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Non-enzymatic browning has been a wide and interesting research area in the food industry, ranging from the complexity of the reaction to its applications in the food industry as well as its ever-debatable health effects. This review provides a new perspective to the Maillard reaction apart from its ubiquitous function in enhancing food flavour, taste and appearance. It focuses on the recent application of Maillard reaction products as an inexpensive and excellent source of emulsifiers as well as superior encapsulating matrices for the entrapment of bioactive compounds. Additionally, it will also discuss the latest approaches employed to perform the Maillard reaction as well as several important reaction parameters that need to be taken into consideration when conducting the Maillard reaction. © 2016 Society of Chemical Industry.

Enzymatic production of diacylglycerol (DAG)-enriched oil has been investigated extensively due to its health benefits with total annual sales of approximately USD 200 million in Japan since its introduction in the late 1990s till 2009. Enzymatic catalysis had been proven to exhibit improved results with respect to yield, purity, reaction time, and stability in comparison with chemical catalysis. The cost of the enzymes, however, is the main hurdle to the widespread use of enzyme for commercial DAG production. This paper attempts to review and summarize various lipase-mediated technological methods for DAG production. Critical aspects such as process considerations on DAG synthesis, mass transfer limitations as well as kinetic mechanism models developed for each enzymatic approach in DAG synthesis are also presented and discussed. In addition, possible reactor configurations were evaluated, if lipase-assisted DAG production is to be technically and economically feasible at an industrial scale.

Diacylglycerol (DAG) is a world leading anti-obesity functional cooking oil synthesized via structural modification of conventional fats and oils. DAG exits in three stereoisomers namely sn-1,2-DAG, sn-1,3-DAG, and sn-2,3-DAG. DAG particularly sn-1,3-DAG demonstrated to have the potential in suppressing body fat accumulation and lowering postprandial serum triacylglycerol, cholesterol and glucose level. DAG also showed to improve bone health. This is attributed to DAG structure itself that caused it to absorb and digest via different metabolic pathway than conventional fats and oils. With its purported health benefits, many studies attempt to enzymatically or chemically synthesis DAG through various routes. DAG has also received wide attention as low calorie fat substitute and has been incorporated into various food matrixes. Despite being claimed as healthy cooking oil the safety of DAG still remained uncertain. DAG was banned from sale as it was found to contain probable carcinogen glycidol fatty acid esters. The article aims to provide a comprehensive and latest review of DAG emphasizing on its structure and properties, safety and regulation, process developments, metabolism and beneficial health attributes as well as its applications in the food industry.

Structured lipid such as medium-and long-chain triacylglycerol (MLCT) is claimed to be able to suppress body fat accumulation and be used to manage obesity. Response surface methodology (RSM) with four factors and three levels (+1,0,-1) faced centered composite design (FCCD) was employed for optimization of the enzymatic interesterification conditions of palm-based MLCT (P-MLCT) production. The effect of the four variables namely: substrate ratio palm kernel oil: palm oil, PKO:PO (40:60-100:0 w/w), temperature (50-70 °C), reaction time (0.5-7.5 h) and enzyme load (5-15 % w/w) on the P-MLCT yield (%) and by products (%) produced were investigated. The responses were determined via acylglycerol composition obtained from high performance liquid chromatography. Well-fitted models were successfully established for both responses: P-MLCT yield (R (2) = 0.9979) and by-products (R (2) = 0.9892). The P-MLCT yield was significantly (P < 0.05) affected by substrate ratio, reaction time and reaction temperature but not enzyme load (P > 0.05). Substrate ratio PKO: PO (100:0 w/w) gave the highest yield of P-MLCT (61 %). Nonetheless, substrate ratio of PKO: PO (90:10w/w) was chosen to improve the fatty acid composition of the P-MLCT. The optimized conditions for substrate ratio PKO: PO (90:10 w/w) was 7.26 h, 50 °C and 5 % (w/w) Lipozyme TLIM lipase, which managed to give 60 % yields of P-MLCT. Up scaled results in stirred tank batch reactor gave similar yields as lab scale. A 20 % increase in P-MLCT yield was obtained via RSM. The effect of enzymatic interesterification on the physicochemical properties of PKO:PO (90:10 w/w) were also studied. Thermoprofile showed that the P-MLCT oil melted below body temperature of 37 °C.

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Lipase-catalyzed glycerolysis of palm olein was used to produce a mixture of acylglycerols with $34-wt% of DAG. The reaction conditions were 5-wt% of Lipozyme TLIM at 55°C and 8 h of reaction time. For commercial purposes, it is required to purify the product up to 80-wt% DAG and with free fatty acids (FFA) content below 0.1-wt%. A single-step distillation process was not sufficient to meet this product requirement. Two distinct 2-step short path distillation approaches were then studied. First scheme involved the removal of TAG by initial distillation step at 250°C, followed by separation of the MAG and FFA from distillate obtained at 180°C during second distillation step at vacuum pressure of 0.1 Pa. Second scheme involved the removal of MAG and FFA in first step at 180°C prior to purification of DAG from residue at 250°C during second distillation step at vacuum achieved up to 0.1 Pa. The results suggested that the first scheme of 2-step distillation operation was able to achieve 89.9-wt% of DAG purity without exceeding the limit of 0.1-wt% of FFA. A final yield of 21.5-wt% and DAG recovery of 47.8% were obtained using the first scheme. A detailed DAG profile was identified and product characterizations such as fatty acid composition, slip melting point, and solid fat content profile were also investigated. It was observed that purified-DAG product showed lower iodine value and higher slip melting point than raw material palm olein. The final product had 1134 AE 10 ppm tocols content.Practical applications: This paper has two main practical applications: (i) Enables production of highly purified DAG-based palm olein via appropriate processing method and processing conditions. (ii) Provide knowledge and understanding of the physicochemical properties of DAG-enriched palm olein fraction, which is a crucial aspect in food applications.

Lipases and esterases are both versatile biocatalysts that catalyse and accelerate the hydrolysis of ester-linked compounds. Lipases preferentially catalyse hydrolysis of water-insoluble esters such as triacylglycerols (TAGs) whereas esterases hydrolyse water-soluble esters or shortchain fatty acid TAG. Their high selectivity with broad substrate range makes these biocatalysts an ideal catalyst for organic synthesis in comparison to conventional chemical catalysts. The present monograph covers topics such as the original sources and classification of lipases and esterases, their respective catalytic properties as well as their substrate selectivity. Moreover, the potential applications of these enzymes with reference to food, cosmetic and pharmaceutical industries in recent years are discussed extensively in this article.