Evaluación del rendimiento extractivo de aceite de semillas de sacha inchi (Plukenetia volubilis Linneo) por prensado y extrusión en frío

Abstract

The main objective of this research study was to focus on the extractive yield of Sacha Inchi (Plukenetia volubilis Linnaeus) seed oil that was evaluated by two methods: continuous pressing (extrusion) and discontinuous pressing (hydraulic pressing). The extrusion process showed a superior yield, obtaining 1000 ml of oil from 6000 g of seeds, compared to 450 ml from 1500 g in the hydraulic method with three consecutive extractions and under the same conditions. The seeds presented specific characteristics: The kernel was lenticular, beige, with a thickness of 7.89 mm and a weight of 0.82 g. While the seed was brown, with a thickness of 8.91 mm and a weight of 1.24 g. Analysis revealed a moisture content of 7.15%, ash of 1.69%, ether extract of 47.55%, rare fiber of 3.04% and protein of 31.26%. FTIR spectroscopy identified functional groups such as aliphatics and ketones, and UV-visible spectroscopy showed bands suggesting the presence of aromatic compounds and flavonoids. Controlled extractions were performed at 40°C and 400 kgf/cm². The oils obtained show similar characteristics in density (0.9260.928 g/mL), iodine value (182-184 g𝐼2/100g), free acidity (0.22 mg KOH/g), and saponification index (189.6 mg KOH/g). Both methods showed low contaminant content, complying with the standards established by the Ecuadorian Technical Standard. The continuous pressing method proved to be more efficient, with a yield of 21.89% versus 15.63% for batch pressing. This was attributed to a constant flow during extraction, optimizing time and reducing exposure to contaminants, which improves the quality of the oil obtained.