Destalking of dry red chillies (Capsicum annum L.) and its characterization.

Abstract: The prevalent manual destalking of dried red chillies is a labour-intensive, tedious, and unhealthy practice that can cause severe health ailments to the labourers. This study focuses on the design and fabrication of a mechanized system for removing stalks from dried chillies to reduce the drudgery involved in manual operation. The machine's primary components including hopper, rotating cylinder, triangular bridges, cutting blades, destalked chilli outlet, and stalk outlet were fabricated based on the design considerations and ease of operation. The machine was evaluated considering the independent parameters viz. feed rate, cylinder speed, and cylinder inclination for optimization of its performance using one-factor-at-a-time statistical design. Physical properties of chillies, destalking efficiency of the machine, and the effect of destalking on powder characteristics were determined. Optimal performance of the machine was achieved with the chillies having 8-10% (moisture), 6.5 kg/h (feed rate), 20 rpm (cylinder's speed), and 3° (cylinder's inclination) with destalking efficiency of 85-87%. The evaluation of powder characteristics also revealed the prominence of destalking with enhanced colour attributes. The developed machine is compact, efficient, economical, requires less labour and thereby it may encourage its adoption at the farmer's level and strengthening of the value chain of dried chillies.

Exploitation of microbial antagonists for the control of postharvest diseases of fruits: a review.

Fungal diseases result in significant losses of fruits and vegetables during handling, transportation and storage. At present, post-production fungal spoilage is predominantly controlled by using synthetic fungicides. Under the global climate change scenario and with the need for sustainable agriculture, biological control methods of fungal diseases, using antagonistic microorganisms, are emerging as ecofriendly alternatives to the use of fungicides. The potential of microbial antagonists, isolated from a diversity of natural habitats, for postharvest disease suppression has been investigated. Postharvest biocontrol systems involve tripartite interaction between microbial antagonists, the pathogen and the host, affected by environmental conditions. Several modes for fungistatic activities of microbial antagonists have been suggested, including competition for nutrients and space, mycoparasitism, secretion of antifungal antibiotics and volatile metabolites and induction of host resistance. Postharvest application of microbial antagonists is more successful for efficient disease control in comparison to pre-harvest application. Attempts have also been made to improve the overall efficacy of antagonists by combining them with different physical and chemical substances and methods. Globally, many microbe-based biocontrol products have been developed and registered for commercial use. The present review provides a brief overview on the use of microbial antagonists as postharvest biocontrol agents and summarises information on their isolation, mechanisms of action, application methods, efficacy enhancement, product formulation and commercialisation.

Status of pulse milling processes and technologies: A review.

Pulses are essential component of the human diet in the underdeveloped and the developing countries. Pulse milling mainly focuses on complete removal of the hull with minimum generation of powder, broken, and in certain cases dehulled split formation. Physical and mechanical properties of different pulses are described and their role in dehulling is discussed in this review. The review discusses nature of gums that binds hull and cotyledons together and their effect on milling characteristics. Pitting operation is performed for all pulses prior to the pretreatment for better dehulling. Various pretreatment processes (soaking, edible oils, chemicals, enzymes, hydrothermal) developed to loosen the bond are examined for their dehulling efficacy from commercial application viewpoint. Dependence of dehulling characteristics of different pulses on size, shape, variety, grain hardness, and moisture content are discussed. Most of the machines developed for pulses dehulling in India are abrasion based emery-cylinder concave system. The studies done for optimization of different pretreatment process conditions are also reviewed. The losses taking place in the form of broken and powder during pulse milling are described. Methods for performance evaluation of the pulse dehulling system are reviewed and expressions are suggested for proper evaluation. This review gives complete overview of the processes and technological status of pulse milling in present context.