RU2292731C2 - Method for utilization of highly wet food wastes - Google Patents

Abstract

FIELD: utilization of agro-industrial complex wastes, in particular, utilization of highly wet perishable wastes of food-processing industry.

SUBSTANCE: method involves performing sequential mixing of grain wastes and highly wet food wastes until process moisture content is 24-40%, said moisture content being reached by altering share of grain wastes; extruding mixture through die with at least one slot-type forming bushing; impregnating extrudate with highly wet food wastes until process moisture content is 65-75%, said moisture content providing stable shape of extrudate to thereby keep its porosity; drying in air flow permeating through product layer until moisture content is 10-12%. Air flow temperature may be lower or higher than environmental temperature.

EFFECT: reduced consumption of moisture absorbing component, such as grain wastes, and improved quality of product.

3 cl

Description

The invention relates to the field of waste disposal of agricultural production and can be used for the disposal of high-moisture perishable waste from food production.

A known method for the disposal of high-moisture food waste (Application No. 2003100285, publ. 07/20/2004), in which grain wastes and high-moisture food waste are mixed to a process humidity of 24 ... 40%, which is provided by changing the proportion of grain waste, extruding the mixture through a matrix s, at least one slotted die, and then cooled and dried in a stream of air penetrating the product layer.

The disadvantage of this method is the great need for a moisture-absorbing component - grain waste.

The technical result of the invention is to reduce the required amount of absorbing moisture component - grain waste.

The specified technical result is achieved by sequentially mixing grain waste and high-moisture food waste to a technological humidity of 24 ... 40%, which is provided by changing the proportion of grain waste, extruding the mixture through a matrix with at least one slotted die, impregnating the extrudate with high-moisture food waste to a technological humidity of 65 ... 75%, which provides a stable form of the extrudate to preserve its porosity, and drying in a stream of air penetrating the product layer, until wet sti 10 ... 12%. The temperature of the air flow can be lower than the ambient temperature, the temperature of the air flow can be higher than the ambient temperature.

The method is as follows.

Pre-crushed grain wastes are added to high-moisture food wastes to increase mixing uniformity. The resulting mixture is subjected to extrusion processing, and the technological humidity of the extruded mixture (from 24% to 40%) is provided by changing the proportion of introduced grain waste. Slit die allows you to get a product with a large surface area relative to its volume. This form increases the evaporation area, which accelerates the removal of moisture during drying. The resulting extrudate is impregnated with high-humidity food waste to the maximum possible moisture content (from 65% to 75%), which provides a stable form of the extruded product so that it has a porosity in the layer that allows free flowing through the air stream. Porosity is determined visually. Then the extrudate is dried by a stream of air in the room to an equilibrium humidity of 10 ... 12%.

In the steady state of the process, the dispersed phase of high-moisture food waste, which remains after the absorption of the dispersion medium by the extrudate, is sent to mixing with the grain waste. Since the moisture content of the dispersed phase is less than the moisture content of the initial waste, a small amount of moisture-absorbing component, grain waste, is required to achieve the technological humidity of the extruded mixture (from 24% to 40%).

The proportion of grain waste in the mixture, providing the required process humidity, is regulated by dispensers depending on the viscosity of the pressed semi-finished product, measured by the electric power of the engine. The engine power spent on extrusion has a correlation with the visco-plastic properties of the extrudable material. At the same time, the combination of viscoplastic properties determines the quality of the products obtained and their ability to lose moisture during drying. The extruded product has a high density and low gas permeability, which prevents its oxidation.

Thus, controlling the humidity of the mixture by engine power allows you to get high-quality products and speed up the drying process.

The initial humidity of the mixture from 24% to 40% provides a mode of warm extrusion with a product temperature of 60 ° C to 120 ° C. Short-term exposure to heat during warm extrusion together with pressure destroys harmful microorganisms and fungi.

Reducing the undesirable decomposition of chemical compounds entering the product during heating in the extruder can be achieved by reducing the time of exposure to temperature by blowing cooled air through the product layer.

The intensification of the drying process can be achieved by blowing heated air through the product layer.

Claims (3)

1. The method of disposal of high-moisture food waste and grain waste, characterized in that it provides for mixing grain waste and high-moisture food waste to a technological humidity of 24-40%, which is provided by changing the proportion of grain waste, extruding the mixture through a matrix with at least one slotted die, impregnation of the extrudate with high-humidity food waste to a technological humidity of 65-75%, providing a stable form of the extrudate to preserve its porosity, and drying in an air stream, penetrating second product layer to a moisture content of 10-12%. 2. The method according to claim 1, characterized in that the temperature of the air stream is lower than the ambient temperature. 3. The method according to claim 1, characterized in that the temperature of the air stream is higher than the ambient temperature.