Ecology, Environment and Conservation Paper

RAPESEED MECHANICAL RESISTANCE TO LOADS

Adel Vahedi, Morteza Almassi, Arzhang Javadi, Saeid Minaei, Ghorbanali Nematzadeh and Esmaeil Yasari

Abstract

The investigations on rapeseed postharvest handling have been carried out in the Science and Research Branch of I.A.U. for many years. They cover the whole technological process of rape handling from harvesting to processing. The aim of the present study was to evaluate the decrease of rapeseed quality during harvesting, cleaning, drying and storing as well as indicate the reasons of the mechanical damage occurred during handling. Therefore the rapeseed samples from Hyola 401 cultivar were collected at all technological operations and the amount of damaged seeds was checked. At the same time laboratory investigations were also performed. The compression test between two parallel heating plates was performed and mechanical strength of whole seed was calculated according to wide range of seed moisture content and temperature. The results showed considerable decrease of rapeseed quality (understanding as number of mechanical damage) during postharvest handling. The most negative effects were observed at low moisture content (below 6% w.b.) and high temperature of seeds (over 50deg.C). The most negative operation was harvesting, when 50-90% of total number of seed damage occurred. Total percentage of damaged seed was from 1.6 till 7.5% of its whole amount. These results were confirmed by laboratory tests. Moisture content influenced seed strength stronger than temperature. Maximal strength was noticed at 6% w.b. and decreased both with increase and decreases of moisture content. With the increase of temperature the strength of seed decreased.