Optimization of parameters for enhanced oil recovery from enzyme treated wild apricot kernels

Abstract

Present investigation was undertaken with the overall objective of optimizing the enzymatic parameters i.e. moisture content during hydrolysis, enzyme concentration, enzyme ratio and incubation period on wild apricot kernel processing for better oil extractability and increased oil recovery. Response surface methodology was adopted in the experimental design. A central composite rotatable design of four variables at five levels was chosen. The parameters and their range for the experiments were moisture content during hydrolysis (20-32%, w.b.), enzyme concentration (12-16% v/w of sample), combination of pectolytic and cellulolytic enzyme i.e. enzyme ratio (30:70-70:30) and incubation period (12-16 h). Aspergillus foetidus and Trichoderma viride was used for production of crude enzyme i.e. pectolytic and cellulolytic enzyme respectively. A complete second order model for increased oil recovery as the function of enzymatic parameters fitted the data well. The best fit model for oil recovery was also developed. The effect of various parameters on increased oil recovery was determined at linear, quadric and interaction level. The increased oil recovery ranged from 0.14 to 2.53%. The corresponding conditions for maximum oil recovery were 23% (w.b.), 15 v/w of the sample, 60:40 (pectolytic: cellulolytic), 13 h. Results of the study indicated that incubation period during enzymatic hydrolysis is the most important factor affecting oil yield followed by enzyme ratio, moisture content and enzyme concentration in the decreasing order. Enzyme ratio, incubation period and moisture content had insignificant effect on oil recovery. Second order model for increased oil recovery as a function of enzymatic hydrolysis parameters predicted the data adequately.

Enzymatic Pretreatment of Plant Cells for Oil Extraction

“…The enzymatic pretreatment of apricot kernels with pectolytic and cellulolytic enzymes was investigated at the amount of moisture added during hydrolysis from 20 to 32 %. The highest value of increased oil recovery (2.53 %) was achieved at 23 % of the applied moisture relative to the weight of the substrate (130). The enzymatic hydrolysis of borage seeds with enzyme preparations Olivex and Celluclast was performed at a moisture content from 20 to 50 %.…”

“…with proteolytic, cellulolytic and pectolytic activity to improve aqueous extraction, organic solvent extraction and press extraction of the oil (3,4,6,9,10,(109)(110)(111)(112)(113)(114)117,118,130,132,133,137).…”

“…Heating to 50-60 °C causes a sharp decrease in its oil viscosity, while with a further increase in temperature, the viscosity changes are less significantly (142). At the same time, a temperature range from 40 to 55 °C is the most optimal for enzymatic pretreatment of oilseeds, at lower temperatures the process will not be efficient enough, and at temperature above 60 °C denaturation of the enzyme protein part and its inactivation will occur (3,4,6,9,10,13,(108)(109)(110)(111)(112)(113)(114)117,118,130,132,133,137).…”

Acute toxicity of refined wild apricot oil in rats

“…Apricot kernels are important raw materials for the production of various products including oils and proteins. About 40-56 g of oil is present in 100 g of wild apricot kernel 1 . Apricot pits have been widely used in Chinese traditional medicine to treat asthma, aplastic anaemia, and tumours 2 .…”

“…They can also be used as lubricants, cosmetics, and surfactants 3 . Recently, researchers have examined the use of the wild apricot oil in many areas 1,3,4 . Although most of these studies suggest that the wild apricot oil is suitable for human consumption, they have found that wild apricot oil also contains up to 8% amygdalin 5,6 .…”