Compressive stress, repetitive strain, and optimum expression of oil from bulk volumes of sesame seeds

摘要

Compressive expression of oil from bulk seeds is a self-limiting process and commonly adopted techniques for optimizing oil recovery result in alterations of the product and its quality. In this study, effects of select magnitudes of compressive stress and repetitive strain on mechanical response and performance during cold compressive expression of oil from sesame seeds were investigated and responses modeled using forward stepwise regression technique. Significant gains in oil yield and performance were achieved through repeated induction of strain and by increasing magnitudes of the applied stress. Cumulative improvement in the performance of the scheme over existing single cycle compression techniques ranged between 34.1 and 161.9% over the range of treatments investigated. Corresponding improvement in mechanical response was also achieved. Specific mechanical energy demand was less with every additional compression cycle. The pressure ratio at the oil point during each compression cycle was an important indicator of recoverable oil.