Sacha inchi oil (Plukenetia volubilis) stabilized with antioxidants for addition in fresh cheese

Sacha Inchi (Plukenetia volubilis) is a nut that has been grown in the Amazon Rainforest and the high Andes Mountains of Peru for countless centuries. The oil of this nut, natural source of omega 3, 6 and 9, has been recognized by its high antioxidant capacity in humans. In this work, oil from Sacha Inchi was fortified with two commercial antioxidants (Ecoprol 2020 and tocopherol) in order to prepare a fresh cheese from cow's milk. The antioxidant capacities of Sacha Inchi and commercial antioxidants were used as preservatives with the purpose to increase the shelf-life of fresh cheese besides nutritional content. The factorial method was necessary to prepare seven formulations in order to find the optimal concentration of the antioxidants added to Sacha Inchi oil andthe addition of this oil to the fresh cheese. A sensory analysis was performed to choose the best formulation. The results showed that an oil formulation (F4) with tocopherol (150 mg/kg of oil) and Ecoprol 2020 (1000 mg/kg of oil) displayed the lowest peroxide values (PI: 2.6 ± 0.1 meq O2/kg of oil, p < 0.001) and it was able to reduce approximately 50% of fatty acid oxidation in Sacha Inchi oil in relation to the PI control. Then, F4 was used to elaborate further nine formulations (F’1 – F’9), enriched with Sacha Inchi oil (1 to 4%) to prepare the fresh cheese. Microbiological analysis for all formulations were performed (limits of mold, yeasts, coliforms, salmonella, and bacteria) in order to meet the legal requirements of health and safety in Peru. The cheese taste acceptability was determined through the sensorial evaluation, which reached 7.2 according to the 9- hedonic scale for F'5. Thus, an optimum fresh cheese was obtained from the formulation (F’5) with 22.5g/L of salt and 2.5% of Sacha Inchi oil enriched with 150 mg/kg of tocopherol and 1000 mg/kg of Ecoprol 2020. The cheese shelf-life was also evaluated, increasing it up from 7 days to 16 days in refrigeration. Key words: cheese, antioxidant, Sacha Inchi, shelf-life, Ecoprol 2020, tocopherol