Saffron Agronomy and Technology

Saffron Agronomy and Technology

Separating Stigma from Saffron Flower: Mechanized Methods (Review)

Document Type : Research Paper

Authors
Danial Gandomadeh 1
Mohammad Hossein Saeidirad 2
Yeganeh Sabeghi 3
1 PostDoc Researcher, Agricultural Engineering Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad, Iran
2 Associated professor, Agricultural Engineering Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad, Iran
3 Ph.D Student, Department of Food Science and Technology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
10.22048/jsat.2024.445321.1525
Abstract
Saffron is recognized as one of the important agricultural products in Iran, but in recent years, its yield production has significantly decreased by 3.42 kilograms per hectare. One of the factors contributing to this decrease is the time-consuming process of harvesting and separating the stigmas from the flowers, which requires approximately 180 to 204 minutes to process 2400 to 2700 flowers. Planting, maintenance, harvesting, and processing saffron stages are done manually, which not only adds value to the product but also raises concerns about microbial and fungal contamination. Various studies have been conducted to separate saffron stigmas from flowers, but so far, there has been no integration of these studies. In this study, different methods of stigma separation are classified into three stages: flower alignment methods before cutting (including human labor, robots, mechanical and airflow mechanisms), methods of cutting flower parts (including pulling out the stigmas, rotational force, and cutting blades), and stigma separation methods (including centrifugal force, friction coefficient, airflow, and porous surfaces). The review and comparison of various saffron stigma separation devices have shown that a combination of image processing techniques, optical sensors, optimized mechanical systems, and the application of airflow is the best method to achieve high precision and quality in stigma separation. These devices benefit from mechanical and suction mechanisms to more advanced systems such as image processing and optical sensors. High-precision image processing methods for identifying the cutting location and optical sensors for accurately detecting the color and shape of the stigmas can increase the speed and accuracy of separation. This combination, along with optimized mechanical systems and the use of airflow as a non-contact method to reduce damage to the stigmas, can help maintain the quality of the final product. This article will review the recent advancements reports by researchers in the field of saffron, particularly in the area of mechanized methods for separating stigmas from fresh saffron flowers. Furthermore, by comprehensively analyzing these methods, their strengths and weaknesses will be discussed, and suggestions for improving the mechanization of the stigma separation process from fresh flowers will be presented.
Keywords
Harvesting
Image Processing
Mechanization
Quality
Saffron
Separation

Subjects

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