Assessment of pretreatment temperature on the oil extraction from the vinification waste

Abstract

The study was carried out to determine the influence of hot air in drying process of grape seeds (Vitis labrusca) as well as in the oil extraction. The drying kinetics of the seeds was measured at different drying temperatures, ranging from 50 to 80 °C. The extraction experiments were conducted varying the operating pressure from 14 to 22 ton/cm 2. A phenomenological mathematical model of distributed parameters to describe the drying process was evaluated. The drying model was validated by comparison with experimental drying data and showed an average error of 2.2% in moisture profiles. In the pressing extractions experiments, the oil content was inversely proportional to the drying temperature of the seeds. The drying condition, which provided the maximum oil yield, was air temperature of 50 °C, in which the grape seed oil yield was 10%. Practical applications This article presents as contribution the filling of the scientific gap related to the evaluation of the drying kinetics and the influence of the drying temperature on the yield of grape seed oil content. For a practical application, our results revealed that the oil content was inversely proportional to the drying temperature of the grape seeds. Thus, considering the high costs related to the drying process, it can be concluded that the optimum temperature of drying the grape seeds must be directly related and the cost of energy and the oil content.

Experimental Investigation on the Effect of Pre-Treatments on Thin Layer Drying and Quality Characteristics of Green Mangoes in Forced Convection Hot Air Drying

“…Pre-treatment quite often proceed with drying operation of fruits and vegetables in order to minimise (or avid) the adverse changes occurring during dehydration and subsequent storage (Abano et al, 2013). The Drying rate can also be improved by pre-treatment"s (Dabhade and Khedkar, 1980) (Doymaz, 2004) (Liu, et al, 2014) (Sufer et al, 2017) (Tummanichanont et al, 2017) (Johann et al, 2018) (Serhat Turgut et al, 2018). Also pre-treatment prevent fruit from darkening and colour changes.…”