Batch and continuous lipase‐catalyzed interesterification of blends containing olive oil for trans‐free margarines

Abstract

The interesterification of natural fats can improve certain physical and nutraceutical properties by modification of their acylglycerol profile. The aim of this study was the production of structured lipids by lipase-catalyzed interesterification of blends of palm stearin (PS), palm kernel oil (PK), and olive oil (OO), to be incorporated in margarines. Interesterification activity was evaluated by the decrease of the solid fat content at 358C (SFC 358C ) of the blends. The best interesterification conditions, found by response surface methodology (RSM), catalyzed by ''Lipozyme 1 TL IM'' or ''Lipozyme 1 RM IM,'' were 658C and a blend of 45% w/w of PS, 30% w/w of PK, and 25% w/w of OO. Under these conditions, after 2 h of batch interesterification, the product had a SFC 358C of 3.0%. The reaction was implemented in a continuous packed-bed bioreactor, under optimized conditions, for 226 h (''Lipozyme 1 TL IM'') or 188 h (''Lipozyme 1 RM IM''), at a residence time of 7 min. The inactivation profile of both biocatalysts followed the first-order deactivation model: half-lives of 88 h (''Lipozyme 1 TL IM'') and 60 h (''Lipozyme 1 RM IM'') were estimated, respectively. Free fatty acid content of continuous interesterified blends (c.a. 1% w/w) was lower than that of batch-interesterified blends (c.a. 4-5% w/w). Practical applications:The obtained structured lipids, with low SFC 358C , are adequate for the production of trans-free table margarines. Using sn-1,3 specific lipases as catalysts, the original fatty acids at sn-2 position will be maintained with nutritional benefits. PS and PK are fats used as trans-free sources of solid fat, for the margarine industry, which are not very sensitive to oxidation. PK, a lauric fat, imparts a fast crystallization rate and confers plasticity to the final products. The incorporation of OO will enrich the blends with natural antioxidants and oleic acid at sn-2 position in acylglycerols. The development of response surface models, describing both final SFC values of interesterified blends and SFC decrease, will allow predicting results for novel proportions of fats and oils and/or a novel combination composition-temperature. The implementation of the interesterification in continuous reactors promotes a faster reaction and lower acidity of interesterified blends, with benefits in terms of product separation and purification. Abbreviations: a, residual activity; a w , water activity; Abs 232 nm , absorbance at 232 nm; Abs 270 nm, absorbance at 270 nm; AI, acidity index; CCRD, central composite rotatable design;

Structured lipids enriched with unsaturated fatty acids produced by enzymatic acidolysis of silkworm pupae oil using oleic acid

“…In human breast milk, PA constitutes the majority of saturated FAs at the sn ‐2 position at over 60% by weight . PA and SA are major contributors to obesity and hyperlipidemia . Therefore, the aim of this work was to reduce the PA and SA content at the sn ‐1,3 positions of silkworm pupae oil by replacement with monounsaturated fatty acids to yield products suitable for human consumption.…”

Specialty oils and fats in margarines and low-fat spreads

“…Fat crystals in the β′ form are smaller and of a lower melting point (Sato, 2001b), properties that impart a smooth texture to the product. As can be seen from blends of OO, PKO, and PS have been interesterified by using sn-1,3-specific lipases (Lipozyme TL IM and Lipozyme RM IM) in order to produce TFA-free margarines (De Martini Soares et al, 2013). This effect increases, in turn, the miscibility between the fat hardstock and liquid oil TAGs, resulting in the formation of mixed crystals and a more homogeneous and tight fat crystal network, with enhanced stabilization and texture properties.…”

“…Furthermore, the analysis of TAG composition of the PS:SO blend demonstrated that the interesterification process catalyzed by Pseudomonas lipase, results in the formation of mixed-acid TAGs with randomized FA. The interesterified blend comprising 25% OO, 30% PKO, and 45% PS produced a randomized FA composition in the TAGs, resulting in an increased intersolubility in the TAGs of the lipid phase (De Martini Soares et al, 2013). Olive oil is obtained by mechanical extraction of the fruit of the olive tree (Olea europea L. tree) (IOOC, 1993).…”

“…This effect increases, in turn, the miscibility between the fat hardstock and liquid oil TAGs, resulting in the formation of mixed crystals and a more homogeneous and tight fat crystal network, with enhanced stabilization and texture properties. This effect led to the formation of a finer fat crystal network with adequate plasticity and SFC to be used in trans-free table margarine formulations (De Martini Soares et al, 2013;Cain and Wesdorp, 1991;Marangoni and Rousseau, 1998). The chemical composition of olive fruit includes water (~52.4%), oil (19.6%), proteins (1.6%), sugars (19.1%), cellulose (6.8%), and ash (1.5%) (Firestone, 2005).…”

“…Olive oil is obtained by mechanical extraction of the fruit of the olive tree (Olea europea L. tree) (IOOC, 1993). In addition, De Martini Soares et al (2013) reported that the resulting fat blend had an increased oxidative stability due to the presence of PS and PKO solid fats, as well as to the presence of natural antioxidants such as the tocopherols from OO. The yield and quality of the extracted oil depends on the cultivar of the olive tree and the ratio of major and minor components in the fruit (Firestone, 2005).…”