Development of a new technology for the production of food-grade soybean meal

Abstract

A mandatory technological operation for the production of food-grade protein products is the dehulling of soybean seeds in order to increase the mass fraction of protein in the soybean oil cake or soybean meal. When the content of the processed hull in the soybean kernels decreases, more soybean kernels are removed and more soy oil is lost together with removed hulls. The aim of this work is to develop an effective technology of separating hulls from cracked soybeans with minimal oil losses and to determine the quality indicators of oil and soybean meal obtained from the kernel fraction. A pilot industrial plant with a maximum productivity of 1000 kg/h of soybean seeds has been developed including a crusher for dehulling soybean seeds, innovative pneumatic separators of the author's design for a two-stage separation of hulls from cracked seeds, a press-extruder for the production of oil and soybean meal from the kernel fraction. Effective technological modes of gradual separation based on innovative pneumatic separators of soybean hulls from cracked soybeans have been developed, which ensure the minimum hull content in the kernel fraction and minimal oil losses, namely. The specific load on the receiving sieve of the first stage pneumatic separator is 18,5 kg /(cm/h), the air flow rate in the upper part of the vertical aspiration channel of the pneumatic separator of the first stage is 3,31 m/s, and 2,71 m/ s in the second stage separator correspondingly. It is shown that when processing soybean seeds of similar quality, the hull content in the kernel fraction obtained at a pilot industrial plant according to the developed technology is lower in comparison with the literature data presented for a modern foreign line when other efficiency indicators are similar. When soybean seeds are processed by pressing method at a pilot industrial plant for dehullling based on the newly developed technology, unrefined premium soybean oil and soybean meal are obtained in accordance with the requirements of the relevant regulatory documents.