Influence of the feed pipe position of an industrial scale two-phase decanter on extraction efficiency and chemical-sensory characteristics of virgin olive oil.

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. © 2018 Society of Chemical Industry.

A Real Case Study of a Full-Scale Anaerobic Digestion Plant Powered by Olive By-Products.

The anaerobic digestion plant studied in this paper is one of the first full-scale plants using olive oil by-products. This is a two-stage plant with a power of 100 kWe. Two tests were performed: the first on olive pulp and pitted pomace and the second on biomass consisting of 10% crushed cereal. In both cycles, the retention time was 40 days. The production of biogas was between 51 and 52 m3/h, with limited fluctuations. The specific production values of biogas indicate that a volume of biogas greater than 1 m3/kg was produced in both tests. The produced biogas had a methane percentage of about 60% and the specific production (over total volatile solids, TVS) of methane was of the order of 0.70 m3methane/kgTVS. FOS/Alk (ratio between volatile organic acids and alkalinity) was always lower than 1 and tended to decrease in the second digester, indicating a stable methanogenic phase and the proper working of the methanogenic bacteria in the second reactor. The concentration of incoming biomass TPC (total polyphenols content) can vary significantly, due to the seasonality of production or inadequate storage conditions, but all measured values of TPC, between 1840 and 3040 mg gallic acid kg-1, are considered toxic both for acidogenic and methanogenic bacteria. By contrast, during the process the polyphenols decreased to the minimum value at the end of the acidogenic phase, biogas production did not stop, and the methane percentage was high.

Modified Rotating Reel for Malaxer Machines: Assessment of Rheological Characteristics, Energy Consumption, Temperature Profile, and Virgin Olive Oil Quality.

The properties of food products are the result of changes produced in raw materials as a result of process treatments. In the olive oil extraction process, these changes can be observed as differences in quality, nutritional characteristics, taste, and flavor, and are especially due to the time and temperature of the malaxation phase. These parameters are closely related to the mechanical design of malaxer machines. In this study, a new reel model for malaxer machines was designed. The new model was incorporated into an industrial malaxer machine and experimental tests were carried out to study the effects of two different reel designs (modified and unmodified profile) on the rheological characteristics of olive paste, the energy consumption of the plant, and the temperature profile inside the machine. The main commercial parameters of the produced olive oil were studied, as well as the extraction yield and the extraction efficiency of the plant. The malaxer machine equipped with the modified reel showed better homogenization of the paste, which led to improved heat exchange and rheological properties. The results of this study showed that a specific modification of the rotating reel can improve the performance of the malaxer in terms of improving the viscosity of the paste, 127,157.67 (mPa sn) for the malaxer with the modified reel at the beginning of malaxation, reaching a final value of 64,626.00 (mPa sn) at the end. The unmodified malaxer showed an initial viscosity coefficient of 133,754.00 (mPa sn) and a final value of 111,990.67 (mPa sn). This led to a reduction in malaxing times, an increase in the work capacity of the plant, and a reduction in total energy consumption and slowed down the oxidative phenomena responsible for the decrease in the quality of olive oil.

Evaluation of ratite skinning force in order to fix plant and mechanical solutions.

The skin is the most requested product of ratite slaughter and 'first-rate' ratite's skin has a high economic market. Ostrich hide is tanned in South Africa and sold all over the world. Besides, the ostrich meat is considered a niche production in the marketplace, thus allowing for another pro t for the ostrich breeding. Theorical analysis of skinning process has been carried out, and an automatic measurement system has been designed to record the drawing-force on the animal's body during skinning tests. The aim of this study was to indentify the best animal position and provide values of drawing-force in order to design a speci c machine for ostrich skinning. Experimental results partially con rm the proposed analysis. They point out that the angle of inclination of drawing-force with back-line mostly in uences the value of drawing-force and that this in uence tends to increase as the angle is near to 90 degrees or exceeds this limit. In any case, the applied drawing-force must not exceed 350.0 daN. Therefore, with respect to their anatomy structure and the tensile strenght of the hide, ostrich skinning should be done with vertical-drawing machines and the animal should be suspended by its wings at the rail. In case of low working capacity (8-10 heads per hour), given the di coulties highlighted during the experiments run in this study, the animal should be skinned suspended by the legs.

A new supporting tool for pig handling in the breeding-slaughterhouse production chain.

This paper focuses on a research concerning the operational management of the pig-handling phase, during the period of breeding and before slaughtering. Given the behaviour of these animals during transfers, a particular tool has been designed to manage them in this phase. A total number of 48 animals, divided in 4 groups, were moved without use of the tool (control groups) and by using the tool described in this article. The time required by the control groups to leave the pen ranges from 21 to 125 seconds; while, when the proposed tool was used, the time for the movement of the animals ranged between 10 and 17 seconds. In particular, in the groups where the tool was deployed the 'waiting phase' (before the first animal goes out) lasted less than half of the time of the 'waiting phase' of the control group, thus showing a minimization of the effects of the 'panic phenomenon' among the animals. Thus, the studied device can be considered as valid guide technique, both for the quick exit of the first animal and for those that follow. Once the row has been formed, the animals continue neatly to leave the box. This study also shows that this solution can also be considered appropriate for reducing the identified critical issues in the traditional handling. The need of only 1 worker to move the group of pigs is important to achieve economic saving. The deployment of this tool, thus, make possible to consider the movement of animals no longer a 'critical stage', but as a routine step of the production cycle of pork's meat.

Microclimate measuring and fluid­dynamic simulation in an industrial broiler house: testing of an experimental ventilation system.

The environment in the broiler house is a combination of physical and biological factors generating a complex dynamic system of interactions between birds, husbandry system, light, temperature, and the aerial environment. Ventilation plays a key role in this scenario. It is pivotal to remove carbon dioxide and water vapor from the air of the hen house. Adequate ventilation rates provide the most effective method of controlling temperature within the hen house. They allow for controlling the relative humidity and can play a key role in alleviating the negative effects of high stocking density and of wet litter. In the present study the results of experimental tests performed in a breeding broiler farm are shown. In particular the efficiency of a semi transversal ventilation system was studied against the use of a pure transversal one. In order to verify the efficiency of the systems, fluid dynamic simulations were carried out using the software Comsol multiphysics. The results of this study show that a correct architectural and structural design of the building must be supported by a design of the ventilation system able to maintain the environmental parameters within the limits of the thermo­neutral and welfare conditions and to achieve the highest levels of productivity.

Characterization of composting mixtures and compost of rabbit by-products to obtain a quality product and plant proposal for industrial production.

In this study we have observed the effects of using rabbit manure and slaughtering by-products in a composting process. Three piles of this material, 4700 kg each, with different amount and C/N ratio, have been investigated and experimental tests were carried out in an industrial horizontal axe reactor using a prototype of turning machine. The composting time lasted 85 days; 2 experimental cycles were conducted: one in Winter and one in Summer. In the Winter test, mesophilic reaction started only in the control mixture (animal manure + slaughtering by-products without straw). It is noteworthy that, the 3 investigated mixtures produced soil amendment by compost with good agronomical potential but with parameters close to the extreme limits of the law. In the Summer test, there was thermophilic fermentation in all mixtures and a better quality compost was obtained, meeting all the agronomic and legislative constraints. For each pile, we examined the progression of fermentation process and thus the plant limitations that did not allow a correct composting process. The results obtained in this study are useful for the development of appropriate mixtures, machines, and plants assuring continuance and reliability in the composting of the biomass coming from rabbit industry.