Intensified synthesis of palm olein designer lipids using sonication

Intensified synthesis of a triglyceride of octanoic acid using sonication and assessment of its frying characteristics

Intensification in synthesis of triglycerides of octanoic acid using a heterogeneous amberlyst-15 catalyst has been investigated with the application of ultrasound under solvent-free conditions. Further, the frying characteristics of medium-chain triglycerides (tricaprin) are evaluated by deep frying of French fries in various combinations of palm oil and tricaprin. Understanding into the effect of parameters such as the temperature of the reaction (over the range of 40 °C-80 °C), loading of amberlyst-15 (1%-5%) and molar ratio of fatty acid to glycerol (3:1-3:5) along with the ultrasound conditions as duty cycle (40%-90%) and time on the conversion (%) has also been developed. Based on the outcomes of the study, optimum reaction conditions seen are 3:4 as the molar ratio of fatty acid (C8): glycerol, amberlyst-15 loading of 3% and a reaction temperature of 50 °C. It was further observed that the optimum ultrasound conditions required for maximum conversion of 99.8% were 240 W power, 80% duty cycle and 15 min as the ultrasound irradiation time. Under similar conditions, the conventional synthesis resulted in only 20% conversion in 15 min. Reusability studies also established that the acid-resin catalyst was effectively reused for 8 times. The PV, p-AV and TPC of frying oil combination containing higher tricaprin (50:50-palm oil: MCT) was 8.4 ± 0.8, 23.1 ± 0.01 and 29.8 ± 0.01 respectively, which were lowest as compared with other blends indicating the beneficial effects of MCT in frying applications. The work clearly shows that the ultrasound application for the synthesis of triglyceride of octanoic acid gives higher conversion (%) in a less time and also demonstrates that MCT could be a good alternative for deep frying of foods in combination with palm oil to enhance the shelf-life of food.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-022-05379-3.

Ultrasound enhanced butyric acid-lauric acid designer lipid synthesis: Based on artificial neural network and changes in enzymatic structure

Ultrasound is a green technology for intensifying enzymatic reactions. In this study, an ultrasonic water bath with equipment parameters of 28 kHz, 1750.1 W/m², 60% duty cycle was used to assist the synthesis of butyric acid-lauric acid designer lipid (BLDL), which was catalyzed by Lipozyme 435. A convincing three-layer feed-forward artificial neural network (ANN) model was established (R² = 0.949, RMSE = 4.759, ADD = 7.329) to accurately predict the optimal parameters combination, which was described as 13.72 mL reaction volume, 15.49% enzyme loading, 0.253 substrate molar ratio (tributyrin/lauric acid), 56.58 °C reaction temperature and 120 min reaction time. The ultrasonic assistance increased actual butyric acid conversion rate by 11.38%, and also enhanced the consumption rate of tributyrin and lauric acid during the reaction. Meanwhile, the esterification activity of Lipozyme 435 was enhanced and its effectiveness up to 6 cycles. Structurally, ultrasound assistance significantly disrupted the secondary structure of the Lipozyme 435: reduced the content of α-helices, increased the content of β-sheet and β-turn. In addition, sonication caused an increase in crevice and micro-damage on the surface of the immobilized enzyme. In conclusion, low-intensity ultrasound at 28 kHz improved the synthesis efficiency of BLDL, which was scientifically predicted by ANN model, and the change of enzyme structure may be the vital reason for ultrasound enhanced reaction. However, the effect of ultrasound on immobilized enzymes' activity needs to be further explored.

Triglycerides of medium-chain fatty acids: a concise review

Medium-chain triglycerides contain medium-chain fatty acid esterified to the glycerol backbone. These MCFA have a shorter chain length and are quickly metabolized in the body serving as an immediate energy source. They are known to have good physiological as well as functional characteristics which help in treating various health disorders. Naturally, they are found in coconut oil, milk fat, and palm kernel oil, and they are synthetically produced by esterification and interesterification reactions. Due to their numerous health benefits, MCT is used as a functional or nutraceutical oil in various food and pharmaceutical formulations. To increase their nutraceutical benefits and food applications MCFA can be used along with polyunsaturated fatty acids in the synthesis of structured lipids. This review aims to provide information about triglycerides of MCFA, structure, metabolism, properties, synthetic routes, intensified synthesis approaches, health benefits, application, and safety of use of MCT in the diet.

Production, Biosynthesis, and Commercial Applications of Fatty Acids From Oleaginous Fungi

Oleaginous fungi (including fungus-like protists) are attractive in lipid production due to their short growth cycle, large biomass and high yield of lipids. Some typical oleaginous fungi including Galactomyces geotrichum, Thraustochytrids, Mortierella isabellina, and Mucor circinelloides, have been well studied for the ability to accumulate fatty acids with commercial application. Here, we review recent progress toward fermentation, extraction, of fungal fatty acids. To reduce cost of the fatty acids, fatty acid productions from raw materials were also summarized. Then, the synthesis mechanism of fatty acids was introduced. We also review recent studies of the metabolic engineering strategies have been developed as efficient tools in oleaginous fungi to overcome the biochemical limit and to improve production efficiency of the special fatty acids. It also can be predictable that metabolic engineering can further enhance biosynthesis of fatty acids and change the storage mode of fatty acids.

Ultrasound-Assisted Production of Xylo-Oligosaccharides From Alkali-Solubilized Corncob Bran Using Penicillium janthinellum XAF01 Acidic Xylanase

A novel treatment involving enzymatic hydrolysis using an acidic xylanase coupled with ultrasound was performed to improve the xylo-oligosaccharides (XOS) yield from corncob bran. The acidic xylanase (XynB) was purified to a most suitable pH, temperature, and operational parameters for ultrasound-assisted hydrolysis were determined. A preliminary mechanistic investigation was performed through circular dichroism (CD) spectroscopy, scanning electron microscope (SEM) and a laser particle size analyzer, and the effects of ultrasound on enzyme (XynB) and substrate (corncob bran) were assessed. The results show that the maximum XOS yield was 20.71% when the reaction pH and temperature were 4.3 and 50°C, the ultrasonic parameters were 50 kHz and 0.40 W/cm², which was 2.55 fold higher than that obtained using a non-ultrasound-assisted enzymatic preparation. Mechanism studies indicated that ultrasonic pretreatment could reduce the β-fold content and increase the random coil content. Changes in structure and size of substrate were observed. The specific surface area of the XAC molecules is easy to carry out enzymatic reaction, which is beneficial to the production of XOS.

Non-thermal Technologies for Food Processing

Food is subjected to various thermal treatments during processes to enhance its shelf-life. But these thermal treatments may result in deterioration of the nutritional and sensory qualities of food. With the change in the lifestyle of people around the globe, their food needs have changed as well. Today's consumer demand is for clean and safe food without compromising the nutritional and sensory qualities of food. This directed the attention of food professionals toward the development of non-thermal technologies that are green, safe, and environment-friendly. In non-thermal processing, food is processed at near room temperature, so there is no damage to food because heat-sensitive nutritious materials are intact in the food, contrary to thermal processing of food. These non-thermal technologies can be utilized for treating all kinds of food like fruits, vegetables, pulses, spices, meat, fish, etc. Non-thermal technologies have emerged largely in the last few decades in food sector.