Aqueous Extraction of Seed Oil from Mamey Sapote (Pouteria sapota) after Viscozyme L Treatment

Veymar G Tacias-Pascacio,Rafael C Rodrigues,Arnulfo Rosales-Quintero,Pablo F Díaz-Suarez,Erik F Jiménez-Gómez,Roberto Fernandez-Lafuente,Daniel Castañeda-Valbuena,Beatriz Torrestiana-Sánchez

doi:10.3390/catal11060748

Abstract

In this study, aqueous enzymatic extraction (AEE) was evaluated during the process of obtaining oil from mamey sapote seed (OMSS). Viscozyme L enzyme complex was used at pH 4 and 50 °C during the optimization of the extraction process by central composite design and response surface methodology. Optimal conditions were: 3.5% (w/w) of enzyme (regarding the seed weight), 5.5 h of incubation time, 235 rpm of agitation rate, and 1:3.5 of solid-to-liquid ratio. These conditions enabled us to obtain an OMSS yield of 66%. No statistically significant differences were found in the fatty acid profile and physicochemical properties, such as the acid and iodine values and the percentage of free fatty acids, between the oil obtained by AEE or by the conventional solvent extraction (SE). However, the oxidative stability of the oil obtained by AEE (11 h) was higher than that obtained by SE (9.33 h), therefore, AEE, in addition to being an environmentally friendly method, produces a superior quality oil in terms of oxidative stability. Finally, the high oil content in mamey sapote seed, and the high percentage of oleic acid (around 50% of the total fatty acid) found in this oil, make it a useful edible vegetable oil.

Highlights

We did not find any previous communications in the literature on the application of AEE to produce oil from mamey sapote seed (OMSS); for this reason, the objective of this study was to optimize, by response surface methodology coupled to central composite design (CCD), the aqueous enzymatic extraction of OMSS using the enzymatic complex Viscozyme L, comparing the fatty acid composition and physicochemical features of the oil that has been obtained by AEE with the one obtained by traditional solvent extraction (SE)
These differences can be attributed to differences in the fruit maturity and variety, or environmental factors of the geographical location
No significant statistical differences were found in the acidity and iodine value, free fatty acids content or in the fatty acid composition of the OMSS obtained by AEE compared to SE

Summary

Introduction

Mamey sapote shape changes from round to ovoid or elliptic, its size is in the range of 10–20 cm in length and its weight ranges from 0.2 to 3 kg; it has a firm, dark-brown, rough, leathery semi-woody rind [1,14,15,16]. This contains one-to-four bright brown oily seeds (40–60% of lipids) with a characteristic almond odor [1,6,15,17]. The possibility of using OMSS for biodiesel production has been explored, obtaining a yield of 92.48%, employing 0.760% of catalyst, 6 methanol equivalents per mol of triglyceride, at 60◦ C and after 90 min of reaction [19]

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Conclusion