Enzymatic fat hydrolysis and synthesis

Abstract

The hydrolysis of tallow, coconut oil and olive oil, by lipase from Candida rugosa, was studied. The reaction approximates a firstorder kinetics model. Its rate is unaffected by temperature in the range of 26-46 C. Olive oil is more rapidly hydrolyzed compared to tallow and coconut oil. tlydrolysis is adversely affected by hydrocarbon solvents and a nonionic surfactanL Since amounts of fatty acids produced are almost directly proportional to the logarithms of reaction time and enzyme concentration, this relationship provides a simple means of determining these parameters for a desired extent of hydrolysis. All three substrates can be hydrolyzed, almost quantitatively, within 72 hr. Lipase from Aspergillus niger performs similarly. The lipase from Rbizopus arrbizus gives a slow hydrolysis rate because of its specificity for the acyl groups attached to the c~hydroxyl groups of glycerol. Esterification of glycerol with fatty acid was studied with the lipase from C rugosa and A. niger. All expected five glycerides are formed at an early stage of the reaction. Removal of water and use of excess fatty acid reverse the reaction towards esterification. However, esterification beyond a 70% triglyceride content is slow.

Lipase‐catalyzed ester exchange reactions in organic media with controlled humidity

“…which is commonly ascribed to "enzyme denaturation" should certainly be explained by microbial breakdown of the catalyst . 6 For these reasons, a systematic study of the control of the amount of water present in an organic reaction medium for enzyme catalysis and of the behavior of an enzyme under conditions of controlled humidity is highly desirable. This paper describes the properties of immobilized lipase in an organic reaction medium of controlled relative humidity and summarizes some preliminary results on the lipase-catalyzed interesterification under these circumstances.…”

The effects of dietary Eleutherine bulbosa on the growth, leukocyte profile, and digestive enzyme activity of the striped catfish Pangasianodon hypophthalmus

“…The protein content in solution was assayed using the Folin phenol method, and bovine serum albumin was used as a standard for protein determination (Hartree 1972). Lipase activity was performed following the method of Linfield et al (1984). One unit of lipase per mL (U mL -1 ) is defined as 1 µmol of fatty acid liberated per minute.…”

Modificação de óleos e gorduras por biotransformação

“…Assim, quanto maior a interface, maior a quantidade de enzima adsorvida, acarretando taxas de hidrólise mais elevadas 42,52 . Diferentes parâmetros podem influenciar o desempenho da hidrólise de óleos e gorduras e, conseqüente-mente, diversas técnicas têm sido utilizadas para aumentar a taxa de hidrólise de gorduras usando lipases como catalisadores [56][57][58][59][60][61][62][63][64][65] . A hidrólise do óleo de palma foi investigada para obtenção de mono e diacilgliceróis empregando preparações de lipases de fontes microbiana (Candida rugosa), vegetal (gérmen de trigo) e animal (pâncreas de porco).…”

“…Entre as lipases testadas, as taxas de conversão de hidrólise mais elevadas foram obtidas com a lipase de Candida rugosa, com atividade ótima a 37 °C e pH = 7,5 56 . Linfield et al 57 estudaram a hidrólise de sebo e óleos de coco e oliva utilizando lipases de Candida rugosa, Aspergillus niger e Rhizopus arrhizus. A reação em emulsão foi conduzida em sistemas de frascos agitados, obtendo-se altos valores de conversão (97-99% em 72 h).…”