Lucio Brunetti

Influence of the feed pipe position of an industrial scale two-phase decanter on extraction efficiency and chemical-sensory characteristics of virgin olive oil: Decanter feeding impact on extraction efficiency and olive oil quality

BACKGROUND Nowadays, olive oil extraction is basically achieved by means of two-phase decanters, which allow a reduction of water consumption and the leaching of phenolic compounds. Despite this, most of the working settings derive from studies carried out on three-phase decanters. Hence, the aim of the present study was to assess the influence of two-phase decanter feed pipe position (FP) on the extraction efficiency and chemical-sensory characteristics of virgin olive oil. Three different positions were considered: at 825 mm (FP1), 610 mm (FP2) and 520 mm (FP3) from the outlet of the oily phase. RESULTS Position FP3 allowed the highest oil recovery (up to 10%), the lowest percentage of oil in the olive pomace and, in general, a regular trend in terms of oil extraction efficiency. However, the oily must that came out of the decanter was not completely clean in terms of residual content of solid sediment and water. The feeding position partially affected the profile of antioxidant compounds. CONCLUSION In two-phase decanters, loading the olive paste close to the outlet of the oily phase is recommended to increase the extraction efficiency without jeopardizing the chemical-sensory characteristics of virgin olive oil.

Renewable and integrative sources of energy: Aspects and technological applications: evaluation of the contribution to the energetic needs provided by the passive solar system

Abstract Aim of the article is the description and the evaluation of the contribution of energetic need provided by the passive solar system in relation to the acclimatisation of residential environment. The applicability of innovative solutions capable of sustaining, energetically, autonomous electrical structures of rural and/or isolated premises is also studied. The realisation of a prototype (wooden prefabricated volume) to test passive solar systems for a bioclimatic and environmental control has been done; experimental tests had been carried out and the results are shown.

Experimental study of a mechanical ventilation system in a greenhouse

Greenhouse cultivation is one of the most energy intensive activities in agriculture. This is especially true in cold climate zone. Generally heating systems involves boilers fed with fossil fuels. This means low yields of the heat generator and high pollutant emissions. Moreover, the increase of annual crop yield in greenhouses is possible only through a very close control of the internal conditions. Ventilation systems could allow proper control of temperature, relative humidity and CO2 rate. For this purpose a prototype of a mechanical ventilation unit was installed at service of a mini-tunnel greenhouse. The recovery unit is equipped with a heat pump and is able to increase the thermal energy recovered, by the flow of exhaust air, through a high efficiency heat exchanger. A first study was carried out to evaluate the thermophysical and energy performances of the system during the heating season. The experimental apparatus consists of mechanical ventilation system, a perforated duct for air distribution, a fog system to adjust humidity and a supervision system to acquire the field data. Another dedicated supervision system allows to measure and collect all the parameters of the prototype, such as thermophysical parameter of the air flow, thermophysical parameter of the refrigerant circuit of the heat pump, status and alarms of the unit. To characterize the whole system under investigation the main data measured are temperature, relative humidity and carbon dioxide inside the greenhouse and temperature in all section of the prototype. Other two mini-tunnel greenhouses are monitored as references. One is heated with radiant tubes placed on the bench and humidified with a fog system, the other is completely passively heated (without heating system) and humidified with the same fog system. A First test was performed to evaluate the ability of the system to regulate the indoor temperature of the greenhouse with a set point of 27 °C. By using a temperature probe installed on the return side of the machine, the results shown an appropriate temperature regulation.