Optimization of oligoglycerol fatty acid esters preparation catalyzed by Lipozyme 435

Abstract

Oli goglycerol fatty acid esters (OGEs) are an important kind of polyglycerol fatty acid esters (PGEs) which have been widely used as emulsifiers in food, medicine and cosmetic industries. The aim of this study was to investigate the preparation of OGEs by the esterification of olig oglycerol with linoleic acid in a solvent-free system using Lipozyme 435 as the catalyst. The effects of substrate molar ratio, reaction time, reaction temperature, enzyme dosage, and water addition on the efficiency of esterification (EE) were studied. Single factor experiments and response surface methodology (RSM) were employed to optimize the reaction parameters. The optimum conditions were obtained as follows: reaction time 4.52 h, reaction temperature 90 °C, enzyme dosage 2 wt% (based on the total substrate mass), the molar ratio of oligoglycerol to linoleic acid 1.59:1 and no water addition. Under these conditions, the experimental EE (95.82±0.22%) fitted well with that predicted by RSM (96.15%). Similar results were obtained when the process was scaled up to a production of 500 g in a pilot bubble column reactor (BCR). The enzyme maintained 98.2% of the relative activity after 10 batches of reaction in the BCR. Electro spray ionization mass spectrum was employed to rapidly analyze the esterification products, and most species of OGEs have been identified. KEYWORDS: Biocat alysis; Bubble column reactor; Esterification; Immobilized enzyme; Lipase; Oligoglycerol fatty acid estersRESUMEN: Optimización de la preparación de ésteres grasos de oligoglicerol catalizada por Lipozyme 435. Los ésteres grasos de oligoglicerol (OGEs) son una clase importante de ésteres de ácidos grasos de poliglicerol (PGE) que han sido ampliamente utilizados como emulsionantes en alimentación, medicina y en la industria cosmé-tica. El objetivo de este estudio fue investigar la preparación de OGEs mediante la esterificación de oligoglicerol con ácido linoleico en un sistema libre de disolvente utilizando Lipozyme 435 como catalizador. Se estudiaron los efectos en la eficiencia de esterificación (EE) de la relación molar de sustratos, de los tiempos de reacción, las temperaturas de reacción, la dosis de la enzima, y de la adición de agua. Se realizaron ensayos factoriales individuales y metodología de superficie de respuesta (RSM) para optimizar los parámetros de la reacción. Las condiciones óptimas se obtuvieron como sigue: tiempo de reacción 4,52 h, temperatura de reacción 90 °C, dosis de enzima 2% en peso (basado en la masa total del sustrato), la relación molar de ácido linoleico:oligoglicerol fue de 1,59:1 sin adición de agua. Bajo estas condiciones, el EE experimental (95,82±0,22%) se corresponde bien con lo predicho mediante RSM (96,15%). Se obtiene un resultado similar cuando el proceso se escaló a una producción piloto de hasta 500 g en un reactor de columna de burbujas (BCR). La enzima mantiene el 98,2% de su actividad relativa después de 10 lotes de reacción en el BCR. Se empleó un espectrómetro de masas de ionización mediante electrosp...

Green Synthesis of Decaglycerol Laurates by Lipase-Catalyzed Transesterification of Methyl Laurate with Decaglycerol

“…is result indicated that the enzymatic transesterification of decaglycerol and methyl laurate in this experiment has excellent monoester selectivity, consistent with our previous results about the lipase-catalytic production of glycerol monolaurate by transesterification of glycerol and methyl laurate [24]. However, the oligoglycerol fatty acid esters enzymatically prepared by the esterification of oligoglycerol (mainly composed of diglycerol, triglycerol, and tetraglycerol) and linoleic acid always give mixtures of monoesters, diesters, triesters, and tetraesters [12]. Figure 7 showed the surface tension (c) profiles of the aqueous solutions of decaglycerol laurates at 25°C.…”

“…e enzymatic esterification of polyglycerol and fatty acids to give PGFE has been carried out using lipase [10,11]. Using diglycerol and oleic acid as starting materials, acid conversion of about 90% and monoester selectivity of >94% have been achieved as the best results [12]. However, the PGFE preparations through the transesterification of polyglycerol and fatty acid esters were rarely reported in the literature [13].…”

Enzymatic Synthesis of Polyglycerol Fatty Acid Esters and Their Application as Emulsion Stabilizers

“…The middle layer comprised the enzyme, which could be isolated by filtration and used repeatedly; the lower layer comprised the polyglycerol, which could be used as raw material. The upper layer comprised the mixture of synthesized polyglycerol fatty acid esters, which were determined according to the EE calculation as follows: where AV 0 is the acid value of rice-bran oil, C. camphora seed oil, or acetic acid, and AV is the acid value of the upper oil phase after the reaction. All determinations were carried out in duplicate and the average values were reported.…”

“…10,11 In a previous study, Wan et al exploited oligoglycerol with linoleic acid in a solvent-free system using Lipozyme 435 as the catalyst to synthesis oligoglycerol fatty acid esters (OGEs). 12 Under the optimum conditions (reaction time of 4.52 h, reaction temperature of 90 °C, and enzyme dosage of 2 wt %), the experimental efficiency of esterification (EE) reached 95.82 ± 0.22%. However, there are few reports on how the chain lengths of fatty acids affect the hydrophilic−lipophilic balance (HLB), thereby affecting the emulsifying properties of the PGFEs.…”

“…Also, the final products used as food additives often have unpleasant organoleptic features . Recently, the green synthesis of PGFEs catalyzed by lipase has gained attention around the world because this synthesis is generally more specific, reacts under mild conditions, and produces less side-products. , In a previous study, Wan et al exploited oligoglycerol with linoleic acid in a solvent-free system using Lipozyme 435 as the catalyst to synthesis oligoglycerol fatty acid esters (OGEs) . Under the optimum conditions (reaction time of 4.52 h, reaction temperature of 90 °C, and enzyme dosage of 2 wt %), the experimental efficiency of esterification (EE) reached 95.82 ± 0.22%.…”