Effect of storage time and temperature on the quality of Sacha Inchi Oil (Plukenetia volubilis) during processing

Abstract

This study investigated the effect of storage time and temperature on the quality of Sacha Inchi (Plukenetia volubilis L.) oil during processing. Storage time and temperature were considered two important factors that affected the oil quality. The oil quality was noticeably decreased by extended storage time and heating treatment via the observation of peroxide value, acid value, iodine value, and saponification value. Physicochemical properties of oil were determined including boiling point (207.33±2.520C), crystallization temperature (-200C), and decomposition temperature (340-350 0C). The quality of oil was declined after 7 months of storage; the peroxide value of fresh Sacha Inchi oil increased from 0.63±0.03 Meq/kg to 1.07±0.06 Meq/kg. Heating process at the temperature of 205 oC for 90 min remarkably affected the peroxide and acid value of oil but these values were still within the allowable limit at the studied. This suggested that Sacha Inchi oil could possibly be processed at higher temperature and extended heating time. Besides, the alterations of peroxide value and acid value were still within the allowable limit when Sacha Inchi was subjected to the 3rd repeated deep-frying cycle of potato slices (5 min for each cycle). This suggested the feasibility of Sacha Inchi to be a suitable alternative to normal cooking oil.