Organic disinfestation and sanitisation
Insect pests, fungi, yeasts and pathogens infestations are a major problem in the storage, processing and marketing of agricultural commodities such as nuts, cereals, grains, pulses, seeds, etc. Typically, chemical fumigants are used for postharvest pest and bacteria control but regulatory issues, environmental concerns, potential health hazards, reduced acceptance by consumers and the increase of the organic products market have pressed the industry to implement non-chemical treatment alternatives, including thermal methods.
Conventional thermal techniques are simple and easy to control, however they are intrinsically slow and it is well known that prolonged heating can be detrimental to quality of food products. Direct heating methods by electromagnetic waves, instead, allow for rapid and uniform heating of many substrates. Recently, specific research has confirmed the viability of the radio frequency technology in this application field.
Fast and effective treatment
The process is 3 to 10 times faster compared to conventional heat treatments: 3÷5 minutes are sufficient to increase from room temperature up to 55÷65°C (for disinfestation) and 7÷10 minutes up to 80÷100°C (for sanitisation). One or two minutes temperature holding time is sufficient to ensure 100% mortality of even the most heat resistant pest species in all their development stages or to achieve 2 to 3 log reduction of the t.b.c. within the commodity.
Organic and chemicals-free process
The physical, chemical, sensorial and nutritional properties are preserved at best during the mild heat treatment, while a healthy and safe commodity can be obtained without using fumigants, anoxic atmosphere or other chemical treatments.
Energy efficient and environmentally friendly technology
Approx. 25 kWh are required to disinfest about 1 ton of product (about the double for a thorough sanitisation process), which translates into a cost of 2÷4 EUR/ton, competitive with the conventional technologies.