicationsOnion is perishable vegetable consumed throughout the year. Being a seasonal crop and to fulfill the demand of consumers it must be stored for off seasonal use. Storage of the onion bulbs at ambient and modified environment condition is the most commonly used methods in a tropical climate. But there were huge postharvest losses mainly in the form of physiological weight loss, sprouting, and decay and considerable loss in nutritional qualities. Properly designed aeration, ventilation, and fumigation system is the only way to reduce such losses. Therefore, the understanding of dynamic behavior of applied ventilation and fumigation with its distribution pattern in a highly porous commodity like an onion is a preliminary requirement for the proper design of storage system. Different model based approach to understand flow dynamics could be used in the dimensional design of a storage system in a tropical climate.